Vibecode Calendly
track this build5 phases, 15 steps, beginner friendly0%KINDA · weekend project
A single-user booking page is easy; production-grade scheduling needs OAuth, availability rules, time zones, reminders, payments, team routing, and trust.
the project pack5 files · written for this build, step by step
You are building a lean indie version of Calendly. Create the following project files first, then implement the application by following them. Keep the files updated as decisions change. Do not collapse this into a single README or prompt. ===== README.md ===== # Calendly · indie build Build a single-owner Google Calendar booking page with conflict-aware confirmation. Estimated effort: **multi-day**. Work `BUILD_PLAN.md` top to bottom · every phase ends in a check that has to pass before the next one starts. ## Stack | Part | Choice | Why | | --- | --- | --- | | Runtime | Python 3.12+ and Flask | A small local HTTP application with readable server-side handlers and no JavaScript build pipeline. | | Storage | SQLite through Python sqlite3 | Local ownership with explicit transactions and a portable backup path. | | Interface | Jinja HTML templates, CSS and vanilla JavaScript | Implement the specified screens directly with labelled controls and progressive enhancement. | | Verification | Python unittest and browser acceptance fixtures | Check invariants and the actual user workflow before the next phase. | | Focused libraries | google-api-python-client, google-auth-httplib2, google-auth-oauthlib | Use these only for the specific file, parsing or provider operations named in the phases; freeze tested versions. | ## Before you start Have every one of these ready. The plan assumes them from step one. - [ ] **Python 3.12 or newer and a terminal** · Python is free; this local prototype requires no hosting subscription. - Why: The local backend, tests and storage use Python. - Get it: Install Python from python.org. Open a terminal in a new empty project folder. On Windows, use py -3 where this guide says python if python is not on PATH; on macOS/Linux use python3 if needed. Create .venv and activate it before installing packages. - Verify: python --version reports 3.12+ and python -c "import sqlite3" succeeds. - [ ] **A current desktop browser and text editor** · No paid service required for this local step. - Why: You need to view the local interface and edit generated project files. - Get it: Use an installed Chrome, Firefox or Edge browser. Open the empty project folder in your editor; open the terminal there, not in this catalog repository. - Verify: You can create a text file in the project folder and open browser developer tools. - [ ] **Calendly acceptance sample** · No paid service required for this local step. - Why: This fixture makes the first end-to-end check reproducible. - Get it: Create synthetic sample data before implementation: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Save it under fixtures/ with the expected results in fixtures/README.md; use no real credentials or customer records. - Verify: The fixture files and expected outcomes exist and can be inspected without a vendor account. - [ ] **Confirm the bounded replacement** · No paid service required for this local step. - Why: The full commercial product is larger than this guide. - Get it: The deliverable is a single-owner Google Calendar booking page with conflict-aware confirmation. Read every exclusion below. Indie mode runs locally; any public or shared use requires the product access and deployment gates first. - Verify: You can name the primary workflow and the vendor features this version deliberately leaves out. - [ ] **Google Calendar OAuth client for one test owner** · Check current Google API quotas and any project billing requirements; this guide assumes no paid quota or production verification exemption. - Why: The booking page must read busy periods and create invited events. - Get it: Follow the official Python quickstart: create a Cloud project, enable Calendar API, configure consent and your test user, and create OAuth credentials. For this web app use a Web application client and register the exact local callback http://127.0.0.1:5000/oauth/callback; use the matching HTTPS callback when deploying. Save the client JSON outside static files. - Verify: The owner completes consent and the app can read the chosen calendar busy data; revoked consent produces reconnect guidance. ## Quick start ```sh python -m venv .venv python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib python -m pip freeze > requirements.txt python -m flask --app app run --host 127.0.0.1 ``` Then copy `.env.example` to `.env` and fill in the values it documents. ## Honest limits This build deliberately does not replace: - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you - team round-robin and routing - SMS reminders - the integrations directory If one of those is essential to you, that is the reason to keep paying for Calendly, and the README should say so rather than pretend. ===== BRIEF.md ===== # Build brief · Calendly The one-shot brief this plan expands. `BUILD_PLAN.md` (or `MILESTONES.md`) is the same sequence broken into steps and checks; where the two disagree, the plan wins. Build me a single-owner Google Calendar booking page with conflict-aware confirmation as a bounded replacement for Calendly. Build it in phases in the order below. Do not write the whole product in one pass. Finish the current phase, run its Done when checks, fix failures, then continue. Indie mode completes Phases 1-5. Phase 6 is required before shared or public deployment. ### Stack (fixed, do not substitute) - Runtime: Python 3.12+ and Flask. A small local HTTP application with readable server-side handlers and no JavaScript build pipeline. - Storage: SQLite through Python sqlite3. Local ownership with explicit transactions and a portable backup path. - Interface: Jinja HTML templates, CSS and vanilla JavaScript. Implement the specified screens directly with labelled controls and progressive enhancement. - Verification: Python unittest and browser acceptance fixtures. Check invariants and the actual user workflow before the next phase. - Focused libraries: google-api-python-client, google-auth-httplib2, google-auth-oauthlib. Use these only for the specific file, parsing or provider operations named in the phases; freeze tested versions. ### Data model (create this before Phase 1) - event_types(id,title,duration_minutes,buffer_minutes) - availability(id,weekday,start_local,end_local,timezone) - bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id) - holds(id,start_utc,end_utc,expires_at) - oauth credentials stored outside public files - Use stable ids and explicit relationships; add auxiliary tables named by the phases before those phases use them. - Acceptance fixture: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. ### Prerequisites and configuration - Python 3.12 or newer and a terminal: Install Python from python.org. Open a terminal in a new empty project folder. On Windows, use py -3 where this guide says python if python is not on PATH; on macOS/Linux use python3 if needed. Create .venv and activate it before installing packages. Verify: python --version reports 3.12+ and python -c "import sqlite3" succeeds. Cost: Python is free; this local prototype requires no hosting subscription. - A current desktop browser and text editor: Use an installed Chrome, Firefox or Edge browser. Open the empty project folder in your editor; open the terminal there, not in this catalog repository. Verify: You can create a text file in the project folder and open browser developer tools. Cost: No paid service required for this local step. - Calendly acceptance sample: Create synthetic sample data before implementation: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Save it under fixtures/ with the expected results in fixtures/README.md; use no real credentials or customer records. Verify: The fixture files and expected outcomes exist and can be inspected without a vendor account. Cost: No paid service required for this local step. - Confirm the bounded replacement: The deliverable is a single-owner Google Calendar booking page with conflict-aware confirmation. Read every exclusion below. Indie mode runs locally; any public or shared use requires the product access and deployment gates first. Verify: You can name the primary workflow and the vendor features this version deliberately leaves out. Cost: No paid service required for this local step. - Google Calendar OAuth client for one test owner: Follow the official Python quickstart: create a Cloud project, enable Calendar API, configure consent and your test user, and create OAuth credentials. For this web app use a Web application client and register the exact local callback http://127.0.0.1:5000/oauth/callback; use the matching HTTPS callback when deploying. Save the client JSON outside static files. Verify: The owner completes consent and the app can read the chosen calendar busy data; revoked consent produces reconnect guidance. Cost: Check current Google API quotas and any project billing requirements; this guide assumes no paid quota or production verification exemption. - Configuration: DATA_DIR, SECRET_KEY, APP_MODE, SITE_URL, GOOGLE_CLIENT_FILE, GOOGLE_TOKEN_FILE, GOOGLE_CALENDAR_ID. Ship .env.example, replace placeholders and exclude secrets from git. ### Phase 1 · Local foundation and data contract Build: Create the runnable local foundation for a single-owner Google Calendar booking page with conflict-aware confirmation, including the real schema and acceptance fixture. - Run the venv command first, then stop and activate it before running the remaining commands. Use your OS instructions: Windows .venv\Scripts\activate.bat in cmd, or .venv\Scripts\Activate.ps1 in PowerShell; macOS/Linux source .venv/bin/activate. Then install the listed packages. Create app.py exposing app, load .env with python-dotenv, and add a /healthz route. Freeze tested dependency versions to requirements.txt. Create .env manually from .env.example; replace SECRET_KEY before launch. Commands, after creating the named files: `python -m venv .venv`; `python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib`; `python -m pip freeze > requirements.txt`; `python -m flask --app app run --host 127.0.0.1`. - For database-backed state create schema.sql and db.py using this model: event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files. Add the auxiliary relationships explicitly used in later phases; use stable ids, foreign keys, parameterized values and transactions. For canonical files use atomic replacement and hashes instead. Implement python manage.py init and python manage.py seed to create only synthetic data: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Re-running init must not erase data. Commands, after creating the named files: `python manage.py init`; `python manage.py seed`. - Install Flask-WTF CSRF protection for forms and same-origin fetches, validate Host and Origin against SITE_URL, bound inputs and escape output. Deliberately public intake endpoints get bounded validation and rate limits; signed provider webhooks use signature checks instead of browser CSRF tokens. All other admin routes stay local until product authentication exists. When a later phase tests viewer/member permissions, implement the users, hashed passwords, expiring server sessions and role checks in this foundation first; product mode must never use a fabricated identity from request input. Add error, empty, keyboard-focus and retry states now. - Trap: The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. Done when: The documented start command serves /healthz and the initial screen at http://127.0.0.1:5000. Restarting preserves the seeded records or canonical files; running init again deletes nothing. A cross-origin state-changing request to an admin route is refused. Do not build yet: Do not start calendar connection before ui until these checks pass. ### Phase 2 · Calendar connection before UI Build: Calendar connection before UI for Calendly: Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. - Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. - Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: An occupied fixture interval is returned as unavailable. Then check: Revoking access prevents booking confirmation and shows a reconnect state. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: A service account is not a drop-in substitute for a personal calendar OAuth consent flow. Done when: An occupied fixture interval is returned as unavailable. Revoking access prevents booking confirmation and shows a reconnect state. Do not build yet: Do not start availability and atomic holds until these checks pass. ### Phase 3 · Availability and atomic holds Build: Availability and atomic holds for Calendly: Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. - Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. - Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: Two concurrent guests for one slot produce one active hold. Then check: A slot inside the external busy period cannot be booked by direct POST. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. Done when: Two concurrent guests for one slot produce one active hold. A slot inside the external busy period cannot be booked by direct POST. Do not build yet: Do not start event and guest lifecycle until these checks pass. ### Phase 4 · Event and guest lifecycle Build: Event and guest lifecycle for Calendly: Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. - Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. - Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: The API timeout followed by reconciliation produces one confirmed event. Then check: An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. Done when: The API timeout followed by reconciliation produces one confirmed event. An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Do not build yet: Do not start portable delivery and clean-start proof until these checks pass. ### Phase 5 · Portable delivery and clean-start proof Build: Finish the Calendly replacement with a documented first-run path and a recoverable export. - Document prerequisites, every configuration variable, data locations and the three domain workflows: Calendar connection before UI; Availability and atomic holds; Event and guest lifecycle. Include the exclusions, actual costs and source check date 2026-09-05. Commands shown earlier that reference project files are files the builder must implement before running them. - Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. - Use a new folder and only README instructions to reach the fixture outcome. Install from requirements.txt, initialize storage, run the tests and exercise the UI at 375px and 1280px; use keyboard-only controls and inspect browser errors. Record exactly what passed; do not mark unrun checks complete. Commands, after creating the named files: `python -m pip install -r requirements.txt`; `python -m unittest discover -s test`. - Trap: Export without an import or restore rehearsal is not verified portability. Done when: A new folder reaches the documented fixture outcome using only README instructions. A backup restored in isolation preserves the proof data and can be opened. Do not build yet: Do not start operate and share with access controls until these checks pass. ### Phase 6 · Operate and share with access controls (product-builder only) Build: Product-builder only: make a single-owner Google Calendar booking page with conflict-aware confirmation operable for its stated audience before allowing remote access. - Add owner/member/viewer authorization as appropriate, password hashes through Werkzeug, expiring server-side sessions, CSRF and login rate limits. Add users, sessions and audit schema migrations plus an owner-init command prompting securely for its password. Enforce ownership on every private read/write/download and fail closed when product setup is incomplete. Existing learner or admin identities must use this same boundary. - Serve app:app with Waitress on loopback behind Caddy HTTPS. Configure trusted proxy headers narrowly, Secure/HttpOnly/SameSite cookies, upload limits, request ids and structured logs without private content. Run background jobs as a separate supervised process when the domain workflow requires them. Commands, after creating the named files: `waitress-serve --listen=127.0.0.1:5000 app:app`. - Add a scheduled encrypted off-host backup using this procedure: Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Monitor health, disk space, failed jobs and backup age. Stop the service to test an alert; rehearse recovery with outbound effects disabled and record recovery time. Rotate any exposed credentials and require reconciliation before resuming queues. - Trap: Product mode is additional engineering, not a switch that makes a local prototype production-ready. Done when: An unauthenticated visitor cannot read private records, download private files or mutate the admin surface. A viewer cannot mutate data by making a direct request, and guessed ids cannot cross ownership boundaries. Stopping the service triggers the configured alert and the latest off-host backup restores the fixture in isolation. Do not build yet: Do not add new providers or vendor-scale features until the release gates are recorded. ### Out of scope (and why) - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you: retain the paid product if this capability is essential; it is outside this bounded build. - team round-robin and routing: retain the paid product if this capability is essential; it is outside this bounded build. - SMS reminders: retain the paid product if this capability is essential; it is outside this bounded build. - the integrations directory: retain the paid product if this capability is essential; it is outside this bounded build. ### README must contain - Exact install, configure, initialize, start, test and recovery commands for a clean folder. - The schema, fixture, acceptance results, private data locations and export format. - Every prerequisite and secret source, actual running costs and deliberately excluded capabilities. - An honest distinction between tests actually run and checks still awaiting real credentials or deployment. - Dependency documentation reviewed 2026-09-05: https://flask.palletsprojects.com/en/stable/installation/ ; https://docs.python.org/3/library/sqlite3.html ; https://flask-wtf.readthedocs.io/en/1.2.x/csrf/ ; https://docs.pylonsproject.org/projects/waitress/en/stable/usage.html ; https://developers.google.com/workspace/calendar/api/quickstart/python ; https://developers.google.com/workspace/calendar/api/guides/create-events. Recheck before upgrading; freeze the versions actually tested. ===== AGENTS.md ===== # Agent instructions · Calendly indie build - Read `README.md` and `BUILD_PLAN.md` before writing code. The stack is fixed: Python 3.12+ and Flask, SQLite through Python sqlite3, Jinja HTML templates, CSS and vanilla JavaScript, Python unittest and browser acceptance fixtures, google-api-python-client, google-auth-httplib2, google-auth-oauthlib. Do not substitute. - Work one phase at a time, in order. Do not start a phase until every "Done when" item of the previous one passes. - Prefer the fewest moving parts that satisfy the step. No frameworks, services or dependencies the plan does not name. - Secrets live in `.env`, never in source or logs. Keep `.env.example` current when a variable is introduced. - Do not invent cryptography, security guarantees, APIs or compliance claims. - Add a focused test for every destructive, security-sensitive or data-loss path the plan names. - Run the project checks before declaring a phase complete, and record any deliberate shortcut in the README under "Tradeoffs". ## Known traps - The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. - No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. - Export without an import or restore rehearsal is not verified portability. ===== BUILD_PLAN.md ===== # Build plan · Calendly Build a single-owner Google Calendar booking page with conflict-aware confirmation. Phases are in dependency order. Each ends in a "Done when" list; treat an unticked item as a blocker, not a note. ## Phase 1 · Local foundation and data contract Create the runnable local foundation for a single-owner Google Calendar booking page with conflict-aware confirmation, including the real schema and acceptance fixture. ### Steps 1. Create and start the local application Run the venv command first, then stop and activate it before running the remaining commands. Use your OS instructions: Windows .venv\Scripts\activate.bat in cmd, or .venv\Scripts\Activate.ps1 in PowerShell; macOS/Linux source .venv/bin/activate. Then install the listed packages. Create app.py exposing app, load .env with python-dotenv, and add a /healthz route. Freeze tested dependency versions to requirements.txt. Create .env manually from .env.example; replace SECRET_KEY before launch. Files: `app.py`, `requirements.txt`, `.env.example`, `.gitignore` ```sh python -m venv .venv python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib python -m pip freeze > requirements.txt python -m flask --app app run --host 127.0.0.1 ``` 2. Implement storage and seed the named fixture For database-backed state create schema.sql and db.py using this model: event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files. Add the auxiliary relationships explicitly used in later phases; use stable ids, foreign keys, parameterized values and transactions. For canonical files use atomic replacement and hashes instead. Implement python manage.py init and python manage.py seed to create only synthetic data: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Re-running init must not erase data. Files: `schema.sql`, `db.py`, `manage.py`, `fixtures/README.md` ```sh python manage.py init python manage.py seed ``` 3. Protect the local request boundary Install Flask-WTF CSRF protection for forms and same-origin fetches, validate Host and Origin against SITE_URL, bound inputs and escape output. Deliberately public intake endpoints get bounded validation and rate limits; signed provider webhooks use signature checks instead of browser CSRF tokens. All other admin routes stay local until product authentication exists. When a later phase tests viewer/member permissions, implement the users, hashed passwords, expiring server sessions and role checks in this foundation first; product mode must never use a fabricated identity from request input. Add error, empty, keyboard-focus and retry states now. Files: `app.py`, `templates/base.html`, `test/test_foundation.py` ### Done when - [ ] The documented start command serves /healthz and the initial screen at http://127.0.0.1:5000. - [ ] Restarting preserves the seeded records or canonical files; running init again deletes nothing. - [ ] A cross-origin state-changing request to an admin route is refused. ### Watch out - The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. ## Phase 2 · Calendar connection before UI Calendar connection before UI for Calendly: Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. ### Steps 1. Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. Files: `features/calendar_connection_before_ui.py`, `templates/calendar_connection_before_ui.html` 2. Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. Files: `features/calendar_connection_before_ui.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: An occupied fixture interval is returned as unavailable. Then check: Revoking access prevents booking confirmation and shows a reconnect state. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_calendar_connection_before_ui.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] An occupied fixture interval is returned as unavailable. - [ ] Revoking access prevents booking confirmation and shows a reconnect state. ### Watch out - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. ## Phase 3 · Availability and atomic holds Availability and atomic holds for Calendly: Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. ### Steps 1. Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. Files: `features/availability_and_atomic_holds.py`, `templates/availability_and_atomic_holds.html` 2. Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. Files: `features/availability_and_atomic_holds.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: Two concurrent guests for one slot produce one active hold. Then check: A slot inside the external busy period cannot be booked by direct POST. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_availability_and_atomic_holds.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] Two concurrent guests for one slot produce one active hold. - [ ] A slot inside the external busy period cannot be booked by direct POST. ### Watch out - Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. ## Phase 4 · Event and guest lifecycle Event and guest lifecycle for Calendly: Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. ### Steps 1. Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. Files: `features/event_and_guest_lifecycle.py`, `templates/event_and_guest_lifecycle.html` 2. Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. Files: `features/event_and_guest_lifecycle.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: The API timeout followed by reconciliation produces one confirmed event. Then check: An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_event_and_guest_lifecycle.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] The API timeout followed by reconciliation produces one confirmed event. - [ ] An invalid cancel token cannot cancel a booking, and cancellation releases the slot. ### Watch out - No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. ## Phase 5 · Portable delivery and clean-start proof Finish the Calendly replacement with a documented first-run path and a recoverable export. ### Steps 1. Write the user-facing runbook Document prerequisites, every configuration variable, data locations and the three domain workflows: Calendar connection before UI; Availability and atomic holds; Event and guest lifecycle. Include the exclusions, actual costs and source check date 2026-09-05. Commands shown earlier that reference project files are files the builder must implement before running them. Files: `README.md`, `.env.example` 2. Create and rehearse a recoverable backup Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. Files: `OPERATIONS.md`, `scripts/backup.py` 3. Reproduce the first-run experience Use a new folder and only README instructions to reach the fixture outcome. Install from requirements.txt, initialize storage, run the tests and exercise the UI at 375px and 1280px; use keyboard-only controls and inspect browser errors. Record exactly what passed; do not mark unrun checks complete. Files: `README.md`, `verification.md` ```sh python -m pip install -r requirements.txt python -m unittest discover -s test ``` ### Done when - [ ] A new folder reaches the documented fixture outcome using only README instructions. - [ ] A backup restored in isolation preserves the proof data and can be opened. ### Watch out - Export without an import or restore rehearsal is not verified portability. ## Not in this build - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you - team round-robin and routing - SMS reminders - the integrations directory ## After v1, if you want it - Extend event and guest lifecycle only after the fixture and recovery checks pass. - Before adding another integration, document its credentials, limits, cost and failure behavior with primary-source links. ===== .env.example ===== # Copy to .env and fill in. Never commit .env; this file documents it. # Required. A new private folder this application creates on first run; never serve it as static files. DATA_DIR=./data/calendly # Required · secret. Generate with python -c "import secrets; print(secrets.token_hex(32))" and save only in .env. SECRET_KEY=replace-with-a-random-secret # Required. Use indie for loopback-only personal work. Product mode must refuse to start until owner login and the deployment gates are configured. APP_MODE=indie # Required. The origin used for local forms and links; replace with the chosen HTTPS origin in product mode. SITE_URL=http://127.0.0.1:5000 # Required · secret. Download the OAuth client JSON from Cloud console; never commit it. GOOGLE_CLIENT_FILE=./secrets/google-client.json # Required · secret. Created by the owner authorization flow; restrict file permissions and exclude from backups shared with others. GOOGLE_TOKEN_FILE=./secrets/google-token.json # Required. The authenticated owner calendar id; choose a dedicated test calendar during development. GOOGLE_CALENDAR_ID=primary
You are building a lean indie version of Calendly. Create the following project files first, then implement the application by following them. Keep the files updated as decisions change. Do not collapse this into a single README or prompt. ===== README.md ===== # Calendly · indie build Build a single-owner Google Calendar booking page with conflict-aware confirmation. Estimated effort: **multi-day**. Work `BUILD_PLAN.md` top to bottom · every phase ends in a check that has to pass before the next one starts. ## Stack | Part | Choice | Why | | --- | --- | --- | | Runtime | Python 3.12+ and Flask | A small local HTTP application with readable server-side handlers and no JavaScript build pipeline. | | Storage | SQLite through Python sqlite3 | Local ownership with explicit transactions and a portable backup path. | | Interface | Jinja HTML templates, CSS and vanilla JavaScript | Implement the specified screens directly with labelled controls and progressive enhancement. | | Verification | Python unittest and browser acceptance fixtures | Check invariants and the actual user workflow before the next phase. | | Focused libraries | google-api-python-client, google-auth-httplib2, google-auth-oauthlib | Use these only for the specific file, parsing or provider operations named in the phases; freeze tested versions. | ## Before you start Have every one of these ready. The plan assumes them from step one. - [ ] **Python 3.12 or newer and a terminal** · Python is free; this local prototype requires no hosting subscription. - Why: The local backend, tests and storage use Python. - Get it: Install Python from python.org. Open a terminal in a new empty project folder. On Windows, use py -3 where this guide says python if python is not on PATH; on macOS/Linux use python3 if needed. Create .venv and activate it before installing packages. - Verify: python --version reports 3.12+ and python -c "import sqlite3" succeeds. - [ ] **A current desktop browser and text editor** · No paid service required for this local step. - Why: You need to view the local interface and edit generated project files. - Get it: Use an installed Chrome, Firefox or Edge browser. Open the empty project folder in your editor; open the terminal there, not in this catalog repository. - Verify: You can create a text file in the project folder and open browser developer tools. - [ ] **Calendly acceptance sample** · No paid service required for this local step. - Why: This fixture makes the first end-to-end check reproducible. - Get it: Create synthetic sample data before implementation: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Save it under fixtures/ with the expected results in fixtures/README.md; use no real credentials or customer records. - Verify: The fixture files and expected outcomes exist and can be inspected without a vendor account. - [ ] **Confirm the bounded replacement** · No paid service required for this local step. - Why: The full commercial product is larger than this guide. - Get it: The deliverable is a single-owner Google Calendar booking page with conflict-aware confirmation. Read every exclusion below. Indie mode runs locally; any public or shared use requires the product access and deployment gates first. - Verify: You can name the primary workflow and the vendor features this version deliberately leaves out. - [ ] **Google Calendar OAuth client for one test owner** · Check current Google API quotas and any project billing requirements; this guide assumes no paid quota or production verification exemption. - Why: The booking page must read busy periods and create invited events. - Get it: Follow the official Python quickstart: create a Cloud project, enable Calendar API, configure consent and your test user, and create OAuth credentials. For this web app use a Web application client and register the exact local callback http://127.0.0.1:5000/oauth/callback; use the matching HTTPS callback when deploying. Save the client JSON outside static files. - Verify: The owner completes consent and the app can read the chosen calendar busy data; revoked consent produces reconnect guidance. ## Quick start ```sh python -m venv .venv python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib python -m pip freeze > requirements.txt python -m flask --app app run --host 127.0.0.1 ``` Then copy `.env.example` to `.env` and fill in the values it documents. ## Honest limits This build deliberately does not replace: - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you - team round-robin and routing - SMS reminders - the integrations directory If one of those is essential to you, that is the reason to keep paying for Calendly, and the README should say so rather than pretend. ===== BRIEF.md ===== # Build brief · Calendly The one-shot brief this plan expands. `BUILD_PLAN.md` (or `MILESTONES.md`) is the same sequence broken into steps and checks; where the two disagree, the plan wins. Build me a single-owner Google Calendar booking page with conflict-aware confirmation as a bounded replacement for Calendly. Build it in phases in the order below. Do not write the whole product in one pass. Finish the current phase, run its Done when checks, fix failures, then continue. Indie mode completes Phases 1-5. Phase 6 is required before shared or public deployment. ### Stack (fixed, do not substitute) - Runtime: Python 3.12+ and Flask. A small local HTTP application with readable server-side handlers and no JavaScript build pipeline. - Storage: SQLite through Python sqlite3. Local ownership with explicit transactions and a portable backup path. - Interface: Jinja HTML templates, CSS and vanilla JavaScript. Implement the specified screens directly with labelled controls and progressive enhancement. - Verification: Python unittest and browser acceptance fixtures. Check invariants and the actual user workflow before the next phase. - Focused libraries: google-api-python-client, google-auth-httplib2, google-auth-oauthlib. Use these only for the specific file, parsing or provider operations named in the phases; freeze tested versions. ### Data model (create this before Phase 1) - event_types(id,title,duration_minutes,buffer_minutes) - availability(id,weekday,start_local,end_local,timezone) - bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id) - holds(id,start_utc,end_utc,expires_at) - oauth credentials stored outside public files - Use stable ids and explicit relationships; add auxiliary tables named by the phases before those phases use them. - Acceptance fixture: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. ### Prerequisites and configuration - Python 3.12 or newer and a terminal: Install Python from python.org. Open a terminal in a new empty project folder. On Windows, use py -3 where this guide says python if python is not on PATH; on macOS/Linux use python3 if needed. Create .venv and activate it before installing packages. Verify: python --version reports 3.12+ and python -c "import sqlite3" succeeds. Cost: Python is free; this local prototype requires no hosting subscription. - A current desktop browser and text editor: Use an installed Chrome, Firefox or Edge browser. Open the empty project folder in your editor; open the terminal there, not in this catalog repository. Verify: You can create a text file in the project folder and open browser developer tools. Cost: No paid service required for this local step. - Calendly acceptance sample: Create synthetic sample data before implementation: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Save it under fixtures/ with the expected results in fixtures/README.md; use no real credentials or customer records. Verify: The fixture files and expected outcomes exist and can be inspected without a vendor account. Cost: No paid service required for this local step. - Confirm the bounded replacement: The deliverable is a single-owner Google Calendar booking page with conflict-aware confirmation. Read every exclusion below. Indie mode runs locally; any public or shared use requires the product access and deployment gates first. Verify: You can name the primary workflow and the vendor features this version deliberately leaves out. Cost: No paid service required for this local step. - Google Calendar OAuth client for one test owner: Follow the official Python quickstart: create a Cloud project, enable Calendar API, configure consent and your test user, and create OAuth credentials. For this web app use a Web application client and register the exact local callback http://127.0.0.1:5000/oauth/callback; use the matching HTTPS callback when deploying. Save the client JSON outside static files. Verify: The owner completes consent and the app can read the chosen calendar busy data; revoked consent produces reconnect guidance. Cost: Check current Google API quotas and any project billing requirements; this guide assumes no paid quota or production verification exemption. - Configuration: DATA_DIR, SECRET_KEY, APP_MODE, SITE_URL, GOOGLE_CLIENT_FILE, GOOGLE_TOKEN_FILE, GOOGLE_CALENDAR_ID. Ship .env.example, replace placeholders and exclude secrets from git. ### Phase 1 · Local foundation and data contract Build: Create the runnable local foundation for a single-owner Google Calendar booking page with conflict-aware confirmation, including the real schema and acceptance fixture. - Run the venv command first, then stop and activate it before running the remaining commands. Use your OS instructions: Windows .venv\Scripts\activate.bat in cmd, or .venv\Scripts\Activate.ps1 in PowerShell; macOS/Linux source .venv/bin/activate. Then install the listed packages. Create app.py exposing app, load .env with python-dotenv, and add a /healthz route. Freeze tested dependency versions to requirements.txt. Create .env manually from .env.example; replace SECRET_KEY before launch. Commands, after creating the named files: `python -m venv .venv`; `python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib`; `python -m pip freeze > requirements.txt`; `python -m flask --app app run --host 127.0.0.1`. - For database-backed state create schema.sql and db.py using this model: event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files. Add the auxiliary relationships explicitly used in later phases; use stable ids, foreign keys, parameterized values and transactions. For canonical files use atomic replacement and hashes instead. Implement python manage.py init and python manage.py seed to create only synthetic data: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Re-running init must not erase data. Commands, after creating the named files: `python manage.py init`; `python manage.py seed`. - Install Flask-WTF CSRF protection for forms and same-origin fetches, validate Host and Origin against SITE_URL, bound inputs and escape output. Deliberately public intake endpoints get bounded validation and rate limits; signed provider webhooks use signature checks instead of browser CSRF tokens. All other admin routes stay local until product authentication exists. When a later phase tests viewer/member permissions, implement the users, hashed passwords, expiring server sessions and role checks in this foundation first; product mode must never use a fabricated identity from request input. Add error, empty, keyboard-focus and retry states now. - Trap: The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. Done when: The documented start command serves /healthz and the initial screen at http://127.0.0.1:5000. Restarting preserves the seeded records or canonical files; running init again deletes nothing. A cross-origin state-changing request to an admin route is refused. Do not build yet: Do not start calendar connection before ui until these checks pass. ### Phase 2 · Calendar connection before UI Build: Calendar connection before UI for Calendly: Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. - Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. - Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: An occupied fixture interval is returned as unavailable. Then check: Revoking access prevents booking confirmation and shows a reconnect state. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: A service account is not a drop-in substitute for a personal calendar OAuth consent flow. Done when: An occupied fixture interval is returned as unavailable. Revoking access prevents booking confirmation and shows a reconnect state. Do not build yet: Do not start availability and atomic holds until these checks pass. ### Phase 3 · Availability and atomic holds Build: Availability and atomic holds for Calendly: Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. - Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. - Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: Two concurrent guests for one slot produce one active hold. Then check: A slot inside the external busy period cannot be booked by direct POST. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. Done when: Two concurrent guests for one slot produce one active hold. A slot inside the external busy period cannot be booked by direct POST. Do not build yet: Do not start event and guest lifecycle until these checks pass. ### Phase 4 · Event and guest lifecycle Build: Event and guest lifecycle for Calendly: Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. - Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. - Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: The API timeout followed by reconciliation produces one confirmed event. Then check: An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. Done when: The API timeout followed by reconciliation produces one confirmed event. An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Do not build yet: Do not start portable delivery and clean-start proof until these checks pass. ### Phase 5 · Portable delivery and clean-start proof Build: Finish the Calendly replacement with a documented first-run path and a recoverable export. - Document prerequisites, every configuration variable, data locations and the three domain workflows: Calendar connection before UI; Availability and atomic holds; Event and guest lifecycle. Include the exclusions, actual costs and source check date 2026-09-05. Commands shown earlier that reference project files are files the builder must implement before running them. - Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. - Use a new folder and only README instructions to reach the fixture outcome. Install from requirements.txt, initialize storage, run the tests and exercise the UI at 375px and 1280px; use keyboard-only controls and inspect browser errors. Record exactly what passed; do not mark unrun checks complete. Commands, after creating the named files: `python -m pip install -r requirements.txt`; `python -m unittest discover -s test`. - Trap: Export without an import or restore rehearsal is not verified portability. Done when: A new folder reaches the documented fixture outcome using only README instructions. A backup restored in isolation preserves the proof data and can be opened. Do not build yet: Do not start operate and share with access controls until these checks pass. ### Phase 6 · Operate and share with access controls (product-builder only) Build: Product-builder only: make a single-owner Google Calendar booking page with conflict-aware confirmation operable for its stated audience before allowing remote access. - Add owner/member/viewer authorization as appropriate, password hashes through Werkzeug, expiring server-side sessions, CSRF and login rate limits. Add users, sessions and audit schema migrations plus an owner-init command prompting securely for its password. Enforce ownership on every private read/write/download and fail closed when product setup is incomplete. Existing learner or admin identities must use this same boundary. - Serve app:app with Waitress on loopback behind Caddy HTTPS. Configure trusted proxy headers narrowly, Secure/HttpOnly/SameSite cookies, upload limits, request ids and structured logs without private content. Run background jobs as a separate supervised process when the domain workflow requires them. Commands, after creating the named files: `waitress-serve --listen=127.0.0.1:5000 app:app`. - Add a scheduled encrypted off-host backup using this procedure: Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Monitor health, disk space, failed jobs and backup age. Stop the service to test an alert; rehearse recovery with outbound effects disabled and record recovery time. Rotate any exposed credentials and require reconciliation before resuming queues. - Trap: Product mode is additional engineering, not a switch that makes a local prototype production-ready. Done when: An unauthenticated visitor cannot read private records, download private files or mutate the admin surface. A viewer cannot mutate data by making a direct request, and guessed ids cannot cross ownership boundaries. Stopping the service triggers the configured alert and the latest off-host backup restores the fixture in isolation. Do not build yet: Do not add new providers or vendor-scale features until the release gates are recorded. ### Out of scope (and why) - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you: retain the paid product if this capability is essential; it is outside this bounded build. - team round-robin and routing: retain the paid product if this capability is essential; it is outside this bounded build. - SMS reminders: retain the paid product if this capability is essential; it is outside this bounded build. - the integrations directory: retain the paid product if this capability is essential; it is outside this bounded build. ### README must contain - Exact install, configure, initialize, start, test and recovery commands for a clean folder. - The schema, fixture, acceptance results, private data locations and export format. - Every prerequisite and secret source, actual running costs and deliberately excluded capabilities. - An honest distinction between tests actually run and checks still awaiting real credentials or deployment. - Dependency documentation reviewed 2026-09-05: https://flask.palletsprojects.com/en/stable/installation/ ; https://docs.python.org/3/library/sqlite3.html ; https://flask-wtf.readthedocs.io/en/1.2.x/csrf/ ; https://docs.pylonsproject.org/projects/waitress/en/stable/usage.html ; https://developers.google.com/workspace/calendar/api/quickstart/python ; https://developers.google.com/workspace/calendar/api/guides/create-events. Recheck before upgrading; freeze the versions actually tested. ===== AGENTS.md ===== # Agent instructions · Calendly indie build - Read `README.md` and `BUILD_PLAN.md` before writing code. The stack is fixed: Python 3.12+ and Flask, SQLite through Python sqlite3, Jinja HTML templates, CSS and vanilla JavaScript, Python unittest and browser acceptance fixtures, google-api-python-client, google-auth-httplib2, google-auth-oauthlib. Do not substitute. - Work one phase at a time, in order. Do not start a phase until every "Done when" item of the previous one passes. - Prefer the fewest moving parts that satisfy the step. No frameworks, services or dependencies the plan does not name. - Secrets live in `.env`, never in source or logs. Keep `.env.example` current when a variable is introduced. - Do not invent cryptography, security guarantees, APIs or compliance claims. - Add a focused test for every destructive, security-sensitive or data-loss path the plan names. - Run the project checks before declaring a phase complete, and record any deliberate shortcut in the README under "Tradeoffs". ## Known traps - The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. - No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. - Export without an import or restore rehearsal is not verified portability. ===== BUILD_PLAN.md ===== # Build plan · Calendly Build a single-owner Google Calendar booking page with conflict-aware confirmation. Phases are in dependency order. Each ends in a "Done when" list; treat an unticked item as a blocker, not a note. ## Phase 1 · Local foundation and data contract Create the runnable local foundation for a single-owner Google Calendar booking page with conflict-aware confirmation, including the real schema and acceptance fixture. ### Steps 1. Create and start the local application Run the venv command first, then stop and activate it before running the remaining commands. Use your OS instructions: Windows .venv\Scripts\activate.bat in cmd, or .venv\Scripts\Activate.ps1 in PowerShell; macOS/Linux source .venv/bin/activate. Then install the listed packages. Create app.py exposing app, load .env with python-dotenv, and add a /healthz route. Freeze tested dependency versions to requirements.txt. Create .env manually from .env.example; replace SECRET_KEY before launch. Files: `app.py`, `requirements.txt`, `.env.example`, `.gitignore` ```sh python -m venv .venv python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib python -m pip freeze > requirements.txt python -m flask --app app run --host 127.0.0.1 ``` 2. Implement storage and seed the named fixture For database-backed state create schema.sql and db.py using this model: event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files. Add the auxiliary relationships explicitly used in later phases; use stable ids, foreign keys, parameterized values and transactions. For canonical files use atomic replacement and hashes instead. Implement python manage.py init and python manage.py seed to create only synthetic data: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Re-running init must not erase data. Files: `schema.sql`, `db.py`, `manage.py`, `fixtures/README.md` ```sh python manage.py init python manage.py seed ``` 3. Protect the local request boundary Install Flask-WTF CSRF protection for forms and same-origin fetches, validate Host and Origin against SITE_URL, bound inputs and escape output. Deliberately public intake endpoints get bounded validation and rate limits; signed provider webhooks use signature checks instead of browser CSRF tokens. All other admin routes stay local until product authentication exists. When a later phase tests viewer/member permissions, implement the users, hashed passwords, expiring server sessions and role checks in this foundation first; product mode must never use a fabricated identity from request input. Add error, empty, keyboard-focus and retry states now. Files: `app.py`, `templates/base.html`, `test/test_foundation.py` ### Done when - [ ] The documented start command serves /healthz and the initial screen at http://127.0.0.1:5000. - [ ] Restarting preserves the seeded records or canonical files; running init again deletes nothing. - [ ] A cross-origin state-changing request to an admin route is refused. ### Watch out - The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. ## Phase 2 · Calendar connection before UI Calendar connection before UI for Calendly: Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. ### Steps 1. Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. Files: `features/calendar_connection_before_ui.py`, `templates/calendar_connection_before_ui.html` 2. Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. Files: `features/calendar_connection_before_ui.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: An occupied fixture interval is returned as unavailable. Then check: Revoking access prevents booking confirmation and shows a reconnect state. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_calendar_connection_before_ui.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] An occupied fixture interval is returned as unavailable. - [ ] Revoking access prevents booking confirmation and shows a reconnect state. ### Watch out - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. ## Phase 3 · Availability and atomic holds Availability and atomic holds for Calendly: Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. ### Steps 1. Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. Files: `features/availability_and_atomic_holds.py`, `templates/availability_and_atomic_holds.html` 2. Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. Files: `features/availability_and_atomic_holds.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: Two concurrent guests for one slot produce one active hold. Then check: A slot inside the external busy period cannot be booked by direct POST. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_availability_and_atomic_holds.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] Two concurrent guests for one slot produce one active hold. - [ ] A slot inside the external busy period cannot be booked by direct POST. ### Watch out - Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. ## Phase 4 · Event and guest lifecycle Event and guest lifecycle for Calendly: Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. ### Steps 1. Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. Files: `features/event_and_guest_lifecycle.py`, `templates/event_and_guest_lifecycle.html` 2. Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. Files: `features/event_and_guest_lifecycle.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: The API timeout followed by reconciliation produces one confirmed event. Then check: An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_event_and_guest_lifecycle.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] The API timeout followed by reconciliation produces one confirmed event. - [ ] An invalid cancel token cannot cancel a booking, and cancellation releases the slot. ### Watch out - No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. ## Phase 5 · Portable delivery and clean-start proof Finish the Calendly replacement with a documented first-run path and a recoverable export. ### Steps 1. Write the user-facing runbook Document prerequisites, every configuration variable, data locations and the three domain workflows: Calendar connection before UI; Availability and atomic holds; Event and guest lifecycle. Include the exclusions, actual costs and source check date 2026-09-05. Commands shown earlier that reference project files are files the builder must implement before running them. Files: `README.md`, `.env.example` 2. Create and rehearse a recoverable backup Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. Files: `OPERATIONS.md`, `scripts/backup.py` 3. Reproduce the first-run experience Use a new folder and only README instructions to reach the fixture outcome. Install from requirements.txt, initialize storage, run the tests and exercise the UI at 375px and 1280px; use keyboard-only controls and inspect browser errors. Record exactly what passed; do not mark unrun checks complete. Files: `README.md`, `verification.md` ```sh python -m pip install -r requirements.txt python -m unittest discover -s test ``` ### Done when - [ ] A new folder reaches the documented fixture outcome using only README instructions. - [ ] A backup restored in isolation preserves the proof data and can be opened. ### Watch out - Export without an import or restore rehearsal is not verified portability. ## Not in this build - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you - team round-robin and routing - SMS reminders - the integrations directory ## After v1, if you want it - Extend event and guest lifecycle only after the fixture and recovery checks pass. - Before adding another integration, document its credentials, limits, cost and failure behavior with primary-source links. ===== .env.example ===== # Copy to .env and fill in. Never commit .env; this file documents it. # Required. A new private folder this application creates on first run; never serve it as static files. DATA_DIR=./data/calendly # Required · secret. Generate with python -c "import secrets; print(secrets.token_hex(32))" and save only in .env. SECRET_KEY=replace-with-a-random-secret # Required. Use indie for loopback-only personal work. Product mode must refuse to start until owner login and the deployment gates are configured. APP_MODE=indie # Required. The origin used for local forms and links; replace with the chosen HTTPS origin in product mode. SITE_URL=http://127.0.0.1:5000 # Required · secret. Download the OAuth client JSON from Cloud console; never commit it. GOOGLE_CLIENT_FILE=./secrets/google-client.json # Required · secret. Created by the owner authorization flow; restrict file permissions and exclude from backups shared with others. GOOGLE_TOKEN_FILE=./secrets/google-token.json # Required. The authenticated owner calendar id; choose a dedicated test calendar during development. GOOGLE_CALENDAR_ID=primary
You are building a production product version of Calendly. Create the following project files first, then implement the application by following them. Keep the files updated as decisions change. Do not collapse this into a single README or prompt. ===== PRODUCT.md ===== # Calendly · product brief ## Problem A single-user booking page is easy; production-grade scheduling needs OAuth, availability rules, time zones, reminders, payments, team routing, and trust. ## Product outcome An operated version of a single-owner Google Calendar booking page with conflict-aware confirmation, with authorized access, restore evidence and honest scope limits. ## Target user A builder who needs a maintainable product foundation, not a one-off demo. ## Required capabilities - Google/Microsoft calendar OAuth - hosted app - email notifications - timezone handling - auth ## Explicit non-goals for v1 - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you - team round-robin and routing - SMS reminders - the integrations directory ## Success criteria - An occupied fixture interval is returned as unavailable. - Two concurrent guests for one slot produce one active hold. - The API timeout followed by reconciliation produces one confirmed event. - A private-data authorization check passes using a second identity. - An off-host restore drill has a date, observed result and recovery time in OPERATIONS.md. - README names the excluded vendor capabilities and actual provider/hosting costs. ===== BRIEF.md ===== # Build brief · Calendly The one-shot brief this plan expands. `BUILD_PLAN.md` (or `MILESTONES.md`) is the same sequence broken into steps and checks; where the two disagree, the plan wins. Build me a single-owner Google Calendar booking page with conflict-aware confirmation as a bounded replacement for Calendly. Build it in phases in the order below. Do not write the whole product in one pass. Finish the current phase, run its Done when checks, fix failures, then continue. Indie mode completes Phases 1-5. Phase 6 is required before shared or public deployment. ### Stack (fixed, do not substitute) - Runtime: Python 3.12+ and Flask. A small local HTTP application with readable server-side handlers and no JavaScript build pipeline. - Storage: SQLite through Python sqlite3. Local ownership with explicit transactions and a portable backup path. - Interface: Jinja HTML templates, CSS and vanilla JavaScript. Implement the specified screens directly with labelled controls and progressive enhancement. - Verification: Python unittest and browser acceptance fixtures. Check invariants and the actual user workflow before the next phase. - Focused libraries: google-api-python-client, google-auth-httplib2, google-auth-oauthlib. Use these only for the specific file, parsing or provider operations named in the phases; freeze tested versions. ### Data model (create this before Phase 1) - event_types(id,title,duration_minutes,buffer_minutes) - availability(id,weekday,start_local,end_local,timezone) - bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id) - holds(id,start_utc,end_utc,expires_at) - oauth credentials stored outside public files - Use stable ids and explicit relationships; add auxiliary tables named by the phases before those phases use them. - Acceptance fixture: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. ### Prerequisites and configuration - Python 3.12 or newer and a terminal: Install Python from python.org. Open a terminal in a new empty project folder. On Windows, use py -3 where this guide says python if python is not on PATH; on macOS/Linux use python3 if needed. Create .venv and activate it before installing packages. Verify: python --version reports 3.12+ and python -c "import sqlite3" succeeds. Cost: Python is free; this local prototype requires no hosting subscription. - A current desktop browser and text editor: Use an installed Chrome, Firefox or Edge browser. Open the empty project folder in your editor; open the terminal there, not in this catalog repository. Verify: You can create a text file in the project folder and open browser developer tools. Cost: No paid service required for this local step. - Calendly acceptance sample: Create synthetic sample data before implementation: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Save it under fixtures/ with the expected results in fixtures/README.md; use no real credentials or customer records. Verify: The fixture files and expected outcomes exist and can be inspected without a vendor account. Cost: No paid service required for this local step. - Confirm the bounded replacement: The deliverable is a single-owner Google Calendar booking page with conflict-aware confirmation. Read every exclusion below. Indie mode runs locally; any public or shared use requires the product access and deployment gates first. Verify: You can name the primary workflow and the vendor features this version deliberately leaves out. Cost: No paid service required for this local step. - Google Calendar OAuth client for one test owner: Follow the official Python quickstart: create a Cloud project, enable Calendar API, configure consent and your test user, and create OAuth credentials. For this web app use a Web application client and register the exact local callback http://127.0.0.1:5000/oauth/callback; use the matching HTTPS callback when deploying. Save the client JSON outside static files. Verify: The owner completes consent and the app can read the chosen calendar busy data; revoked consent produces reconnect guidance. Cost: Check current Google API quotas and any project billing requirements; this guide assumes no paid quota or production verification exemption. - Configuration: DATA_DIR, SECRET_KEY, APP_MODE, SITE_URL, GOOGLE_CLIENT_FILE, GOOGLE_TOKEN_FILE, GOOGLE_CALENDAR_ID. Ship .env.example, replace placeholders and exclude secrets from git. ### Phase 1 · Local foundation and data contract Build: Create the runnable local foundation for a single-owner Google Calendar booking page with conflict-aware confirmation, including the real schema and acceptance fixture. - Run the venv command first, then stop and activate it before running the remaining commands. Use your OS instructions: Windows .venv\Scripts\activate.bat in cmd, or .venv\Scripts\Activate.ps1 in PowerShell; macOS/Linux source .venv/bin/activate. Then install the listed packages. Create app.py exposing app, load .env with python-dotenv, and add a /healthz route. Freeze tested dependency versions to requirements.txt. Create .env manually from .env.example; replace SECRET_KEY before launch. Commands, after creating the named files: `python -m venv .venv`; `python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib`; `python -m pip freeze > requirements.txt`; `python -m flask --app app run --host 127.0.0.1`. - For database-backed state create schema.sql and db.py using this model: event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files. Add the auxiliary relationships explicitly used in later phases; use stable ids, foreign keys, parameterized values and transactions. For canonical files use atomic replacement and hashes instead. Implement python manage.py init and python manage.py seed to create only synthetic data: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Re-running init must not erase data. Commands, after creating the named files: `python manage.py init`; `python manage.py seed`. - Install Flask-WTF CSRF protection for forms and same-origin fetches, validate Host and Origin against SITE_URL, bound inputs and escape output. Deliberately public intake endpoints get bounded validation and rate limits; signed provider webhooks use signature checks instead of browser CSRF tokens. All other admin routes stay local until product authentication exists. When a later phase tests viewer/member permissions, implement the users, hashed passwords, expiring server sessions and role checks in this foundation first; product mode must never use a fabricated identity from request input. Add error, empty, keyboard-focus and retry states now. - Trap: The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. Done when: The documented start command serves /healthz and the initial screen at http://127.0.0.1:5000. Restarting preserves the seeded records or canonical files; running init again deletes nothing. A cross-origin state-changing request to an admin route is refused. Do not build yet: Do not start calendar connection before ui until these checks pass. ### Phase 2 · Calendar connection before UI Build: Calendar connection before UI for Calendly: Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. - Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. - Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: An occupied fixture interval is returned as unavailable. Then check: Revoking access prevents booking confirmation and shows a reconnect state. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: A service account is not a drop-in substitute for a personal calendar OAuth consent flow. Done when: An occupied fixture interval is returned as unavailable. Revoking access prevents booking confirmation and shows a reconnect state. Do not build yet: Do not start availability and atomic holds until these checks pass. ### Phase 3 · Availability and atomic holds Build: Availability and atomic holds for Calendly: Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. - Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. - Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: Two concurrent guests for one slot produce one active hold. Then check: A slot inside the external busy period cannot be booked by direct POST. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. Done when: Two concurrent guests for one slot produce one active hold. A slot inside the external busy period cannot be booked by direct POST. Do not build yet: Do not start event and guest lifecycle until these checks pass. ### Phase 4 · Event and guest lifecycle Build: Event and guest lifecycle for Calendly: Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. - Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. - Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: The API timeout followed by reconciliation produces one confirmed event. Then check: An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. Done when: The API timeout followed by reconciliation produces one confirmed event. An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Do not build yet: Do not start portable delivery and clean-start proof until these checks pass. ### Phase 5 · Portable delivery and clean-start proof Build: Finish the Calendly replacement with a documented first-run path and a recoverable export. - Document prerequisites, every configuration variable, data locations and the three domain workflows: Calendar connection before UI; Availability and atomic holds; Event and guest lifecycle. Include the exclusions, actual costs and source check date 2026-09-05. Commands shown earlier that reference project files are files the builder must implement before running them. - Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. - Use a new folder and only README instructions to reach the fixture outcome. Install from requirements.txt, initialize storage, run the tests and exercise the UI at 375px and 1280px; use keyboard-only controls and inspect browser errors. Record exactly what passed; do not mark unrun checks complete. Commands, after creating the named files: `python -m pip install -r requirements.txt`; `python -m unittest discover -s test`. - Trap: Export without an import or restore rehearsal is not verified portability. Done when: A new folder reaches the documented fixture outcome using only README instructions. A backup restored in isolation preserves the proof data and can be opened. Do not build yet: Do not start operate and share with access controls until these checks pass. ### Phase 6 · Operate and share with access controls (product-builder only) Build: Product-builder only: make a single-owner Google Calendar booking page with conflict-aware confirmation operable for its stated audience before allowing remote access. - Add owner/member/viewer authorization as appropriate, password hashes through Werkzeug, expiring server-side sessions, CSRF and login rate limits. Add users, sessions and audit schema migrations plus an owner-init command prompting securely for its password. Enforce ownership on every private read/write/download and fail closed when product setup is incomplete. Existing learner or admin identities must use this same boundary. - Serve app:app with Waitress on loopback behind Caddy HTTPS. Configure trusted proxy headers narrowly, Secure/HttpOnly/SameSite cookies, upload limits, request ids and structured logs without private content. Run background jobs as a separate supervised process when the domain workflow requires them. Commands, after creating the named files: `waitress-serve --listen=127.0.0.1:5000 app:app`. - Add a scheduled encrypted off-host backup using this procedure: Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Monitor health, disk space, failed jobs and backup age. Stop the service to test an alert; rehearse recovery with outbound effects disabled and record recovery time. Rotate any exposed credentials and require reconciliation before resuming queues. - Trap: Product mode is additional engineering, not a switch that makes a local prototype production-ready. Done when: An unauthenticated visitor cannot read private records, download private files or mutate the admin surface. A viewer cannot mutate data by making a direct request, and guessed ids cannot cross ownership boundaries. Stopping the service triggers the configured alert and the latest off-host backup restores the fixture in isolation. Do not build yet: Do not add new providers or vendor-scale features until the release gates are recorded. ### Out of scope (and why) - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you: retain the paid product if this capability is essential; it is outside this bounded build. - team round-robin and routing: retain the paid product if this capability is essential; it is outside this bounded build. - SMS reminders: retain the paid product if this capability is essential; it is outside this bounded build. - the integrations directory: retain the paid product if this capability is essential; it is outside this bounded build. ### README must contain - Exact install, configure, initialize, start, test and recovery commands for a clean folder. - The schema, fixture, acceptance results, private data locations and export format. - Every prerequisite and secret source, actual running costs and deliberately excluded capabilities. - An honest distinction between tests actually run and checks still awaiting real credentials or deployment. - Dependency documentation reviewed 2026-09-05: https://flask.palletsprojects.com/en/stable/installation/ ; https://docs.python.org/3/library/sqlite3.html ; https://flask-wtf.readthedocs.io/en/1.2.x/csrf/ ; https://docs.pylonsproject.org/projects/waitress/en/stable/usage.html ; https://developers.google.com/workspace/calendar/api/quickstart/python ; https://developers.google.com/workspace/calendar/api/guides/create-events. Recheck before upgrading; freeze the versions actually tested. ===== ARCHITECTURE.md ===== # Architecture · Calendly ## Stack | Part | Choice | Why | | --- | --- | --- | | Runtime | Python 3.12+ and Flask | A small local HTTP application with readable server-side handlers and no JavaScript build pipeline. | | Storage | SQLite through Python sqlite3 | Local ownership with explicit transactions and a portable backup path. | | Interface | Jinja HTML templates, CSS and vanilla JavaScript | Implement the specified screens directly with labelled controls and progressive enhancement. | | Verification | Python unittest and browser acceptance fixtures | Check invariants and the actual user workflow before the next phase. | | Focused libraries | google-api-python-client, google-auth-httplib2, google-auth-oauthlib | Use these only for the specific file, parsing or provider operations named in the phases; freeze tested versions. | ## Modules Each module has one owner concern and a documented way to replace it. | Module | Owns | How to replace it | | --- | --- | --- | | Data and identity | event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files | Keep stable ids and a versioned repository interface; migrate storage behind it with a fixture round-trip. | | Calendar connection before UI | Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. | Keep the acceptance contract: An occupied fixture interval is returned as unavailable. Replace only this module after replaying its fixture; preserve ids and existing records. | | Availability and atomic holds | Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. | Keep the acceptance contract: Two concurrent guests for one slot produce one active hold. Replace only this module after replaying its fixture; preserve ids and existing records. | | Event and guest lifecycle | Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. | Keep the acceptance contract: The API timeout followed by reconciliation produces one confirmed event. Replace only this module after replaying its fixture; preserve ids and existing records. | | Operations | Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. | Change host or backup destination only after an isolated restore and authorization check. | ## Configuration Every runtime setting is an environment variable documented in `.env.example`, validated at startup, with a safe local default wherever one exists. - `DATA_DIR` · required · A new private folder this application creates on first run; never serve it as static files. - `SECRET_KEY` · required, secret · Generate with python -c "import secrets; print(secrets.token_hex(32))" and save only in .env. - `APP_MODE` · required · Use indie for loopback-only personal work. Product mode must refuse to start until owner login and the deployment gates are configured. - `SITE_URL` · required · The origin used for local forms and links; replace with the chosen HTTPS origin in product mode. - `GOOGLE_CLIENT_FILE` · required, secret · Download the OAuth client JSON from Cloud console; never commit it. - `GOOGLE_TOKEN_FILE` · required, secret · Created by the owner authorization flow; restrict file permissions and exclude from backups shared with others. - `GOOGLE_CALENDAR_ID` · required · The authenticated owner calendar id; choose a dedicated test calendar during development. ## Production baseline - Security: least privilege, input validation at every boundary, secret redaction in logs, rate limits on abuse-prone paths, no invented security primitives. - Data: explicit schema and migrations, transactional writes where integrity matters, backup and restore procedures that have been exercised. - Integrations: adapters around third-party providers, idempotent webhook or job processing, bounded retries, timeouts. - Observability: structured logs with request or operation ids, an error-tracking hook, and health and readiness checks where a server exists. - Quality: unit tests for domain rules, integration tests at module boundaries, one end-to-end test of the critical path. ## Decision records For each dependency in the stack table, keep a short note: why it was chosen, its failure mode, and how it is replaced. Do not add infrastructure until a requirement in `PRODUCT.md` justifies it. ===== AGENTS.md ===== # Agent instructions · Calendly product build - Read `PRODUCT.md` and `ARCHITECTURE.md` before changing code. The stack is fixed: Python 3.12+ and Flask, SQLite through Python sqlite3, Jinja HTML templates, CSS and vanilla JavaScript, Python unittest and browser acceptance fixtures, google-api-python-client, google-auth-httplib2, google-auth-oauthlib. - Implement milestone by milestone from `MILESTONES.md`; keep each change reviewable and leave the application runnable at every commit. - Treat authentication, payments, encryption, imports, webhooks and destructive actions as high-risk boundaries when present. - Never invent cryptography or silently weaken a requirement to make a check pass. - Put every external service behind an interface with a deterministic fake for tests. - Add migrations and rollback or recovery notes for every persistent data change. - Log useful operational context without credentials, tokens, passwords or personal data. - Update documentation and run every check before completing a milestone. ## Known traps - The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. - No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. - Export without an import or restore rehearsal is not verified portability. - Product mode is additional engineering, not a switch that makes a local prototype production-ready. ===== MILESTONES.md ===== # Delivery milestones · Calendly Estimated effort: **multi-day** for the indie phases; the production-only milestones add the trust and operability layer. ## M1 · Local foundation and data contract Create the runnable local foundation for a single-owner Google Calendar booking page with conflict-aware confirmation, including the real schema and acceptance fixture. ### Steps 1. Create and start the local application Run the venv command first, then stop and activate it before running the remaining commands. Use your OS instructions: Windows .venv\Scripts\activate.bat in cmd, or .venv\Scripts\Activate.ps1 in PowerShell; macOS/Linux source .venv/bin/activate. Then install the listed packages. Create app.py exposing app, load .env with python-dotenv, and add a /healthz route. Freeze tested dependency versions to requirements.txt. Create .env manually from .env.example; replace SECRET_KEY before launch. Files: `app.py`, `requirements.txt`, `.env.example`, `.gitignore` ```sh python -m venv .venv python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib python -m pip freeze > requirements.txt python -m flask --app app run --host 127.0.0.1 ``` 2. Implement storage and seed the named fixture For database-backed state create schema.sql and db.py using this model: event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files. Add the auxiliary relationships explicitly used in later phases; use stable ids, foreign keys, parameterized values and transactions. For canonical files use atomic replacement and hashes instead. Implement python manage.py init and python manage.py seed to create only synthetic data: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Re-running init must not erase data. Files: `schema.sql`, `db.py`, `manage.py`, `fixtures/README.md` ```sh python manage.py init python manage.py seed ``` 3. Protect the local request boundary Install Flask-WTF CSRF protection for forms and same-origin fetches, validate Host and Origin against SITE_URL, bound inputs and escape output. Deliberately public intake endpoints get bounded validation and rate limits; signed provider webhooks use signature checks instead of browser CSRF tokens. All other admin routes stay local until product authentication exists. When a later phase tests viewer/member permissions, implement the users, hashed passwords, expiring server sessions and role checks in this foundation first; product mode must never use a fabricated identity from request input. Add error, empty, keyboard-focus and retry states now. Files: `app.py`, `templates/base.html`, `test/test_foundation.py` ### Done when - [ ] The documented start command serves /healthz and the initial screen at http://127.0.0.1:5000. - [ ] Restarting preserves the seeded records or canonical files; running init again deletes nothing. - [ ] A cross-origin state-changing request to an admin route is refused. ### Watch out - The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. ## M2 · Calendar connection before UI Calendar connection before UI for Calendly: Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. ### Steps 1. Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. Files: `features/calendar_connection_before_ui.py`, `templates/calendar_connection_before_ui.html` 2. Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. Files: `features/calendar_connection_before_ui.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: An occupied fixture interval is returned as unavailable. Then check: Revoking access prevents booking confirmation and shows a reconnect state. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_calendar_connection_before_ui.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] An occupied fixture interval is returned as unavailable. - [ ] Revoking access prevents booking confirmation and shows a reconnect state. ### Watch out - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. ## M3 · Availability and atomic holds Availability and atomic holds for Calendly: Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. ### Steps 1. Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. Files: `features/availability_and_atomic_holds.py`, `templates/availability_and_atomic_holds.html` 2. Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. Files: `features/availability_and_atomic_holds.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: Two concurrent guests for one slot produce one active hold. Then check: A slot inside the external busy period cannot be booked by direct POST. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_availability_and_atomic_holds.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] Two concurrent guests for one slot produce one active hold. - [ ] A slot inside the external busy period cannot be booked by direct POST. ### Watch out - Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. ## M4 · Event and guest lifecycle Event and guest lifecycle for Calendly: Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. ### Steps 1. Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. Files: `features/event_and_guest_lifecycle.py`, `templates/event_and_guest_lifecycle.html` 2. Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. Files: `features/event_and_guest_lifecycle.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: The API timeout followed by reconciliation produces one confirmed event. Then check: An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_event_and_guest_lifecycle.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] The API timeout followed by reconciliation produces one confirmed event. - [ ] An invalid cancel token cannot cancel a booking, and cancellation releases the slot. ### Watch out - No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. ## M5 · Portable delivery and clean-start proof Finish the Calendly replacement with a documented first-run path and a recoverable export. ### Steps 1. Write the user-facing runbook Document prerequisites, every configuration variable, data locations and the three domain workflows: Calendar connection before UI; Availability and atomic holds; Event and guest lifecycle. Include the exclusions, actual costs and source check date 2026-09-05. Commands shown earlier that reference project files are files the builder must implement before running them. Files: `README.md`, `.env.example` 2. Create and rehearse a recoverable backup Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. Files: `OPERATIONS.md`, `scripts/backup.py` 3. Reproduce the first-run experience Use a new folder and only README instructions to reach the fixture outcome. Install from requirements.txt, initialize storage, run the tests and exercise the UI at 375px and 1280px; use keyboard-only controls and inspect browser errors. Record exactly what passed; do not mark unrun checks complete. Files: `README.md`, `verification.md` ```sh python -m pip install -r requirements.txt python -m unittest discover -s test ``` ### Done when - [ ] A new folder reaches the documented fixture outcome using only README instructions. - [ ] A backup restored in isolation preserves the proof data and can be opened. ### Watch out - Export without an import or restore rehearsal is not verified portability. ## M6 · Operate and share with access controls (production only) Product-builder only: make a single-owner Google Calendar booking page with conflict-aware confirmation operable for its stated audience before allowing remote access. ### Steps 1. Establish owner access before exposure Add owner/member/viewer authorization as appropriate, password hashes through Werkzeug, expiring server-side sessions, CSRF and login rate limits. Add users, sessions and audit schema migrations plus an owner-init command prompting securely for its password. Enforce ownership on every private read/write/download and fail closed when product setup is incomplete. Existing learner or admin identities must use this same boundary. Files: `ARCHITECTURE.md`, `OPERATIONS.md` 2. Deploy a monitored service Serve app:app with Waitress on loopback behind Caddy HTTPS. Configure trusted proxy headers narrowly, Secure/HttpOnly/SameSite cookies, upload limits, request ids and structured logs without private content. Run background jobs as a separate supervised process when the domain workflow requires them. Files: `Caddyfile`, `OPERATIONS.md` ```sh waitress-serve --listen=127.0.0.1:5000 app:app ``` 3. Rehearse loss and recovery Add a scheduled encrypted off-host backup using this procedure: Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Monitor health, disk space, failed jobs and backup age. Stop the service to test an alert; rehearse recovery with outbound effects disabled and record recovery time. Rotate any exposed credentials and require reconciliation before resuming queues. Files: `OPERATIONS.md`, `release-checklist.md` ### Done when - [ ] An unauthenticated visitor cannot read private records, download private files or mutate the admin surface. - [ ] A viewer cannot mutate data by making a direct request, and guessed ids cannot cross ownership boundaries. - [ ] Stopping the service triggers the configured alert and the latest off-host backup restores the fixture in isolation. ### Watch out - Product mode is additional engineering, not a switch that makes a local prototype production-ready. ===== OPERATIONS.md ===== # Operations · Calendly ## Backup Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. ## Restore Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. Do a restore drill before the first real user, and write the date here when it passes. ## Monitoring Check HTTP availability, free disk, backup age and domain failures for Calendar connection before UI, Availability and atomic holds, Event and guest lifecycle. Alert without logging private payloads. ## Incident checklist Pause outbound jobs and public intake as appropriate, preserve redacted diagnostics, restore an isolated verified backup, rotate affected credentials and reconcile uncertain effects before reopening. 1. Contain the issue without destroying evidence or user data. 2. Record the timeline and affected scope. 3. Rotate exposed secrets and revoke compromised sessions or credentials. 4. Restore from a verified backup when needed. 5. Document the root cause, the remediation and the regression test. ## Release gate - [ ] An occupied fixture interval is returned as unavailable. - [ ] Two concurrent guests for one slot produce one active hold. - [ ] The API timeout followed by reconciliation produces one confirmed event. - [ ] A private-data authorization check passes using a second identity. - [ ] An off-host restore drill has a date, observed result and recovery time in OPERATIONS.md. - [ ] README names the excluded vendor capabilities and actual provider/hosting costs. ## Launch constraint Do not market omitted Calendly capabilities as implemented. The non-goals in `PRODUCT.md` remain user-visible limitations until they are deliberately delivered. ===== .env.example ===== # Copy to .env and fill in. Never commit .env; this file documents it. # Required. A new private folder this application creates on first run; never serve it as static files. DATA_DIR=./data/calendly # Required · secret. Generate with python -c "import secrets; print(secrets.token_hex(32))" and save only in .env. SECRET_KEY=replace-with-a-random-secret # Required. Use indie for loopback-only personal work. Product mode must refuse to start until owner login and the deployment gates are configured. APP_MODE=indie # Required. The origin used for local forms and links; replace with the chosen HTTPS origin in product mode. SITE_URL=http://127.0.0.1:5000 # Required · secret. Download the OAuth client JSON from Cloud console; never commit it. GOOGLE_CLIENT_FILE=./secrets/google-client.json # Required · secret. Created by the owner authorization flow; restrict file permissions and exclude from backups shared with others. GOOGLE_TOKEN_FILE=./secrets/google-token.json # Required. The authenticated owner calendar id; choose a dedicated test calendar during development. GOOGLE_CALENDAR_ID=primary
README.md
# Calendly · indie build Build a single-owner Google Calendar booking page with conflict-aware confirmation. Estimated effort: **multi-day**. Work `BUILD_PLAN.md` top to bottom · every phase ends in a check that has to pass before the next one starts. ## Stack | Part | Choice | Why | | --- | --- | --- | | Runtime | Python 3.12+ and Flask | A small local HTTP application with readable server-side handlers and no JavaScript build pipeline. | | Storage | SQLite through Python sqlite3 | Local ownership with explicit transactions and a portable backup path. | | Interface | Jinja HTML templates, CSS and vanilla JavaScript | Implement the specified screens directly with labelled controls and progressive enhancement. | | Verification | Python unittest and browser acceptance fixtures | Check invariants and the actual user workflow before the next phase. | | Focused libraries | google-api-python-client, google-auth-httplib2, google-auth-oauthlib | Use these only for the specific file, parsing or provider operations named in the phases; freeze tested versions. | ## Before you start Have every one of these ready. The plan assumes them from step one. - [ ] **Python 3.12 or newer and a terminal** · Python is free; this local prototype requires no hosting subscription. - Why: The local backend, tests and storage use Python. - Get it: Install Python from python.org. Open a terminal in a new empty project folder. On Windows, use py -3 where this guide says python if python is not on PATH; on macOS/Linux use python3 if needed. Create .venv and activate it before installing packages. - Verify: python --version reports 3.12+ and python -c "import sqlite3" succeeds. - [ ] **A current desktop browser and text editor** · No paid service required for this local step. - Why: You need to view the local interface and edit generated project files. - Get it: Use an installed Chrome, Firefox or Edge browser. Open the empty project folder in your editor; open the terminal there, not in this catalog repository. - Verify: You can create a text file in the project folder and open browser developer tools. - [ ] **Calendly acceptance sample** · No paid service required for this local step. - Why: This fixture makes the first end-to-end check reproducible. - Get it: Create synthetic sample data before implementation: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Save it under fixtures/ with the expected results in fixtures/README.md; use no real credentials or customer records. - Verify: The fixture files and expected outcomes exist and can be inspected without a vendor account. - [ ] **Confirm the bounded replacement** · No paid service required for this local step. - Why: The full commercial product is larger than this guide. - Get it: The deliverable is a single-owner Google Calendar booking page with conflict-aware confirmation. Read every exclusion below. Indie mode runs locally; any public or shared use requires the product access and deployment gates first. - Verify: You can name the primary workflow and the vendor features this version deliberately leaves out. - [ ] **Google Calendar OAuth client for one test owner** · Check current Google API quotas and any project billing requirements; this guide assumes no paid quota or production verification exemption. - Why: The booking page must read busy periods and create invited events. - Get it: Follow the official Python quickstart: create a Cloud project, enable Calendar API, configure consent and your test user, and create OAuth credentials. For this web app use a Web application client and register the exact local callback http://127.0.0.1:5000/oauth/callback; use the matching HTTPS callback when deploying. Save the client JSON outside static files. - Verify: The owner completes consent and the app can read the chosen calendar busy data; revoked consent produces reconnect guidance. ## Quick start ```sh python -m venv .venv python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib python -m pip freeze > requirements.txt python -m flask --app app run --host 127.0.0.1 ``` Then copy `.env.example` to `.env` and fill in the values it documents. ## Honest limits This build deliberately does not replace: - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you - team round-robin and routing - SMS reminders - the integrations directory If one of those is essential to you, that is the reason to keep paying for Calendly, and the README should say so rather than pretend.
BRIEF.md
# Build brief · Calendly The one-shot brief this plan expands. `BUILD_PLAN.md` (or `MILESTONES.md`) is the same sequence broken into steps and checks; where the two disagree, the plan wins. Build me a single-owner Google Calendar booking page with conflict-aware confirmation as a bounded replacement for Calendly. Build it in phases in the order below. Do not write the whole product in one pass. Finish the current phase, run its Done when checks, fix failures, then continue. Indie mode completes Phases 1-5. Phase 6 is required before shared or public deployment. ### Stack (fixed, do not substitute) - Runtime: Python 3.12+ and Flask. A small local HTTP application with readable server-side handlers and no JavaScript build pipeline. - Storage: SQLite through Python sqlite3. Local ownership with explicit transactions and a portable backup path. - Interface: Jinja HTML templates, CSS and vanilla JavaScript. Implement the specified screens directly with labelled controls and progressive enhancement. - Verification: Python unittest and browser acceptance fixtures. Check invariants and the actual user workflow before the next phase. - Focused libraries: google-api-python-client, google-auth-httplib2, google-auth-oauthlib. Use these only for the specific file, parsing or provider operations named in the phases; freeze tested versions. ### Data model (create this before Phase 1) - event_types(id,title,duration_minutes,buffer_minutes) - availability(id,weekday,start_local,end_local,timezone) - bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id) - holds(id,start_utc,end_utc,expires_at) - oauth credentials stored outside public files - Use stable ids and explicit relationships; add auxiliary tables named by the phases before those phases use them. - Acceptance fixture: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. ### Prerequisites and configuration - Python 3.12 or newer and a terminal: Install Python from python.org. Open a terminal in a new empty project folder. On Windows, use py -3 where this guide says python if python is not on PATH; on macOS/Linux use python3 if needed. Create .venv and activate it before installing packages. Verify: python --version reports 3.12+ and python -c "import sqlite3" succeeds. Cost: Python is free; this local prototype requires no hosting subscription. - A current desktop browser and text editor: Use an installed Chrome, Firefox or Edge browser. Open the empty project folder in your editor; open the terminal there, not in this catalog repository. Verify: You can create a text file in the project folder and open browser developer tools. Cost: No paid service required for this local step. - Calendly acceptance sample: Create synthetic sample data before implementation: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Save it under fixtures/ with the expected results in fixtures/README.md; use no real credentials or customer records. Verify: The fixture files and expected outcomes exist and can be inspected without a vendor account. Cost: No paid service required for this local step. - Confirm the bounded replacement: The deliverable is a single-owner Google Calendar booking page with conflict-aware confirmation. Read every exclusion below. Indie mode runs locally; any public or shared use requires the product access and deployment gates first. Verify: You can name the primary workflow and the vendor features this version deliberately leaves out. Cost: No paid service required for this local step. - Google Calendar OAuth client for one test owner: Follow the official Python quickstart: create a Cloud project, enable Calendar API, configure consent and your test user, and create OAuth credentials. For this web app use a Web application client and register the exact local callback http://127.0.0.1:5000/oauth/callback; use the matching HTTPS callback when deploying. Save the client JSON outside static files. Verify: The owner completes consent and the app can read the chosen calendar busy data; revoked consent produces reconnect guidance. Cost: Check current Google API quotas and any project billing requirements; this guide assumes no paid quota or production verification exemption. - Configuration: DATA_DIR, SECRET_KEY, APP_MODE, SITE_URL, GOOGLE_CLIENT_FILE, GOOGLE_TOKEN_FILE, GOOGLE_CALENDAR_ID. Ship .env.example, replace placeholders and exclude secrets from git. ### Phase 1 · Local foundation and data contract Build: Create the runnable local foundation for a single-owner Google Calendar booking page with conflict-aware confirmation, including the real schema and acceptance fixture. - Run the venv command first, then stop and activate it before running the remaining commands. Use your OS instructions: Windows .venv\Scripts\activate.bat in cmd, or .venv\Scripts\Activate.ps1 in PowerShell; macOS/Linux source .venv/bin/activate. Then install the listed packages. Create app.py exposing app, load .env with python-dotenv, and add a /healthz route. Freeze tested dependency versions to requirements.txt. Create .env manually from .env.example; replace SECRET_KEY before launch. Commands, after creating the named files: `python -m venv .venv`; `python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib`; `python -m pip freeze > requirements.txt`; `python -m flask --app app run --host 127.0.0.1`. - For database-backed state create schema.sql and db.py using this model: event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files. Add the auxiliary relationships explicitly used in later phases; use stable ids, foreign keys, parameterized values and transactions. For canonical files use atomic replacement and hashes instead. Implement python manage.py init and python manage.py seed to create only synthetic data: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Re-running init must not erase data. Commands, after creating the named files: `python manage.py init`; `python manage.py seed`. - Install Flask-WTF CSRF protection for forms and same-origin fetches, validate Host and Origin against SITE_URL, bound inputs and escape output. Deliberately public intake endpoints get bounded validation and rate limits; signed provider webhooks use signature checks instead of browser CSRF tokens. All other admin routes stay local until product authentication exists. When a later phase tests viewer/member permissions, implement the users, hashed passwords, expiring server sessions and role checks in this foundation first; product mode must never use a fabricated identity from request input. Add error, empty, keyboard-focus and retry states now. - Trap: The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. Done when: The documented start command serves /healthz and the initial screen at http://127.0.0.1:5000. Restarting preserves the seeded records or canonical files; running init again deletes nothing. A cross-origin state-changing request to an admin route is refused. Do not build yet: Do not start calendar connection before ui until these checks pass. ### Phase 2 · Calendar connection before UI Build: Calendar connection before UI for Calendly: Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. - Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. - Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: An occupied fixture interval is returned as unavailable. Then check: Revoking access prevents booking confirmation and shows a reconnect state. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: A service account is not a drop-in substitute for a personal calendar OAuth consent flow. Done when: An occupied fixture interval is returned as unavailable. Revoking access prevents booking confirmation and shows a reconnect state. Do not build yet: Do not start availability and atomic holds until these checks pass. ### Phase 3 · Availability and atomic holds Build: Availability and atomic holds for Calendly: Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. - Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. - Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: Two concurrent guests for one slot produce one active hold. Then check: A slot inside the external busy period cannot be booked by direct POST. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. Done when: Two concurrent guests for one slot produce one active hold. A slot inside the external busy period cannot be booked by direct POST. Do not build yet: Do not start event and guest lifecycle until these checks pass. ### Phase 4 · Event and guest lifecycle Build: Event and guest lifecycle for Calendly: Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. - Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. - Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: The API timeout followed by reconciliation produces one confirmed event. Then check: An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. Done when: The API timeout followed by reconciliation produces one confirmed event. An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Do not build yet: Do not start portable delivery and clean-start proof until these checks pass. ### Phase 5 · Portable delivery and clean-start proof Build: Finish the Calendly replacement with a documented first-run path and a recoverable export. - Document prerequisites, every configuration variable, data locations and the three domain workflows: Calendar connection before UI; Availability and atomic holds; Event and guest lifecycle. Include the exclusions, actual costs and source check date 2026-09-05. Commands shown earlier that reference project files are files the builder must implement before running them. - Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. - Use a new folder and only README instructions to reach the fixture outcome. Install from requirements.txt, initialize storage, run the tests and exercise the UI at 375px and 1280px; use keyboard-only controls and inspect browser errors. Record exactly what passed; do not mark unrun checks complete. Commands, after creating the named files: `python -m pip install -r requirements.txt`; `python -m unittest discover -s test`. - Trap: Export without an import or restore rehearsal is not verified portability. Done when: A new folder reaches the documented fixture outcome using only README instructions. A backup restored in isolation preserves the proof data and can be opened. Do not build yet: Do not start operate and share with access controls until these checks pass. ### Phase 6 · Operate and share with access controls (product-builder only) Build: Product-builder only: make a single-owner Google Calendar booking page with conflict-aware confirmation operable for its stated audience before allowing remote access. - Add owner/member/viewer authorization as appropriate, password hashes through Werkzeug, expiring server-side sessions, CSRF and login rate limits. Add users, sessions and audit schema migrations plus an owner-init command prompting securely for its password. Enforce ownership on every private read/write/download and fail closed when product setup is incomplete. Existing learner or admin identities must use this same boundary. - Serve app:app with Waitress on loopback behind Caddy HTTPS. Configure trusted proxy headers narrowly, Secure/HttpOnly/SameSite cookies, upload limits, request ids and structured logs without private content. Run background jobs as a separate supervised process when the domain workflow requires them. Commands, after creating the named files: `waitress-serve --listen=127.0.0.1:5000 app:app`. - Add a scheduled encrypted off-host backup using this procedure: Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Monitor health, disk space, failed jobs and backup age. Stop the service to test an alert; rehearse recovery with outbound effects disabled and record recovery time. Rotate any exposed credentials and require reconciliation before resuming queues. - Trap: Product mode is additional engineering, not a switch that makes a local prototype production-ready. Done when: An unauthenticated visitor cannot read private records, download private files or mutate the admin surface. A viewer cannot mutate data by making a direct request, and guessed ids cannot cross ownership boundaries. Stopping the service triggers the configured alert and the latest off-host backup restores the fixture in isolation. Do not build yet: Do not add new providers or vendor-scale features until the release gates are recorded. ### Out of scope (and why) - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you: retain the paid product if this capability is essential; it is outside this bounded build. - team round-robin and routing: retain the paid product if this capability is essential; it is outside this bounded build. - SMS reminders: retain the paid product if this capability is essential; it is outside this bounded build. - the integrations directory: retain the paid product if this capability is essential; it is outside this bounded build. ### README must contain - Exact install, configure, initialize, start, test and recovery commands for a clean folder. - The schema, fixture, acceptance results, private data locations and export format. - Every prerequisite and secret source, actual running costs and deliberately excluded capabilities. - An honest distinction between tests actually run and checks still awaiting real credentials or deployment. - Dependency documentation reviewed 2026-09-05: https://flask.palletsprojects.com/en/stable/installation/ ; https://docs.python.org/3/library/sqlite3.html ; https://flask-wtf.readthedocs.io/en/1.2.x/csrf/ ; https://docs.pylonsproject.org/projects/waitress/en/stable/usage.html ; https://developers.google.com/workspace/calendar/api/quickstart/python ; https://developers.google.com/workspace/calendar/api/guides/create-events. Recheck before upgrading; freeze the versions actually tested.
AGENTS.md
# Agent instructions · Calendly indie build - Read `README.md` and `BUILD_PLAN.md` before writing code. The stack is fixed: Python 3.12+ and Flask, SQLite through Python sqlite3, Jinja HTML templates, CSS and vanilla JavaScript, Python unittest and browser acceptance fixtures, google-api-python-client, google-auth-httplib2, google-auth-oauthlib. Do not substitute. - Work one phase at a time, in order. Do not start a phase until every "Done when" item of the previous one passes. - Prefer the fewest moving parts that satisfy the step. No frameworks, services or dependencies the plan does not name. - Secrets live in `.env`, never in source or logs. Keep `.env.example` current when a variable is introduced. - Do not invent cryptography, security guarantees, APIs or compliance claims. - Add a focused test for every destructive, security-sensitive or data-loss path the plan names. - Run the project checks before declaring a phase complete, and record any deliberate shortcut in the README under "Tradeoffs". ## Known traps - The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. - No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. - Export without an import or restore rehearsal is not verified portability.
BUILD_PLAN.md
# Build plan · Calendly Build a single-owner Google Calendar booking page with conflict-aware confirmation. Phases are in dependency order. Each ends in a "Done when" list; treat an unticked item as a blocker, not a note. ## Phase 1 · Local foundation and data contract Create the runnable local foundation for a single-owner Google Calendar booking page with conflict-aware confirmation, including the real schema and acceptance fixture. ### Steps 1. Create and start the local application Run the venv command first, then stop and activate it before running the remaining commands. Use your OS instructions: Windows .venv\Scripts\activate.bat in cmd, or .venv\Scripts\Activate.ps1 in PowerShell; macOS/Linux source .venv/bin/activate. Then install the listed packages. Create app.py exposing app, load .env with python-dotenv, and add a /healthz route. Freeze tested dependency versions to requirements.txt. Create .env manually from .env.example; replace SECRET_KEY before launch. Files: `app.py`, `requirements.txt`, `.env.example`, `.gitignore` ```sh python -m venv .venv python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib python -m pip freeze > requirements.txt python -m flask --app app run --host 127.0.0.1 ``` 2. Implement storage and seed the named fixture For database-backed state create schema.sql and db.py using this model: event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files. Add the auxiliary relationships explicitly used in later phases; use stable ids, foreign keys, parameterized values and transactions. For canonical files use atomic replacement and hashes instead. Implement python manage.py init and python manage.py seed to create only synthetic data: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Re-running init must not erase data. Files: `schema.sql`, `db.py`, `manage.py`, `fixtures/README.md` ```sh python manage.py init python manage.py seed ``` 3. Protect the local request boundary Install Flask-WTF CSRF protection for forms and same-origin fetches, validate Host and Origin against SITE_URL, bound inputs and escape output. Deliberately public intake endpoints get bounded validation and rate limits; signed provider webhooks use signature checks instead of browser CSRF tokens. All other admin routes stay local until product authentication exists. When a later phase tests viewer/member permissions, implement the users, hashed passwords, expiring server sessions and role checks in this foundation first; product mode must never use a fabricated identity from request input. Add error, empty, keyboard-focus and retry states now. Files: `app.py`, `templates/base.html`, `test/test_foundation.py` ### Done when - [ ] The documented start command serves /healthz and the initial screen at http://127.0.0.1:5000. - [ ] Restarting preserves the seeded records or canonical files; running init again deletes nothing. - [ ] A cross-origin state-changing request to an admin route is refused. ### Watch out - The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. ## Phase 2 · Calendar connection before UI Calendar connection before UI for Calendly: Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. ### Steps 1. Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. Files: `features/calendar_connection_before_ui.py`, `templates/calendar_connection_before_ui.html` 2. Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. Files: `features/calendar_connection_before_ui.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: An occupied fixture interval is returned as unavailable. Then check: Revoking access prevents booking confirmation and shows a reconnect state. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_calendar_connection_before_ui.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] An occupied fixture interval is returned as unavailable. - [ ] Revoking access prevents booking confirmation and shows a reconnect state. ### Watch out - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. ## Phase 3 · Availability and atomic holds Availability and atomic holds for Calendly: Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. ### Steps 1. Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. Files: `features/availability_and_atomic_holds.py`, `templates/availability_and_atomic_holds.html` 2. Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. Files: `features/availability_and_atomic_holds.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: Two concurrent guests for one slot produce one active hold. Then check: A slot inside the external busy period cannot be booked by direct POST. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_availability_and_atomic_holds.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] Two concurrent guests for one slot produce one active hold. - [ ] A slot inside the external busy period cannot be booked by direct POST. ### Watch out - Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. ## Phase 4 · Event and guest lifecycle Event and guest lifecycle for Calendly: Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. ### Steps 1. Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. Files: `features/event_and_guest_lifecycle.py`, `templates/event_and_guest_lifecycle.html` 2. Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. Files: `features/event_and_guest_lifecycle.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: The API timeout followed by reconciliation produces one confirmed event. Then check: An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_event_and_guest_lifecycle.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] The API timeout followed by reconciliation produces one confirmed event. - [ ] An invalid cancel token cannot cancel a booking, and cancellation releases the slot. ### Watch out - No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. ## Phase 5 · Portable delivery and clean-start proof Finish the Calendly replacement with a documented first-run path and a recoverable export. ### Steps 1. Write the user-facing runbook Document prerequisites, every configuration variable, data locations and the three domain workflows: Calendar connection before UI; Availability and atomic holds; Event and guest lifecycle. Include the exclusions, actual costs and source check date 2026-09-05. Commands shown earlier that reference project files are files the builder must implement before running them. Files: `README.md`, `.env.example` 2. Create and rehearse a recoverable backup Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. Files: `OPERATIONS.md`, `scripts/backup.py` 3. Reproduce the first-run experience Use a new folder and only README instructions to reach the fixture outcome. Install from requirements.txt, initialize storage, run the tests and exercise the UI at 375px and 1280px; use keyboard-only controls and inspect browser errors. Record exactly what passed; do not mark unrun checks complete. Files: `README.md`, `verification.md` ```sh python -m pip install -r requirements.txt python -m unittest discover -s test ``` ### Done when - [ ] A new folder reaches the documented fixture outcome using only README instructions. - [ ] A backup restored in isolation preserves the proof data and can be opened. ### Watch out - Export without an import or restore rehearsal is not verified portability. ## Not in this build - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you - team round-robin and routing - SMS reminders - the integrations directory ## After v1, if you want it - Extend event and guest lifecycle only after the fixture and recovery checks pass. - Before adding another integration, document its credentials, limits, cost and failure behavior with primary-source links.
.env.example
# Copy to .env and fill in. Never commit .env; this file documents it. # Required. A new private folder this application creates on first run; never serve it as static files. DATA_DIR=./data/calendly # Required · secret. Generate with python -c "import secrets; print(secrets.token_hex(32))" and save only in .env. SECRET_KEY=replace-with-a-random-secret # Required. Use indie for loopback-only personal work. Product mode must refuse to start until owner login and the deployment gates are configured. APP_MODE=indie # Required. The origin used for local forms and links; replace with the chosen HTTPS origin in product mode. SITE_URL=http://127.0.0.1:5000 # Required · secret. Download the OAuth client JSON from Cloud console; never commit it. GOOGLE_CLIENT_FILE=./secrets/google-client.json # Required · secret. Created by the owner authorization flow; restrict file permissions and exclude from backups shared with others. GOOGLE_TOKEN_FILE=./secrets/google-token.json # Required. The authenticated owner calendar id; choose a dedicated test calendar during development. GOOGLE_CALENDAR_ID=primary
PRODUCT.md
# Calendly · product brief ## Problem A single-user booking page is easy; production-grade scheduling needs OAuth, availability rules, time zones, reminders, payments, team routing, and trust. ## Product outcome An operated version of a single-owner Google Calendar booking page with conflict-aware confirmation, with authorized access, restore evidence and honest scope limits. ## Target user A builder who needs a maintainable product foundation, not a one-off demo. ## Required capabilities - Google/Microsoft calendar OAuth - hosted app - email notifications - timezone handling - auth ## Explicit non-goals for v1 - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you - team round-robin and routing - SMS reminders - the integrations directory ## Success criteria - An occupied fixture interval is returned as unavailable. - Two concurrent guests for one slot produce one active hold. - The API timeout followed by reconciliation produces one confirmed event. - A private-data authorization check passes using a second identity. - An off-host restore drill has a date, observed result and recovery time in OPERATIONS.md. - README names the excluded vendor capabilities and actual provider/hosting costs.
BRIEF.md
# Build brief · Calendly The one-shot brief this plan expands. `BUILD_PLAN.md` (or `MILESTONES.md`) is the same sequence broken into steps and checks; where the two disagree, the plan wins. Build me a single-owner Google Calendar booking page with conflict-aware confirmation as a bounded replacement for Calendly. Build it in phases in the order below. Do not write the whole product in one pass. Finish the current phase, run its Done when checks, fix failures, then continue. Indie mode completes Phases 1-5. Phase 6 is required before shared or public deployment. ### Stack (fixed, do not substitute) - Runtime: Python 3.12+ and Flask. A small local HTTP application with readable server-side handlers and no JavaScript build pipeline. - Storage: SQLite through Python sqlite3. Local ownership with explicit transactions and a portable backup path. - Interface: Jinja HTML templates, CSS and vanilla JavaScript. Implement the specified screens directly with labelled controls and progressive enhancement. - Verification: Python unittest and browser acceptance fixtures. Check invariants and the actual user workflow before the next phase. - Focused libraries: google-api-python-client, google-auth-httplib2, google-auth-oauthlib. Use these only for the specific file, parsing or provider operations named in the phases; freeze tested versions. ### Data model (create this before Phase 1) - event_types(id,title,duration_minutes,buffer_minutes) - availability(id,weekday,start_local,end_local,timezone) - bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id) - holds(id,start_utc,end_utc,expires_at) - oauth credentials stored outside public files - Use stable ids and explicit relationships; add auxiliary tables named by the phases before those phases use them. - Acceptance fixture: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. ### Prerequisites and configuration - Python 3.12 or newer and a terminal: Install Python from python.org. Open a terminal in a new empty project folder. On Windows, use py -3 where this guide says python if python is not on PATH; on macOS/Linux use python3 if needed. Create .venv and activate it before installing packages. Verify: python --version reports 3.12+ and python -c "import sqlite3" succeeds. Cost: Python is free; this local prototype requires no hosting subscription. - A current desktop browser and text editor: Use an installed Chrome, Firefox or Edge browser. Open the empty project folder in your editor; open the terminal there, not in this catalog repository. Verify: You can create a text file in the project folder and open browser developer tools. Cost: No paid service required for this local step. - Calendly acceptance sample: Create synthetic sample data before implementation: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Save it under fixtures/ with the expected results in fixtures/README.md; use no real credentials or customer records. Verify: The fixture files and expected outcomes exist and can be inspected without a vendor account. Cost: No paid service required for this local step. - Confirm the bounded replacement: The deliverable is a single-owner Google Calendar booking page with conflict-aware confirmation. Read every exclusion below. Indie mode runs locally; any public or shared use requires the product access and deployment gates first. Verify: You can name the primary workflow and the vendor features this version deliberately leaves out. Cost: No paid service required for this local step. - Google Calendar OAuth client for one test owner: Follow the official Python quickstart: create a Cloud project, enable Calendar API, configure consent and your test user, and create OAuth credentials. For this web app use a Web application client and register the exact local callback http://127.0.0.1:5000/oauth/callback; use the matching HTTPS callback when deploying. Save the client JSON outside static files. Verify: The owner completes consent and the app can read the chosen calendar busy data; revoked consent produces reconnect guidance. Cost: Check current Google API quotas and any project billing requirements; this guide assumes no paid quota or production verification exemption. - Configuration: DATA_DIR, SECRET_KEY, APP_MODE, SITE_URL, GOOGLE_CLIENT_FILE, GOOGLE_TOKEN_FILE, GOOGLE_CALENDAR_ID. Ship .env.example, replace placeholders and exclude secrets from git. ### Phase 1 · Local foundation and data contract Build: Create the runnable local foundation for a single-owner Google Calendar booking page with conflict-aware confirmation, including the real schema and acceptance fixture. - Run the venv command first, then stop and activate it before running the remaining commands. Use your OS instructions: Windows .venv\Scripts\activate.bat in cmd, or .venv\Scripts\Activate.ps1 in PowerShell; macOS/Linux source .venv/bin/activate. Then install the listed packages. Create app.py exposing app, load .env with python-dotenv, and add a /healthz route. Freeze tested dependency versions to requirements.txt. Create .env manually from .env.example; replace SECRET_KEY before launch. Commands, after creating the named files: `python -m venv .venv`; `python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib`; `python -m pip freeze > requirements.txt`; `python -m flask --app app run --host 127.0.0.1`. - For database-backed state create schema.sql and db.py using this model: event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files. Add the auxiliary relationships explicitly used in later phases; use stable ids, foreign keys, parameterized values and transactions. For canonical files use atomic replacement and hashes instead. Implement python manage.py init and python manage.py seed to create only synthetic data: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Re-running init must not erase data. Commands, after creating the named files: `python manage.py init`; `python manage.py seed`. - Install Flask-WTF CSRF protection for forms and same-origin fetches, validate Host and Origin against SITE_URL, bound inputs and escape output. Deliberately public intake endpoints get bounded validation and rate limits; signed provider webhooks use signature checks instead of browser CSRF tokens. All other admin routes stay local until product authentication exists. When a later phase tests viewer/member permissions, implement the users, hashed passwords, expiring server sessions and role checks in this foundation first; product mode must never use a fabricated identity from request input. Add error, empty, keyboard-focus and retry states now. - Trap: The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. Done when: The documented start command serves /healthz and the initial screen at http://127.0.0.1:5000. Restarting preserves the seeded records or canonical files; running init again deletes nothing. A cross-origin state-changing request to an admin route is refused. Do not build yet: Do not start calendar connection before ui until these checks pass. ### Phase 2 · Calendar connection before UI Build: Calendar connection before UI for Calendly: Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. - Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. - Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: An occupied fixture interval is returned as unavailable. Then check: Revoking access prevents booking confirmation and shows a reconnect state. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: A service account is not a drop-in substitute for a personal calendar OAuth consent flow. Done when: An occupied fixture interval is returned as unavailable. Revoking access prevents booking confirmation and shows a reconnect state. Do not build yet: Do not start availability and atomic holds until these checks pass. ### Phase 3 · Availability and atomic holds Build: Availability and atomic holds for Calendly: Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. - Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. - Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: Two concurrent guests for one slot produce one active hold. Then check: A slot inside the external busy period cannot be booked by direct POST. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. Done when: Two concurrent guests for one slot produce one active hold. A slot inside the external busy period cannot be booked by direct POST. Do not build yet: Do not start event and guest lifecycle until these checks pass. ### Phase 4 · Event and guest lifecycle Build: Event and guest lifecycle for Calendly: Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. - Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. - Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. - Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: The API timeout followed by reconciliation produces one confirmed event. Then check: An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Commands, after creating the named files: `python -m unittest discover -s test`. - Trap: No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. Done when: The API timeout followed by reconciliation produces one confirmed event. An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Do not build yet: Do not start portable delivery and clean-start proof until these checks pass. ### Phase 5 · Portable delivery and clean-start proof Build: Finish the Calendly replacement with a documented first-run path and a recoverable export. - Document prerequisites, every configuration variable, data locations and the three domain workflows: Calendar connection before UI; Availability and atomic holds; Event and guest lifecycle. Include the exclusions, actual costs and source check date 2026-09-05. Commands shown earlier that reference project files are files the builder must implement before running them. - Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. - Use a new folder and only README instructions to reach the fixture outcome. Install from requirements.txt, initialize storage, run the tests and exercise the UI at 375px and 1280px; use keyboard-only controls and inspect browser errors. Record exactly what passed; do not mark unrun checks complete. Commands, after creating the named files: `python -m pip install -r requirements.txt`; `python -m unittest discover -s test`. - Trap: Export without an import or restore rehearsal is not verified portability. Done when: A new folder reaches the documented fixture outcome using only README instructions. A backup restored in isolation preserves the proof data and can be opened. Do not build yet: Do not start operate and share with access controls until these checks pass. ### Phase 6 · Operate and share with access controls (product-builder only) Build: Product-builder only: make a single-owner Google Calendar booking page with conflict-aware confirmation operable for its stated audience before allowing remote access. - Add owner/member/viewer authorization as appropriate, password hashes through Werkzeug, expiring server-side sessions, CSRF and login rate limits. Add users, sessions and audit schema migrations plus an owner-init command prompting securely for its password. Enforce ownership on every private read/write/download and fail closed when product setup is incomplete. Existing learner or admin identities must use this same boundary. - Serve app:app with Waitress on loopback behind Caddy HTTPS. Configure trusted proxy headers narrowly, Secure/HttpOnly/SameSite cookies, upload limits, request ids and structured logs without private content. Run background jobs as a separate supervised process when the domain workflow requires them. Commands, after creating the named files: `waitress-serve --listen=127.0.0.1:5000 app:app`. - Add a scheduled encrypted off-host backup using this procedure: Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Monitor health, disk space, failed jobs and backup age. Stop the service to test an alert; rehearse recovery with outbound effects disabled and record recovery time. Rotate any exposed credentials and require reconciliation before resuming queues. - Trap: Product mode is additional engineering, not a switch that makes a local prototype production-ready. Done when: An unauthenticated visitor cannot read private records, download private files or mutate the admin surface. A viewer cannot mutate data by making a direct request, and guessed ids cannot cross ownership boundaries. Stopping the service triggers the configured alert and the latest off-host backup restores the fixture in isolation. Do not build yet: Do not add new providers or vendor-scale features until the release gates are recorded. ### Out of scope (and why) - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - This is a single-owner Google Calendar booking page with conflict-aware confirmation; full Calendly feature parity, vendor hosting and support are not included. - polished Google/Outlook OAuth kept working for you: retain the paid product if this capability is essential; it is outside this bounded build. - team round-robin and routing: retain the paid product if this capability is essential; it is outside this bounded build. - SMS reminders: retain the paid product if this capability is essential; it is outside this bounded build. - the integrations directory: retain the paid product if this capability is essential; it is outside this bounded build. ### README must contain - Exact install, configure, initialize, start, test and recovery commands for a clean folder. - The schema, fixture, acceptance results, private data locations and export format. - Every prerequisite and secret source, actual running costs and deliberately excluded capabilities. - An honest distinction between tests actually run and checks still awaiting real credentials or deployment. - Dependency documentation reviewed 2026-09-05: https://flask.palletsprojects.com/en/stable/installation/ ; https://docs.python.org/3/library/sqlite3.html ; https://flask-wtf.readthedocs.io/en/1.2.x/csrf/ ; https://docs.pylonsproject.org/projects/waitress/en/stable/usage.html ; https://developers.google.com/workspace/calendar/api/quickstart/python ; https://developers.google.com/workspace/calendar/api/guides/create-events. Recheck before upgrading; freeze the versions actually tested.
ARCHITECTURE.md
# Architecture · Calendly ## Stack | Part | Choice | Why | | --- | --- | --- | | Runtime | Python 3.12+ and Flask | A small local HTTP application with readable server-side handlers and no JavaScript build pipeline. | | Storage | SQLite through Python sqlite3 | Local ownership with explicit transactions and a portable backup path. | | Interface | Jinja HTML templates, CSS and vanilla JavaScript | Implement the specified screens directly with labelled controls and progressive enhancement. | | Verification | Python unittest and browser acceptance fixtures | Check invariants and the actual user workflow before the next phase. | | Focused libraries | google-api-python-client, google-auth-httplib2, google-auth-oauthlib | Use these only for the specific file, parsing or provider operations named in the phases; freeze tested versions. | ## Modules Each module has one owner concern and a documented way to replace it. | Module | Owns | How to replace it | | --- | --- | --- | | Data and identity | event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files | Keep stable ids and a versioned repository interface; migrate storage behind it with a fixture round-trip. | | Calendar connection before UI | Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. | Keep the acceptance contract: An occupied fixture interval is returned as unavailable. Replace only this module after replaying its fixture; preserve ids and existing records. | | Availability and atomic holds | Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. | Keep the acceptance contract: Two concurrent guests for one slot produce one active hold. Replace only this module after replaying its fixture; preserve ids and existing records. | | Event and guest lifecycle | Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. | Keep the acceptance contract: The API timeout followed by reconciliation produces one confirmed event. Replace only this module after replaying its fixture; preserve ids and existing records. | | Operations | Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. | Change host or backup destination only after an isolated restore and authorization check. | ## Configuration Every runtime setting is an environment variable documented in `.env.example`, validated at startup, with a safe local default wherever one exists. - `DATA_DIR` · required · A new private folder this application creates on first run; never serve it as static files. - `SECRET_KEY` · required, secret · Generate with python -c "import secrets; print(secrets.token_hex(32))" and save only in .env. - `APP_MODE` · required · Use indie for loopback-only personal work. Product mode must refuse to start until owner login and the deployment gates are configured. - `SITE_URL` · required · The origin used for local forms and links; replace with the chosen HTTPS origin in product mode. - `GOOGLE_CLIENT_FILE` · required, secret · Download the OAuth client JSON from Cloud console; never commit it. - `GOOGLE_TOKEN_FILE` · required, secret · Created by the owner authorization flow; restrict file permissions and exclude from backups shared with others. - `GOOGLE_CALENDAR_ID` · required · The authenticated owner calendar id; choose a dedicated test calendar during development. ## Production baseline - Security: least privilege, input validation at every boundary, secret redaction in logs, rate limits on abuse-prone paths, no invented security primitives. - Data: explicit schema and migrations, transactional writes where integrity matters, backup and restore procedures that have been exercised. - Integrations: adapters around third-party providers, idempotent webhook or job processing, bounded retries, timeouts. - Observability: structured logs with request or operation ids, an error-tracking hook, and health and readiness checks where a server exists. - Quality: unit tests for domain rules, integration tests at module boundaries, one end-to-end test of the critical path. ## Decision records For each dependency in the stack table, keep a short note: why it was chosen, its failure mode, and how it is replaced. Do not add infrastructure until a requirement in `PRODUCT.md` justifies it.
AGENTS.md
# Agent instructions · Calendly product build - Read `PRODUCT.md` and `ARCHITECTURE.md` before changing code. The stack is fixed: Python 3.12+ and Flask, SQLite through Python sqlite3, Jinja HTML templates, CSS and vanilla JavaScript, Python unittest and browser acceptance fixtures, google-api-python-client, google-auth-httplib2, google-auth-oauthlib. - Implement milestone by milestone from `MILESTONES.md`; keep each change reviewable and leave the application runnable at every commit. - Treat authentication, payments, encryption, imports, webhooks and destructive actions as high-risk boundaries when present. - Never invent cryptography or silently weaken a requirement to make a check pass. - Put every external service behind an interface with a deterministic fake for tests. - Add migrations and rollback or recovery notes for every persistent data change. - Log useful operational context without credentials, tokens, passwords or personal data. - Update documentation and run every check before completing a milestone. ## Known traps - The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. - Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. - No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. - Export without an import or restore rehearsal is not verified portability. - Product mode is additional engineering, not a switch that makes a local prototype production-ready.
MILESTONES.md
# Delivery milestones · Calendly Estimated effort: **multi-day** for the indie phases; the production-only milestones add the trust and operability layer. ## M1 · Local foundation and data contract Create the runnable local foundation for a single-owner Google Calendar booking page with conflict-aware confirmation, including the real schema and acceptance fixture. ### Steps 1. Create and start the local application Run the venv command first, then stop and activate it before running the remaining commands. Use your OS instructions: Windows .venv\Scripts\activate.bat in cmd, or .venv\Scripts\Activate.ps1 in PowerShell; macOS/Linux source .venv/bin/activate. Then install the listed packages. Create app.py exposing app, load .env with python-dotenv, and add a /healthz route. Freeze tested dependency versions to requirements.txt. Create .env manually from .env.example; replace SECRET_KEY before launch. Files: `app.py`, `requirements.txt`, `.env.example`, `.gitignore` ```sh python -m venv .venv python -m pip install Flask Flask-WTF python-dotenv waitress tzdata google-api-python-client google-auth-httplib2 google-auth-oauthlib python -m pip freeze > requirements.txt python -m flask --app app run --host 127.0.0.1 ``` 2. Implement storage and seed the named fixture For database-backed state create schema.sql and db.py using this model: event_types(id,title,duration_minutes,buffer_minutes); availability(id,weekday,start_local,end_local,timezone); bookings(id,start_utc,end_utc,state,guest_email,cancel_token_hash,google_event_id); holds(id,start_utc,end_utc,expires_at); oauth credentials stored outside public files. Add the auxiliary relationships explicitly used in later phases; use stable ids, foreign keys, parameterized values and transactions. For canonical files use atomic replacement and hashes instead. Implement python manage.py init and python manage.py seed to create only synthetic data: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Re-running init must not erase data. Files: `schema.sql`, `db.py`, `manage.py`, `fixtures/README.md` ```sh python manage.py init python manage.py seed ``` 3. Protect the local request boundary Install Flask-WTF CSRF protection for forms and same-origin fetches, validate Host and Origin against SITE_URL, bound inputs and escape output. Deliberately public intake endpoints get bounded validation and rate limits; signed provider webhooks use signature checks instead of browser CSRF tokens. All other admin routes stay local until product authentication exists. When a later phase tests viewer/member permissions, implement the users, hashed passwords, expiring server sessions and role checks in this foundation first; product mode must never use a fabricated identity from request input. Add error, empty, keyboard-focus and retry states now. Files: `app.py`, `templates/base.html`, `test/test_foundation.py` ### Done when - [ ] The documented start command serves /healthz and the initial screen at http://127.0.0.1:5000. - [ ] Restarting preserves the seeded records or canonical files; running init again deletes nothing. - [ ] A cross-origin state-changing request to an admin route is refused. ### Watch out - The Flask development server is for local development only. Loopback binding alone does not replace CSRF and origin validation. ## M2 · Calendar connection before UI Calendar connection before UI for Calendly: Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. ### Steps 1. Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. Follow Google OAuth setup for one test owner, enable Calendar API and authorize only the scopes needed for free/busy and event management. Files: `features/calendar_connection_before_ui.py`, `templates/calendar_connection_before_ui.html` 2. Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. Store refresh credentials server-side and implement a free/busy probe with explicit reauthorization guidance. Files: `features/calendar_connection_before_ui.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: An occupied fixture interval is returned as unavailable. Then check: Revoking access prevents booking confirmation and shows a reconnect state. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_calendar_connection_before_ui.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] An occupied fixture interval is returned as unavailable. - [ ] Revoking access prevents booking confirmation and shows a reconnect state. ### Watch out - A service account is not a drop-in substitute for a personal calendar OAuth consent flow. ## M3 · Availability and atomic holds Availability and atomic holds for Calendly: Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. ### Steps 1. Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. Compute a fourteen-day window from weekly rules, timezone-aware instants, buffers and current external busy ranges. Files: `features/availability_and_atomic_holds.py`, `templates/availability_and_atomic_holds.html` 2. Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. Create short-lived interval holds in a serialized transaction; recheck overlaps and external busy data immediately before attempting confirmation. Files: `features/availability_and_atomic_holds.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: Two concurrent guests for one slot produce one active hold. Then check: A slot inside the external busy period cannot be booked by direct POST. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_availability_and_atomic_holds.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] Two concurrent guests for one slot produce one active hold. - [ ] A slot inside the external busy period cannot be booked by direct POST. ### Watch out - Local locking cannot eliminate a race with a calendar edited elsewhere; surface that limitation. ## M4 · Event and guest lifecycle Event and guest lifecycle for Calendly: Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. ### Steps 1. Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. Use a valid deterministic Google event id derived from the booking id, add the guest and use sendUpdates for Calendar invitations. Files: `features/event_and_guest_lifecycle.py`, `templates/event_and_guest_lifecycle.html` 2. Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. Handle cancel/reschedule with expiring hashed tokens; on ambiguous creation query the event id before any retry and expire unused holds. Files: `features/event_and_guest_lifecycle.py` 3. Exercise the acceptance fixture Use A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Check: The API timeout followed by reconciliation produces one confirmed event. Then check: An invalid cancel token cannot cancel a booking, and cancellation releases the slot. Add a focused regression for the failure case under test/ using a temporary database or folder and fake external services; also perform the visible workflow in a browser. Files: `test/test_event_and_guest_lifecycle.py` ```sh python -m unittest discover -s test ``` ### Done when - [ ] The API timeout followed by reconciliation produces one confirmed event. - [ ] An invalid cancel token cannot cancel a booking, and cancellation releases the slot. ### Watch out - No separate SMTP, Meet promise, SMS, round-robin or Microsoft adapter is included in this one-calendar build. ## M5 · Portable delivery and clean-start proof Finish the Calendly replacement with a documented first-run path and a recoverable export. ### Steps 1. Write the user-facing runbook Document prerequisites, every configuration variable, data locations and the three domain workflows: Calendar connection before UI; Availability and atomic holds; Event and guest lifecycle. Include the exclusions, actual costs and source check date 2026-09-05. Commands shown earlier that reference project files are files the builder must implement before running them. Files: `README.md`, `.env.example` 2. Create and rehearse a recoverable backup Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. Files: `OPERATIONS.md`, `scripts/backup.py` 3. Reproduce the first-run experience Use a new folder and only README instructions to reach the fixture outcome. Install from requirements.txt, initialize storage, run the tests and exercise the UI at 375px and 1280px; use keyboard-only controls and inspect browser errors. Record exactly what passed; do not mark unrun checks complete. Files: `README.md`, `verification.md` ```sh python -m pip install -r requirements.txt python -m unittest discover -s test ``` ### Done when - [ ] A new folder reaches the documented fixture outcome using only README instructions. - [ ] A backup restored in isolation preserves the proof data and can be opened. ### Watch out - Export without an import or restore rehearsal is not verified portability. ## M6 · Operate and share with access controls (production only) Product-builder only: make a single-owner Google Calendar booking page with conflict-aware confirmation operable for its stated audience before allowing remote access. ### Steps 1. Establish owner access before exposure Add owner/member/viewer authorization as appropriate, password hashes through Werkzeug, expiring server-side sessions, CSRF and login rate limits. Add users, sessions and audit schema migrations plus an owner-init command prompting securely for its password. Enforce ownership on every private read/write/download and fail closed when product setup is incomplete. Existing learner or admin identities must use this same boundary. Files: `ARCHITECTURE.md`, `OPERATIONS.md` 2. Deploy a monitored service Serve app:app with Waitress on loopback behind Caddy HTTPS. Configure trusted proxy headers narrowly, Secure/HttpOnly/SameSite cookies, upload limits, request ids and structured logs without private content. Run background jobs as a separate supervised process when the domain workflow requires them. Files: `Caddyfile`, `OPERATIONS.md` ```sh waitress-serve --listen=127.0.0.1:5000 app:app ``` 3. Rehearse loss and recovery Add a scheduled encrypted off-host backup using this procedure: Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. Monitor health, disk space, failed jobs and backup age. Stop the service to test an alert; rehearse recovery with outbound effects disabled and record recovery time. Rotate any exposed credentials and require reconciliation before resuming queues. Files: `OPERATIONS.md`, `release-checklist.md` ### Done when - [ ] An unauthenticated visitor cannot read private records, download private files or mutate the admin surface. - [ ] A viewer cannot mutate data by making a direct request, and guessed ids cannot cross ownership boundaries. - [ ] Stopping the service triggers the configured alert and the latest off-host backup restores the fixture in isolation. ### Watch out - Product mode is additional engineering, not a switch that makes a local prototype production-ready.
OPERATIONS.md
# Operations · Calendly ## Backup Use sqlite3.Connection.backup for the database in DATA_DIR and pause writers while taking the matching attachment snapshot. Keep schema version, hashes and a manifest for calendly. ## Restore Restore into a separate empty directory or isolated deployment, with all outbound actions and schedules disabled. Recreate this proof: A thirty-minute event type, one external busy period, two simultaneous guest requests and a Google API timeout. Compare ids/counts and open the result before recording the restore date. Never test a restore over the only live copy. Do a restore drill before the first real user, and write the date here when it passes. ## Monitoring Check HTTP availability, free disk, backup age and domain failures for Calendar connection before UI, Availability and atomic holds, Event and guest lifecycle. Alert without logging private payloads. ## Incident checklist Pause outbound jobs and public intake as appropriate, preserve redacted diagnostics, restore an isolated verified backup, rotate affected credentials and reconcile uncertain effects before reopening. 1. Contain the issue without destroying evidence or user data. 2. Record the timeline and affected scope. 3. Rotate exposed secrets and revoke compromised sessions or credentials. 4. Restore from a verified backup when needed. 5. Document the root cause, the remediation and the regression test. ## Release gate - [ ] An occupied fixture interval is returned as unavailable. - [ ] Two concurrent guests for one slot produce one active hold. - [ ] The API timeout followed by reconciliation produces one confirmed event. - [ ] A private-data authorization check passes using a second identity. - [ ] An off-host restore drill has a date, observed result and recovery time in OPERATIONS.md. - [ ] README names the excluded vendor capabilities and actual provider/hosting costs. ## Launch constraint Do not market omitted Calendly capabilities as implemented. The non-goals in `PRODUCT.md` remain user-visible limitations until they are deliberately delivered.
.env.example
# Copy to .env and fill in. Never commit .env; this file documents it. # Required. A new private folder this application creates on first run; never serve it as static files. DATA_DIR=./data/calendly # Required · secret. Generate with python -c "import secrets; print(secrets.token_hex(32))" and save only in .env. SECRET_KEY=replace-with-a-random-secret # Required. Use indie for loopback-only personal work. Product mode must refuse to start until owner login and the deployment gates are configured. APP_MODE=indie # Required. The origin used for local forms and links; replace with the chosen HTTPS origin in product mode. SITE_URL=http://127.0.0.1:5000 # Required · secret. Download the OAuth client JSON from Cloud console; never commit it. GOOGLE_CLIENT_FILE=./secrets/google-client.json # Required · secret. Created by the owner authorization flow; restrict file permissions and exclude from backups shared with others. GOOGLE_TOKEN_FILE=./secrets/google-token.json # Required. The authenticated owner calendar id; choose a dedicated test calendar during development. GOOGLE_CALENDAR_ID=primary
$ choose a build depth, inspect the files, then open the complete pack in your agent
They pay because double-booking or missed meeting invites is costly.
xpolished Google/Outlook OAuth kept working for you
xteam round-robin and routing
xSMS reminders
xthe integrations directory
share on X ↗"I just replaced Calendly ($12/mo) with one prompt"
Don't feel like building it? These folks already made it free.
Cal.com FreeUnlimited solo event types, calendars and bookings, with payments and notifications; team routing costs money.free↗
Google Calendar appointment schedulesOne bare appointment page inside the calendar you already use; reminders, payments and polish are paid.free↗
Koalendar FreeUnlimited booking pages and two calendar connections; payments, forms, reminders and team routing are paid.free↗all 7 free alternatives to Calendly →· no votes, no pay-to-list · just what's real
Calendly pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| free | $0/user | $0/user | 1 one-on-one event type, 1 connected calendar and unlimited scheduled meetings. |
| standard | $12/user | $10/user | Unlimited event types; connect up to 6 calendars; 1 seat per paid user. |
| teams | $20/user | $16/user | Unlimited event types; up to 6 connected calendars; round-robin and routing. |
| enterprise | — | $1250/workspace | Starts at a $15,000 annual contract; numeric user and event limits are custom. |
free tier1 one-on-one event type, 1 connected calendar and unlimited meetings.
billingmonthly + annual; 14-day paid-plan trial falls back to Free; Enterprise starts at $15,000/year
hidden costsEvery owner and admin occupies a paid seat; newly added seats are prorated and all users in one organization must share a plan. SAML SSO is a paid add-on with no public price.
verified 2026-08-11 · source ↗
Is Calendly free?
The free plan covers one event type on one connected calendar. Paid is Standard at $12/mo (checked 2026-08-07).
Vibecode Calendly
Kinda. The core of Calendly is buildable in a weekend with the prompt on this page, but there are real gaps: polished Google/Outlook OAuth kept working for you, team round-robin and routing. Read the honest list above before committing.
How much does Calendly cost?
Calendly costs about $12/month (Standard, checked 2026-08-07), which is $144 per year.
What do I lose by replacing Calendly?
Honestly: polished Google/Outlook OAuth kept working for you; team round-robin and routing; SMS reminders; the integrations directory. If any of those are load-bearing for you, keep paying.
Is there an open-source alternative to Calendly?
Yes: Cal.com Free (Unlimited solo event types, calendars and bookings, with payments and notifications; team routing costs money.) Google Calendar appointment schedules (One bare appointment page inside the calendar you already use; reminders, payments and polish are paid.) Koalendar Free (Unlimited booking pages and two calendar connections; payments, forms, reminders and team routing are paid.) All 7 curated free alternatives are at vibecodeit.com/calendly/alternatives. The prompt is for when you want it exactly your way.