Vibecode Wanderfugl
track this build5 steps, step by step0%KINDA · weekend project
Trip planning is one of the most one-shottable categories there is: it is days, places, times, notes and a map, which is a CRUD app with a calendar view. An agent can give you a local itinerary builder with day-by-day cards, confirmation numbers, an ICS export and a pinned map in a single sitting, and it will feel better than a spreadsheet. The gap is everything that touches live travel data: flight and hotel prices, schedule changes, timezone-correct arrival math, place search with real coordinates, and inbox parsing of booking emails. If the paid product's value is mostly structure and a nice UI, self-hosting wins; if it is live data feeds or a polished phone app you use offline in an airport, it does not. Rate it kinda until you know which of those you are actually paying for.
the project pack4 files · fastest path to a working personal build
You are building a lean indie version of Wanderfugl. 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 ===== # Wanderfugl indie build ## Goal Build the smallest trustworthy replacement for the core Wanderfugl workflow for one developer or a tiny team. ## Scope A local trip planner where you create a trip, add day-by-day items with times, places, links and confirmation numbers, see them on a map, and export the whole thing to calendar or a printable page. ## Quick start 1. Install the documented dependencies. 2. Copy `.env.example` to `.env`. 3. Run the development command chosen during implementation. 4. Complete the acceptance checks in `BUILD_PLAN.md`. ## Honest limits This build deliberately does not replace: - Live flight, train and hotel pricing or availability - Automatic booking email parsing into your itinerary - A real mobile app with offline access while travelling - Timezone and schedule-change handling done correctly by someone else - Sharing a polished read-only itinerary with travel companions If those capabilities are essential, use Wanderfugl instead of pretending the gap is solved. ===== AGENTS.md ===== # Agent instructions - Optimize for a working, understandable weekend build. - Prefer the fewest moving parts that satisfy the brief. - Do not invent cryptography, security guarantees, APIs, or compliance claims. - Keep secrets out of source control and logs. - Add focused tests for destructive, security-sensitive, and data-loss paths. - Run the project checks before declaring the build complete. - Record any deliberate shortcut in the README under "Tradeoffs". ===== BUILD_PLAN.md ===== # Build plan ## Original build brief Build a local-first trip planner web app called Fugl. No accounts, no cloud, no telemetry. Stack, non negotiable: - Next.js with the App Router and TypeScript - SQLite via better-sqlite3, file at ./data/fugl.db, created and migrated on first run - Tailwind for styling, no component library - Leaflet with OpenStreetMap tiles for the map - Runs with: npm install, npm run dev Data model: - Trip: id, name, destination label, start date, end date, notes, home timezone - Item: id, trip id, kind (flight, train, lodging, activity, food, note), title, start datetime, end datetime nullable, timezone, location name, lat nullable, lng nullable, confirmation code, url, cost, currency, notes - Packing item: id, trip id, label, packed boolean Features in scope: - Trip list page, create and edit trips - Trip detail page grouped by day, each day showing items sorted by start time, with kind icons and a running per-day cost total - Add and edit items in a side drawer, with lat and lng entered manually or pasted from a maps URL - Map panel showing all items with coordinates for the trip, pins numbered by day - Packing list with checkboxes, persisted - Export trip to .ics with one VEVENT per item, timezone aware - Printable itinerary view at /trips/[id]/print, clean single column, no nav chrome - JSON export and import of a whole trip - Full text search across item titles, notes and confirmation codes Explicitly out of scope: - Flight, hotel or price lookups of any kind - Email parsing, OAuth, sharing links, multi user - Push notifications and native apps Use .env for the optional map tile URL and nothing else. Seed one demo trip with three days of items so the UI is not empty. Write a README with run steps and a one line note that all data stays in ./data. ## Required capabilities - Node and a browser - A maps tile key if you want a real map instead of a static list - Optional: a place search API key for coordinates ## Delivery order 1. Scaffold the smallest runnable application and document its commands. 2. Implement the primary data model and core workflow. 3. Add validation, safe failure states, and persistence. 4. Cover the critical path with automated tests. 5. Exercise a clean install from the README and fix every missing step. ## Done when - A new user can go from clone to first successful workflow using only the README. - The core workflow works without paid infrastructure unless the brief requires it. - Tests cover the highest-risk behavior. - Known limitations are explicit rather than hidden. ===== .env.example ===== # Copy to .env and document every variable when it is introduced. # Never put real credentials in this file. APP_ENV=development # Add only values required by the selected implementation.
You are building a lean indie version of Wanderfugl. 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 ===== # Wanderfugl indie build ## Goal Build the smallest trustworthy replacement for the core Wanderfugl workflow for one developer or a tiny team. ## Scope A local trip planner where you create a trip, add day-by-day items with times, places, links and confirmation numbers, see them on a map, and export the whole thing to calendar or a printable page. ## Quick start 1. Install the documented dependencies. 2. Copy `.env.example` to `.env`. 3. Run the development command chosen during implementation. 4. Complete the acceptance checks in `BUILD_PLAN.md`. ## Honest limits This build deliberately does not replace: - Live flight, train and hotel pricing or availability - Automatic booking email parsing into your itinerary - A real mobile app with offline access while travelling - Timezone and schedule-change handling done correctly by someone else - Sharing a polished read-only itinerary with travel companions If those capabilities are essential, use Wanderfugl instead of pretending the gap is solved. ===== AGENTS.md ===== # Agent instructions - Optimize for a working, understandable weekend build. - Prefer the fewest moving parts that satisfy the brief. - Do not invent cryptography, security guarantees, APIs, or compliance claims. - Keep secrets out of source control and logs. - Add focused tests for destructive, security-sensitive, and data-loss paths. - Run the project checks before declaring the build complete. - Record any deliberate shortcut in the README under "Tradeoffs". ===== BUILD_PLAN.md ===== # Build plan ## Original build brief Build a local-first trip planner web app called Fugl. No accounts, no cloud, no telemetry. Stack, non negotiable: - Next.js with the App Router and TypeScript - SQLite via better-sqlite3, file at ./data/fugl.db, created and migrated on first run - Tailwind for styling, no component library - Leaflet with OpenStreetMap tiles for the map - Runs with: npm install, npm run dev Data model: - Trip: id, name, destination label, start date, end date, notes, home timezone - Item: id, trip id, kind (flight, train, lodging, activity, food, note), title, start datetime, end datetime nullable, timezone, location name, lat nullable, lng nullable, confirmation code, url, cost, currency, notes - Packing item: id, trip id, label, packed boolean Features in scope: - Trip list page, create and edit trips - Trip detail page grouped by day, each day showing items sorted by start time, with kind icons and a running per-day cost total - Add and edit items in a side drawer, with lat and lng entered manually or pasted from a maps URL - Map panel showing all items with coordinates for the trip, pins numbered by day - Packing list with checkboxes, persisted - Export trip to .ics with one VEVENT per item, timezone aware - Printable itinerary view at /trips/[id]/print, clean single column, no nav chrome - JSON export and import of a whole trip - Full text search across item titles, notes and confirmation codes Explicitly out of scope: - Flight, hotel or price lookups of any kind - Email parsing, OAuth, sharing links, multi user - Push notifications and native apps Use .env for the optional map tile URL and nothing else. Seed one demo trip with three days of items so the UI is not empty. Write a README with run steps and a one line note that all data stays in ./data. ## Required capabilities - Node and a browser - A maps tile key if you want a real map instead of a static list - Optional: a place search API key for coordinates ## Delivery order 1. Scaffold the smallest runnable application and document its commands. 2. Implement the primary data model and core workflow. 3. Add validation, safe failure states, and persistence. 4. Cover the critical path with automated tests. 5. Exercise a clean install from the README and fix every missing step. ## Done when - A new user can go from clone to first successful workflow using only the README. - The core workflow works without paid infrastructure unless the brief requires it. - Tests cover the highest-risk behavior. - Known limitations are explicit rather than hidden. ===== .env.example ===== # Copy to .env and document every variable when it is introduced. # Never put real credentials in this file. APP_ENV=development # Add only values required by the selected implementation.
You are building a production product version of Wanderfugl. 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 ===== # Wanderfugl product brief ## Problem Trip planning is one of the most one-shottable categories there is: it is days, places, times, notes and a map, which is a CRUD app with a calendar view. An agent can give you a local itinerary builder with day-by-day cards, confirmation numbers, an ICS export and a pinned map in a single sitting, and it will feel better than a spreadsheet. The gap is everything that touches live travel data: flight and hotel prices, schedule changes, timezone-correct arrival math, place search with real coordinates, and inbox parsing of booking emails. If the paid product's value is mostly structure and a nice UI, self-hosting wins; if it is live data feeds or a polished phone app you use offline in an airport, it does not. Rate it kinda until you know which of those you are actually paying for. ## Product outcome A local trip planner where you create a trip, add day-by-day items with times, places, links and confirmation numbers, see them on a map, and export the whole thing to calendar or a printable page. ## Target user A serious builder who needs a maintainable product foundation rather than a one-off demo. ## Required capabilities - Node and a browser - A maps tile key if you want a real map instead of a static list - Optional: a place search API key for coordinates ## Explicit non-goals for v1 - Live flight, train and hotel pricing or availability - Automatic booking email parsing into your itinerary - A real mobile app with offline access while travelling - Timezone and schedule-change handling done correctly by someone else - Sharing a polished read-only itinerary with travel companions ## Success criteria - The primary workflow is measurable end to end. - Setup is reproducible in a clean environment. - Failure, recovery, and support paths are documented. - Product claims match what the implementation actually guarantees. ===== ARCHITECTURE.md ===== # Architecture ## Starting brief Build a local-first trip planner web app called Fugl. No accounts, no cloud, no telemetry. Stack, non negotiable: - Next.js with the App Router and TypeScript - SQLite via better-sqlite3, file at ./data/fugl.db, created and migrated on first run - Tailwind for styling, no component library - Leaflet with OpenStreetMap tiles for the map - Runs with: npm install, npm run dev Data model: - Trip: id, name, destination label, start date, end date, notes, home timezone - Item: id, trip id, kind (flight, train, lodging, activity, food, note), title, start datetime, end datetime nullable, timezone, location name, lat nullable, lng nullable, confirmation code, url, cost, currency, notes - Packing item: id, trip id, label, packed boolean Features in scope: - Trip list page, create and edit trips - Trip detail page grouped by day, each day showing items sorted by start time, with kind icons and a running per-day cost total - Add and edit items in a side drawer, with lat and lng entered manually or pasted from a maps URL - Map panel showing all items with coordinates for the trip, pins numbered by day - Packing list with checkboxes, persisted - Export trip to .ics with one VEVENT per item, timezone aware - Printable itinerary view at /trips/[id]/print, clean single column, no nav chrome - JSON export and import of a whole trip - Full text search across item titles, notes and confirmation codes Explicitly out of scope: - Flight, hotel or price lookups of any kind - Email parsing, OAuth, sharing links, multi user - Push notifications and native apps Use .env for the optional map tile URL and nothing else. Seed one demo trip with three days of items so the UI is not empty. Write a README with run steps and a one line note that all data stays in ./data. ## Boundaries Separate the product into replaceable modules for interface, application logic, persistence, external integrations, and operational concerns. Keep domain logic independent from delivery frameworks and vendors. ## Production baseline - Configuration: validated at startup with safe local defaults where possible. - Security: least privilege, input validation, secret redaction, rate limits on abuse-prone paths, and no invented security primitives. - Data: explicit schema and migrations, transactional writes where integrity matters, backup and restore instructions. - Integrations: adapters around third-party providers, idempotent webhook or job processing, bounded retries, and timeouts. - Observability: structured logs with request or operation IDs, an error-tracking hook, and health/readiness checks where a server exists. - Quality: unit tests for domain rules, integration tests at module boundaries, and one end-to-end critical-path test. ## Decision records For each major dependency, document why it was chosen, its failure mode, and how it can be replaced. Do not introduce infrastructure until a requirement justifies it. ===== AGENTS.md ===== # Agent instructions - Read `PRODUCT.md` and `ARCHITECTURE.md` before changing code. - Implement milestone by milestone; keep each change reviewable and leave the application runnable. - 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 test pass. - Use provider interfaces for external services and deterministic fakes in tests. - Add migrations and rollback or recovery notes for persistent data changes. - Log useful operational context without credentials, tokens, passwords, or personal data. - Update documentation and run all checks before completing a milestone. ===== MILESTONES.md ===== # Delivery milestones ## M0 — Decisions and scaffold - Confirm the runtime, persistence model, threat boundaries, and deployment target. - Create a reproducible local environment and continuous checks. ## M1 — Core workflow - Implement the smallest end-to-end product path with validation and tests. - Keep integrations behind interfaces. ## M2 — Trust layer - Add secure failure behavior, recovery paths, audit-relevant events, and data safeguards. - Test abuse cases and destructive operations. ## M3 — Operability - Add structured logs, error reporting hooks, health signals, backup/restore documentation, and deployment configuration. ## M4 — Release gate - Run a clean-install test, critical-path end-to-end test, dependency review, and documented rollback exercise. - Compare the shipped behavior with `PRODUCT.md` and publish remaining limitations. ===== OPERATIONS.md ===== # Operations ## Before release - Validate configuration and secrets at startup. - Define backup, restore, and rollback procedures and test them. - Document logs, error tracking, health signals, and alert ownership. - Set dependency update and vulnerability review expectations. ## Incident checklist 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 source when needed. 5. Document the root cause, remediation, and regression test. ## Launch constraint Do not market omitted Wanderfugl capabilities as implemented. The v1 non-goals in `PRODUCT.md` remain user-visible limitations until they are deliberately delivered.
README.md
# Wanderfugl indie build ## Goal Build the smallest trustworthy replacement for the core Wanderfugl workflow for one developer or a tiny team. ## Scope A local trip planner where you create a trip, add day-by-day items with times, places, links and confirmation numbers, see them on a map, and export the whole thing to calendar or a printable page. ## Quick start 1. Install the documented dependencies. 2. Copy `.env.example` to `.env`. 3. Run the development command chosen during implementation. 4. Complete the acceptance checks in `BUILD_PLAN.md`. ## Honest limits This build deliberately does not replace: - Live flight, train and hotel pricing or availability - Automatic booking email parsing into your itinerary - A real mobile app with offline access while travelling - Timezone and schedule-change handling done correctly by someone else - Sharing a polished read-only itinerary with travel companions If those capabilities are essential, use Wanderfugl instead of pretending the gap is solved.
AGENTS.md
# Agent instructions - Optimize for a working, understandable weekend build. - Prefer the fewest moving parts that satisfy the brief. - Do not invent cryptography, security guarantees, APIs, or compliance claims. - Keep secrets out of source control and logs. - Add focused tests for destructive, security-sensitive, and data-loss paths. - Run the project checks before declaring the build complete. - Record any deliberate shortcut in the README under "Tradeoffs".
BUILD_PLAN.md
# Build plan ## Original build brief Build a local-first trip planner web app called Fugl. No accounts, no cloud, no telemetry. Stack, non negotiable: - Next.js with the App Router and TypeScript - SQLite via better-sqlite3, file at ./data/fugl.db, created and migrated on first run - Tailwind for styling, no component library - Leaflet with OpenStreetMap tiles for the map - Runs with: npm install, npm run dev Data model: - Trip: id, name, destination label, start date, end date, notes, home timezone - Item: id, trip id, kind (flight, train, lodging, activity, food, note), title, start datetime, end datetime nullable, timezone, location name, lat nullable, lng nullable, confirmation code, url, cost, currency, notes - Packing item: id, trip id, label, packed boolean Features in scope: - Trip list page, create and edit trips - Trip detail page grouped by day, each day showing items sorted by start time, with kind icons and a running per-day cost total - Add and edit items in a side drawer, with lat and lng entered manually or pasted from a maps URL - Map panel showing all items with coordinates for the trip, pins numbered by day - Packing list with checkboxes, persisted - Export trip to .ics with one VEVENT per item, timezone aware - Printable itinerary view at /trips/[id]/print, clean single column, no nav chrome - JSON export and import of a whole trip - Full text search across item titles, notes and confirmation codes Explicitly out of scope: - Flight, hotel or price lookups of any kind - Email parsing, OAuth, sharing links, multi user - Push notifications and native apps Use .env for the optional map tile URL and nothing else. Seed one demo trip with three days of items so the UI is not empty. Write a README with run steps and a one line note that all data stays in ./data. ## Required capabilities - Node and a browser - A maps tile key if you want a real map instead of a static list - Optional: a place search API key for coordinates ## Delivery order 1. Scaffold the smallest runnable application and document its commands. 2. Implement the primary data model and core workflow. 3. Add validation, safe failure states, and persistence. 4. Cover the critical path with automated tests. 5. Exercise a clean install from the README and fix every missing step. ## Done when - A new user can go from clone to first successful workflow using only the README. - The core workflow works without paid infrastructure unless the brief requires it. - Tests cover the highest-risk behavior. - Known limitations are explicit rather than hidden.
.env.example
# Copy to .env and document every variable when it is introduced. # Never put real credentials in this file. APP_ENV=development # Add only values required by the selected implementation.
PRODUCT.md
# Wanderfugl product brief ## Problem Trip planning is one of the most one-shottable categories there is: it is days, places, times, notes and a map, which is a CRUD app with a calendar view. An agent can give you a local itinerary builder with day-by-day cards, confirmation numbers, an ICS export and a pinned map in a single sitting, and it will feel better than a spreadsheet. The gap is everything that touches live travel data: flight and hotel prices, schedule changes, timezone-correct arrival math, place search with real coordinates, and inbox parsing of booking emails. If the paid product's value is mostly structure and a nice UI, self-hosting wins; if it is live data feeds or a polished phone app you use offline in an airport, it does not. Rate it kinda until you know which of those you are actually paying for. ## Product outcome A local trip planner where you create a trip, add day-by-day items with times, places, links and confirmation numbers, see them on a map, and export the whole thing to calendar or a printable page. ## Target user A serious builder who needs a maintainable product foundation rather than a one-off demo. ## Required capabilities - Node and a browser - A maps tile key if you want a real map instead of a static list - Optional: a place search API key for coordinates ## Explicit non-goals for v1 - Live flight, train and hotel pricing or availability - Automatic booking email parsing into your itinerary - A real mobile app with offline access while travelling - Timezone and schedule-change handling done correctly by someone else - Sharing a polished read-only itinerary with travel companions ## Success criteria - The primary workflow is measurable end to end. - Setup is reproducible in a clean environment. - Failure, recovery, and support paths are documented. - Product claims match what the implementation actually guarantees.
ARCHITECTURE.md
# Architecture ## Starting brief Build a local-first trip planner web app called Fugl. No accounts, no cloud, no telemetry. Stack, non negotiable: - Next.js with the App Router and TypeScript - SQLite via better-sqlite3, file at ./data/fugl.db, created and migrated on first run - Tailwind for styling, no component library - Leaflet with OpenStreetMap tiles for the map - Runs with: npm install, npm run dev Data model: - Trip: id, name, destination label, start date, end date, notes, home timezone - Item: id, trip id, kind (flight, train, lodging, activity, food, note), title, start datetime, end datetime nullable, timezone, location name, lat nullable, lng nullable, confirmation code, url, cost, currency, notes - Packing item: id, trip id, label, packed boolean Features in scope: - Trip list page, create and edit trips - Trip detail page grouped by day, each day showing items sorted by start time, with kind icons and a running per-day cost total - Add and edit items in a side drawer, with lat and lng entered manually or pasted from a maps URL - Map panel showing all items with coordinates for the trip, pins numbered by day - Packing list with checkboxes, persisted - Export trip to .ics with one VEVENT per item, timezone aware - Printable itinerary view at /trips/[id]/print, clean single column, no nav chrome - JSON export and import of a whole trip - Full text search across item titles, notes and confirmation codes Explicitly out of scope: - Flight, hotel or price lookups of any kind - Email parsing, OAuth, sharing links, multi user - Push notifications and native apps Use .env for the optional map tile URL and nothing else. Seed one demo trip with three days of items so the UI is not empty. Write a README with run steps and a one line note that all data stays in ./data. ## Boundaries Separate the product into replaceable modules for interface, application logic, persistence, external integrations, and operational concerns. Keep domain logic independent from delivery frameworks and vendors. ## Production baseline - Configuration: validated at startup with safe local defaults where possible. - Security: least privilege, input validation, secret redaction, rate limits on abuse-prone paths, and no invented security primitives. - Data: explicit schema and migrations, transactional writes where integrity matters, backup and restore instructions. - Integrations: adapters around third-party providers, idempotent webhook or job processing, bounded retries, and timeouts. - Observability: structured logs with request or operation IDs, an error-tracking hook, and health/readiness checks where a server exists. - Quality: unit tests for domain rules, integration tests at module boundaries, and one end-to-end critical-path test. ## Decision records For each major dependency, document why it was chosen, its failure mode, and how it can be replaced. Do not introduce infrastructure until a requirement justifies it.
AGENTS.md
# Agent instructions - Read `PRODUCT.md` and `ARCHITECTURE.md` before changing code. - Implement milestone by milestone; keep each change reviewable and leave the application runnable. - 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 test pass. - Use provider interfaces for external services and deterministic fakes in tests. - Add migrations and rollback or recovery notes for persistent data changes. - Log useful operational context without credentials, tokens, passwords, or personal data. - Update documentation and run all checks before completing a milestone.
MILESTONES.md
# Delivery milestones ## M0 — Decisions and scaffold - Confirm the runtime, persistence model, threat boundaries, and deployment target. - Create a reproducible local environment and continuous checks. ## M1 — Core workflow - Implement the smallest end-to-end product path with validation and tests. - Keep integrations behind interfaces. ## M2 — Trust layer - Add secure failure behavior, recovery paths, audit-relevant events, and data safeguards. - Test abuse cases and destructive operations. ## M3 — Operability - Add structured logs, error reporting hooks, health signals, backup/restore documentation, and deployment configuration. ## M4 — Release gate - Run a clean-install test, critical-path end-to-end test, dependency review, and documented rollback exercise. - Compare the shipped behavior with `PRODUCT.md` and publish remaining limitations.
OPERATIONS.md
# Operations ## Before release - Validate configuration and secrets at startup. - Define backup, restore, and rollback procedures and test them. - Document logs, error tracking, health signals, and alert ownership. - Set dependency update and vulnerability review expectations. ## Incident checklist 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 source when needed. 5. Document the root cause, remediation, and regression test. ## Launch constraint Do not market omitted Wanderfugl capabilities as implemented. The v1 non-goals in `PRODUCT.md` remain user-visible limitations until they are deliberately delivered.
$ choose a build depth, inspect the files, then open the complete pack in your agent · this prompt is generated from the build plan · improve it via PR
Because the hard part of trip planning is not storing the plan, it is getting the plan in and out without typing. Forwarding a confirmation email and having flights, seats and hotel nights appear correctly, with the right timezones and the right dates, is worth money to people who travel often. Add a phone app that works in an airport with no data and a share link your travel partner can actually read, and a self-hosted version starts to feel like homework right when you least want homework.
xLive flight, train and hotel pricing or availability
xAutomatic booking email parsing into your itinerary
xA real mobile app with offline access while travelling
xTimezone and schedule-change handling done correctly by someone else
xSharing a polished read-only itinerary with travel companions
Nothing worth pointing at. That's why the prompt exists.
share on X ↗"I just replaced Wanderfugl ($9/mo) with one prompt"
Vibecode Wanderfugl
Kinda. The core of Wanderfugl is buildable in a weekend with the prompt on this page, but there are real gaps: Live flight, train and hotel pricing or availability, Automatic booking email parsing into your itinerary. Read the honest list above before committing.
How much does Wanderfugl cost?
Wanderfugl costs about $9/month (Plus, checked 2026-08-18), which is $108 per year.
What do I lose by replacing Wanderfugl?
Honestly: Live flight, train and hotel pricing or availability; Automatic booking email parsing into your itinerary; A real mobile app with offline access while travelling; Timezone and schedule-change handling done correctly by someone else; Sharing a polished read-only itinerary with travel companions. If any of those are load-bearing for you, keep paying.
Is there an open-source alternative to Wanderfugl?
No mature open-source alternative worth pointing at, which is exactly why the one-shot prompt on this page exists.