Vibecode CodeSandbox
track this build5 steps, step by step0%You can self-host a browser IDE, but fast templates, previews, cloud VMs, collaboration, and workflow integrations are the product.
You are building a lean indie version of CodeSandbox. 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 ===== # CodeSandbox indie build ## Goal Build the smallest trustworthy replacement for the core CodeSandbox workflow for one developer or a tiny team. ## Scope Run code-server or dev containers, expose preview URLs, sync git repos, and add templates. ## 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: - instant templates - cloud sandboxes - preview URLs - collaboration - managed infrastructure - integration polish If those capabilities are essential, use code-server 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 me a personal cloud dev environment to replace CodeSandbox. Requirements: - Do not write an IDE. Set up code-server (VS Code in the browser) on my VPS via its official install script, running under systemd, bound to localhost. - Access over Tailscale or an SSH tunnel only; no public exposure, built-in password auth switched off. That is the whole security model, keep it that simple. - A sandbox CLI: sandbox new <name> --template node|python|static copies a folder from templates/ into ~/sandboxes/<name>, runs its install step, and prints the code-server URL opened to it. - Three templates: node (Express hello world + nodemon), python (venv + Flask), static (index.html served with live-server). - Previews: each sandbox's dev server gets its own port, reachable through the same tunnel; a tiny index page lists sandboxes and their ports. - sandbox rm <name> archives the folder to a tarball before deleting it. - No accounts, no telemetry; everything lives on my own server. - Out of scope: multi-user collaboration, instant VM forking, and public preview URLs; managed infrastructure is the hosted product. - README: install steps, tunnel setup, and how to add a template. ## Required capabilities - container host - code-server/devcontainer tooling - reverse proxy - git integration - auth ## 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 CodeSandbox. 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 ===== # CodeSandbox indie build ## Goal Build the smallest trustworthy replacement for the core CodeSandbox workflow for one developer or a tiny team. ## Scope Run code-server or dev containers, expose preview URLs, sync git repos, and add templates. ## 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: - instant templates - cloud sandboxes - preview URLs - collaboration - managed infrastructure - integration polish If those capabilities are essential, use code-server 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 me a personal cloud dev environment to replace CodeSandbox. Requirements: - Do not write an IDE. Set up code-server (VS Code in the browser) on my VPS via its official install script, running under systemd, bound to localhost. - Access over Tailscale or an SSH tunnel only; no public exposure, built-in password auth switched off. That is the whole security model, keep it that simple. - A sandbox CLI: sandbox new <name> --template node|python|static copies a folder from templates/ into ~/sandboxes/<name>, runs its install step, and prints the code-server URL opened to it. - Three templates: node (Express hello world + nodemon), python (venv + Flask), static (index.html served with live-server). - Previews: each sandbox's dev server gets its own port, reachable through the same tunnel; a tiny index page lists sandboxes and their ports. - sandbox rm <name> archives the folder to a tarball before deleting it. - No accounts, no telemetry; everything lives on my own server. - Out of scope: multi-user collaboration, instant VM forking, and public preview URLs; managed infrastructure is the hosted product. - README: install steps, tunnel setup, and how to add a template. ## Required capabilities - container host - code-server/devcontainer tooling - reverse proxy - git integration - auth ## 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 CodeSandbox. 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 ===== # CodeSandbox product brief ## Problem You can self-host a browser IDE, but fast templates, previews, cloud VMs, collaboration, and workflow integrations are the product. ## Product outcome Run code-server or dev containers, expose preview URLs, sync git repos, and add templates. ## Target user A serious builder who needs a maintainable product foundation rather than a one-off demo. ## Required capabilities - container host - code-server/devcontainer tooling - reverse proxy - git integration - auth ## Explicit non-goals for v1 - instant templates - cloud sandboxes - preview URLs - collaboration - managed infrastructure - integration polish ## 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 me a personal cloud dev environment to replace CodeSandbox. Requirements: - Do not write an IDE. Set up code-server (VS Code in the browser) on my VPS via its official install script, running under systemd, bound to localhost. - Access over Tailscale or an SSH tunnel only; no public exposure, built-in password auth switched off. That is the whole security model, keep it that simple. - A sandbox CLI: sandbox new <name> --template node|python|static copies a folder from templates/ into ~/sandboxes/<name>, runs its install step, and prints the code-server URL opened to it. - Three templates: node (Express hello world + nodemon), python (venv + Flask), static (index.html served with live-server). - Previews: each sandbox's dev server gets its own port, reachable through the same tunnel; a tiny index page lists sandboxes and their ports. - sandbox rm <name> archives the folder to a tarball before deleting it. - No accounts, no telemetry; everything lives on my own server. - Out of scope: multi-user collaboration, instant VM forking, and public preview URLs; managed infrastructure is the hosted product. - README: install steps, tunnel setup, and how to add a template. ## 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 CodeSandbox capabilities as implemented. The v1 non-goals in `PRODUCT.md` remain user-visible limitations until they are deliberately delivered.
# CodeSandbox indie build ## Goal Build the smallest trustworthy replacement for the core CodeSandbox workflow for one developer or a tiny team. ## Scope Run code-server or dev containers, expose preview URLs, sync git repos, and add templates. ## 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: - instant templates - cloud sandboxes - preview URLs - collaboration - managed infrastructure - integration polish If those capabilities are essential, use code-server instead of pretending the gap is solved.
# 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 ## Original build brief Build me a personal cloud dev environment to replace CodeSandbox. Requirements: - Do not write an IDE. Set up code-server (VS Code in the browser) on my VPS via its official install script, running under systemd, bound to localhost. - Access over Tailscale or an SSH tunnel only; no public exposure, built-in password auth switched off. That is the whole security model, keep it that simple. - A sandbox CLI: sandbox new <name> --template node|python|static copies a folder from templates/ into ~/sandboxes/<name>, runs its install step, and prints the code-server URL opened to it. - Three templates: node (Express hello world + nodemon), python (venv + Flask), static (index.html served with live-server). - Previews: each sandbox's dev server gets its own port, reachable through the same tunnel; a tiny index page lists sandboxes and their ports. - sandbox rm <name> archives the folder to a tarball before deleting it. - No accounts, no telemetry; everything lives on my own server. - Out of scope: multi-user collaboration, instant VM forking, and public preview URLs; managed infrastructure is the hosted product. - README: install steps, tunnel setup, and how to add a template. ## Required capabilities - container host - code-server/devcontainer tooling - reverse proxy - git integration - auth ## 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.
# 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.
# CodeSandbox product brief ## Problem You can self-host a browser IDE, but fast templates, previews, cloud VMs, collaboration, and workflow integrations are the product. ## Product outcome Run code-server or dev containers, expose preview URLs, sync git repos, and add templates. ## Target user A serious builder who needs a maintainable product foundation rather than a one-off demo. ## Required capabilities - container host - code-server/devcontainer tooling - reverse proxy - git integration - auth ## Explicit non-goals for v1 - instant templates - cloud sandboxes - preview URLs - collaboration - managed infrastructure - integration polish ## 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 ## Starting brief Build me a personal cloud dev environment to replace CodeSandbox. Requirements: - Do not write an IDE. Set up code-server (VS Code in the browser) on my VPS via its official install script, running under systemd, bound to localhost. - Access over Tailscale or an SSH tunnel only; no public exposure, built-in password auth switched off. That is the whole security model, keep it that simple. - A sandbox CLI: sandbox new <name> --template node|python|static copies a folder from templates/ into ~/sandboxes/<name>, runs its install step, and prints the code-server URL opened to it. - Three templates: node (Express hello world + nodemon), python (venv + Flask), static (index.html served with live-server). - Previews: each sandbox's dev server gets its own port, reachable through the same tunnel; a tiny index page lists sandboxes and their ports. - sandbox rm <name> archives the folder to a tarball before deleting it. - No accounts, no telemetry; everything lives on my own server. - Out of scope: multi-user collaboration, instant VM forking, and public preview URLs; managed infrastructure is the hosted product. - README: install steps, tunnel setup, and how to add a template. ## 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.
# 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.
# 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 ## 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 CodeSandbox 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
They pay to avoid managing dev machines for experiments and previews.
xinstant templates
xcloud sandboxes
xpreview URLs
xcollaboration
xmanaged infrastructure
xintegration polish
Don't feel like building it? These folks already made it free.
all 3 free alternatives to CodeSandbox →· no votes, no pay-to-list · just what's real
Vibecode CodeSandbox
Kinda. The core of CodeSandbox is buildable in a weekend with the prompt on this page, but there are real gaps: instant templates, cloud sandboxes. Read the honest list above before committing.
How much does CodeSandbox cost?
CodeSandbox costs about $12/month (Pro, checked 2026-07-30), which is $144 per year.
What do I lose by replacing CodeSandbox?
Honestly: instant templates; cloud sandboxes; preview URLs; collaboration; managed infrastructure; integration polish. If any of those are load-bearing for you, keep paying.
Is there an open-source alternative to CodeSandbox?
Yes: code-server (VS Code in a browser; the cloud part is your server.) Coder (Full cloud workspaces on your infrastructure; Terraform and PostgreSQL come along for the ride.) Eclipse Che (A real browser IDE platform, assuming Kubernetes already counts as normal in your house.) All 3 curated free alternatives are at vibecodeit.com/codesandbox/alternatives. The prompt is for when you want it exactly your way.