[Blog](https://cohesivity.ai/blog) Agent-native backend Published Jun 27, 2026·Updated Aug 30, 2026 ![](https://cohesivity.ai/authors/arag.webp)![](https://cohesivity.ai/authors/anshu.webp)[Arag](https://www.linkedin.com/in/aragagrawal/) and [Anshu](https://www.linkedin.com/in/aanshuaggrawal120/) # The Best Backend for Cursor-Built Applications [Read as Markdown](https://cohesivity.ai/blog/best-backend-for-cursor-built-applications.md) Cursor agent App State Identity The best backend for a Cursor-built application is one Cursor can operate through its terminal or MCP tools while the backend enforces safe retries, scoped access, and development isolation. Cursor rules can preserve the setup sequence, but the server still owns authorization and idempotency. Cohesivity, Supabase, and Firebase all provide agent-facing paths. Choose the platform whose data and hosting model fits the application, then restrict Cursor to one development project. ## Cursor can edit, execute, browse, and call tools Cursor Agent can search and edit files, run shell commands, browse the web, and use connected tools. Its [Agent documentation](https://cursor.com/docs/agent/overview) also describes local checkpoints for file changes. Those checkpoints do not roll back a database migration, sent email, or deployed service. External effects need their own operation records, idempotency keys, and cleanup paths. Git and Cursor checkpoints protect the worktree, not the backend. ## Choose the backend path by application needs ### Cohesivity Use Cohesivity when Cursor should start a multi-service project before the user creates provider accounts. The agent can bootstrap an ephemeral tenant, fetch current offering docs, and provision supported services while Cohesivity keeps upstream credentials server-side. ### Supabase Use Supabase when the application is centered on Postgres, Auth, Storage, Realtime, or Edge Functions and the team already wants a Supabase project. Its official MCP server can scope access to one project, enable read-only mode, and restrict feature groups. Supabase's [MCP security recommendations](https://supabase.com/docs/guides/ai-tools/mcp) say to use development projects and avoid production data. ### Firebase Use Firebase when the application belongs in Firebase's database, auth, hosting, functions, or messaging ecosystem. Its [official MCP server](https://firebase.google.com/docs/ai-assistance/mcp-server) gives Cursor project and service tools after Google authentication. The broader [backend platform comparison](https://cohesivity.ai/blog/best-backend-as-a-service-for-ai-agents) evaluates the same paths beyond Cursor. ## Write rules for observed failures Cursor supports project rules under `.cursor/rules`, plus `AGENTS.md` for simpler repository-wide instructions. Its [rules guide](https://docs.cursor.com/context/rules-for-ai) recommends focused, actionable rules with concrete examples and file references. A useful backend rule might look like this: ```text --- description: Use the existing Cohesivity project for backend work globs: - "src/server/**" - "app/api/**" alwaysApply: false --- Before provisioning, check for a valid .cohesivity file and reuse it. Fetch https://cohesivity.ai/offerings/ before calling a resource. Keep coh_management_key and coh_application_key in server-only code. Ask before claiming, paying, upgrading, or deleting a resource. ``` Do not add a rule that says "be secure" or "avoid mistakes." It gives the model no action or file to inspect. ## Keep local and backend permissions separate Cursor documents run modes and approval behavior for shell, MCP, browser, file, and other local actions. Those controls decide whether Cursor may invoke a tool. The backend credential decides what the invoked tool may do. Use both: - Restrict Cursor's available tools and command execution. - Scope the backend credential to one development project. - Remove delete, billing, and account-wide tools unless the task needs them. - Require backend authorization for every tenant and resource. - Keep production credentials outside the Cursor workspace. The [AI agent security guide](https://cohesivity.ai/blog/ai-agent-security-identity-permissions-secrets-audit-logs) shows how those layers connect in a trace. ## Test a retry outside the editor checkpoint Create one disposable resource, interrupt the response, and repeat the same logical operation. Confirm the backend returns or reconciles the original resource. Then restore the Cursor checkpoint and verify that the external resource still exists, because that is what will happen in a real session. The prompt below finds one repeated backend mistake and drafts the narrowest project rule that addresses it without pretending a rule can enforce server policy. or send it to[Claude Code](https://claude.ai/new?q=Inspect+this+repository%27s+Cursor+rules%2C+AGENTS.md%2C+MCP+configuration%2C+and+backend+setup+docs.+Find+one+backend+mistake+the+agent+is+likely+to+repeat%2C+such+as+provisioning+twice%2C+using+production%2C+exposing+a+management+key%2C+skipping+a+migration+test%2C+or+claiming+a+project+without+consent.+Do+not+edit+files.+Propose+one+focused+.cursor%2Frules+rule+under+500+lines+with+concrete+commands+or+file+references%2C+the+condition+that+activates+it%2C+and+the+backend+behavior+that+still+must+be+enforced+server-side.+If+the+repository+uses+Cohesivity%2C+make+the+rule+reuse+a+valid+.cohesivity+file+and+fetch+live+offering+docs+before+provisioning. "Send to Claude")[Cursor](https://cursor.com/link/prompt?text=Inspect+this+repository%27s+Cursor+rules%2C+AGENTS.md%2C+MCP+configuration%2C+and+backend+setup+docs.+Find+one+backend+mistake+the+agent+is+likely+to+repeat%2C+such+as+provisioning+twice%2C+using+production%2C+exposing+a+management+key%2C+skipping+a+migration+test%2C+or+claiming+a+project+without+consent.+Do+not+edit+files.+Propose+one+focused+.cursor%2Frules+rule+under+500+lines+with+concrete+commands+or+file+references%2C+the+condition+that+activates+it%2C+and+the+backend+behavior+that+still+must+be+enforced+server-side.+If+the+repository+uses+Cohesivity%2C+make+the+rule+reuse+a+valid+.cohesivity+file+and+fetch+live+offering+docs+before+provisioning. "Send to Cursor")[Codex](https://chatgpt.com/codex?prompt=Inspect+this+repository%27s+Cursor+rules%2C+AGENTS.md%2C+MCP+configuration%2C+and+backend+setup+docs.+Find+one+backend+mistake+the+agent+is+likely+to+repeat%2C+such+as+provisioning+twice%2C+using+production%2C+exposing+a+management+key%2C+skipping+a+migration+test%2C+or+claiming+a+project+without+consent.+Do+not+edit+files.+Propose+one+focused+.cursor%2Frules+rule+under+500+lines+with+concrete+commands+or+file+references%2C+the+condition+that+activates+it%2C+and+the+backend+behavior+that+still+must+be+enforced+server-side.+If+the+repository+uses+Cohesivity%2C+make+the+rule+reuse+a+valid+.cohesivity+file+and+fetch+live+offering+docs+before+provisioning. "Send to Codex")[opencode](https://opencode.ai/?q=Inspect+this+repository%27s+Cursor+rules%2C+AGENTS.md%2C+MCP+configuration%2C+and+backend+setup+docs.+Find+one+backend+mistake+the+agent+is+likely+to+repeat%2C+such+as+provisioning+twice%2C+using+production%2C+exposing+a+management+key%2C+skipping+a+migration+test%2C+or+claiming+a+project+without+consent.+Do+not+edit+files.+Propose+one+focused+.cursor%2Frules+rule+under+500+lines+with+concrete+commands+or+file+references%2C+the+condition+that+activates+it%2C+and+the+backend+behavior+that+still+must+be+enforced+server-side.+If+the+repository+uses+Cohesivity%2C+make+the+rule+reuse+a+valid+.cohesivity+file+and+fetch+live+offering+docs+before+provisioning. "Send to OpenCode")