A practical way to configure Claude Code for FastAPI, Flask and Django projects: architecture boundaries, tests, migrations, security and evidence-driven completion.
A good CLAUDE.md reduces avoidable ambiguity: it teaches the agent where boundaries live, which risks require review and what must be verified before work is complete.
Give your Python backend a better operating manual.
Get the production-minded CLAUDE.md for FastAPI, Flask and Django: boundaries, transactions, tests, security, background work and a definition of done.
- Framework-specific rules without framework lock-in
- Guardrails for migrations, retries and external effects
- Verification commands and an evidence-based completion format
Treat CLAUDE.md as a project operating manual
A useful CLAUDE.md does not try to document every framework feature. It records the decisions an agent cannot safely infer: module boundaries, testing commands, database and migration ownership, security constraints and the expected completion report.
Keep it short enough to be read on every task, and link to deeper documents where needed. Stale instructions are worse than missing instructions because they create confident, incorrect changes.
Give the agent backend-specific guardrails
FastAPI needs clear separation between Depends-based adapters and services. Flask benefits from factory and blueprint conventions. Django needs explicit rules for transaction boundaries, migrations and ORM query behaviour. The shared intent is the same: framework convenience must not leak through all business logic.
Tell the agent which changes require extra care: external calls, idempotency, authorization, migration safety, background jobs and public API compatibility. These are the places where plausible code can still create a production incident.
Require evidence, not a polished summary
Ask Claude Code to identify the contract and failure path before editing, run the project checks after editing and report what could not be verified. That transforms a coding assistant from an autocomplete layer into a constrained engineering collaborator.
The resulting file is a starting point, not a substitute for review. Adapt commands, tools and architectural vocabulary to the repository, then maintain it as the system evolves.
Evidence to take into review
- CLAUDE.md names architecture and transaction boundaries.
- Framework-specific guidance matches the repository.
- Security, secrets and sensitive-data rules are explicit.
- Tests and verification commands are current.
- Completion requires evidence and operational follow-up where relevant.
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Use PRODUCTION-7 to connect this concern with the other dimensions of a trustworthy backend.
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