Backendgen: Instructions file for Codex

Project: Backend Compiler

Mission

Build a deterministic backend feature compiler for coding agents. Agents submit a compact, versioned specification; the compiler validates it, creates a normalized intermediate representation, and eventually generates tested backend repositories.

Current scope

• TypeScript 5 and Node.js 22.
• npm workspaces.
• NestJS + Prisma + PostgreSQL is the first future target.
• FastAPI is explicitly out of scope until the first target and feature conformance tests are stable.
• The compiler must work locally without a SaaS account.

Commands

• Install: npm install
• Build: npm run build
• Test: npm test
• Validate example: npm run validate:example
• Inspect example IR: npm run inspect:example

Architecture rules

• The versioned specification is the public contract.
• YAML/JSON input must never be passed directly to target templates.
• All generators consume the normalized BackendIR.
• Validation errors must include a stable code and a useful path.
• Agent-facing output should be concise and structured; never return generated file contents by default.
• Features own domain semantics; targets own framework-specific rendering.
• Generated and custom application code must remain separable.

Code conventions

• Use named exports.
• Keep modules focused and colocate tests with source.
• Prefer immutable data and pure compilation steps.
• Do not silently invent defaults that change security or data ownership.
• Add tests for every validation rule and IR transformation.

Boundaries

• Never commit secrets or generated customer projects.
• Do not add a second target before the first target passes conformance tests.
• Do not add SaaS infrastructure before local design-partner validation.
• Run build and tests before considering a change complete.