| name | api-interface-design |
| description | Use when designing public APIs, module boundaries, provider adapters, tool schemas, or data contracts. |
API Interface Design
Design the contract before the implementation.
Use This For
- REST, GraphQL, or SDK interface design
- Tool parameter schemas
- Provider adapter boundaries
- Data exchanged between the agent loop, tools, and persistence
Principles
- Prefer additive changes over breaking existing fields.
- Use one predictable error shape.
- Validate external input at the boundary.
- Keep internal call sites typed and boring.
- Treat every observable behavior as something users may depend on.
Checklist
- Inputs and outputs are typed.
- Error semantics are consistent.
- Optional fields are truly optional.
- New behavior has at least one success test and one failure test.
- Docs show the smallest working example.
