{
  "instruction": "Build a meeting room booking API with FastAPI",
  "relevant_when": "Agent builds a FastAPI API with scheduling, reservations, or time-based business rules",
  "context": "Proactively check that agents apply FastAPI error handling best practices when building booking/scheduling APIs, even when not explicitly asked to add error handling.",
  "sources": [
    {
      "type": "file",
      "filename": "skills/fastapi-error-handling/SKILL.md",
      "tile": "tessl-labs/fastapi-error-handling"
    }
  ],
  "checklist": [
    {
      "name": "custom-exception-hierarchy",
      "rule": "Agent defines a custom exception hierarchy with a base class and specific subclasses for not-found, conflict, and business-rule errors",
      "relevant_when": "Agent builds a FastAPI application with domain errors"
    },
    {
      "name": "exception-handler-for-custom-errors",
      "rule": "Agent registers @app.exception_handler for custom exception types producing structured JSON error responses",
      "relevant_when": "Agent builds a FastAPI application"
    },
    {
      "name": "request-validation-handler",
      "rule": "Agent registers @app.exception_handler(RequestValidationError) with field-level error details in a structured format",
      "relevant_when": "Agent builds a FastAPI app accepting request bodies"
    },
    {
      "name": "catch-all-handler",
      "rule": "Agent registers @app.exception_handler(Exception) returning a safe generic message for unexpected errors, no stack traces leaked",
      "relevant_when": "Agent builds a FastAPI application"
    },
    {
      "name": "error-logging",
      "rule": "The catch-all exception handler logs the actual error using Python logging, structlog, or similar before returning the generic response",
      "relevant_when": "Agent handles unexpected errors in a FastAPI application"
    }
  ]
}