What are Output Parameters?
Output parameters are the typed fields that define what a capability operation returns to its consumers. Each parameter has a name, type, description, and a JSONPath mapping expression that extracts the value from the upstream API response.
How they work
In a capability spec, output parameters are declared per operation:
- Type – The data type of the output field (string, number, boolean, array, object).
- Description – Human-readable description used for documentation and AI semantic discovery.
- Mapping – A JSONPath expression that extracts the value from the upstream response.
- Static values – Optional static values for mocking and design-first development.
Why it matters
Output parameters are the mechanism for right-sizing context. Instead of passing raw upstream API responses to consumers, capabilities shape their output to include only what is relevant for the task at hand. For AI consumers, this means smaller prompts, less hallucination, and more predictable behavior. For API consumers, it means stable contracts independent of upstream API changes.
