OpenAPI provides a language-agnostic way to describe HTTP APIs. AI runtimes can use OpenAPI descriptions to turn external APIs into typed tools with documented parameters, authentication expectations, responses, and failure behavior.
At a glance
- Organization
- OpenAPI Initiative
- Runtime role
- API contract specification
- Category
- Protocols and Contracts
- Official documentation
- Visit official documentation opens in a new tab
Where it fits in the runtime stack
Layer 5 and Layer 6 boundary: tool contracts between the runtime and product or enterprise APIs.
Primary runtime role
Use OpenAPI for API-backed tools, tool catalogs, validation scaffolding, and documentation that is independent of prompt wording.
Not the same as
OpenAPI describes HTTP interfaces; it does not define agent state, model routing, memory policy, or runtime observability.
Integration notes
- Generate tool input schemas only after reviewing authentication, side effects, and rate limits.
- Prefer explicit operation allowlists over exposing entire enterprise APIs to a model-facing runtime.
- Map HTTP errors into a runtime error envelope rather than leaking raw provider details to end users.
Questions before production use
- Which OpenAPI operations are safe to expose as tools?
- Are write operations separated from read operations and approval-gated?
- How are response schemas validated before model-visible summarization?
Review and deprecation posture
This profile is reviewed as part of the aRuntime.com quarterly resource audit. If the official documentation moves, the project is archived, or the resource changes scope, this page should be updated with a dated status note rather than silently removed.
Sources and further reading
- OpenAPI Specification opens in a new tab — OpenAPI Initiative; official specification; accessed 2026-06-20 UTC.
Last reviewed: .