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Prism

Apache-2.0

Turns an OpenAPI description into a running mock server that validates requests and returns example or dynamic responses — an API you can call before one exists.

OpenAPI

Specifications it implements

What this tool does to each specification, in the role vocabulary. Follow a standard through to standards.apievangelist.com for what it actually specifies.

StandardRoleWhat that means
OpenAPI mocks
Using this from an agent
Interfaces
clicontainerlibrary
Install
npm @stoplight/prism-cli
Invoke
npx @stoplight/prism-cli mock <spec.yaml> --port 4010
Consumes
openapi
Emits
http
Runtime
Runs offline Non-deterministic Read-only No credentials

Where it applies

Jobs this tool actually does, and the surface each one is exercised on.

Exercise an integration end to end with no credentials, no cost and no production side effects.
coding-agent

The safest way for an autonomous agent to verify its own integration code. A mock cannot charge a card, send an email, or delete a record.

Unblock frontend work while the backend is still being built.
coding-agenthuman
Run contract validation in proxy mode against a real API to find where it diverges from its description.
ci-pipeline
Website
https://stoplight.io/open-source/prism
Repository
https://github.com/stoplightio/prism
License
Apache-2.0 — reported by the GitHub API, verified 2026-08-11
Stars
5004 · last commit 2026-08-07
Matching caveat
The name is an ordinary English word, so the job-corpus matcher cannot use it — sampled matches were "Raytheon financial systems (i.e. IPDS, APEX, Prism)", "Workday Report Writer … Prism" The bare name is blocked in the matcher, so this count reflects only qualified matches. Real adoption needs another source.
Reading this as an agent? Don't scrape the page — this entry is published as structured data at /tools.json, against the tool.schema.json schema, using the roles.json vocabulary. Start at /llms.txt.
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