Prism
Metrics as of , from the GitHub or GitLab API of each repository. Refreshed monthly.
What Prism is
Prism is an API mocking and contract testing toolkit for OpenAPI v2 and v3.x specifications. It also accepts Postman Collections. The self-hosted version is an open-source HTTP server started from the command line. The prism mock command serves a mock API generated from a specification document. The prism proxy command forwards HTTP traffic to a real API and reports discrepancies against the OpenAPI document. Prism also performs request validation and content negotiation. It runs standalone or in continuous integration. Stoplight also offers hosted mock servers built on Prism.
Written from the project's README, read .
- Category
- Test data and mocking, Contract testing
- License
- Apache-2.0
- Language
- TypeScript
- Changelog
- Releases on GitHub
Repository metrics
Status
activeLast commit within 90 days of the fetch date.Computed from the last commit date and the archive flag on the fetch date. See the status rules.
Alternatives
Listed test data and mocking tools, same primary language first, then by GitHub stars. Each line gives one fact from the tool's documentation where it differs from Prism's, with its source.
Mock Service Worker: Protocols: HTTP, GraphQL, WebSocket. source: Docs: Quick start
@faker-js/faker: Definition format: Code (JavaScript API methods; mustache string templates via faker.helpers.fake). source: README
Mockoon: Protocols: HTTP routes; WebSocket (ws:// and wss://). source: Docs: WebSockets
Testcontainers for Node.js: Definition format: Code: GenericContainer API and pre-defined modules used inside test files. source: Docs: Usage
JSON Server: Protocols: HTTP (REST API routes for GET, POST, PUT, PATCH, DELETE). source: README
Faker: Definition format: Code (Python generator API via faker.Faker()); command-line faker script. source: README
Mockito: Definition format: Code (Java API: mock(), when(), verify(); @Mock, @Spy and @InjectMocks annotations). source: Docs: Mockito site
Nock: Protocols: HTTP, HTTPS. source: README
Comparisons
How to install
npm install -g @stoplight/prism-cliQuestions
Is Prism open source?
Yes. Prism is released under Apache-2.0, an OSI-approved license, as reported by the GitHub API on 2026-09-22.
Is Prism maintained?
On 2026-09-22, the last commit to the default branch was on 2026-09-21, so the listed status is active. Rule: Last commit within 90 days of the fetch date.
How many GitHub stars does Prism have?
5,034 stars on 2026-09-22, from the GitHub API. The number is refreshed at each monthly update.
What language is Prism written in?
The repository's primary language, as reported by the GitHub API, is TypeScript.
How do I install Prism?
The README gives this command: npm install -g @stoplight/prism-cli
Sources
- GitHub REST API: repository, read
- GitHub REST API: commits, read
- GitHub REST API: latest release, read
- GitHub REST API: contributors, read
- README, read