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SPECIFICTION
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OpenAPI Server

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Spec score 7.0 #22 of 26 in API Mocking Tools

Spec sheet

Purpose
OpenAPI Server is a local mock server for development that can proxy requests to a real backend.Read 5 Oct 2026 · github.com
License
The package declares the ISC license.Read 5 Oct 2026 · github.com
Additional features
It supports serving static files, HTTP and HTTPS, watch mode, and custom Express middleware.Read 5 Oct 2026 · github.com
Configuration
Configuration is available through command-line options, environment variables, and environment files.Read 5 Oct 2026 · github.com
Default behavior
Mocks are enabled by default and take precedence over proxying when a matching mock exists.Read 4 Oct 2026 · github.com
End-to-end testing
Mocks can provide predictable API responses for end-to-end tests.Read 4 Oct 2026 · github.com
Install
The README instructs users to install it from its GitHub repository with npm.Read 4 Oct 2026 · github.com
Installation
The README gives a GitHub-based npm install command and a quick start that serves the API at localhost:3000/api.Read 5 Oct 2026 · github.com
Integration
The project can run as a command-line server or be imported programmatically as an application or Express router.Read 5 Oct 2026 · github.com
Intended use
The README describes using it to mock services while prototyping a single-page application without a working backend.Read 4 Oct 2026 · github.com
Maker location
The Intesys GitHub organization profile lists Italy as its location.Read 4 Oct 2026 · github.com
Mock formats
Mocks can be JSON files, JavaScript modules, or Express middleware.Read 4 Oct 2026 · github.com
Mocking
Mocks can be JSON files, JavaScript modules, or Express middleware, and mocks are enabled by default.Read 5 Oct 2026 · github.com
Multiple specifications
It supports multiple specification files and directories and checks paths and methods for conflicts.Read 4 Oct 2026 · github.com
Notable limits
JavaScript mocks must run at runtime; the README says TypeScript mock files are not allowed because they cannot be transpiled at runtime.Read 4 Oct 2026 · github.com
OpenAPI support
It validates OpenAPI version 3 and Swagger version 2 specifications in YAML format.Read 5 Oct 2026 · github.com
Other features
The README lists a static file server, HTTP and HTTPS support, watch mode, and configuration through environment variables, files, or CLI parameters.Read 4 Oct 2026 · github.com
Proxy
When proxying is enabled, valid requests without a matching mock are forwarded to the configured backend.Read 5 Oct 2026 · github.com
Proxy and validation
It can proxy requests to another server and optionally validate responses.Read 4 Oct 2026 · github.com
Publishing security
The README says releases use npm Trusted Publishing with GitHub Actions OIDC and provenance.Read 5 Oct 2026 · github.com
Response validation
The server can optionally validate responses.Read 5 Oct 2026 · github.com
Runtime requirement
The package declares Node.js version 18 or later as its engine requirement.Read 5 Oct 2026 · github.com
Use case
The README describes using it to develop a single-page application before its backend is ready and to run end-to-end tests with predictable API responses.Read 5 Oct 2026 · github.com

Where Specifiction places it

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