json-server

What json-server is

json-server creates a fake REST API from a JSON data file, giving developers a local endpoint for testing and prototyping without writing API code. It reads `db.json` or `db.json5` and starts a server at `http://localhost:3000`. Array resources support GET, POST, PUT, PATCH and DELETE requests; object resources support GET, PUT and PATCH. Requests can filter by comparison operators, membership, case-insensitive string matching and nested fields. Results can also be sorted and paginated with `_page` and `_per_page`, with a documented default page size of 10. Use `_embed` to include related resources, or `_dependent` with DELETE requests for dependents. json-server serves files from `./public` by default and can serve other directories supplied with `-s`. The package is installed with npm and its package metadata requires Node.js >=22.12.0. It is an MIT-licensed, open-source package available for free. The displayed v1 documentation is marked beta and warns that breaking changes are expected.

Who it suits

json-server suits developers who need a local REST API backed by JSON data for testing or prototyping. It is also useful when a project needs mock data, dynamic responses, filtering, sorting or pagination without building an API first.

Limits

The displayed v1 documentation is beta and warns users to expect breaking changes. The package metadata requires Node.js >=22.12.0.

Getting started

1. Install the package with npm.
2. Prepare a `db.json` or `db.json5` data file.
3. Run json-server to start the local server at `http://localhost:3000`.
4. Place static files in `./public`, or pass additional directories with `-s`.
5. Use the available routes and query parameters to work with the data.

Verdict

Choose json-server for a free local REST API built from JSON or JSON5 files, with routes and query features for testing and prototyping. Look elsewhere if you need a version with no expected breaking changes or cannot use Node.js >=22.12.0.