GraphQL API

• Introduced in GitLab 11.0 (enabled by feature flag graphql).
• Always enabled in GitLab 12.1.

GraphQL is a query language for APIs that allows clients to request exactly the data they need, making it possible to get all required data in a limited number of requests.

The GraphQL data (fields) can be described in the form of types, allowing clients to use clientside GraphQL libraries to consume the API and avoid manual parsing.

Since there's no fixed endpoints and datamodel, new abilities can be added to the API without creating breaking changes. This allows us to have a versionless API as described in the GraphQL documentation.

Vision

We want the GraphQL API to be the primary means of interacting programmatically with GitLab. To achieve this, it needs full coverage - anything possible in the REST API should also be possible in the GraphQL API.

To help us meet this vision, the frontend should use GraphQL in preference to the REST API for new features.

There are no plans to deprecate the REST API. To reduce the technical burden of supporting two APIs in parallel, they should share implementations as much as possible.

Available queries

A first iteration of a GraphQL API includes the following queries

1. project : Within a project it is also possible to fetch a mergeRequest by IID.
2. group : Basic group information and epics (ULTIMATE) are currently supported.
3. namespace : Within a namespace it is also possible to fetch projects.

Multiplex queries

GitLab supports batching queries into a single request using apollo-link-batch-http. More info about multiplexed queries is also available for graphql-ruby the library GitLab uses on the backend.

Reference

GitLab's GraphQL reference is available.

It is automatically generated from GitLab's GraphQL schema and embedded in a Markdown file.

GraphiQL

The API can be explored by using the GraphiQL IDE, it is available on your instance on gitlab.example.com/-/graphql-explorer.