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GitLab

GraphQL API

Getting Started

For those new to the GitLab GraphQL API, see Getting started with GitLab GraphQL API.

Quick Reference

Examples

To work with sample queries that pull data from public projects on GitLab.com, see the menu options in the left-hand documentation menu, under API > GraphQL at https://docs.gitlab.com/ee/api/graphql/.

The Getting started page includes different methods to customize GraphQL queries.

GraphiQL

Explore the GraphQL API using the interactive GraphiQL explorer, or on your self-managed GitLab instance on https://<your-gitlab-site.com>/-/graphql-explorer.

See the GitLab GraphQL overview for more information about the GraphiQL Explorer.

What is GraphQL?

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 client-side GraphQL libraries to consume the API and avoid manual parsing.

Since there's no fixed endpoints and data model, 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.

Deprecation process

Fields marked for removal from the GitLab GraphQL API are first deprecated but still available for at least six releases, and then removed entirely. Removals occur at X.0 and X.6 releases.

For example, a field can be marked as deprecated (but still usable) in %12.7, but can be used until its removal in %13.6. When marked as deprecated, an alternative should be provided if there is one. That gives consumers of the GraphQL API a minimum of six months to update their GraphQL queries.

The process is as follows:

  1. The field is listed as deprecated in GraphQL API Reference.
  2. Removals are announced at least one release prior in the Deprecation Warnings section of the release post (at or prior to X.11 and X.5 releases).
  3. Fields meeting criteria are removed in X.0 or X.6.

NOTE: Fields behind a feature flag and disabled by default are exempt from the deprecation process, and can be removed at any time without notice.

List of removed items

View the fields, enums, and other items we removed from the GraphQL API.

Available queries

The GraphQL API includes the following queries at the root level:

  1. project : Project information, with many of its associations such as issues and merge requests.
  2. group : Basic group information and epics (ULTIMATE) are currently supported.
  3. user : Information about a particular user.
  4. namespace : Within a namespace it is also possible to fetch projects.
  5. currentUser: Information about the currently logged in user.
  6. users: Information about a collection of users.
  7. metaData: Metadata about GitLab and the GraphQL API.
  8. snippets: Snippets visible to the currently logged in user.

New associations and root level objects are constantly being added. See the GraphQL API Reference for up-to-date information.

Root-level queries are defined in app/graphql/types/query_type.rb.

Multiplex queries

GitLab supports batching queries into a single request using apollo-link-batch-http. More information about multiplexed queries is also available for GraphQL Ruby, the library GitLab uses on the backend.

Limits

The following limits apply to the GitLab GraphQL API.

Max page size

By default, connections return at most 100 records ("nodes") per page, and this limit applies to most connections in the API. Particular connections may have different max page size limits that are higher or lower.

Max query complexity

The GitLab GraphQL API scores the complexity of a query. Generally, larger queries will have a higher complexity score. This limit is designed to protect the API from performing queries that could negatively impact its overall performance.

The complexity of a single query is limited to a maximum of:

  • 200 for unauthenticated requests.
  • 250 for authenticated requests.

There is no way to discover the complexity of a query except by exceeding the limit.

If a query exceeds the complexity limit an error message response will be returned.

In general, each field in a query will add 1 to the complexity score, although this can be higher or lower for particular fields. Sometimes the addition of certain arguments may also increase the complexity of a query.

The complexity limits may be revised in future, and additionally, the complexity of a query may be altered.

Request timeout

Requests time out at 30 seconds.

Reference

The GitLab GraphQL reference is available.

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

Machine-readable versions are also available:

Generate updates for documentation

If you've changed the GraphQL schema, you should set up an MR to gain approval of your changes. To generate the required documentation and schema, follow the instructions given in the Rake tasks for developers page.

Be sure to run these commands using the GitLab Development Kit.