gitlab-org--gitlab-foss/doc/api

GitLab API

Automate GitLab via a simple and powerful API. All definitions can be found under /lib/api.

Resources

Documentation for various API resources can be found separately in the following locations:

• Award Emoji
• Branches
• Broadcast Messages
• Project-level Variables
• Group-level Variables
• Commits
• Deployments
• Deploy Keys
• Environments
• Events
• Feature flags
• Gitignores templates
• GitLab CI Config templates
• Groups
• Group Access Requests
• Group Members
• Issues
• Issue Boards
• Jobs
• Keys
• Labels
• Merge Requests
• Project milestones
• Group milestones
• Namespaces
• Notes (comments)
• Notification settings
• Open source license templates
• Pipelines
• Pipeline Triggers
• Pipeline Schedules
• Projects including setting Webhooks
• Project Access Requests
• Project Members
• Project Snippets
• Protected Branches
• Repositories
• Repository Files
• Runners
• Services
• Session
• Settings
• Sidekiq metrics
• System Hooks
• Tags
• Todos
• Users
• Validate CI configuration
• V3 to V4
• Version

Road to GraphQL

Going forward, we will start on moving to GraphQL and deprecate the use of controller-specific endpoints. GraphQL has a number of benefits:

1. We avoid having to maintain two different APIs.
2. Callers of the API can request only what they need.
3. It is versioned by default.

It will co-exist with the current v4 REST API. If we have a v5 API, this should be a compatibility layer on top of GraphQL.

Basic usage

API requests should be prefixed with api and the API version. The API version is defined in lib/api.rb. For example, the root of the v4 API is at /api/v4.

For endpoints that require authentication, you need to pass a private_token parameter via query string or header. If passed as a header, the header name must be PRIVATE-TOKEN (uppercase and with a dash instead of an underscore).

Example of a valid API request:

GET /projects?private_token=9koXpg98eAheJpvBs5tK

Example of a valid API request using cURL and authentication via header:

curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects"

Example of a valid API request using cURL and authentication via a query string:

curl "https://gitlab.example.com/api/v4/projects?private_token=9koXpg98eAheJpvBs5tK"

The API uses JSON to serialize data. You don't need to specify .json at the end of an API URL.

Authentication

Most API requests require authentication via a session cookie or token. For those cases where it is not required, this will be mentioned in the documentation for each individual endpoint. For example, the /projects/:id endpoint.

There are three types of access tokens available:

1. OAuth2 tokens
2. Private tokens
3. Personal access tokens

If authentication information is invalid or omitted, an error message will be returned with status code 401:

{
  "message": "401 Unauthorized"
}

Session cookie

When signing in to GitLab as an ordinary user, a _gitlab_session cookie is set. The API will use this cookie for authentication if it is present, but using the API to generate a new session cookie is currently not supported.

OAuth2 tokens

You can use an OAuth 2 token to authenticate with the API by passing it either in the access_token parameter or in the Authorization header.

Example of using the OAuth2 token in the header:

curl --header "Authorization: Bearer OAUTH-TOKEN" https://gitlab.example.com/api/v4/projects

Read more about GitLab as an OAuth2 client.

Private tokens

Private tokens provide full access to the GitLab API. Anyone with access to them can interact with GitLab as if they were you. You can find or reset your private token in your account page (/profile/account).

For examples of usage, read the basic usage section.

Personal access tokens

Instead of using your private token which grants full access to your account, personal access tokens could be a better fit because of their granular permissions.

Once you have your token, pass it to the API using either the private_token parameter or the PRIVATE-TOKEN header. For examples of usage, read the basic usage section.

Read more about personal access tokens.

Impersonation tokens

Introduced in GitLab 9.0. Needs admin permissions.

Impersonation tokens are a type of personal access token that can only be created by an admin for a specific user.

They are a better alternative to using the user's password/private token or using the Sudo feature which also requires the admin's password or private token, since the password/token can change over time. Impersonation tokens are a great fit if you want to build applications or tools which authenticate with the API as a specific user.

For more information, refer to the users API docs.

For examples of usage, read the basic usage section.

Sudo

Needs admin permissions.

All API requests support performing an API call as if you were another user, provided your private token is from an administrator account. You need to pass the sudo parameter either via query string or a header with an ID/username of the user you want to perform the operation as. If passed as a header, the header name must be SUDO (uppercase).

If a non administrative private_token is provided, then an error message will be returned with status code 403:

{
  "message": "403 Forbidden - Must be admin to use sudo"
}

If the sudo user ID or username cannot be found, an error message will be returned with status code 404:

{
  "message": "404 Not Found: No user id or username for: <id/username>"
}

---

Example of a valid API call and a request using cURL with sudo request, providing a username:

GET /projects?private_token=9koXpg98eAheJpvBs5tK&sudo=username

curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" --header "SUDO: username" "https://gitlab.example.com/api/v4/projects"

Example of a valid API call and a request using cURL with sudo request, providing an ID:

GET /projects?private_token=9koXpg98eAheJpvBs5tK&sudo=23

curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" --header "SUDO: 23" "https://gitlab.example.com/api/v4/projects"

Status codes

The API is designed to return different status codes according to context and action. This way, if a request results in an error, the caller is able to get insight into what went wrong.

The following table gives an overview of how the API functions generally behave.

Request type	Description
GET	Access one or more resources and return the result as JSON.
POST	Return 201 Created if the resource is successfully created and return the newly created resource as JSON.
GET / PUT / DELETE	Return 200 OK if the resource is accessed, modified or deleted successfully. The (modified) result is returned as JSON.
DELETE	Designed to be idempotent, meaning a request to a resource still returns 200 OK even it was deleted before or is not available. The reasoning behind this, is that the user is not really interested if the resource existed before or not.

The following table shows the possible return codes for API requests.

Return values	Description
200 OK	The GET, PUT or DELETE request was successful, the resource(s) itself is returned as JSON.
204 No Content	The server has successfully fulfilled the request and that there is no additional content to send in the response payload body.
201 Created	The POST request was successful and the resource is returned as JSON.
304 Not Modified	Indicates that the resource has not been modified since the last request.
400 Bad Request	A required attribute of the API request is missing, e.g., the title of an issue is not given.
401 Unauthorized	The user is not authenticated, a valid user token is necessary.
403 Forbidden	The request is not allowed, e.g., the user is not allowed to delete a project.
404 Not Found	A resource could not be accessed, e.g., an ID for a resource could not be found.
405 Method Not Allowed	The request is not supported.
409 Conflict	A conflicting resource already exists, e.g., creating a project with a name that already exists.
422 Unprocessable	The entity could not be processed.
500 Server Error	While handling the request something went wrong server-side.

Pagination

Sometimes the returned result will span across many pages. When listing resources you can pass the following parameters:

Parameter	Description
page	Page number (default: 1)
per_page	Number of items to list per page (default: 20, max: 100)

In the example below, we list 50 namespaces per page.

curl --request PUT --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/namespaces?per_page=50

Pagination Link header

Link headers are sent back with each response. They have rel set to prev/next/first/last and contain the relevant URL. Please use these links instead of generating your own URLs.

In the cURL example below, we limit the output to 3 items per page (per_page=3) and we request the second page (page=2) of comments of the issue with ID 8 which belongs to the project with ID 8:

curl --head --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/projects/8/issues/8/notes?per_page=3&page=2

The response will then be:

HTTP/1.1 200 OK
Cache-Control: no-cache
Content-Length: 1103
Content-Type: application/json
Date: Mon, 18 Jan 2016 09:43:18 GMT
Link: <https://gitlab.example.com/api/v4/projects/8/issues/8/notes?page=1&per_page=3>; rel="prev", <https://gitlab.example.com/api/v4/projects/8/issues/8/notes?page=3&per_page=3>; rel="next", <https://gitlab.example.com/api/v4/projects/8/issues/8/notes?page=1&per_page=3>; rel="first", <https://gitlab.example.com/api/v4/projects/8/issues/8/notes?page=3&per_page=3>; rel="last"
Status: 200 OK
Vary: Origin
X-Next-Page: 3
X-Page: 2
X-Per-Page: 3
X-Prev-Page: 1
X-Request-Id: 732ad4ee-9870-4866-a199-a9db0cde3c86
X-Runtime: 0.108688
X-Total: 8
X-Total-Pages: 3

Other pagination headers

Additional pagination headers are also sent back.

Header	Description
X-Total	The total number of items
X-Total-Pages	The total number of pages
X-Per-Page	The number of items per page
X-Page	The index of the current page (starting at 1)
X-Next-Page	The index of the next page
X-Prev-Page	The index of the previous page

Namespaced path encoding

If using namespaced API calls, make sure that the NAMESPACE/PROJECT_NAME is URL-encoded.

For example, / is represented by %2F:

GET /api/v4/projects/diaspora%2Fdiaspora

Branches & tags name encoding

If your branch or tag contains a /, make sure the branch/tag name is URL-encoded.

For example, / is represented by %2F:

GET /api/v4/projects/1/branches/my%2Fbranch/commits

id vs iid

When you work with the API, you may notice two similar fields in API entities: id and iid. The main difference between them is scope.

For example, an issue might have id: 46 and iid: 5.

Parameter	Description
id	Is unique across all issues and is used for any API call
iid	Is unique only in scope of a single project. When you browse issues or merge requests with the Web UI, you see the iid

That means that if you want to get an issue via the API you should use the id:

GET /projects/42/issues/:id

On the other hand, if you want to create a link to a web page you should use the iid:

GET /projects/42/issues/:iid

Data validation and error reporting

When working with the API you may encounter validation errors, in which case the API will answer with an HTTP 400 status.

Such errors appear in two cases:

• A required attribute of the API request is missing, e.g., the title of an issue is not given
• An attribute did not pass the validation, e.g., user bio is too long

When an attribute is missing, you will get something like:

HTTP/1.1 400 Bad Request
Content-Type: application/json
{
    "message":"400 (Bad request) \"title\" not given"
}

When a validation error occurs, error messages will be different. They will hold all details of validation errors:

HTTP/1.1 400 Bad Request
Content-Type: application/json
{
    "message": {
        "bio": [
            "is too long (maximum is 255 characters)"
        ]
    }
}

This makes error messages more machine-readable. The format can be described as follows:

{
    "message": {
        "<property-name>": [
            "<error-message>",
            "<error-message>",
            ...
        ],
        "<embed-entity>": {
            "<property-name>": [
                "<error-message>",
                "<error-message>",
                ...
            ],
        }
    }
}

Unknown route

When you try to access an API URL that does not exist you will receive 404 Not Found.

HTTP/1.1 404 Not Found
Content-Type: application/json
{
    "error": "404 Not Found"
}

Clients

There are many unofficial GitLab API Clients for most of the popular programming languages. Visit the GitLab website for a complete list.