GitLab API | GitLab

  • Available API resources
  • SCIM
  • Road to GraphQL
  • Compatibility guidelines

    • Current status
  • Basic usage
  • Authentication

    • OAuth2 tokens
    • Personal access tokens
    • Session cookie
    • Impersonation tokens

      • Disable impersonation
    • Sudo
  • Status codes
  • Pagination

    • Pagination Link header
    • Other pagination headers
  • Namespaced path encoding
  • Branches and tags name encoding
  • Encoding API parameters of array and hash types

    • array
    • hash
    • Array of hashes
  • id vs iid
  • Data validation and error reporting
  • Unknown route
  • Encoding + in ISO 8601 dates
  • Clients
  • Rate limits

Automate GitLab via a simple and powerful API.

The main GitLab API is a REST API. Therefore, documentation in this section assumes knowledge of REST concepts.

Available API resources

For a list of the available resources and their endpoints, see
API resources.

SCIM

GitLab.com Silver and above provides an SCIM API that implements the RFC7644 protocol and provides
the /Users endpoint. The base URL is: /api/scim/v2/groups/:group_path/Users/.

Road to GraphQL

GraphQL is available in GitLab, which will
allow deprecation 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.

Although there were some patenting and licensing concerns with GraphQL, these
have been resolved to our satisfaction by the relicensing of the reference
implementations under MIT, and the use of the OWF license for the GraphQL
specification.

Compatibility guidelines

The HTTP API is versioned using a single number, the current one being 4. This
number symbolizes the same as the major version number as described by
SemVer. This mean that backward incompatible changes
will require this version number to change. However, the minor version is
not explicit. This allows for a stable API endpoint, but also means new
features can be added to the API in the same version number.

New features and bug fixes are released in tandem with a new GitLab, and apart
from incidental patch and security releases, are released on the 22nd of each
month. Backward incompatible changes (e.g. endpoints removal, parameters
removal etc.), as well as removal of entire API versions are done in tandem
with a major point release of GitLab itself. All deprecations and changes
between two versions should be listed in the documentation. For the changes
between v3 and v4; please read the v3 to v4 documentation

Current status

Currently only API version v4 is available. Version v3 was removed in
GitLab 11.0.

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.

Example of a valid API request using cURL:

curl “https://gitlab.example.com/api/v4/projects”

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, or will only return public data when
authentication is not provided. 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 ways to authenticate with the GitLab API:

  1. OAuth2 tokens
  2. Personal access tokens
  3. Session cookie

For admins who want to authenticate with the API as a specific user, or who want to build applications or scripts that do so, two options are available:

  1. Impersonation tokens
  2. Sudo

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

{
“message”: “401 Unauthorized”
}

OAuth2 tokens

You can use an OAuth2 token to authenticate with the API by passing it in either the
access_token parameter or the Authorization header.

Example of using the OAuth2 token in a parameter:

curl https://gitlab.example.com/api/v4/projects?access_token=OAUTH-TOKEN

Example of using the OAuth2 token in a header:

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

Read more about GitLab as an OAuth2 provider.

Personal access tokens

You can use a personal access token to authenticate with the API by passing it in either the
private_token parameter or the Private-Token header.

Example of using the personal access token in a parameter:

curl https://gitlab.example.com/api/v4/projects?private_token=<your_access_token>

Example of using the personal access token in a header:

curl –header “Private-Token: <your_access_token>” https://gitlab.example.com/api/v4/projects

You can also use personal access tokens with OAuth-compliant headers:

curl –header “Authorization: Bearer <your_access_token>” https://gitlab.example.com/api/v4/projects

Read more about personal access tokens.

Session cookie

When signing in to the main GitLab application, 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.

The primary user of this authentication method is the web frontend of GitLab itself,
which can use the API as the authenticated user to get a list of their projects,
for example, without needing to explicitly pass an access token.

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 great fit
if you want to build applications or scripts that authenticate with the API as a specific user.

They are an alternative to directly using the user’s password or one of their
personal access tokens, and to using the Sudo feature, since the user’s (or admin’s, in the case of Sudo)
password/token may not be known or may change over time.

For more information, refer to the
users API docs.

Impersonation tokens are used exactly like regular personal access tokens, and can be passed in either the
private_token parameter or the Private-Token header.

Disable impersonation

Introduced in GitLab
11.6.

By default, impersonation is enabled. To disable impersonation:

For Omnibus installations

  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails[‘impersonation_enabled’] = false

  2. Save the file and reconfigure
    GitLab for the changes to take effect.

To re-enable impersonation, remove this configuration and reconfigure GitLab.

For installations from source

  1. Edit config/gitlab.yml:

    gitlab:
    impersonation_enabled: false

  2. Save the file and restart
    GitLab for the changes to take effect.

To re-enable impersonation, remove this configuration and restart GitLab.

Sudo

All API requests support performing an API call as if you were another user,
provided you are authenticated as an administrator with an OAuth or Personal Access Token that has the sudo scope.

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.

Note:
Usernames are case insensitive.

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

{
“message”: “403 Forbidden – Must be admin to use sudo”
}

If an access token without the sudo scope is provided, an error message will
be returned with status code 403:

{
“error”: “insufficient_scope”,
“error_description”: “The request requires higher privileges than provided by the access token.”,
“scope”: “sudo”
}

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

{
“message”: “404 User with ID or username ‘123’ Not Found”
}

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

GET /projects?private_token=<your_access_token>&sudo=username

curl –header “Private-Token: <your_access_token>” –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=<your_access_token>&sudo=23

curl –header “Private-Token: <your_access_token>” –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 Return 200 OK if the resource is accessed or modified successfully. The (modified) result is returned as JSON.
DELETE Returns 204 No Content if the resource was deleted successfully.

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.
412 Indicates the request was denied. May happen if the If-Unmodified-Since header is provided when trying to delete a resource, which was modified in between.
422 Unprocessable The entity could not be processed.
500 Server Error While handling the request something went wrong server-side.

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: <your_access_token>” “https://gitlab.example.com/api/v4/namespaces?per_page=50

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: <your_access_token>” 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

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

Caution:

For performance reasons since

GitLab 11.8

and

behind the api_kaminari_count_with_limit
feature flag

, if the number of resources is
more than 10,000, the

X-Total

and

X-Total-Pages

headers as well as the

rel=”last” Link

are not present in the response headers.

Namespaced path encoding

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

For example, / is represented by %2F:

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

Note:
A project’s path is not necessarily the same as its name. A
project’s path can found in the project’s URL or in the project’s settings
under General > Advanced > Change path.

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

Encoding API parameters of array and hash types

We can call the API with array and hash types parameters as shown below:

array

import_sources is a parameter of type array:

curl –request POST –header “PRIVATE-TOKEN: <your_access_token>”
-d “import_sources[]=github”
-d “import_sources[]=bitbucket”
“https://gitlab.example.com/api/v4/some_endpoint

hash

override_params is a parameter of type hash:

curl –request POST –header “PRIVATE-TOKEN: <your_access_token>”
–form “namespace=email”
–form “path=impapi”
–form “file=@/path/to/somefile.txt”
–form “override_params[visibility]=private”
–form “override_params[some_other_param]=some_value”
https://gitlab.example.com/api/v4/projects/import

Array of hashes

variables is a parameter of type array containing hash key/value pairs [{ ‘key’ => ‘UPLOAD_TO_S3’, ‘value’ => ‘true’ }]:

curl –globoff –request POST –header “PRIVATE-TOKEN: ********************”
“https://gitlab.example.com/api/v4/projects/169/pipeline?ref=master&variables[][key]=VAR1&variables[][value]=hello&variables[][key]=VAR2&variables[][value]=world”

curl –request POST –header “PRIVATE-TOKEN: ********************”
–header “Content-Type: application/json”
–data ‘{ “ref”: “master”, “variables”: [ {“key”: “VAR1”, “value”: “hello”}, {“key”: “VAR2”, “value”: “world”} ] }’
“https://gitlab.example.com/api/v4/projects/169/pipeline”

id vs iid

Some resources have two similarly-named fields. For example, issues, merge requests, and project milestones. The fields are:

  • id: ID that is unique across all projects.
  • iid: additional, internal ID that is unique in the scope of a single project.

Note:
The iid is displayed in the web UI.

If a resource has the iid field and the id field, the iid field is usually used instead of id to fetch the resource.

For example, suppose a project with id: 42 has an issue with id: 46 and iid: 5. In this case:

  • A valid API call to retrieve the issue is GET /projects/42/issues/5
  • An invalid API call to retrieve the issue is GET /projects/42/issues/46.

Note:
Not all resources with the iid field are fetched by iid. For guidance on which field to use, see the documentation for the specific resource.

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”
}

Encoding + in ISO 8601 dates

If you need to include a + in a query parameter, you may need to use %2B instead due
to a W3 recommendation that
causes a + to be interpreted as a space. For example, in an ISO 8601 date, you may want to pass
a time in Mountain Standard Time, such as:

2017-10-17T23:11:13.000+05:30

The correct encoding for the query parameter would be:

2017-10-17T23:11:13.000%2B05:30

Clients

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

Rate limits

For administrator documentation on rate limit settings, see
Rate limits. To find the settings that are
specifically used by GitLab.com, see
GitLab.com-specific rate limits.

Source

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