Commits API

This API operates on repository commits. Read more about GitLab-specific information for commits.

List repository commits

Get a list of repository commits in a project. 

GET /projects/:id/repository/commits
Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
ref_name string no The name of a repository branch, tag or revision range, or if not given the default branch
since string no Only commits after or on this date are returned in ISO 8601 format YYYY-MM-DDTHH:MM:SSZ
until string no Only commits before or on this date are returned in ISO 8601 format YYYY-MM-DDTHH:MM:SSZ
path string no The file path
all boolean no Retrieve every commit from the repository
with_stats boolean no Stats about each commit are added to the response
first_parent boolean no Follow only the first parent commit upon seeing a merge commit
order string no List commits in order. Possible values: default, topo. Defaults to default, the commits are shown in reverse chronological order.
trailers boolean no Parse and include Git trailers for every commit 
curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/5/repository/commits"

Example response: 

[
  {
    "id": "ed899a2f4b50b4370feeea94676502b42383c746",
    "short_id": "ed899a2f4b5",
    "title": "Replace sanitize with escape once",
    "author_name": "Example User",
    "author_email": "user@example.com",
    "authored_date": "2012-09-20T11:50:22+03:00",
    "committer_name": "Administrator",
    "committer_email": "admin@example.com",
    "committed_date": "2012-09-20T11:50:22+03:00",
    "created_at": "2012-09-20T11:50:22+03:00",
    "message": "Replace sanitize with escape once",
    "parent_ids": [
      "6104942438c14ec7bd21c6cd5bd995272b3faff6"
    ],
    "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/ed899a2f4b50b4370feeea94676502b42383c746"
  },
  {
    "id": "6104942438c14ec7bd21c6cd5bd995272b3faff6",
    "short_id": "6104942438c",
    "title": "Sanitize for network graph",
    "author_name": "randx",
    "author_email": "user@example.com",
    "committer_name": "ExampleName",
    "committer_email": "user@example.com",
    "created_at": "2012-09-20T09:06:12+03:00",
    "message": "Sanitize for network graph",
    "parent_ids": [
      "ae1d9fb46aa2b07ee9836d49862ec4e2c46fbbba"
    ],
    "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/ed899a2f4b50b4370feeea94676502b42383c746"
  }
]

Create a commit with multiple files and actions

Introduced in GitLab 8.13.

Create a commit by posting a JSON payload 

POST /projects/:id/repository/commits
Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project
branch string yes Name of the branch to commit into. To create a new branch, also provide either start_branch or start_sha, and optionally start_project.
commit_message string yes Commit message
start_branch string no Name of the branch to start the new branch from
start_sha string no SHA of the commit to start the new branch from
start_project integer/string no The project ID or URL-encoded path of the project to start the new branch from. Defaults to the value of id.
actions[] array yes An array of action hashes to commit as a batch. See the next table for what attributes it can take.
author_email string no Specify the commit author’s email address
author_name string no Specify the commit author’s name
stats boolean no Include commit stats. Default is true
force boolean no When true overwrites the target branch with a new commit based on the start_branch or start_sha
actions[] Attribute Type Required Description
action string yes The action to perform, create, delete, move, update, chmod
file_path string yes Full path to the file. Ex. lib/class.rb
previous_path string no Original full path to the file being moved. Ex. lib/class1.rb. Only considered for move action.
content string no File content, required for all except delete, chmod, and move. Move actions that do not specify content preserve the existing file content, and any other value of content overwrites the file content.
encoding string no text or base64. text is default.
last_commit_id string no Last known file commit ID. Only considered in update, move, and delete actions.
execute_filemode boolean no When true/false enables/disables the execute flag on the file. Only considered for chmod action. 
PAYLOAD=$(cat << 'JSON'
{
  "branch": "master",
  "commit_message": "some commit message",
  "actions": [
    {
      "action": "create",
      "file_path": "foo/bar",
      "content": "some content"
    },
    {
      "action": "delete",
      "file_path": "foo/bar2"
    },
    {
      "action": "move",
      "file_path": "foo/bar3",
      "previous_path": "foo/bar4",
      "content": "some content"
    },
    {
      "action": "update",
      "file_path": "foo/bar5",
      "content": "new content"
    },
    {
      "action": "chmod",
      "file_path": "foo/bar5",
      "execute_filemode": true
    }
  ]
}
JSON
)
curl --request POST --header "PRIVATE-TOKEN: <your_access_token>" --header "Content-Type: application/json" \
     --data "$PAYLOAD" "https://gitlab.example.com/api/v4/projects/1/repository/commits"

Example response: 

{
  "id": "ed899a2f4b50b4370feeea94676502b42383c746",
  "short_id": "ed899a2f4b5",
  "title": "some commit message",
  "author_name": "Example User",
  "author_email": "user@example.com",
  "committer_name": "Example User",
  "committer_email": "user@example.com",
  "created_at": "2016-09-20T09:26:24.000-07:00",
  "message": "some commit message",
  "parent_ids": [
    "ae1d9fb46aa2b07ee9836d49862ec4e2c46fbbba"
  ],
  "committed_date": "2016-09-20T09:26:24.000-07:00",
  "authored_date": "2016-09-20T09:26:24.000-07:00",
  "stats": {
    "additions": 2,
    "deletions": 2,
    "total": 4
  },
  "status": null,
  "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/ed899a2f4b50b4370feeea94676502b42383c746"
}

GitLab supports form encoding. The following is an example using Commit API with form encoding: 

curl --request POST \
     --form "branch=master" \
     --form "commit_message=some commit message" \
     --form "start_branch=master" \
     --form "actions[][action]=create" \
     --form "actions[][file_path]=foo/bar" \
     --form "actions[][content]=</path/to/local.file" \
     --form "actions[][action]=delete" \
     --form "actions[][file_path]=foo/bar2" \
     --form "actions[][action]=move" \
     --form "actions[][file_path]=foo/bar3" \
     --form "actions[][previous_path]=foo/bar4" \
     --form "actions[][content]=</path/to/local1.file" \
     --form "actions[][action]=update" \
     --form "actions[][file_path]=foo/bar5" \
     --form "actions[][content]=</path/to/local2.file" \
     --form "actions[][action]=chmod" \
     --form "actions[][file_path]=foo/bar5" \
     --form "actions[][execute_filemode]=true" \
     --header "PRIVATE-TOKEN: <your_access_token>" \
     "https://gitlab.example.com/api/v4/projects/1/repository/commits"

Get a single commit

Get a specific commit identified by the commit hash or name of a branch or tag. 

GET /projects/:id/repository/commits/:sha

Parameters:

Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit hash or name of a repository branch or tag
stats boolean no Include commit stats. Default is true 
curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/5/repository/commits/master"

Example response: 

{
  "id": "6104942438c14ec7bd21c6cd5bd995272b3faff6",
  "short_id": "6104942438c",
  "title": "Sanitize for network graph",
  "author_name": "randx",
  "author_email": "user@example.com",
  "committer_name": "Dmitriy",
  "committer_email": "user@example.com",
  "created_at": "2012-09-20T09:06:12+03:00",
  "message": "Sanitize for network graph",
  "committed_date": "2012-09-20T09:06:12+03:00",
  "authored_date": "2012-09-20T09:06:12+03:00",
  "parent_ids": [
    "ae1d9fb46aa2b07ee9836d49862ec4e2c46fbbba"
  ],
  "last_pipeline" : {
    "id": 8,
    "ref": "master",
    "sha": "2dc6aa325a317eda67812f05600bdf0fcdc70ab0",
    "status": "created"
  },
  "stats": {
    "additions": 15,
    "deletions": 10,
    "total": 25
  },
  "status": "running",
  "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/6104942438c14ec7bd21c6cd5bd995272b3faff6"
}

Get references a commit is pushed to

Introduced in GitLab 10.6

Get all references (from branches or tags) a commit is pushed to. The pagination parameters page and per_page can be used to restrict the list of references. 

GET /projects/:id/repository/commits/:sha/refs

Parameters:

Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit hash
type string no The scope of commits. Possible values branch, tag, all. Default is all. 
curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/5/repository/commits/5937ac0a7beb003549fc5fd26fc247adbce4a52e/refs?type=all"

Example response: 

[
  {"type": "branch", "name": "'test'"},
  {"type": "branch", "name": "add-balsamiq-file"},
  {"type": "branch", "name": "wip"},
  {"type": "tag", "name": "v1.1.0"}
 ]

Cherry pick a commit

Introduced in GitLab 8.15.

Cherry picks a commit to a given branch. 

POST /projects/:id/repository/commits/:sha/cherry_pick

Parameters:

Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit hash
branch string yes The name of the branch
dry_run boolean no Does not commit any changes. Default is false. Introduced in GitLab 13.3
message string no A custom commit message to use for the new commit. Introduced in GitLab 14.0 
curl --request POST --header "PRIVATE-TOKEN: <your_access_token>" \
     --form "branch=master" "https://gitlab.example.com/api/v4/projects/5/repository/commits/master/cherry_pick"

Example response: 

{
  "id": "8b090c1b79a14f2bd9e8a738f717824ff53aebad",
  "short_id": "8b090c1b",
  "author_name": "Example User",
  "author_email": "user@example.com",
  "authored_date": "2016-12-12T20:10:39.000+01:00",
  "created_at": "2016-12-12T20:10:39.000+01:00",
  "committer_name": "Administrator",
  "committer_email": "admin@example.com",
  "committed_date": "2016-12-12T20:10:39.000+01:00",
  "title": "Feature added",
  "message": "Feature added\n\nSigned-off-by: Example User <user@example.com>\n",
  "parent_ids": [
    "a738f717824ff53aebad8b090c1b79a14f2bd9e8"
  ],
  "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/8b090c1b79a14f2bd9e8a738f717824ff53aebad"
}

In the event of a failed cherry-pick, the response provides context about why: 

{
  "message": "Sorry, we cannot cherry-pick this commit automatically. This commit may already have been cherry-picked, or a more recent commit may have updated some of its content.",
  "error_code": "empty"
}

In this case, the cherry-pick failed because the changeset was empty and likely indicates that the commit already exists in the target branch. The other possible error code is conflict, which indicates that there was a merge conflict.

When dry_run is enabled, the server attempts to apply the cherry-pick but not actually commit any resulting changes. If the cherry-pick applies cleanly, the API responds with 200 OK: 

{
  "dry_run": "success"
}

In the event of a failure, an error displays that is identical to a failure without dry run.

Revert a commit

Introduced in GitLab 11.5.

Reverts a commit in a given branch. 

POST /projects/:id/repository/commits/:sha/revert

Parameters:

Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project
sha string yes Commit SHA to revert
branch string yes Target branch name
dry_run boolean no Does not commit any changes. Default is false. Introduced in GitLab 13.3 
curl --request POST --header "PRIVATE-TOKEN: <your_access_token>" --form "branch=master" \
     "https://gitlab.example.com/api/v4/projects/5/repository/commits/a738f717824ff53aebad8b090c1b79a14f2bd9e8/revert"

Example response: 

{
  "id":"8b090c1b79a14f2bd9e8a738f717824ff53aebad",
  "short_id": "8b090c1b",
  "title":"Revert \"Feature added\"",
  "created_at":"2018-11-08T15:55:26.000Z",
  "parent_ids":["a738f717824ff53aebad8b090c1b79a14f2bd9e8"],
  "message":"Revert \"Feature added\"\n\nThis reverts commit a738f717824ff53aebad8b090c1b79a14f2bd9e8",
  "author_name":"Administrator",
  "author_email":"admin@example.com",
  "authored_date":"2018-11-08T15:55:26.000Z",
  "committer_name":"Administrator",
  "committer_email":"admin@example.com",
  "committed_date":"2018-11-08T15:55:26.000Z",
  "web_url": "https://gitlab.example.com/thedude/gitlab-foss/-/commit/8b090c1b79a14f2bd9e8a738f717824ff53aebad"
}

In the event of a failed revert, the response provides context about why: 

{
  "message": "Sorry, we cannot revert this commit automatically. This commit may already have been reverted, or a more recent commit may have updated some of its content.",
  "error_code": "conflict"
}

In this case, the revert failed because the attempted revert generated a merge conflict. The other possible error code is empty, which indicates that the changeset was empty, likely due to the change having already been reverted.

When dry_run is enabled, the server attempts to apply the revert but not actually commit any resulting changes. If the revert applies cleanly, the API responds with 200 OK: 

{
  "dry_run": "success"
}

In the event of a failure, an error displays that is identical to a failure without dry run.

Get the diff of a commit

Get the diff of a commit in a project. 

GET /projects/:id/repository/commits/:sha/diff

Parameters:

Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit hash or name of a repository branch or tag 
curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/5/repository/commits/master/diff"

Example response: 

[
  {
    "diff": "--- a/doc/update/5.4-to-6.0.md\n+++ b/doc/update/5.4-to-6.0.md\n@@ -71,6 +71,8 @@\n sudo -u git -H bundle exec rake migrate_keys RAILS_ENV=production\n sudo -u git -H bundle exec rake migrate_inline_notes RAILS_ENV=production\n \n+sudo -u git -H bundle exec rake gitlab:assets:compile RAILS_ENV=production\n+\n ```\n \n ### 6. Update config files",
    "new_path": "doc/update/5.4-to-6.0.md",
    "old_path": "doc/update/5.4-to-6.0.md",
    "a_mode": null,
    "b_mode": "100644",
    "new_file": false,
    "renamed_file": false,
    "deleted_file": false
  }
]

Get the comments of a commit

Get the comments of a commit in a project. 

GET /projects/:id/repository/commits/:sha/comments

Parameters:

Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit hash or name of a repository branch or tag 
curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/5/repository/commits/master/comments"

Example response: 

[
  {
    "note": "this code is really nice",
    "author": {
      "id": 11,
      "username": "admin",
      "email": "admin@local.host",
      "name": "Administrator",
      "state": "active",
      "created_at": "2014-03-06T08:17:35.000Z"
    }
  }
]

Post comment to commit

Adds a comment to a commit.

In order to post a comment in a particular line of a particular file, you must specify the full commit SHA, the path, the line and line_type should be new.

The comment is added at the end of the last commit if at least one of the cases below is valid:

  • the sha is instead a branch or a tag and the line or path are invalid
  • the line number is invalid (does not exist)
  • the path is invalid (does not exist)

In any of the above cases, the response of line, line_type and path is set to null. 

POST /projects/:id/repository/commits/:sha/comments
Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit SHA or name of a repository branch or tag
note string yes The text of the comment
path string no The file path relative to the repository
line integer no The line number where the comment should be placed
line_type string no The line type. Takes new or old as arguments 
curl --request POST --header "PRIVATE-TOKEN: <your_access_token>" \
     --form "note=Nice picture man\!" --form "path=dudeism.md" --form "line=11" --form "line_type=new" \
     "https://gitlab.example.com/api/v4/projects/17/repository/commits/18f3e63d05582537db6d183d9d557be09e1f90c8/comments"

Example response: 

{
   "author" : {
      "web_url" : "https://gitlab.example.com/thedude",
      "avatar_url" : "https://gitlab.example.com/uploads/user/avatar/28/The-Big-Lebowski-400-400.png",
      "username" : "thedude",
      "state" : "active",
      "name" : "Jeff Lebowski",
      "id" : 28
   },
   "created_at" : "2016-01-19T09:44:55.600Z",
   "line_type" : "new",
   "path" : "dudeism.md",
   "line" : 11,
   "note" : "Nice picture man!"
}

Get the discussions of a commit

Get the discussions of a commit in a project. 

GET /projects/:id/repository/commits/:sha/discussions

Parameters:

Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit hash or name of a repository branch or tag 
curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/5/repository/commits/4604744a1c64de00ff62e1e8a6766919923d2b41/discussions"

Example response: 

[
  {
    "id": "4604744a1c64de00ff62e1e8a6766919923d2b41",
    "individual_note": true,
    "notes": [
      {
        "id": 334686748,
        "type": null,
        "body": "I'm the Dude, so that's what you call me.",
        "attachment": null,
        "author" : {
          "id" : 28,
          "name" : "Jeff Lebowski",
          "username" : "thedude",
          "web_url" : "https://gitlab.example.com/thedude",
          "state" : "active",
          "avatar_url" : "https://gitlab.example.com/uploads/user/avatar/28/The-Big-Lebowski-400-400.png"
        },
        "created_at": "2020-04-30T18:48:11.432Z",
        "updated_at": "2020-04-30T18:48:11.432Z",
        "system": false,
        "noteable_id": null,
        "noteable_type": "Commit",
        "resolvable": false,
        "confidential": null,
        "noteable_iid": null,
        "commands_changes": {}
      }
    ]
  }
]

Commit status

In GitLab 8.1 and later, this is the new commit status API.

List the statuses of a commit

List the statuses of a commit in a project. The pagination parameters page and per_page can be used to restrict the list of references. 

GET /projects/:id/repository/commits/:sha/statuses
Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit SHA
ref string no The name of a repository branch or tag or, if not given, the default branch
stage string no Filter by build stage, e.g., test
name string no Filter by job name, e.g., bundler:audit
all boolean no Return all statuses, not only the latest ones 
curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/17/repository/commits/18f3e63d05582537db6d183d9d557be09e1f90c8/statuses"

Example response: 

[
   ...

   {
      "status" : "pending",
      "created_at" : "2016-01-19T08:40:25.934Z",
      "started_at" : null,
      "name" : "bundler:audit",
      "allow_failure" : true,
      "author" : {
         "username" : "thedude",
         "state" : "active",
         "web_url" : "https://gitlab.example.com/thedude",
         "avatar_url" : "https://gitlab.example.com/uploads/user/avatar/28/The-Big-Lebowski-400-400.png",
         "id" : 28,
         "name" : "Jeff Lebowski"
      },
      "description" : null,
      "sha" : "18f3e63d05582537db6d183d9d557be09e1f90c8",
      "target_url" : "https://gitlab.example.com/thedude/gitlab-foss/builds/91",
      "finished_at" : null,
      "id" : 91,
      "ref" : "master"
   },
   {
      "started_at" : null,
      "name" : "test",
      "allow_failure" : false,
      "status" : "pending",
      "created_at" : "2016-01-19T08:40:25.832Z",
      "target_url" : "https://gitlab.example.com/thedude/gitlab-foss/builds/90",
      "id" : 90,
      "finished_at" : null,
      "ref" : "master",
      "sha" : "18f3e63d05582537db6d183d9d557be09e1f90c8",
      "author" : {
         "id" : 28,
         "name" : "Jeff Lebowski",
         "username" : "thedude",
         "web_url" : "https://gitlab.example.com/thedude",
         "state" : "active",
         "avatar_url" : "https://gitlab.example.com/uploads/user/avatar/28/The-Big-Lebowski-400-400.png"
      },
      "description" : null
   },

   ...
]

Post the build status to a commit

Adds or updates a build status of a commit. 

POST /projects/:id/statuses/:sha
Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit SHA
state string yes The state of the status. Can be one of the following: pending, running, success, failed, canceled
ref string no The ref (branch or tag) to which the status refers
name or context string no The label to differentiate this status from the status of other systems. Default value is default
target_url string no The target URL to associate with this status
description string no The short description of the status
coverage float no The total code coverage
pipeline_id integer no The ID of the pipeline to set status. Use in case of several pipeline on same SHA. 
curl --request POST --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/17/statuses/18f3e63d05582537db6d183d9d557be09e1f90c8?state=success"

Example response: 

{
   "author" : {
      "web_url" : "https://gitlab.example.com/thedude",
      "name" : "Jeff Lebowski",
      "avatar_url" : "https://gitlab.example.com/uploads/user/avatar/28/The-Big-Lebowski-400-400.png",
      "username" : "thedude",
      "state" : "active",
      "id" : 28
   },
   "name" : "default",
   "sha" : "18f3e63d05582537db6d183d9d557be09e1f90c8",
   "status" : "success",
   "coverage": 100.0,
   "description" : null,
   "id" : 93,
   "target_url" : null,
   "ref" : null,
   "started_at" : null,
   "created_at" : "2016-01-19T09:05:50.355Z",
   "allow_failure" : false,
   "finished_at" : "2016-01-19T09:05:50.365Z"
}

List Merge Requests associated with a commit

Introduced in GitLab 10.7.

Get a list of Merge Requests related to the specified commit. 

GET /projects/:id/repository/commits/:sha/merge_requests
Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit SHA 
curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/5/repository/commits/af5b13261899fb2c0db30abdd0af8b07cb44fdc5/merge_requests"

Example response: 

[
   {
      "id":45,
      "iid":1,
      "project_id":35,
      "title":"Add new file",
      "description":"",
      "state":"opened",
      "created_at":"2018-03-26T17:26:30.916Z",
      "updated_at":"2018-03-26T17:26:30.916Z",
      "target_branch":"master",
      "source_branch":"test-branch",
      "upvotes":0,
      "downvotes":0,
      "author" : {
        "web_url" : "https://gitlab.example.com/thedude",
        "name" : "Jeff Lebowski",
        "avatar_url" : "https://gitlab.example.com/uploads/user/avatar/28/The-Big-Lebowski-400-400.png",
        "username" : "thedude",
        "state" : "active",
        "id" : 28
      },
      "assignee":null,
      "source_project_id":35,
      "target_project_id":35,
      "labels":[ ],
      "draft":false,
      "work_in_progress":false,
      "milestone":null,
      "merge_when_pipeline_succeeds":false,
      "merge_status":"can_be_merged",
      "sha":"af5b13261899fb2c0db30abdd0af8b07cb44fdc5",
      "merge_commit_sha":null,
      "squash_commit_sha":null,
      "user_notes_count":0,
      "discussion_locked":null,
      "should_remove_source_branch":null,
      "force_remove_source_branch":false,
      "web_url":"http://https://gitlab.example.com/root/test-project/merge_requests/1",
      "time_stats":{
         "time_estimate":0,
         "total_time_spent":0,
         "human_time_estimate":null,
         "human_total_time_spent":null
      }
   }
]

Get GPG signature of a commit

Get the GPG signature from a commit, if it is signed. For unsigned commits, it results in a 404 response. 

GET /projects/:id/repository/commits/:sha/signature

Parameters:

Attribute Type Required Description
id integer/string yes The ID or URL-encoded path of the project owned by the authenticated user
sha string yes The commit hash or name of a repository branch or tag 
curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/projects/1/repository/commits/da738facbc19eb2fc2cef57c49be0e6038570352/signature"

Example response if commit is GPG signed: 

{
  "signature_type": "PGP",
  "verification_status": "verified",
  "gpg_key_id": 1,
  "gpg_key_primary_keyid": "8254AAB3FBD54AC9",
  "gpg_key_user_name": "John Doe",
  "gpg_key_user_email": "johndoe@example.com",
  "gpg_key_subkey_id": null,
  "commit_source": "gitaly"
}

Example response if commit is X.509 signed: 

{
  "signature_type": "X509",
  "verification_status": "unverified",
  "x509_certificate": {
    "id": 1,
    "subject": "CN=gitlab@example.org,OU=Example,O=World",
    "subject_key_identifier": "BC:BC:BC:BC:BC:BC:BC:BC:BC:BC:BC:BC:BC:BC:BC:BC:BC:BC:BC:BC",
    "email": "gitlab@example.org",
    "serial_number": 278969561018901340486471282831158785578,
    "certificate_status": "good",
    "x509_issuer": {
      "id": 1,
      "subject": "CN=PKI,OU=Example,O=World",
      "subject_key_identifier": "AB:AB:AB:AB:AB:AB:AB:AB:AB:AB:AB:AB:AB:AB:AB:AB:AB:AB:AB:AB",
      "crl_url": "http://example.com/pki.crl"
    }
  },
  "commit_source": "gitaly"
}

Example response if commit is unsigned: 

{
  "message": "404 GPG Signature Not Found"
}