Automatic token authentication

About the GITHUB_TOKEN secret

At the start of each workflow run, GitHub automatically creates a unique GITHUB_TOKEN secret to use in your workflow. You can use the GITHUB_TOKEN to authenticate in a workflow run.

When you enable GitHub Actions, GitHub installs a GitHub App on your repository. The GITHUB_TOKEN secret is a GitHub App installation access token. You can use the installation access token to authenticate on behalf of the GitHub App installed on your repository. The token's permissions are limited to the repository that contains your workflow. For more information, see "Permissions for the GITHUB_TOKEN."

Before each job begins, GitHub fetches an installation access token for the job. The GITHUB_TOKEN expires when a job finishes or after a maximum of 24 hours.

The token is also available in the github.token context. For more information, see "Contexts."

Using the GITHUB_TOKEN in a workflow

You can use the GITHUB_TOKEN by using the standard syntax for referencing secrets: ${{ secrets.GITHUB_TOKEN }}. Examples of using the GITHUB_TOKEN include passing the token as an input to an action, or using it to make an authenticated GitHub Enterprise Server API request.

When you use the repository's GITHUB_TOKEN to perform tasks, events triggered by the GITHUB_TOKEN will not create a new workflow run. This prevents you from accidentally creating recursive workflow runs. For example, if a workflow run pushes code using the repository's GITHUB_TOKEN, a new workflow will not run even when the repository contains a workflow configured to run when push events occur.

Commits pushed by a GitHub Actions workflow that uses the GITHUB_TOKEN do not trigger a GitHub Pages build.

Example 1: passing the GITHUB_TOKEN as an input

This example workflow uses the labeler action, which requires the GITHUB_TOKEN as the value for the repo-token input parameter:

name: Pull request labeler
on: [ pull_request_target ]

jobs:
  triage:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
    steps:
      - uses: actions/labeler@v3
        with:
          repo-token: ${{ secrets.GITHUB_TOKEN }}

Example 2: calling the REST API

You can use the GITHUB_TOKEN to make authenticated API calls. This example workflow creates an issue using the GitHub REST API:

name: Create issue on commit

on: [ push ]

jobs:
  create_issue:
    runs-on: ubuntu-latest
    permissions:
      issues: write
    steps:
      - name: Create issue using REST API
        run: |
          curl --request POST \
          --url http(s)://HOSTNAME/api/v3/repos/${{ github.repository }}/issues \
          --header 'authorization: Bearer ${{ secrets.GITHUB_TOKEN }}' \
          --header 'content-type: application/json' \
          --data '{
            "title": "Automated issue for commit: ${{ github.sha }}",
            "body": "This issue was automatically created by the GitHub Action workflow **${{ github.workflow }}**. \n\n The commit hash was: _${{ github.sha }}_."
            }' \
          --fail

Permissions for the GITHUB_TOKEN

For information about the API endpoints GitHub Apps can access with each permission, see "Permissions required for GitHub Apps."

The following table shows the permissions granted to the GITHUB_TOKEN by default. People with admin permissions to an organization or repository can set the default permissions to be either permissive or restricted. For information on how to set the default permissions for the GITHUB_TOKEN for your enterprise, organization, or repository, see "Enforcing policies for GitHub Actions in your enterprise," "Disabling or limiting GitHub Actions for your organization," or "Managing GitHub Actions settings for a repository."

Modifying the permissions for the GITHUB_TOKEN

You can modify the permissions for the GITHUB_TOKEN in individual workflow files. If the default permissions for the GITHUB_TOKEN are restrictive, you may have to elevate the permissions to allow some actions and commands to run successfully. If the default permissions are permissive, you can edit the workflow file to remove some permissions from the GITHUB_TOKEN. As a good security practice, you should grant the GITHUB_TOKEN the least required access.

You can see the permissions that GITHUB_TOKEN had for a specific job in the "Set up job" section of the workflow run log. For more information, see "Using workflow run logs."

You can use the permissions key in your workflow file to modify permissions for the GITHUB_TOKEN for an entire workflow or for individual jobs. This allows you to configure the minimum required permissions for a workflow or job. When the permissions key is used, all unspecified permissions are set to no access, with the exception of the metadata scope, which always gets read access.

You can use the permissions key to add and remove read permissions for forked repositories, but typically you can't grant write access. The exception to this behavior is where an admin user has selected the Send write tokens to workflows from pull requests option in the GitHub Actions settings. For more information, see "Managing GitHub Actions settings for a repository."

The two workflow examples earlier in this article show the permissions key being used at the workflow level, and at the job level. In Example 1 the two permissions are specified for the entire workflow. In Example 2 write access is granted for one scope for a single job.

For full details of the permissions key, see "Workflow syntax for GitHub Actions."

How the permissions are calculated for a workflow job

The permissions for the GITHUB_TOKEN are initially set to the default setting for the enterprise, organization, or repository. If the default is set to the restricted permissions at any of these levels then this will apply to the relevant repositories. For example, if you choose the restricted default at the organization level then all repositories in that organization will use the restricted permissions as the default. The permissions are then adjusted based on any configuration within the workflow file, first at the workflow level and then at the job level. Finally, if the workflow was triggered by a pull request from a forked repository, and the Send write tokens to workflows from pull requests setting is not selected, the permissions are adjusted to change any write permissions to read only.

Granting additional permissions

If you need a token that requires permissions that aren't available in the GITHUB_TOKEN, you can create a GitHub App and generate an installation access token within your workflow. For more information, see "Making authenticated API requests with a GitHub App in a GitHub Actions workflow." Alternatively, you can create a personal access token, store it as a secret in your repository, and use the token in your workfow with the ${{ secrets.SECRET_NAME }} syntax. For more information, see "Managing your personal access tokens" and "Encrypted secrets."

Further reading

• "Resources in the REST API"