Automatic token authentication

About the GITHUB_TOKEN secret

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

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. O GITHUB_TOKEN expira quando um trabalho é concluído ou após, no máximo, 24 horas.

The token is also available in the github.token context. For more information, see Acessar informações contextuais sobre execuções de fluxo de trabalho.

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 API request.

Quando você usar o GITHUB_TOKEN do repositório para executar tarefas, os eventos disparados pelo GITHUB_TOKEN, com exceção de workflow_dispatch e repository_dispatch, não criarão uma execução de fluxo de trabalho. Isso impede que você crie execuções de fluxo de trabalho recursivo. Por exemplo, se uma execução de fluxo de trabalho efetuar push do código usando o GITHUB_TOKEN do repositório, um novo fluxo de trabalho não será executado mesmo quando o repositório contiver um fluxo de trabalho configurado para ser executado quando os eventos do push ocorrerem.

Commits enviados por push por um fluxo de trabalho de GitHub Actions que usa o GITHUB_TOKEN não disparam um build de GitHub Pages.

Example 1: passing the GITHUB_TOKEN as an input

Este exemplo de fluxo de trabalho usa a CLI do GitHub, que requer o GITHUB_TOKEN como o valor para o parâmetro de entrada GH_TOKEN:

name: Open new issue
on: workflow_dispatch

jobs:
  open-issue:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      issues: write
    steps:
      - run: |
          gh issue --repo ${{ github.repository }} \
            create --title "Issue title" --body "Issue body"
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

name: Open new issue
on: workflow_dispatch

jobs:
  open-issue:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      issues: write
    steps:
      - run: |
          gh issue --repo ${{ github.repository }} \
            create --title "Issue title" --body "Issue body"
        env:
          GH_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 https://api.github.com/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 Permissões necessárias para os aplicativos GitHub.

The following table shows the permissions granted to the GITHUB_TOKEN by default. People with admin permissions to an enterprise, 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 Aplicando políticas para o GitHub Actions na sua empresa, Desabilitar ou limitar o GitHub Actions para sua organização, or Gerenciando as configurações do GitHub Actions para um repositório.

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.

Além disso, você pode usar a chave permissions para adicionar e remover permissões de leitura para repositórios com fork, mas normalmente não pode permitir acesso de gravação. A exceção desse comportamento é quando um usuário administrador selecionou a opção Enviar tokens para fluxos de trabalho de solicitações de pull nas configurações do GitHub Actions. Para saber mais, confira Gerenciando as configurações do GitHub Actions para um repositório.

The two workflow examples earlier in this article show the permissions key being used at the job level, as it is best practice to limit the permissions' scope.

For full details of the permissions key, see Sintaxe de fluxo de trabalho para o 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 Fazer solicitações de API autenticadas com um Aplicativo do GitHub em um fluxo de trabalho do GitHub Actions. Alternatively, you can create a personal access token, store it as a secret in your repository, and use the token in your workflow with the ${{ secrets.SECRET_NAME }} syntax. For more information, see Gerenciar seus tokens de acesso pessoal and Using secrets in GitHub Actions.

Further reading

• Limites de taxa para a API REST