Reuse workflows

Learn how to avoid duplication when creating a workflow by reusing existing workflows.

In this article

Creating a reusable workflow

Reusable workflows are YAML-formatted files, very similar to any other workflow file. As with other workflow files, you locate reusable workflows in the .github/workflows directory of a repository. Subdirectories of the workflows directory are not supported.

You can standardize deployments by creating a self-hosted runner group that can only execute a specific reusable workflow. For more information, see Managing access to self-hosted runners using groups.

For a workflow to be reusable, the values for on must include workflow_call:

on:
  workflow_call:

Using inputs and secrets in a reusable workflow

You can define inputs and secrets, which can be passed from the caller workflow and then used within the called workflow. There are three stages to using an input or a secret in a reusable workflow.

  1. In the reusable workflow, use the inputs and secrets keywords to define inputs or secrets that will be passed from a caller workflow.

    on:
  workflow_call:
    inputs:
      config-path:
        required: true
        type: string
    secrets:
      personal_access_token:
        required: true

    For details of the syntax for defining inputs and secrets, see on.workflow_call.inputs and on.workflow_call.secrets.

  2. In the reusable workflow, reference the input or secret that you defined in the on key in the previous step.

    Note

    If the secrets are inherited by using secrets: inherit in the calling workflow, you can reference them even if they are not explicitly defined in the on key. For more information, see Workflow syntax for GitHub Actions.

    jobs:
  reusable_workflow_job:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/labeler@v4
      with:
        repo-token: ${{ secrets.personal_access_token }}
        configuration-path: ${{ inputs.config-path }}

    In the example above, personal_access_token is a secret that's defined at the repository or organization level.

    Warning

    Environment secrets cannot be passed from the caller workflow as on.workflow_call does not support the environment keyword. If you include environment in the reusable workflow at the job level, the environment secret will be used, and not the secret passed from the caller workflow. For more information, see Managing environments for deployment and Workflow syntax for GitHub Actions.

  3. Pass the input or secret from the caller workflow.

    To pass named inputs to a called workflow, use the with keyword in a job. Use the secrets keyword to pass named secrets. For inputs, the data type of the input value must match the type specified in the called workflow (either boolean, number, or string).

    jobs:
  call-workflow-passing-data:
    uses: octo-org/example-repo/.github/workflows/reusable-workflow.yml@main
    with:
      config-path: .github/labeler.yml
    secrets:
      personal_access_token: ${{ secrets.token }}

    Workflows that call reusable workflows in the same organization or enterprise can use the inherit keyword to implicitly pass the secrets.

    jobs:
  call-workflow-passing-data:
    uses: octo-org/example-repo/.github/workflows/reusable-workflow.yml@main
    with:
      config-path: .github/labeler.yml
    secrets: inherit

Example reusable workflow

This reusable workflow file named workflow-B.yml (we'll refer to this later in the example caller workflow) takes an input string and a secret from the caller workflow and uses them in an action.

YAML
name: Reusable workflow example

on:
  workflow_call:
    inputs:
      config-path:
        required: true
        type: string
    secrets:
      token:
        required: true

jobs:
  triage:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/labeler@v4
      with:
        repo-token: ${{ secrets.token }}
        configuration-path: ${{ inputs.config-path }}

Calling a reusable workflow

You call a reusable workflow by using the uses keyword. Unlike when you are using actions within a workflow, you call reusable workflows directly within a job, and not from within job steps.

jobs.<job_id>.uses

You reference reusable workflow files using one of the following syntaxes:

  • {owner}/{repo}/.github/workflows/{filename}@{ref} for reusable workflows in public, internal and private repositories.
  • ./.github/workflows/{filename} for reusable workflows in the same repository.

In the first option, {ref} can be a SHA, a release tag, or a branch name. If a release tag and a branch have the same name, the release tag takes precedence over the branch name. Using the commit SHA is the safest option for stability and security. For more information, see Security hardening for GitHub Actions.

If you use the second syntax option (without {owner}/{repo} and @{ref}) the called workflow is from the same commit as the caller workflow. Ref prefixes such as refs/heads and refs/tags are not allowed. You cannot use contexts or expressions in this keyword.

You can call multiple workflows, referencing each in a separate job.

jobs:
  call-workflow-1-in-local-repo:
    uses: octo-org/this-repo/.github/workflows/workflow-1.yml@172239021f7ba04fe7327647b213799853a9eb89
  call-workflow-2-in-local-repo:
    uses: ./.github/workflows/workflow-2.yml
  call-workflow-in-another-repo:
    uses: octo-org/another-repo/.github/workflows/workflow.yml@v1

Example caller workflow

This workflow file calls two workflow files. The second of these, workflow-B.yml (shown in the example reusable workflow), is passed an input (config-path) and a secret (token).

YAML
name: Call a reusable workflow

on:
  pull_request:
    branches:
      - main

jobs:
  call-workflow:
    uses: octo-org/example-repo/.github/workflows/workflow-A.yml@v1

  call-workflow-passing-data:
    permissions:
      contents: read
      pull-requests: write
    uses: octo-org/example-repo/.github/workflows/workflow-B.yml@main
    with:
      config-path: .github/labeler.yml
    secrets:
      token: ${{ secrets.GITHUB_TOKEN }}

Passing inputs and secrets to a reusable workflow

To pass named inputs to a called workflow, use the with keyword in a job. Use the secrets keyword to pass named secrets. For inputs, the data type of the input value must match the type specified in the called workflow (either boolean, number, or string).

jobs:
  call-workflow-passing-data:
    uses: octo-org/example-repo/.github/workflows/reusable-workflow.yml@main
    with:
      config-path: .github/labeler.yml
    secrets:
      personal_access_token: ${{ secrets.token }}

Workflows that call reusable workflows in the same organization or enterprise can use the inherit keyword to implicitly pass the secrets.

jobs:
  call-workflow-passing-data:
    uses: octo-org/example-repo/.github/workflows/reusable-workflow.yml@main
    with:
      config-path: .github/labeler.yml
    secrets: inherit

Using a matrix strategy with a reusable workflow

Jobs using the matrix strategy can call a reusable workflow.

A matrix strategy lets you use variables in a single job definition to automatically create multiple job runs that are based on the combinations of the variables. For example, you can use a matrix strategy to pass different inputs to a reusable workflow. For more information about matrices, see Running variations of jobs in a workflow.

This example job below calls a reusable workflow and references the matrix context by defining the variable target with the values [dev, stage, prod]. It will run three jobs, one for each value in the variable.

YAML
jobs:
  ReusableMatrixJobForDeployment:
    strategy:
      matrix:
        target: [dev, stage, prod]
    uses: octocat/octo-repo/.github/workflows/deployment.yml@main
    with:
      target: ${{ matrix.target }}

Nesting reusable workflows

You can connect a maximum of four levels of workflows - that is, the top-level caller workflow and up to three levels of reusable workflows. For example: caller-workflow.yml → called-workflow-1.yml → called-workflow-2.yml → called-workflow-3.yml. Loops in the workflow tree are not permitted.

Note

Nested reusable workflows require all workflows in the chain to be accessible to the caller, and permissions can only be maintained or reduced—not elevated—throughout the chain. For more information, see Reusable workflows reference.

From within a reusable workflow you can call another reusable workflow.

YAML
name: Reusable workflow

on:
  workflow_call:

jobs:
  call-another-reusable:
    uses: octo-org/example-repo/.github/workflows/another-reusable.yml@v1

Passing secrets to nested workflows

You can use jobs.<job_id>.secrets in a calling workflow to pass named secrets to a directly called workflow. Alternatively, you can use jobs.<job_id>.secrets.inherit to pass all of the calling workflow's secrets to a directly called workflow. For more information, see the section Reuse workflows above, and the reference article Workflow syntax for GitHub Actions. Secrets are only passed to directly called workflow, so in the workflow chain A > B > C, workflow C will only receive secrets from A if they have been passed from A to B, and then from B to C.

In the following example, workflow A passes all of its secrets to workflow B, by using the inherit keyword, but workflow B only passes one secret to workflow C. Any of the other secrets passed to workflow B are not available to workflow C.

jobs:
  workflowA-calls-workflowB:
    uses: octo-org/example-repo/.github/workflows/B.yml@main
    secrets: inherit # pass all secrets

jobs:
  workflowB-calls-workflowC:
    uses: different-org/example-repo/.github/workflows/C.yml@main
    secrets:
      repo-token: ${{ secrets.personal_access_token }} # pass just this secret

Using outputs from a reusable workflow

A reusable workflow may generate data that you want to use in the caller workflow. To use these outputs, you must specify them as the outputs of the reusable workflow.

If a reusable workflow that sets an output is executed with a matrix strategy, the output will be the output set by the last successful completing reusable workflow of the matrix which actually sets a value. That means if the last successful completing reusable workflow sets an empty string for its output, and the second last successful completing reusable workflow sets an actual value for its output, the output will contain the value of the second last completing reusable workflow.

The following reusable workflow has a single job containing two steps. In each of these steps we set a single word as the output: "hello" and "world." In the outputs section of the job, we map these step outputs to job outputs called: output1 and output2. In the on.workflow_call.outputs section we then define two outputs for the workflow itself, one called firstword which we map to output1, and one called secondword which we map to output2.

The value must be set to the value of a job-level output within the called workflow. Step-level outputs must first be mapped to job-level outputs as shown below.

For more information, see Passing information between jobs and Workflow syntax for GitHub Actions.

YAML
name: Reusable workflow

on:
  workflow_call:
    # Map the workflow outputs to job outputs
    outputs:
      firstword:
        description: "The first output string"
        value: ${{ jobs.example_job.outputs.output1 }}
      secondword:
        description: "The second output string"
        value: ${{ jobs.example_job.outputs.output2 }}

jobs:
  example_job:
    name: Generate output
    runs-on: ubuntu-latest
    # Map the job outputs to step outputs
    outputs:
      output1: ${{ steps.step1.outputs.firstword }}
      output2: ${{ steps.step2.outputs.secondword }}
    steps:
      - id: step1
        run: echo "firstword=hello" >> $GITHUB_OUTPUT
      - id: step2
        run: echo "secondword=world" >> $GITHUB_OUTPUT

We can now use the outputs in the caller workflow, in the same way you would use the outputs from a job within the same workflow. We reference the outputs using the names defined at the workflow level in the reusable workflow: firstword and secondword. In this workflow, job1 calls the reusable workflow and job2 prints the outputs from the reusable workflow ("hello world") to standard output in the workflow log.

YAML
name: Call a reusable workflow and use its outputs

on:
  workflow_dispatch:

jobs:
  job1:
    uses: octo-org/example-repo/.github/workflows/called-workflow.yml@v1

  job2:
    runs-on: ubuntu-latest
    needs: job1
    steps:
      - run: echo ${{ needs.job1.outputs.firstword }} ${{ needs.job1.outputs.secondword }}

For more information on using job outputs, see Workflow syntax for GitHub Actions. If you want to share something other than a variable (e.g. a build artifact) between workflows, see Storing and sharing data from a workflow.

Monitoring which workflows are being used

You can use the GitHub REST API to monitor how reusable workflows are being used. The prepared_workflow_job audit log action is triggered when a workflow job is started. Included in the data recorded are:

  • repo - the organization/repository where the workflow job is located. For a job that calls another workflow, this is the organization/repository of the caller workflow.
  • @timestamp - the date and time that the job was started, in Unix epoch format.
  • job_name - the name of the job that was run.
  • calling_workflow_refs - an array of file paths for all the caller workflows involved in this workflow job. The items in the array are in the reverse order that they were called in. For example, in a chain of workflows A > B > C, when viewing the logs for a job in workflow C, the array would be ["octo-org/octo-repo/.github/workflows/B.yml", "octo-org/octo-repo/.github/workflows/A.yml"].
  • calling_workflow_shas - an array of SHAs for all the caller workflows involved in this workflow job. The array contains the same number of items, in the same order, as the calling_workflow_refs array.
  • job_workflow_ref - the workflow file that was used, in the form {owner}/{repo}/{path}/{filename}@{ref}. For a job that calls another workflow, this identifies the called workflow.

For more information, see Reviewing the audit log for your organization.

Note

Audit data for prepared_workflow_job can only be viewed using the REST API. It is not visible in the GitHub web interface, or included in JSON/CSV exported audit data.

Next steps

To find information on the intricacies of reusing workflows, see Reusable workflows reference.