Using an action

Reference an action from a step with uses, pass inputs with with, and give the step an id to read the action's outputs in later steps:

jobs:
  hello:
    steps:
      - uses: global:greet@latest
        id: greeting
        with:
          name: "Workflows"

      - name: Print greeting
        run: echo "${{ .steps.greeting.outputs.message }}"

The action's steps run inline in the hello job, so the "Print greeting" step shares their filesystem and can read the message output.

A step that uses uses must not also set run, upload, or download.

Reference formats

The uses value identifies an action revision. Two equivalent forms are accepted; both require a workspace, an action, and a revision:

<reference>     ::= <resource-name> | <compact>
<resource-name> ::= workspaces/{ws}/actions/{action}/revisions/{rev}
<compact>       ::= {ws}:{action}@{rev}
<rev>           ::= <canonical-id> | "latest"

Intent	Full resource name	Compact
Latest revision	`workspaces/global/actions/greet/revisions/latest`	`global:greet@latest`
Pinned revision	`workspaces/global/actions/greet/revisions/c7cfa2a8`	`global:greet@c7cfa2a8`

A workspace, action, and revision are all required. A value containing / is the full resource name, otherwise it is the compact form.
The revision is either a canonical revision id (returned when you publish; pin it for reproducible runs) or the reserved alias latest (the newest revision, resolved when the step runs). See Publishing and revisions.

Full example

A complete workflow that calls the greet action and uses its output in a later step:

id: hello-workflow
name: Hello

jobs:
  hello:
    steps:
      - uses: global:greet@latest
        id: greeting
        with:
          name: "Workflows"

      - name: Print greeting
        env:
          MESSAGE: ${{ .steps.greeting.outputs.message }}
        run: echo "$MESSAGE"