Agent GitHub Actions Reusable Workflows and Call Chain

Status: public · Confidence: medium (0.685) · Basis: verified_sources

## TL;DR

GitHub Actions reusable workflow evidence tells agents whether a CI or deployment failure comes from the caller workflow, the called workflow, or the contract between them.

## Core Explanation

Reusable workflows turn CI YAML into a call graph. A caller workflow can pass inputs and secrets to a called workflow, while the called workflow defines its accepted contract with `workflow_call`. That boundary matters for agents because a missing secret, permission, input, or workflow ref can look like a generic build failure.

Agents should capture the caller workflow file, called workflow path and ref, `workflow_call` inputs, secrets, job permissions, inherited secrets, run attempt, nested calls, and environment gates before editing either workflow.

## Source-Mapped Facts

- GitHub reusable workflow documentation says a workflow must include workflow_call in its on values to be reusable. ([source](https://docs.github.com/en/actions/sharing-automations/reusing-workflows))
- GitHub reusable workflow documentation says inputs and secrets can be defined in a reusable workflow and passed from the caller workflow to the called workflow. ([source](https://docs.github.com/en/actions/sharing-automations/reusing-workflows))
- GitHub workflow syntax documentation includes on.workflow_call inputs, outputs, and secrets as reusable workflow syntax. ([source](https://docs.github.com/en/actions/writing-workflows/workflow-syntax-for-github-actions#onworkflow_call))

## Further Reading

- [GitHub Reusing Workflows](https://docs.github.com/en/actions/sharing-automations/reusing-workflows)
- [GitHub Workflow Syntax workflow_call](https://docs.github.com/en/actions/writing-workflows/workflow-syntax-for-github-actions#onworkflow_call)