GitHub Actions Cheat Sheet

Core Philosophy

1. Optimize for syntax recall — Cheat sheets are for quickly reconstructing working YAML under pressure.
2. Group by workflow concern — Triggers, jobs, expressions, matrices, and reusable workflows should be easy to find separately.
3. Show the sharp edges — Contexts, expressions, and if: logic are where most syntax mistakes happen.
4. Prefer minimal working snippets — Dense, copyable examples beat broad prose.
5. Remember CI is a control system — Syntax matters because release safety depends on it.

Quick-Start: Common Problems

"What is the basic workflow shape?"

1. name
2. on
3. jobs
4. runs-on
5. steps -> See references/syntax.md

"How do I add a matrix or conditional?"

Need	Syntax area
matrix builds	strategy.matrix
conditional step/job	if:
expressions	${{ ... }}
-> See references/syntax.md

Decision Trees

Signal	Focus area
need trigger syntax	on:
need job/step structure	jobs: / steps:
need reuse	workflow_call / reusable workflows
need dynamic logic	expressions, contexts, if:

Reference Index

File	Contents
references/syntax.md	GitHub Actions syntax, triggers, jobs, matrices, expressions, contexts, env/secrets, reusable workflows, artifacts, and common snippets