Memory hook: Automation runs work; an editor changes files; a runtime executes them.
Must remember
GitHub Actions automates repository events through workflows containing jobs and steps. Runners execute jobs; reusable actions package operations. Typical uses include tests, builds, releases and deployment. A workflow's permissions and event trust boundary determine what it can safely do.
Codespaces provides a hosted development environment with compute and terminal access. A dev container definition describes a repeatable environment, including supported tools, extensions and setup. Stop/delete unused resources according to retention and cost requirements; closing a browser tab is not necessarily immediate resource deletion.
The github.dev editor offers lightweight browser editing without the full compute/terminal environment of Codespaces. Choose it for quick edits and reviews; choose Codespaces or local development when you must run builds, tests or services. GitHub Desktop is a local Git client, not a cloud runtime.
Copilot assists with suggestions, chat and supported agent workflows. Agent Mode can plan and modify multiple files or invoke permitted tools; a coding agent can work through a delegated development workflow. Both need clear tasks, limited permissions, review and tests. Model selection changes capabilities and behavior; it does not remove the need to validate output.
Individual plans focus on personal use; Business and Enterprise offerings add organizational administration, policy and eligible capabilities. Plan names/features evolve, so distinguish governance needs from memorizing a transient price. Organization policies can constrain features even when a user has a license. Review generated code for correctness, security, dependencies and licensing implications.
Choose under exam pressure
| Requirement | Choice and reason |
|---|---|
| Quick browser edit without running commands | github.dev. |
| Reproducible remote build/test environment | Codespaces with a dev container. |
| Run tests when a PR changes | An Actions workflow with scoped permissions. |
Traps
- A browser editor is not automatically a compute environment.
- AI-generated code still needs review and tests.
Active recall
1. What executes an Actions job?
A matching available runner.
2. What does a dev container describe?
A repeatable development environment and its supported setup.
3. Codespaces versus github.dev?
Hosted compute/runtime versus lightweight web editing.
4. Why constrain an agent?
It can act across files/tools, so mistakes can have broader effects.
5. Why check organization policy?
A license alone does not guarantee every feature is enabled or allowed.