Act

What it does

When your agent uses it

• A user asks to test GitHub Actions workflows locally
• Debug a failing CI pipeline
• Inputs to a local run
• Run workflows offline

Example prompts

• “/act”

Requirements

• Docker
• A credential in NPM_TOKEN
• A credential in GITHUB_TOKEN
• Compatibility (from SKILL.md): Docker Engine required (podman is not supported); Linux, macOS, Windows

Workflow steps

5 steps, taken from the step headings in SKILL.md.

1. 1Install
2. 2Pick runner images
3. 3Run
4. 4Secrets, variables, local-only behavior
5. 5Debug

What it can do on your machine

Read from SKILL.md and the folder at commit a021875. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • brew
  • winget
  • choco
  • gh
  • docker

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Hosts in commands or code, which the agent is likely to contact:

  • github.com

  Also links to:

  • nektosact.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names these keys or tokens, usually read from environment variables:

  • GITHUB_TOKEN
  • NPM_TOKEN

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

• Compatibility

  Docker Engine required (podman is not supported); Linux, macOS, Windows

  From compatibility in the SKILL.md frontmatter.

Context cost

Act loads about 1.4k tokens when it runs. Until then it costs about 70 tokens; SKILL.md has 507 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~70

When it runs · the whole SKILL.md, loaded when a task matches

~1.4k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

• NoteMentions a .env fileSKILL.md:38

  --env-file .env

• NoteMentions a .env fileSKILL.md:63

  act --env-file .env                 # plain environment variables

• NoteMentions a .env fileSKILL.md:108

  - Add `.secrets`, `.vars` and `.env` to `.gitignore`; use throwaway values locally, never production credentials.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from TerminalSkills/skills at commit a021875, republished under its Apache-2.0 licence (© TerminalSkills). 507 words, ~1,389 tokens.

name

act

description

Runs GitHub Actions workflows on your own machine in Docker containers with act, so CI can be tested without pushing. Use when a user asks to test GitHub Actions workflows locally, debug a failing CI pipeline, pass secrets or inputs to a local run, or run workflows offline.

compatibility

Docker Engine required (podman is not supported); Linux, macOS, Windows

license

Apache-2.0

metadata.author

terminal-skills

metadata.version

1.2.0

metadata.category

development

metadata.tags

act, github-actions, ci, local, docker

metadata.repository

https://github.com/nektos/act

-P ubuntu-latest=catthehacker/ubuntu:act-latest
--env-file .env
--action-offline-mode

act -l                              # list jobs and their events
act                                 # run the "on: push" workflows
act pull_request                    # run a specific event
act -j test                         # one job (its `needs` jobs run too)
act -W .github/workflows/ci.yml     # one workflow file
act workflow_dispatch --input target=production
act push --matrix node:22          # only matrix entries that include node 22
act -e event.json                   # custom event payload

act --secret-file .secrets          # KEY=value lines; default file is .secrets
act -s NPM_TOKEN                    # take the value from your shell environment
act --var-file .vars                # values for ${{ vars.NAME }}
act --env-file .env                 # plain environment variables

act -n          # dry run: validates and prints the plan without creating containers
act --validate  # check workflow schema
act -g          # draw the job graph
act -v          # verbose logs
act -r          # keep the container after success to inspect state between runs
act --artifact-server-path .artifacts   # enable upload-artifact/download-artifact

printf -- '-P ubuntu-latest=catthehacker/ubuntu:act-latest\n' > .actrc
act -j test --secret-file .secrets -v

printf 'AWS_REGION=eu-west-1\n' > .vars
printf 'NPM_TOKEN=npm_localdummy\n' > .secrets
act workflow_dispatch --input target=production

© TerminalSkills, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file in skills/act of TerminalSkills/skills.

• SKILL.md
• _scores.json

Open the folder on GitHubat commit a021875