Use when testing VCL against real Fastly edge infrastructure, writing assertion-based Fiddle tests, producing shareable fiddle URLs for bug reproductions, running VCL integration tests in CI, linting VCL remotely via the Fiddle API, or working with clientFetch/events/originFetches test expressions.
Install
npx skills add fastly/fastly-agent-toolkit --skill fastly-fiddlenpx skills add fastly/fastly-agent-toolkit --skill fastly-fiddle -a claude-code -gnpx skills add fastly/fastly-agent-toolkit --skill fastly-fiddle -a codex -ggemini skills install https://github.com/fastly/fastly-agent-toolkit.git --path skills/fastly-fiddlegh skill install fastly/fastly-agent-toolkit fastly-fiddlegit clone --depth 1 https://github.com/fastly/fastly-agent-toolkit /tmp/fastly__fastly-agent-toolkit
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/fastly__fastly-agent-toolkit/skills/fastly-fiddle ~/.claude/skills/fastly-fiddle # Claude Code
cp -R /tmp/fastly__fastly-agent-toolkit/skills/fastly-fiddle ~/.agents/skills/fastly-fiddle # Codex, Cursor, Gemini CLI, Copilot, OpenCode