Install Anvil

What you’ll have at the end: a working anvil command built from source, and a real compiled bundle to prove it — no global install, no registry, no network beyond the clone.

Anvil is a pnpm + Turbo monorepo that runs from source. There is no npm i -g anvil; you build the workspace once and call the CLI from its build output (or behind a shell alias). This page is the copy-paste path.

Prerequisites

• Node.js ≥ 22.17 — node --version
• pnpm 10.x — corepack enable && corepack prepare pnpm@latest --activate, or see pnpm.io/installation
• git

That’s the whole list. No database, no Docker, no cloud account — the compiler and its tests run entirely on your machine.

1. Clone, install, build

git clone https://github.com/vamsiramakrishnan/anvil.git
cd anvil
pnpm install
pnpm build

pnpm build compiles every workspace package, including the CLI entrypoint at packages/cli/dist/bin-anvil.js. That file is the anvil command.

2. Make anvil a command

Call the built entrypoint directly, or alias it for the rest of your session:

alias anvil='node packages/cli/dist/bin-anvil.js'
anvil --help

Every command on this site is written as anvil <command>; with the alias in place, they run verbatim.

3. Prove it runs

Don’t take the build’s word for it — compile the bundled payments example and read it back. This is the whole toolchain end to end: parse a spec, classify every operation, write an aligned bundle, and inspect it.

# [docs-tested]
WORK=$(mktemp -d)
# The built CLI answers:
node packages/cli/dist/bin-anvil.js --help >/dev/null
# Compile the bundled payments example into a full bundle:
node packages/cli/dist/bin-anvil.js compile examples/payments/openapi.yaml \
  --manifest examples/payments/anvil.yaml --service payments \
  --out "$WORK/payments" --root "$WORK"
# The bundle is real, and inspect reads every operation's effect and risk:
test -f "$WORK/payments/catalog.json"
node packages/cli/dist/bin-anvil.js inspect "$WORK/payments" >/dev/null
rm -rf "$WORK"

If those commands complete without error, Anvil is installed and working. You just compiled a spec into an aligned CLI + MCP server + skill + hooks bundle and inspected its safety contract.

Sanity-check the whole workspace (optional)

pnpm test        # the full suite, including the tested snippets on this site
pnpm typecheck   # every package typechecks

What next

• Quickstart — the compile → inspect → approve → deploy loop on your own spec.
• Operating Anvil — the progressive-disclosure manual, and the safety rules that keep unapproved operations out of every tool an agent sees.
• Behind a gateway instead of a spec file? Import the estate — the catalog of APIs behind Apigee, Kong, WSO2, MuleSoft, or IBM API Connect — with anvil estate.

If something breaks

• anvil: command not found — the alias is per-shell; re-run the alias line, or call node packages/cli/dist/bin-anvil.js directly.
• A command errors with “cannot find module” under dist/ — the build didn’t finish. Re-run pnpm build and watch for the failing package.
• pnpm version mismatch — this repo pins pnpm via packageManager; corepack enable lets pnpm match it automatically.