chainsaw yarn

Run yarn through Chainsaw — refuse malicious/typosquatted packages at install time

chainsaw yarn [args...]

Run yarn with an install-time supply-chain check in front of it.

Chainsaw evaluates the packages yarn would install, refuses on a hit, and otherwise hands off to the real yarn with your arguments untouched. Anything that is not an install verb (yarn build, yarn run, …) delegates immediately.

Guarded: yarn add, yarn global add, yarn install and a bare yarn. yarn install (or a bare yarn) scans the resolved lockfile, yarn.lock first.

Offline by default. The bundled checks — typosquat detection and a known-malicious floor — run entirely on your machine and send nothing. For the full OpenSSF malicious-packages feed, run the opt-in chainsaw guard update, which is the only networked step. Set CHAINSAW_OFFLINE=1 to refuse network access outright.

Fails open by default: when a signal cannot be evaluated, Chainsaw prints a visible notice and lets the install proceed, so a thin feed never breaks your build. See chainsaw guard coverage to make that fail closed instead.

Exit codes: 0 when the install proceeds (Chainsaw then returns the real tool’s own exit code), 1 when Chainsaw refuses.

--help and every other flag are forwarded to yarn untouched, so chainsaw yarn --help shows yarn’s help, not this text. Use chainsaw help yarn to see this page.

To make the check automatic, add the shell shims: eval "$(chainsaw guard init)".

Examples

chainsaw yarn add lodash

# scans yarn.lock
chainsaw yarn install

Flags

This command forwards its arguments to the underlying tool unchanged, so it parses no flags of its own. Anything after the command name goes to the wrapped package manager verbatim.