poetry lock: Resolve the Lockfile Command Reference

Produce a deterministic lockfile without installing anything.

poetry lock resolves the dependency graph and writes poetry.lock without installing packages. CI commits the lock so every machine resolves to identical versions.

Common flags / usage

poetry lock -- resolve and write poetry.lock
--no-update -- refresh the lock to match pyproject.toml without upgrading
poetry check --lock -- assert the lock matches pyproject.toml

Example

shell

# CI gate: fail the build if the committed lock is stale
- run: poetry check --lock

In CI

Use "poetry check --lock" as a fast gate that fails when poetry.lock does not match pyproject.toml, without resolving everything from scratch. This catches a forgotten re-lock before merge.

Key takeaways

poetry lock writes a pinned resolution without installing.
--no-update refreshes the lock without upgrading existing pins.
poetry check --lock is a cheap staleness gate for CI.

Related guides

poetry install: Install from Lock Command ReferenceReference for poetry install in CI: installing from poetry.lock, the --no-root, --only, and --no-interaction… poetry add: Add a Dependency Command ReferenceReference for poetry add in CI and dev: adding a dependency to pyproject.toml and the lock, group and dry-run… poetry run: Run in the Project Env Command ReferenceReference for poetry run in CI: executing a command inside the project virtualenv without activating it, comm…