> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/oven-sh/bun/llms.txt
> Use this file to discover all available pages before exploring further.

# Lockfile

> Bun's lockfile ensures reproducible installs across machines and over time.

Running `bun install` creates a lockfile called `bun.lock` in the project root. The lockfile records the exact resolved version of every dependency in the tree, ensuring that installs are reproducible across machines and over time.

## Should I commit `bun.lock`?

**Yes.** Committing `bun.lock` to version control ensures that everyone on your team and your CI environment installs the exact same package versions.

## Lockfile format

Bun v1.2 introduced a text-based lockfile (`bun.lock`). Prior to v1.2, the lockfile was a binary file named `bun.lockb`.

The text-based format has several advantages:

* **Human-readable**: you can inspect and review changes in pull requests
* **Diffable**: standard `git diff` works on `bun.lock`
* **Mergeable**: conflicts can be resolved manually

To migrate an existing `bun.lockb` to the new text format:

```bash theme={null}
bun install --save-text-lockfile --frozen-lockfile --lockfile-only
rm bun.lockb
```

## Frozen lockfile

Use `--frozen-lockfile` to install exact versions from `bun.lock` without modifying it. The install will fail if `package.json` and `bun.lock` are out of sync.

```bash theme={null}
bun install --frozen-lockfile
```

This is the recommended flag for CI/CD pipelines. `bun ci` is a convenient alias:

```bash theme={null}
bun ci
```

Configure it permanently in `bunfig.toml`:

```toml theme={null}
[install]
frozenLockfile = true
```

## Generating a lockfile without installing

To resolve dependencies and write `bun.lock` without touching `node_modules`:

```bash theme={null}
bun install --lockfile-only
```

<Note>
  `--lockfile-only` still populates the global install cache with registry metadata and any git or tarball dependencies.
</Note>

## Skipping the lockfile

To install without creating or updating the lockfile:

```bash theme={null}
bun install --no-save
```

## Generating a Yarn-compatible lockfile

To write a Yarn v1-style `yarn.lock` alongside `bun.lock`:

<CodeGroup>
  ```bash theme={null}
  bun install --yarn
  ```

  ```toml theme={null}
  [install.lockfile]
  # only "yarn" is supported
  print = "yarn"
  ```
</CodeGroup>

## Automatic lockfile migration

When `bun install` runs in a project without a `bun.lock`, Bun automatically migrates from existing lockfiles:

* `yarn.lock` (Yarn v1)
* `package-lock.json` (npm)
* `pnpm-lock.yaml` (pnpm v7+)

The original lockfile is preserved. You can remove it manually after verifying the migration.

## Lockfile hash

To inspect the lockfile hash (useful for caching in CI):

```bash theme={null}
bun pm hash          # generate and print the hash
bun pm hash-print    # print the hash stored in bun.lock
bun pm hash-string   # print the string used to compute the hash
```