> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rigbox.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Build and dependency caching

> Choose the cache mechanism that matches your deployment strategy.

## Incremental dependency outputs

For an incremental app, declare both the files that determine installation and the directories installation creates:

```yaml theme={null}
install: npm ci
dependencyInputs:
  - package.json
  - package-lock.json
dependencyOutputs:
  - node_modules
```

Outputs allow prepared dependency directories to be reused when the relevant inputs and install configuration match. `dependencyInputs` alone does not declare any installed files to restore. Keep generated dependencies out of uploaded source.

The parser requires nonempty inputs and an install command when outputs are present. It rejects outputs combined with `build`, `lifecycle.configure`, or `lifecycle.reconfigure`. Outputs must be relative, nonoverlapping directories, at most 32, and must not overlap input or source files. Do not declare database or user-upload directories as dependency outputs.

## Image cache

Image deployments use frozen build inputs rather than incremental dependency outputs. `dependencyOutputs` is rejected for image deployment. To prebuild a reproducible project without creating or re-imaging a workspace:

```bash theme={null}
rig deploy --strategy image --build-only
```

A later image deploy can reuse its frozen result. Changes to relevant inputs, including a resolved Git commit, can invalidate the image cache.

## Diagnose a miss

Compare the install command, declared input files, source revision, and strategy. Read the release logs for incremental preparation or `rig build logs <BUILD_ID>` for an image build. Correct declarations instead of relying on undeclared files left in an older directory.