# crust

> Route-level bundle attribution, static shell composition and regression blame for Next.js App Router.

## Docs

- [Attribution](https://docs.crust.moumen.dev/concepts/attribution.md): How bytes in a chunk are traced back to the file that produced them.
- [Build identity](https://docs.crust.moumen.dev/concepts/build-identity.md): Why a git SHA is not enough to key a performance history on.
- [Shell engine](https://docs.crust.moumen.dev/concepts/shell-engine.md): Predicting the static shell from source, then checking the prediction against what the build actually produced.
- [Unknowns](https://docs.crust.moumen.dev/concepts/unknowns.md): What crust refuses to guess, and why that is the feature.
- [CI and pull requests](https://docs.crust.moumen.dev/guides/ci.md): Budgets, a PR comment that updates in place, and snapshot history on an orphan branch.
- [Monorepos](https://docs.crust.moumen.dev/guides/monorepos.md): Workspace roots, per-package tsconfig paths, and where snapshots land.
- [Runtime collector](https://docs.crust.moumen.dev/guides/runtime.md): Web Vitals, long animation frames, an image audit and the streaming waterfall.
- [Staging and synthetic runs](https://docs.crust.moumen.dev/guides/staging.md): An ingest endpoint that cannot be vandalised, and measurements you can actually compare.
- [The in-app widget](https://docs.crust.moumen.dev/guides/widget.md): A floating panel in your running app, eliminated from production builds.
- [Introduction](https://docs.crust.moumen.dev/index.md): What crust measures, and the one thing nothing else catches.
- [Quickstart](https://docs.crust.moumen.dev/quickstart.md): From a production build to a report in two commands.
- [Budgets](https://docs.crust.moumen.dev/reference/budgets.md): The shape of .perf/budgets.json.
- [CLI](https://docs.crust.moumen.dev/reference/cli.md): Every command, every flag.
- [Files on disk](https://docs.crust.moumen.dev/reference/files.md): What crust writes, what to commit, and the two escape hatches.
- [Support and non-goals](https://docs.crust.moumen.dev/support.md): What is supported, what will never be built, and what to expect from maintenance.