Fuse loads the solution through MSBuild and Roslyn, persists the derived index locally, and updates changed files incrementally. The same index supplies exact symbol lookup, .NET framework wiring, reduced task-scoped source, change impact, and Git-seeded review.

For proposed single-file C# content, fuse_check uses compiler state captured from the real build when available. It falls back to a scoped build and abstains if neither path can run.

This is not a claim that repository indexes or code graphs are new. CodeGraphContext, Serena, Sourcegraph, and coding-client indexes cover related parts of the category. Fuse is narrower: local .NET analysis through MSBuild and Roslyn, including framework-specific wiring and captured-compiler checks.

On the recorded NodaTime semantic index with 14,760 symbols, exact lookup was 1.8 ms at the median and task localization was 15.7 ms. In a separate compiler-labeled suite over the OrderingApp test families, Fuse recorded 0 false green and 0 false red on 1,000 generated single-file edits plus 8 curated cases. Both results are machine- and sample-bounded.

Analysis runs locally and can work offline. No model is required. The update check and a build using configured package feeds are the network-dependent cases.

Methods and limits: https://fuse.codes/docs/project/benchmarks

Reproduction: https://fuse.codes/docs/project/reproduce

Install: dotnet tool install -g Fuse

Repository: https://github.com/Litenova-Solutions/Fuse