Fuse is a local .NET tool with a persistent syntax index, typed-graph wiring
resolution on demand, reduced task-scoped source, and pre-write compiler verification
for coding agents. It stores repository facts in .fuse/fuse.db and reuses them across
agent turns instead of rediscovering the same structure through repeated file reads and
text searches.
From a .NET project inside a Git repository:
dotnet tool install -g Fuse
fuse mcp installThe installer supports Claude Code, Cursor, GitHub Copilot, OpenCode, Kilo Code, Codex,
and Grok Build. Use --client <name> to configure one client; the default all configures
all seven for the selected scope. fuse mcp install writes MCP registration and a short,
versioned managed block in the client's documented instruction file, such as AGENTS.md or
CLAUDE.md. Pass --no-rules to register MCP without the managed block. --with-hooks
separately writes project-scoped Claude Code hooks. Run fuse mcp doctor after installation
to inspect registration, managed guidance, daemon reachability, and index state. See Connect
your coding agent
for the exact file and scope matrix.
Reload your MCP client, then ask:
Resolve IOrderService to its implementation, then check the proposed OrderService.cs edit
with fuse_check before writing it.
When the MCP server starts, its shared local daemon owns one index job for the repository.
A cold read starts a syntax index and reports its job state. Run fuse index to render
progress in a terminal, fuse index --semantic for explicit compiler analysis, and
fuse index status or fuse index cancel to control the job. The installer adds .fuse/
to .gitignore at project scope.
Every MCP operation except fuse_reduce requires a Git repository identity. Fuse walks upward to the nearest
.git directory or file, so a call from a nested source or output folder uses the same
repository-root daemon, lock, and index. A non-Git folder returns
workspace_identity_unresolved: without starting a daemon or writing an index;
fuse_reduce remains available. Each warm index records its repository root and complete
file inventory. A missing or incomplete manifest rebuilds automatically even when the
database already contains file rows.
Analysis runs locally and can work offline. Fuse walks a typed graph of DI registrations, handlers, routes, and callers, emits reduced source for a selected scope, and lets a coding agent typecheck proposed single-file content before writing it. No model is required. The optional update check can contact NuGet, and build-grade operations can use the package feeds configured for the repository.