Fuse

Fuse is a local .NET tool with a persistent semantic index, typed-graph wiring resolution, reduced task-scoped source, and pre-write compiler verification for coding agents. It indexes a solution through MSBuild and Roslyn, stores the result in .fuse/fuse.db, and reuses it 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 install --rules

The 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 client registration only. --rules also writes the client's documented instruction file, such as AGENTS.md or CLAUDE.md; it does not install a skill. --with-hooks separately writes project-scoped Claude Code hooks. 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 begins warming .fuse/fuse.db in the background. A cold read waits for a bounded syntax-first pass and reports when the semantic graph is still upgrading. Run fuse index when you want a synchronous full index before connecting the agent. fuse mcp install --rules also 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.

Persistent Discovery and Reduced Context

Coding agents can inspect a repository through file reads, grep, and regex. On a large solution, those operations can rediscover the same symbols, references, registrations, and project structure across several turns. Fuse performs that discovery through MSBuild and Roslyn, persists the result, and incrementally re-indexes files as they change.

When a project loa

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