Throughline MCP server

Throughline

Give Claude complete understanding of your software project.

Point it at a repository on your machine. It reads every file, extracts symbols with tree-sitter, resolves imports into a call graph, ingests git history, and exposes the whole thing to Claude as precise retrieval tools.

Then you can ask the questions you actually have — "where is rate limiting handled?", "what breaks if I change this?" — and get real file paths and line numbers instead of plausible-sounding guesses.

Everything runs locally. This extension makes no network requests of any kind.

What it looks like

You: where does indexing decide a file has changed?

3 matches for "where does indexing decide a file has changed"

### src/core/services/index-repository.ts:171-186
method IndexingService.index — src/core/services/index-repository.ts:171-186
why: text match; 15 inbound references; 6 matches in this file

      const hash = contentHash(buffer);
      const previous = known.get(scanned.relPath);
      ...
      if (mode === 'incremental' && previous === hash) {
        unchanged.push(scanned.relPath);
        continue;
      }

That why: line is the point. Results are ranked by how structurally central they are — inbound references, export status, architectural role — not by how many times a word appears. A file that mentions caching loses to the one that implements it.

What you can ask

Eighteen tools in total — see docs/TOOLS.md.

Supported languages

Full symbol extraction — TypeScript · TSX · JavaScript · JSX · Python · Go · Java · Kotlin · C# · Rust · C · C++ · YAML · JSON

Text-searchable only — SQL · Markdown · Dockerfile · Terraform (grammars not yet vendored; files are indexed and searchable, but no symbols are extracted)

Anything else is still catalogued and searchable as text.

Install

From a release — download throughline.mcpb, then in Claude Desktop go to Settings → Extensions → Advanced settings → Install Extension. You'll be asked which directories the connector may read.

From source — see docs/INSTALL.md:

npm install
npm run grammars     # vendor tree-sitter WASM grammars
npm run build
npm run smoke -- .   # watch it index itself

Requires Claude Desktop on macOS or Windows. Node ships with Claude Desktop, so there's nothing else to install.

First run

Shortened. The full README is on GitHub.