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A code index for coding agents

Loom gives coding agents a shared index of your git repositories, served over MCP, so an agent asks a structure question and gets the lines that answer it instead of reading whole files. Needs a repository added and LOOM_CODE_INGEST_ENABLED=true. How the index is built and kept fresh is in the code index overview; what it gives in each language is in code index by language.

What you get

  • Definitions, callers and impact. code.symbol, code.callers and code.impact answer with the file and line, and each answer names the commit and index tier behind it. Code operations
  • Search by meaning and by exact string. code.search finds where a mechanism lives; code.grep finds an exact message or identifier.
  • History and pull requests. Merged-PR history with review comments, a pre-PR duplicate check and bisect candidates for a regression. These need PR history turned on (LOOM_CODE_PR_HISTORY_ENABLED); review comments and open PRs also need a GitHub token. History, PRs and releases says what each needs.
  • Freshness you can see. The index trails the branch by merged commits, and a stale answer says so. Freshness
  • Plugins and MCP clients. The Claude Code plugin connects on the coding toolset and the Codex plugin on core,coding,tracker,tasks; both list the code tools. Cursor, GitHub Copilot, Gemini CLI, Cline, Kilo Code, OpenCode and other MCP clients list them with ?toolset=coding on their URL (loom install adds it for Cursor; --toolset coding adds it for the others it writes). Connect a coding agent · MCP clients

Measured

On the ClickHouse repository, Claude Code was asked to end each answer with up to three files. With Loom it named the right file for 96.4% of 36 conceptual questions (10 paired runs), against 91.4% without Loom, and the runs with Loom cost 21% less (the agent's model bill; Loom's own model calls excluded). On 200 SWE-bench Verified issues, code.search ranked a changed file in its first 10 results for 82% (file localization, not issue resolution), against 57% for BM25 over every indexed file and 79% for BM25 over .py files only; the .py-only gap is within noise. With and without Loom · SWE-bench Verified file localization

Start

Adding repositories turns the index on for a repository; the code index overview explains the tiers.

Some ops on this page are marked experimental on the status page.