codeindex MCP server

A structural code intelligence engine that runs as an MCP server for AI coding agents.

It indexes your codebase with tree-sitter (40+ languages), builds a trigram full-text index, an inverted word index, and a dependency graph — then exposes them through 16 MCP tools.

┌─────────────┐   MCP (stdio)   ┌───────────┐            ┌──────────────────┐
 │  AI Agent   │ ◄─────────────► │ codeindex │  socket    │ codeindex daemon │
 │ (Claude,    │ 16 tools,       │  (relay)  │ ◄────────► │  one per         │
 │  Cursor…)   │ JSON-RPC        └───────────┘            │  workspace       │
 └─────────────┘                                          └────────┬─────────┘
 ┌─────────────┐   MCP (stdio)   ┌───────────┐                     │
 │  AI Agent   │ ◄─────────────► │ codeindex │ ◄───────────────────┘
 │  (session 2)│                 │  (relay)  │   tree-sitter parse (40+ langs)
 └─────────────┘                 └───────────┘   trigram + word index
                                                 dependency graph
                                                 one file watcher
                                                 snapshot persistence

Every session on a repository speaks plain stdio MCP, as before. Behind that, they share one index: the tree is parsed once, watched once and written once, however many agents are attached. Eight sessions on one repository used to be eight copies of the same index, eight file watchers and eight writers of the same snapshot; measured on a 720-file project, each session went from 87 MB to 7 MB, against one shared 77 MB daemon.

Why

AI coding agents spend tokens reading entire files. codeindex answers structural questions — symbol outlines, definitions, callers, blast radius, dependency chains — in a few hundred tokens instead of thousands.

One plan_change call returns: where a symbol is defined, every call site, the file's architectural role (god module / stable core / island / driver), hardcoded literals to check, and the full transitive blast radius if the file changes.

Quickstart

The shortest path, if you have Node 18+. Nothing else to install, no key, no config — the package is a 4 KB wrapper that fetches the binary for your platform and verifies it against the published checksums:

claude mcp add codeindex -- npx -y @munhq/codeindex

No Node, or you want the skill and the hook as well:

# Prebuilt binary + skill + MCP registration, in one command
curl -fsSL https://raw.githubusercontent.com/munhq/codeindex/main/install.sh | sh

# Or build from source:
cd zig && ./fetch-vendor.sh && zig build -Doptimize=ReleaseFast

Docker, for hosts that install MCP servers as images. The workspace is bind-mounted read-only; codeindex never writes to it:

docker run -i --rm -v "$PWD:/workspace:ro" munhq/codeindex

Shortened. The full README is on GitHub.