Codeintel MCP Server

codeintel

Local-first code intelligence for coding agents. Precomputed SCIP navigation (go-to-definition, find-references, call hierarchy, document symbols), Zoekt lexical search, cross-repo blast radius, and semantic search — exposed as MCP tools to Claude Code, Cursor, or any MCP client.

Runs as a single stdio process reading local SQLite files. No server, no auth, no network, nothing leaves your machine.

Quick Start

# 1. External indexer binaries (scip, zoekt, per-language indexers)
curl -fsSL https://raw.githubusercontent.com/phuongddx/codeintel/main/setup.sh | sh

# 2. codeintel itself
uv tool install codeintel-navigation-mcp

# 3. Index a repo (slug defaults to the directory name)
codeintel index /path/to/your/repo

4. Register the MCP server. Using Claude Code, install the plugin and it registers itself:

/plugin marketplace add phuongddx/codeintel
/plugin install codeintel@codeintel

Any other MCP client (or Claude Code without the plugin) registers manually:

claude mcp add codeintel --scope user -- codeintel-server

That's it — ask your agent "find all references to AuthService" and it will call findReferences instead of grepping.

{
  "mcpServers": {
    "codeintel": {
      "command": "codeintel-server"
    }
  }
}

If your client can't find codeintel-server on PATH (GUI apps often don't inherit your shell's), use the absolute path from which codeintel-server.

git clone https://github.com/phuongddx/codeintel && cd codeintel
uv sync
claude mcp add codeintel --scope user -- uv --directory "$(pwd)" run codeintel-server

MCP tools

Every nav tool takes repo (the slug from codeintel index) plus a tool-specific symbol or path. All tools report failure the same way — a {"error": "..."} payload rather than a transport-level error, so a query bug never kills the stdio server.

Requirements and limits

Read this before installing — codeintel is deliberately narrow.

• macOS and Linux only. Windows is not supported.

• One language per repo. Language is detected by extension plurality across git-tracked files; a polyglot monorepo gets indexed as whichever language has the most files. Multi-language merge is out of scope. Override with --language.

• Four language families: TypeScript/TSX, Python, Java/Kotlin, Swift. Rust, Go, C/C++, C#, Ruby, and PHP are not supported.

• Navigation and search only — codeintel never edits code. If you want an agent that can perform semantic renames and refactors, you want Serena; the two are complementary.

• Indexing is a separate, explicit step. Nothing is live-analyzed. Run codeintel index (or codeintel watch) to publish an index before querying.

• Requires external binaries that setup.sh installs:

  Purpose	Binary	Source
  SCIP → SQLite conversion	scip	prebuilt, pinned v0.9.0 (minimum — older versions silently drop occurrence ranges)
  Lexical search	zoekt-index · zoekt-webserver	cross-compiled by our CI — upstream publishes no binaries
  TypeScript indexing	scip-typescript	npm install -g
  Python indexing	scip-python	npm install -g
  Swift indexing	scip-swift	prebuilt, macOS arm64 only
  Java/Kotlin indexing	scip-java	detect-only — Docker image, asks before pulling

  Options: --only <name> to install one dependency, --force to reinstall, --help for usage. Re-running is safe: anything already present is skipped.

Optional extras:

uv tool install "codeintel-navigation-mcp[watch]"      # + watchdog, for `codeintel watch`
uv tool install "codeintel-navigation-mcp[semantic]"   # + lancedb/sentence-transformers/tree-sitter, for semanticSearch

Why it's built this way

Overview — client, server, the 3 engines (Query / Search / Graph), and storage:

Index pipeline & package graph — how codeintel index builds and publishes an index, how the package dependency graph feeds blastRadius, and how codeintel watch debounces a burst of edits into one reindex:

Three things worth reading the diagrams for:

• The runtime path never writes. Queries open a published index-<sha>.db read-only (mode=ro&immutable=1). Index files are never mutated in place.
• Publishing is atomic. A reindex writes a new versioned .db, populates the package graph, and runs zoekt-index — only once all of that succeeds does os.replace (POSIX rename(2)) flip the small current pointer. A query already reading the old file keeps working; there is no downtime window, and a failure anywhere leaves the previously published index live.
• The package graph is rebuilt, not accumulated. Each reindex clears that repo's own outgoing edges before recomputing them, so a removed dependency's edge is retracted — blastRadius always reflects each repo's last index run.

Editable sources: docs/assets/codeintel-architecture.excalidraw · docs/assets/codeintel-system-architecture.excalidraw

Core query/search logic is ported from an internal reference implementation; the enterprise shell (FastAPI, Postgres, hosted-git auth, Cloud Build) is dropped in favor of a single stdio process reading local SQLite files.

Indexing a repo

codeintel index /path/to/your/repo            # slug defaults to the directory name
codeintel index /path/to/your/repo --slug foo # or pick one explicitly
codeintel index /path/to/your/repo --scheme MyScheme # Swift repo with an ambiguous Xcode scheme
codeintel index /path/to/your/repo --language python # force the language instead of detecting it from git-tracked files
codeintel index /path/to/your/repo --semantic-include vendor/generated # force-include a path the generated-file filter would otherwise skip
codeintel list
codeintel status foo
codeintel reindex foo
codeintel forget foo

status (as shown by both list and status) is usually indexed or failed, but can also be partial: the index published real symbols but no navigable positions (an indexer/converter bug) — check the stderr warning from codeintel index for details.

--semantic-include is repeatable — pass it once per path prefix to force-include several. Like --scheme and --language, once set there is no flag to clear it; change it by re-running codeintel index with the new value(s).

Language detection counts source files by extension across git-tracked files and picks the winner — one language per index:

Ties break by fixed priority (.ts → .tsx → .py → .java → .kt → .swift). .git, node_modules, .venv, __pycache__, dist, and build are skipped. Reading git rather than walking the filesystem is deliberate: a walk also counts gitignored scratch directories, which can outnumber a repo's own code and pick a language it doesn't use.

The pipeline then runs: chosen indexer → scip expt-convert → populate the package dependency graph (packages/edges tables in registry.db) → zoekt-index into ~/.codeintel/.zoekt → copy to ~/.codeintel/scip/_/<slug>/_/index-<sha>.db → atomic current pointer flip → registry update.

The scip/_/<slug>/_/ path shape reuses the vendored IndexConnectionCache's (project, repo, branch) 3-tuple layout with the outer two pinned to _ (see src/codeintel/config.py). It is not a user-facing contract — only <slug> matters when calling tools.

Swift indexing works end-to-end. It requires scip >= v0.9.0: older converters cannot read scip.proto's typed_range oneof, which is the only range encoding scip-swift emits, and silently produce an index with no navigable positions. codeintel index refuses an older scip rather than publishing one.

Indexing a Swift repo with code-signed app-extension targets additionally requires scip-swift >= v0.1.2: earlier versions pass no code-signing overrides to xcodebuild, which then fails provisioning for every signed target before compiling anything. Because setup.sh skips any dependency that is merely present, an existing install is not upgraded by re-running it — use sh ./setup.sh --only scip-swift --force.

Watching a repo (auto-reindex)

codeintel watch /path/to/your/repo             # debounce defaults to 5s
codeintel watch /path/to/your/repo --debounce 3
codeintel watch /path/to/your/repo --scheme MyScheme
codeintel watch /path/to/your/repo --language python

Runs in the foreground (not a daemon) using watchdog — install it with the watch extra. A burst of file changes (e.g. an editor's atomic save touching several files) coalesces into exactly one reindex. The reindex fires once --debounce seconds (default 5) have passed since the last file change — this prevents thrashing on rapid edits. .git, node_modules, .venv, __pycache__, dist, and build are ignored.

Tool details

• getIndexStatus takes an optional repo_path (the repo's local git working directory) to compare the published commit against git rev-parse HEAD. Omitted, freshness is reported without a staleness check — never stale: true without evidence.
• searchCode takes query plus an optional repo filter. On first call it lazy-spawns an embedded zoekt-webserver (pidfile'd so a second codeintel process reuses it instead of spawning a duplicate; killed on clean exit via atexit).
• blastRadius takes repo plus symbol_or_package (e.g. "npm:@scope/ name", the same "{manager}:{name}" string codeintel index derives from each repo's SCIP symbols). Returns every other indexed repo whose package depends on it, up to 2 hops, each tagged with its hop distance. The package graph has no per-node timestamp, so freshness is always "unknown" here — an honest limitation of the schema, not a bug. Cross-repo edges resolve by exact package name against whatever has already been indexed: index the dependency first, or re-run codeintel index/reindex after indexing it, for an edge to appear. Each reindex retracts that repo's own stale edges before recomputing them, so a removed dependency's edge disappears too — the graph always reflects each repo's last index run, not an accumulation of every run it's ever had.
• semanticSearch takes repo plus a natural-language query. Requires the optional semantic extra. Results fuse a LanceDB vector search over tree-sitter-chunked code with searchCode's Zoekt hits via reciprocal rank fusion. Raises a clear error if the repo has never been indexed with the extra installed (codeintel reindex <slug> after installing it builds the missing table); indexing itself is non-fatal — a failure there never blocks the rest of codeintel index. Semantic indexing also respects .gitignore (on top of the hardcoded ignore-directory list) and skips any file over 1 MB, in addition to the existing generated-file banner/long-line detection — --semantic-include overrides all three.

Known upstream limitations

These are real behaviors of scip expt-convert (as of v0.9.0), not codeintel bugs:

• typeHierarchy returns an explicit {"error": ...}, not empty arrays, on every real-world index — the converter declares global_symbols.relationships in its schema but never writes it. An empty result would wrongly assert "no supertypes"; the error says "cannot tell" instead. Reported upstream: scip-code/scip#464, fixed by scip-code/scip#465 (open, CI green).
• displayName / kind are often null for symbols the converter only ever sees as bare occurrences (no defining SymbolInformation was indexed).
• searchCode's repo filter matches Zoekt's own repository name, which codeintel index now names after the slug via zoekt-index -meta — so this no longer diverges for repos indexed with current code. Shards published by an older codeintel still carry their old directory-derived name until you codeintel reindex <slug>.

Configuration

Data directory (default ~/.codeintel):

CODEINTEL_DATA_DIR=/custom/path codeintel index /path/to/repo

Environment variables:

• CODEINTEL_DATA_DIR — override default ~/.codeintel for all indexes and registry
• CODEINTEL_EMBEDDING_QUERY_PREFIX / CODEINTEL_EMBEDDING_DOC_PREFIX — override the query/document instruction prefix applied before embedding. Auto-detected for bge-m3, e5, and nomic-embed; set these if using a different model that needs one — semanticSearch warns when an unlisted model has no prefix configured.

Agent skills

Three agent skills ship in the Claude Code plugin, under plugin/skills/:

• codeintel-setup — install, register, index, verify.
• codeintel-use — prefer codeintel for structural queries (find references, go-to-definition, hierarchy).
• codeintel-issues — file codeintel bugs/features via gh.

Install them, and register the MCP server, with:

/plugin marketplace add phuongddx/codeintel
/plugin install codeintel@codeintel

See Quick Start above for the manual registration alternative.

Standards

Blob decoding follows the SCIP protocol: scip_pb2.py is generated from scip.proto at scip-code/scip tag v0.9.0 (regenerated up from v0.7.0, which lacked the typed_range oneof scip-swift requires), and occurrence/relationship blobs are decoded as real scip.Document / scip.SymbolInformation messages.

The SQLite layer (documents, chunks, global_symbols, mentions, defn_enclosing_ranges) is not part of that published spec — it is the output shape of the experimental scip expt-convert sub-command, verified by hand against a real index. Treat it as a moving target across scip releases.

Tests

uv run pytest

Integration tests that shell out to the real scip-python / scip / zoekt-index binaries are marked integration:

uv run pytest -m "not integration"   # unit only
uv run pytest -m integration         # real-binary pipeline

Documentation

• docs/project-overview-pdr.md — scope, value prop, out-of-scope items
• docs/system-architecture.md — architectural guarantees, storage layout, query paths
• docs/codebase-summary.md — module map, test coverage
• docs/code-standards.md — code patterns and conventions
• docs/project-roadmap.md — all phases complete, future ideas

All 4 planned phases are shipped — see plans/0724-2316-codeintel-mcp-implementation/plan.md.

License

MIT