@codesift/mcp
MCP server for local-first lexical code search, providing tools for searching code, finding symbols, and reading chunks from indexed repositories.
README
codesift
Local-first lexical code search for repositories, delivered as one TypeScript core with three thin interfaces:
codesiftCLI@codesift/coreSDK@codesift/mcpserver
Status
M5 interfaces are complete on top of the completed M3/M4 slices: streamable HTTP MCP transport with optional bearer token, opt-in cloud embedding providers (Voyage, OpenAI) with secret-scan/redaction, repo config + provider resolution + guided --rebuild, and a frozen SDK surface with typedoc.
Implemented today:
- repository scan with
.gitignore/.codesiftignoresupport - TS/JS structural chunking via the TypeScript compiler API
- Python structural definition chunking
- M3 parser-quality structural scanners + symbols for Go, Java, Ruby, and Rust
- accepted M3 decision: no tree-sitter WASM dependency yet; deterministic scanners avoid native/postinstall grammar pain and are hardened with comment/string masking plus real-world fixtures
- heading-aware Markdown chunks and top-level key/section chunks for JSON, YAML, and TOML
- fallback line-window chunking for other supported text files
- SQLite-backed local index with FTS and lazy
sqlite-vecloading - end-to-end
index,search,sym,grep,status, andcleanCLI flows - manifest-diff incremental
sync()/indexupdates for changed, touched, and removed files - content-addressed embedding cache so delete+add/rename cases with identical code reuse embeddings
- stable chunk ids plus on-demand chunk/range reads from disk
- real MCP stdio transport with
search_code,find_symbol,grep_code,read_chunk, andindex_status - token-budgeted compact search results (
maxTokens/max_tokens), overlap dedupe, single-best identifier answers, query-centered snippets, reason tags, and stale-hit annotations - oversized structural chunk splitting, nested ignore-file handling, default vendor ignores, generated/minified code down-ranking, generated result annotations, and generated counts in status
- real
status().stalefrom mtime/size manifest drift plus git branch/HEAD drift status().sync/ MCPindex_statuscrash-state metadata for running, failed, and aborted syncs- shadow database sync writes with atomic index-file swap so failed rebuilds keep the previous index readable
- native
fs.watch-basedwatch()/codesift index --watchwith a safety poll fallback, refreshing through the same incremental path - daemon-backed
codesift mcpshim: the CLI fast-path starts/proxies to a long-lived local daemon so repo handles and MCP routing are amortized across agent sessions - real streamable HTTP MCP transport (
codesift serve) over the same tool registry, binding127.0.0.1by default with an optional constant-time bearer token - opt-in cloud embedding providers
voyage-code-3andopenai-text-embedding-3-small(lazy key reads, no egress until an embed runs) behind the sameEmbeddingProviderinterface - secret-scan + redaction gate on the cloud document-embed path (
--allow-secrets); the local default path never egresses .codesift/config.json+codesift config get|setprovider/model/ignore/allowSecrets, with provider resolution precedence and guided--rebuildon a provider switch- frozen
@codesift/coreSDK surface with a typedoc reference (pnpm run docs) and a documented quickstart proven by a test - pinned-OSS + local M3 fixture eval harness with paired tokens-to-resolution plus stdio cold-start latency vs ripgrep and a checked-in loss budget
For the current one-call structural-search moat, including diagrams of the query path and efficiency model, see docs/moat.md.
Still intentionally deferred to later milestones:
- production-default learned embedding provider (cloud providers ship opt-in in M5; a default learned/local model is M6)
- optional future tree-sitter WASM migration if bundled grammars can be added without install pain
- sqlite-vec
vec0virtual-table vector arm (M6; gated on a default-supported learned provider — seePLAN.md§12.8/§12.11) - broader M6-quality golden sets and learned-vector ranking work
Supported platforms
| Environment | Node | Notes |
|---|---|---|
macOS (macos-latest) |
20.x, 22.x | GitHub Actions coverage |
Ubuntu (ubuntu-latest) |
20.x, 22.x | glibc coverage |
Alpine Linux (node:<version>-alpine) |
20.x, 22.x | musl coverage + packed-install smoke test |
Windows (windows-latest) |
20.x, 22.x | GitHub Actions coverage |
Trust posture
- Telemetry: none.
- Default local
index/search/sym/statusflows are covered by offline / zero-egress CI checks. - Cloud embedding is opt-in only (explicit provider config + an API key env var); content is secret-scanned and refuses to send without
--allow-secrets, which redacts first. .codesift/self-installs a local.gitignorewith*on first open/index so the index never shows up ingit status.- If
sqlite-vecis unavailable, lexical and symbol queries still work; vector search reports degraded mode instead of failing at repo open.
M3 chunking hardening
- Default ignored directories include
vendor/,third_party/, and__generated__/; nested.gitignoreand.codesiftignorefiles are honored. - Generated files are detected from path patterns (
*.generated.*,*.gen.*,*.pb.go,*_pb2.py,*_pb.rb,*.designer.*), header markers (@generated,Code generated by,DO NOT EDIT, etc.), and minified shape (average nonblank line length >300 or any line >2000 chars). - Generated files outside ignored directories are indexed, not dropped: search down-ranks them, result formatters annotate them, and
statusreports generated file/chunk counts. - Oversized structural chunks split into bounded overlapping windows before indexing; Markdown headings and JSON/YAML/TOML top-level keys become named chunks.
Workspace
packages/
core/ @codesift/core
cli/ codesift
mcp/ @codesift/mcp
eval/ private eval harness
Quickstart
pnpm install
pnpm build
pnpm test
node packages/cli/dist/bin.js index .
node packages/cli/dist/bin.js search "where is the sqlite database opened" -k 5
node packages/cli/dist/bin.js grep -e "SqliteRepo" --path 'packages/core/**'
node packages/cli/dist/bin.js sym SqliteRepo
MCP recipe
After indexing a repo, point an MCP client at the stdio command:
codesift mcp /path/to/repo
Routing policy for agents: find_symbol for identifiers/definitions, grep_code for exact strings or regex, and search_code for behavior/concept queries. Keep host grep as fallback, not the first tool. search_code is compact by default and accepts max_tokens for strict context budgets.
Cold-start note: codesift mcp is now a small stdio shim that starts or reuses a local codesift daemon, then proxies MCP JSON-RPC to it. The daemon exits after an idle timeout and can be pinned with CODESIFT_DAEMON_SOCKET / CODESIFT_DAEMON_IDLE_MS when tests need isolation.
HTTP transport (second machine / shared index)
codesift serve /path/to/repo --port 7345 --token <bearer> # streamable HTTP MCP, binds 127.0.0.1
serve exposes the same five tools over the MCP streamable-HTTP transport. It binds 127.0.0.1 by default; pass --host to widen and --token to require Authorization: Bearer <token> (compared in constant time). Use it for a second process/machine on a trusted network — multi-repo/team auth remains post-MVP.
Cloud embedding providers (opt-in)
Local lexical search is the zero-config default and never leaves the machine. To use a learned cloud provider:
export VOYAGE_API_KEY=... # or OPENAI_API_KEY
codesift config set provider voyage-code-3 # or openai-text-embedding-3-small
codesift index . --rebuild # rebuild with the new provider's vectors
Before any cloud send, indexed content is secret-scanned: a detected secret aborts the sync unless you pass index --allow-secrets, which sends a redacted copy instead. API keys are read lazily and only on the embed path; the default local flows stay zero-egress (enforced by pnpm run test:offline). Config precedence: explicit SDK providerId > CODESIFT_EMBEDDING_PROVIDER env > .codesift/config.json > local default.
SDK reference
See docs/sdk.md for the frozen @codesift/core quickstart; pnpm run docs generates the full typedoc API reference into docs/api/.
Commands
pnpm build
pnpm test
pnpm typecheck
pnpm run test:offline
pnpm --filter @codesift/eval run bench
pnpm run test:smoke-install
pnpm run docs
pnpm run ci
See PLAN.md for the full product plan.
Recommended Servers
playwright-mcp
A Model Context Protocol server that enables LLMs to interact with web pages through structured accessibility snapshots without requiring vision models or screenshots.
Magic Component Platform (MCP)
An AI-powered tool that generates modern UI components from natural language descriptions, integrating with popular IDEs to streamline UI development workflow.
Audiense Insights MCP Server
Enables interaction with Audiense Insights accounts via the Model Context Protocol, facilitating the extraction and analysis of marketing insights and audience data including demographics, behavior, and influencer engagement.
VeyraX MCP
Single MCP tool to connect all your favorite tools: Gmail, Calendar and 40 more.
graphlit-mcp-server
The Model Context Protocol (MCP) Server enables integration between MCP clients and the Graphlit service. Ingest anything from Slack to Gmail to podcast feeds, in addition to web crawling, into a Graphlit project - and then retrieve relevant contents from the MCP client.
Kagi MCP Server
An MCP server that integrates Kagi search capabilities with Claude AI, enabling Claude to perform real-time web searches when answering questions that require up-to-date information.
Neon Database
MCP server for interacting with Neon Management API and databases
E2B
Using MCP to run code via e2b.
Exa Search
A Model Context Protocol (MCP) server lets AI assistants like Claude use the Exa AI Search API for web searches. This setup allows AI models to get real-time web information in a safe and controlled way.
Qdrant Server
This repository is an example of how to create a MCP server for Qdrant, a vector search engine.