π§ Codebase Synapse
Give your AI agent a deep understanding of your entire codebase.
An MCP server that indexes your codebase into a local knowledge graph with 52 AI tools β semantic search, call-graph traversal, git archaeology, blast-radius analysis, and more.
Works with Claude Code Β· Cursor Β· Windsurf Β· Zed Β· Any MCP client
The Problem
AI coding agents (Claude, Cursor, etc.) are powerful β but they work with limited context. They can only see the files you open or feed them. Ask about call chains, architectural patterns, or blast-radius impact, and they guess.
Codebase Synapse fixes this. It indexes your entire repo into a local knowledge graph stored in SQLite, giving your AI agent real answers backed by structural analysis β not hallucinations.
How it works
graph LR
A["π Your Codebase"] -->|Tree-sitter| B["π§© Parser"]
B -->|Symbols & Edges| C["πΈοΈ Knowledge Graph"]
C -->|SQLite| D["πΎ Local DB"]
D -->|52 MCP Tools| E["π€ AI Agent"]
style A fill:#1a1b26,stroke:#7aa2f7,color:#c0caf5
style B fill:#1a1b26,stroke:#bb9af7,color:#c0caf5
style C fill:#1a1b26,stroke:#9ece6a,color:#c0caf5
style D fill:#1a1b26,stroke:#e0af68,color:#c0caf5
style E fill:#1a1b26,stroke:#f7768e,color:#c0caf5
β‘ Quick Start
1. Index your project (CLI, Zoekt-style)
codebase-synapse index /path/to/your/repo
Indexing runs as a separate CLI command and writes into ~/.codebase-synapse/codebase.db. The first index is the slow one; re-running it only re-indexes changed files. The MCP server never indexes β it only reads the pre-built index.
2. Start the MCP server
npx codebase-synapse
That's it. No Docker. No database setup. No cloud. The server starts via stdio and serves the pre-built index to your MCP client.
Configure your client
Claude Code / Claude Desktop
Add to your claude_desktop_config.json or mcp_servers.json:
{
"mcpServers": {
"codebase-synapse": {
"command": "npx",
"args": ["-y", "codebase-synapse"]
}
}
}
Cursor
Add to your .cursor/mcp.json:
{
"mcpServers": {
"codebase-synapse": {
"command": "npx",
"args": ["-y", "codebase-synapse"]
}
}
}
Other MCP clients
Any MCP client that supports stdio transport works. Just point it at:
npx -y codebase-synapse
β¨ What It Does
π Search & Discovery
| Tool | Description |
|---|---|
semantic_search | Vector similarity search using local embeddings (all-MiniLM-L6-v2) |
search_code | Full-text search across code (FTS5 + BM25 ranking) |
search_symbol | Find functions, classes, types by name or pattern |
hybrid_search | Combined semantic + lexical search with RRF fusion |
find_similar | Find structurally similar code using MinHash + LSH |
find_symbol_everywhere | Locate a symbol across all indexed projects |
πΈοΈ Knowledge Graph
| Tool | Description |
|---|---|
get_callers / get_callees | Navigate the call graph in either direction |
get_imports / get_dependents | Trace dependency chains |
impact_analysis | Compute blast radius before editing a file |
find_path | Find the shortest connection between two symbols |
find_dead_code | Detect unreachable functions and unused exports |
get_pagerank | Identify the most critical nodes in your architecture |
query_graph | Run Cypher-like queries against the knowledge graph |
ποΈ Architecture
| Tool | Description |
|---|---|
get_architecture | Full project architecture overview (languages, entry points, hotspots) |
get_file_structure | Directory tree with symbol annotations |
project_overview | High-level summary with key metrics |
get_route_map | Extract HTTP routes and their handler mappings |
suggest_boundaries | Detect module boundaries via Leiden clustering |
check_boundaries | Validate cross-module dependencies against defined boundaries |
get_clusters | Community detection across the codebase |
π¬ Git Archaeology
| Tool | Description |
|---|---|
git_archaeology | Deep history analysis of a file (authors, churn, evolution) |
get_hotspots | Files with highest complexity Γ change frequency |
detect_change_coupling | Files that always change together |
get_recent_semantic_changes | Semantically meaningful recent changes |
index_git_history | Build temporal analysis from git log |
π§ Memory & Context
| Tool | Description |
|---|---|
memory_store / memory_search / memory_list | Persistent notes, facts, and decisions across sessions |
session_remember / session_recall | Short-term memory within a session |
get_context | Budgeted context preparation for AI agents |
get_edit_context | Focused context for a specific file edit |
get_working_set | Recently accessed and modified files |
manage_adr | Architecture Decision Records management |
π‘οΈ Codebase Guard
Included as a bonus: codebase-guard is a PreToolUse hook for Claude Code that blocks writes to high-impact files until the agent runs impact_analysis first.
It uses PageRank scores and blast-radius data from the knowledge graph to identify architectural hubs. No more accidental edits to core files.
π§ Technical Details
| Language | Rust (compiled native binary) |
| Transport | MCP stdio (JSON-RPC) |
| Storage | SQLite (WAL mode, zero config) |
| Embeddings | all-MiniLM-L6-v2 via Candle (offline, local, lazy-loaded) |
| Parsing | Tree-sitter (10 languages) |
| Distribution | npm with prebuilt binaries (Windows, macOS, Linux Γ x64, arm64) |
Supported Languages
Rust Β· Python Β· TypeScript Β· JavaScript Β· Go Β· Java Β· C# Β· PHP Β· C Β· C++
Architecture
src/
βββ parser/ # Tree-sitter parsing & entity extraction
βββ graph/ # Knowledge graph, PageRank, Leiden clustering
βββ indexer/ # Repository indexing pipeline
βββ search/ # BM25 full-text + vector cosine + hybrid RRF
βββ embedding/ # Candle-based local embeddings (feature-gated)
βββ memory/ # Persistent & session memory stores
βββ mcp/ # MCP protocol transport + 52 tool handlers
βββ git/ # Git archaeology, intent classification, hotspots
βββ context/ # Budgeted context preparation for AI
βββ cypher/ # Nom-based Cypher parser β SQL CTE planner
βββ similarity/ # MinHash + LSH structural similarity
βββ semantic/ # Multi-signal scoring (tokens, directory, AST)
βββ cli/ # Interactive TUI installer + artifact export/import
π€ Contributing
Contributions are welcome! The project uses standard Rust tooling:
# Run tests
cargo test
# Lint
cargo clippy -- -D warnings
# Format
cargo fmt --all