🦀 Crabmap

Crabmap builds a durable, queryable knowledge graph of any Rust project. Give it to an AI agent — it understands the entire codebase without reading files one by one.

Think of it as a satellite map of your Rust codebase, while LSP (rust-analyzer) gives you a microscope for individual symbols.

✨ Why Crabmap?

🚀 Quick Start

# Install
cargo install crabmap

# Index a project
crabmap index /path/to/rust/project
# ✓ indexed 9089 nodes, 14355 edges in 168 files

# AI architecture overview (compact)
crabmap nav map
# --full for entry points + feature clusters

# Find anything by name
crabmap query find "handler"
# --mode similar for structurally similar symbols

# Inspect a symbol (with source code)
crabmap query inspect main

# Trace call chains (both directions by default)
crabmap query trace load_config
# --direction up | down for one-way

# Scope: what's in a file or module?
crabmap query scope src/lib.rs
# --kind module for module declarations

# Explore interactively in the browser
crabmap serve

📦 Commands

crabmap index — Build the graph

crabmap index .                           # Index current project
crabmap index --all .                     # Discover & index all Cargo projects
crabmap index --no-tests                  # Skip test files
crabmap index --no-semantic               # Skip rust-analyzer enrichment
crabmap index --output custom.json.gz     # Custom output path (gzipped)

crabmap query — Ask questions

Discover & Understand

crabmap query stats                       # Node/edge counts by kind/source/certainty
crabmap query symbols --limit 10          # List symbols (8 filter flags: --dead, --no-docs, --visibility, …)
crabmap query inspect main                # Symbol detail + source code
crabmap query find "config"               # Text search (--mode similar for structural similarity)
crabmap query scope src/lib.rs            # File contents (--kind module for module declarations)

Trace Relationships

crabmap query trace main                  # Both directions (--direction up | down)
crabmap query impact Runtime --depth 2    # Full impact: files_affected + call_sites + change_hints
crabmap query path main load_config       # Shortest call path between two symbols

Export

crabmap query export                      # JSON export (--format dot | mermaid)

crabmap nav — AI-oriented navigation

crabmap nav map               # Compact overview (~8k tokens, hot symbols)
crabmap nav map --full        # + entry points & feature clusters
crabmap nav quality           # Graph confidence score
crabmap nav health            # Cycles, god modules, dead code
crabmap nav report            # Generate GRAPH_REPORT.md + AGENT_GUIDE.md

crabmap analyze — Static analysis

crabmap analyze deps          # Module dependency matrix + recompile impact
crabmap analyze fanout        # File-level fan-in / fan-out
crabmap analyze tests <name>  # Call-graph-based test impact (score + call path)
crabmap analyze hotspots      # Git churn hotspots
crabmap analyze diff          # Graph diff vs git base

crabmap serve — Web UI

crabmap serve                         # Index + serve
crabmap serve --graph graph.json.gz   # Serve a pre-built graph
crabmap serve --watch                 # Auto-reindex on file changes

crabmap config — API Keys (for LLM features)

crabmap config --api-key sk-... --model gpt-4

🌐 Web UI

Launch crabmap serve and open http://127.0.0.1:7878:

• Graph visualization — force-directed layout, color-coded by node/edge kind
• Interactive exploration — click nodes to expand, drag to rearrange
• Edge filtering — toggle relationship types (calls, declares, uses_type, …)
• Detail drawer — inspect symbols, files, edges
• Chinese UI — full zh-CN interface

🧪 Tested On

All three projects indexed with zero warnings.

🔧 How It Works

1. cargo metadata → discovers packages, targets, source files
2. syn AST walk → extracts structs, enums, functions, methods, impls, macros…
3. Call resolution → same-module priority, method-to-trait-impl matching
4. rust-analyzer enrichment (optional) → LSP call hierarchy for confirmed edges
5. MIR lowering (optional) → rustc MIR for dispatch sites
6. Graph persistence → gzip-compressed JSON (14× smaller than raw)

📄 Graph Format

The output is a single JSON file (gzipped by default):

{
  "schema_version": 2,
  "project": { "root": ".", "packages": […] },
  "nodes": [
    { "id": "function:crabmap::run", "kind": "function", "name": "run", … }
  ],
  "edges": [
    { "from": "function:crabmap::main", "to": "function:crabmap::run",
      "kind": "calls", "source": "ast", "certainty": "definite" }
  ]
}

🛠 Building from Source

git clone https://github.com/trtyr/crabmap.git
cd crabmap
cargo build --release
./target/release/crabmap --version
# crabmap 0.1.2 (abc1234 2026-05-21)

Requires Rust ≥ 1.85 (edition 2024).

📁 Project Layout

src/
├── main.rs            # CLI entry & command dispatch
├── cli.rs             # clap argument definitions
├── model.rs           # Core data model (Node, Edge, CodeGraph)
├── analyzer/          # AST indexer (syn walk, 6 sub-modules)
├── query/             # Graph traversal, search, filtering (6 sub-modules)
│   ├── commands.rs    # inspect, trace, find, scope, impact
│   ├── filter.rs      # SymbolFilter — 8 lightweight query flags
│   ├── similar.rs     # Structural similarity by callee overlap
│   └── source.rs      # Source code retrieval by line range
├── ai/                # AI nav: map, guide, clusters, quality (5 sub-modules)
├── web/               # Embedded HTTP server + viewer (6 sub-modules)
├── rag/               # Retrieval: lexical → embedding → rerank (6 sub-modules)
├── semantic/          # rust-analyzer LSP enrichment (3 sub-modules)
├── store.rs           # Gzip JSON load/save + multi-project auto-discovery
├── config.rs          # Global config (~/.config/crabmap/)
├── health.rs          # Architecture risk detection
├── mir.rs             # MIR lowering
├── deps.rs            # Module dependency + recompile impact
├── test_impact.rs     # Call-graph-based test impact analysis
└── …

web/
├── index.html
├── styles/            # CSS (dark theme)
└── src/               # JS (microkernel architecture)

skills/
└── crabmap.md         # AI agent usage guide (skill file)

📝 License

MIT