Smart Code Search
Search code and docs by meaning, not just strings.
Powered by ColGREP and NextPlaid from LightOn — the engine behind the #1 ranked code retrieval model on MTEB and the #1 retriever on BrowseComp-Plus, OpenAI's hardest agentic search benchmark.
grep finds strings. This finds intent. Ask "payment capture logic" and get results from files that never contain those exact words — because it understands what your code does, not just what it says.
Why This Exists
Every developer has been here: you know what you're looking for but not where it lives. You chain 4 different grep -r attempts, guess filenames, scroll through directory trees. Coding agents are even worse — they grep, miss things, hallucinate file paths, waste tokens exploring blind.
ColGREP fixes this with multi-vector semantic search. It parses your code with Tree-sitter, embeds each function/method/class with token-level vectors, and ranks results by meaning. The model is 17M parameters, runs on CPU, and returns results in under a second.
The Numbers
| Metric | Value |
|---|
| MTEB Code Leaderboard | #1 (LateOn-Code) |
| BrowseComp-Plus | 87.59% accuracy, beating all models up to 8B params (blog) |
| vs grep in coding agents | 70% win rate head-to-head |
| Model size | 17M params — 54× smaller than competing 8B models |
| Search latency | 200–900ms on CPU |
| API cost | $0. Forever. Runs 100% local |
| Privacy | Code never leaves your machine |
Install
brew install lightonai/tap/colgrep
Verify: colgrep --version
Quick Start
1. Index Your Project
cd /path/to/project
colgrep init
That's it. ColGREP parses every file with Tree-sitter, builds multi-vector embeddings on CPU, and stores the index in .colgrep/. Takes 30–60 seconds for ~1000 files. After this, the index auto-updates on every search — changed files are detected and re-indexed automatically.
2. Search
colgrep "natural language description of what you want"
Results are ranked by semantic relevance score. Higher = better match.
Examples:
colgrep "authentication middleware token validation"
colgrep "database migration rollback strategy"
colgrep "React form validation with error display"
colgrep "webhook retry logic with exponential backoff"
3. Combine Regex + Semantics
Filter files by regex pattern first, then rank semantically:
colgrep -e "async.*await" "error handling patterns"
colgrep -e "def test_" "payment capture edge cases"
colgrep -e "\.tsx$" "patient dashboard layout"
Search Options
colgrep "query" # Default output: file:lines (score: X.XX)
colgrep "query" --json # JSON output for piping to other tools
colgrep "query" -n 5 # Top 5 results only
When to Use This vs grep
| You know... | Use |
|---|
| The exact string or function name | grep -r "functionName" |
| The concept but not the words | colgrep "what it does" |
| A pattern + a concept | colgrep -e "pattern" "meaning" |
| Where something is implemented | colgrep "description of behavior" |
| How a feature works across files | colgrep "feature workflow" |
Coding Agent Integration
ColGREP provides built-in integration with popular coding agents. After installing, restart your agent to enable semantic search:
- Claude Code:
colgrep --install-claude-code
- OpenCode:
colgrep --install-opencode
- Codex:
colgrep --install-codex
These commands register ColGREP as a search tool within the agent. The agent will automatically use semantic search when navigating indexed projects.
Multi-Project Setup
Index each project independently. Search from the project directory:
cd ~/code/api && colgrep init
cd ~/code/frontend && colgrep init
cd ~/code/infrastructure && colgrep init
cd ~/docs && colgrep init
# Search each independently
cd ~/code/api && colgrep "payment processing service"
cd ~/code/frontend && colgrep "checkout form validation"
Works great for monorepos, microservices, documentation vaults, and any directory with text/code files.
How It Works
ColGREP uses ColBERT late-interaction retrieval — a fundamentally different approach than traditional single-vector embeddings:
- Tree-sitter parses your code into structured units (functions, methods, classes, signatures)
- LateOn-Code-edge (17M params) creates multiple token-level embeddings per code unit — not one lossy summary vector
- NextPlaid stores these in a quantized, memory-mapped Rust index
- At search time, query tokens interact with document tokens for fine-grained relevance scoring
This is why a 17M model beats 8B models — late interaction preserves token-level semantics that single-vector approaches compress away. Read the full technical story: The Bloated Retriever Era Is Over
Interpreting Scores
- 6.0+ — Near-exact conceptual match. The code does exactly what you described.
- 5.0–6.0 — Strong semantic match. Highly relevant code.
- 4.0–5.0 — Good match. Related code worth reviewing.
- 3.0–4.0 — Weak match. May or may not be relevant.
- Below 3.0 — Likely noise. Ignore these results.
Troubleshooting
"Index is being updated by another process" — Another colgrep instance is updating. Current search uses existing index. Safe to ignore.
Re-index from scratch:
rm -rf .colgrep/ && colgrep init
Add to .gitignore:
.colgrep/
Links
