ontomics
ontomics extracts domain knowledge from codebases to reduce LLM token consumption by 20x and time in agentic search by 10x. It gathers the concepts, naming conventions, and vocabulary embedded in your code and makes them queryable via MCP.
Benchmark
Tested with Claude Sonnet — same question, with and without ontomics.
"What does 'transform' mean in this codebase?" on voxelmorph (full transcript):
| With ontomics | Without | |
|---|---|---|
| Tool calls | 1 | 19 |
| Tokens | ~3.7k | ~76k |
| Time | 5s | 1m 15s |
| Answer quality | Complete | Complete |
"What are the main domain concepts in this codebase?" on ScribblePrompt (full transcript):
| With ontomics | Without | |
|---|---|---|
| Tool calls | 1 | 26 |
| Tokens | ~3.7k | ~61.6k |
| Time | ~5s | 56s |
| Answer quality | Complete | Complete |
Both conditions produced complete, correct answers. ontomics got there in one call.
What it does that search can't
Search tells you where a string appears. An LSP tells you where a symbol is defined and referenced. Neither answers: what are the domain concepts in this codebase? How do they relate? What naming conventions emerged? What changed in the domain vocabulary since last release?
ontomics builds a semantic index of your project's domain — clustering related symbols into concepts, detecting naming conventions from usage frequency, resolving abbreviations, and tracking how the vocabulary evolves over time. That index can be exported as a portable artifact to bootstrap conventions in other repos.
Install
Install once, available in every project. No configuration needed — ontomics auto-detects the repo and indexes it on first run.
Claude Code
npm (macOS/Linux):
npm install -g @ontomics/ontomics
claude mcp add -s user ontomics -- ontomics
macOS (Homebrew):
brew install EtienneChollet/tap/ontomics
claude mcp add -s user ontomics -- ontomics
Shell installer (macOS/Linux):
curl --proto '=https' --tlsv1.2 -LsSf https://github.com/EtienneChollet/ontomics/releases/latest/download/ontomics-installer.sh | sh
claude mcp add -s user ontomics -- ontomics
From source:
git clone https://github.com/EtienneChollet/ontomics.git
cd ontomics
cargo build --release
claude mcp add -s user ontomics -- ontomics
pi-coding-agent
pi install npm:@ontomics/ontomics
Tools appear automatically as ontomics_* in pi config.
Share with your team — drop an .mcp.json in your repo root:
{
"mcpServers": {
"ontomics": {
"command": "npx",
"args": ["-y", "@ontomics/ontomics", "--repo", "."]
}
}
}
Supported languages
Python, TypeScript, JavaScript, Rust. Auto-detected from file extensions.
Tools
| Tool | What it does |
|---|---|
query_concept | Find all variants, related concepts, and occurrences of a term |
locate_concept | Find the key signatures, classes, and files for a concept |
describe_symbol | Get the signature, docstring, and relationships for a function or class |
trace_concept | Trace how a concept flows through the codebase via call chains |
list_concepts | List the top domain concepts by frequency |
list_conventions | List all detected naming patterns (prefixes, suffixes, conversions) |
list_entities | List code entities (classes, functions) filtered by concept, role, or kind |
check_naming | Check an identifier against project conventions; suggests the canonical form |
suggest_name | Generate an identifier name that fits the project's vocabulary |
vocabulary_health | Measure convention coverage, naming consistency, and cluster cohesion |
ontology_diff | Show new, changed, or removed domain concepts since a git ref |
export_domain_pack | Export domain knowledge as portable YAML for use in other repos |
Resources
| Resource | What it does |
|---|---|
ontomics://briefing | Session briefing: top conventions, abbreviations, key concepts, contrastive pairs, and vocabulary warnings. Also available via ontomics briefing CLI. |
How it works
ontomics parses every file in your repo, extracts identifiers and docstrings, clusters related terms by embedding similarity, and detects naming conventions through frequency analysis. The index lives at <repo>/.ontomics/index.db — subsequent startups load from cache and watch for changes.
Configuration via .ontomics/config.toml in the repo root. All fields have sensible defaults. See SPEC.md for the full design contract.