Locus
The exact code chunk for the job
Locus gives coding agents fast, local code search that returns complete,implementation-ready chunks instead of grep dumps or whole-file guesses.
npx -y @sylphx/locus --root=/absolute/path/to/project
For Claude Code:
claude mcp add locus -- npx -y @sylphx/locus --root=/absolute/path/to/project
The fastest useful workflow
Ask a natural-language question:
{
"query": "where is user authentication enforced?",
"limit": 5
}
Locus returns ranked AST chunks with file paths, line ranges, symbol names,score explanations, freshness, and explicit gaps.
Jobs Locus is built for
| Ask your agent | Locus returns |
|---|---|
| “Where is this behavior implemented?” | codebase_search |
| “What code is related to this function?” | find_related |
| “Search across these repositories.” | cross-repo search |
| “Find the implementation, not tests or declarations.” | ranked code chunks |
| “Give me enough context to edit safely.” | compact, deduplicated results |
Tool surface
| Tool | Purpose |
|---|---|
codebase_search |
Hybrid local search over code chunks |
find_related |
Find related chunks from a known file and line |
The public surface stays small. Indexing is cached locally and refreshed whenthe repository changes. Optional embeddings are opt-in and never required forthe default path.
Predictable defaults
Locus does not hide expensive work behind “auto”.
fastis the default local TF-IDF and AST path.qualityenables optional vectors and reranking when configured.researchis not a Locus mode; use a separate web tool for external sources.- No Docker, vector database, or API key is required.
- Generated files, dependencies, and build output are excluded by default.
Why agents use it
- AST boundaries return functions, classes, and methods.
- Hybrid ranking combines lexical and semantic evidence when available.
- Results include score components instead of opaque ordering.
- Token budgets and dedup keep context small.
- Local indexes keep code on the machine.
Companion MCP tools
| Product | Job |
|---|---|
| Citra | PDF answers with page-level proof |
| Iris | Image facts and pixel evidence |
| Cue | Video timelines and timestamp evidence |
| Spine | Repository architecture and impact |
| Lookout | Web research with source excerpts |
Locus finds the code chunk; Spine maps the repository architecture. Each productis independent, so install only the tools your agent needs.
Development
bun install
bun run build
bun test
cargo test
bun run benchmark:public-proof
bun run benchmark:release-gate
License
MIT
