Claude reads entire files to find what it needs. Lumen gives it a map.
Lumen is a 100% local semantic code search engine for AI coding agents. No API
keys, no cloud, no external database, just open-source embedding models
(Ollama or LM Studio), SQLite,
and your CPU. A single static binary and your own local embedding server.
The payoff is measurable and reproducible: across 9 benchmark runs on 9
languages and real GitHub bug-fix tasks, Lumen cuts cost in every single
language — up to 39%. Output tokens drop by up to 66%, sessions complete up to
53% faster, and patch quality is maintained in every task. All verified with a
transparent, open-source benchmark framework that you can
run yourself.
| With Lumen | Baseline (no Lumen) |
|---|
| Cost (avg, bug-fix) | $0.29 (-26%) | $0.40 |
| Time (avg, bug-fix) | 125s (-28%) | 174s |
| Output tokens (avg) | 5,247 (-37%) | 8,323 |
| JavaScript (marked) | $0.32, 119s (-33%, -53%) | $0.48, 255s |
| Rust (toml) | $0.38, 204s (-39%, -34%) | $0.61, 310s |
| PHP (monolog) | $0.14, 34s (-27%, -34%) | $0.19, 52s |
| TypeScript (commander) | $0.14, 56s (-27%, -33%) | $0.19, 84s |
| Svelte (chat-ui) | $0.10, 56s (-26%, -31%) | $0.14, 80s |
| Patch quality | Maintained in all 9 tasks | — |
Table of contents
Demo
Claude Code asking about the
Prometheus codebase. Lumen's
semantic_search finds the relevant code without reading entire files.
Quick start
Prerequisites:
Platform support: Linux, macOS, and Windows. File locking for background
indexing coordination uses flock(2) on Unix and LockFileEx on Windows
(via gofrs/flock).
- Ollama installed and running, then pull the default
embedding model:
ollama pull ordis/jina-embeddings-v2-base-code
- One of:
Claude Code,
Cursor,
Codex, or
OpenCode
Note: Installation differs by platform. Claude Code is installed from a
plugin marketplace. Codex uses a local MCP server plus native skill discovery.
OpenCode installs from npm. Cursor packaging is shipped in this repository and
is ready for Cursor's plugin distribution workflow.
Install:
Claude Code
/plugin marketplace add ory/claude-plugins
/plugin install lumen@ory
Verify by starting a new Claude session and running /lumen:doctor.
Cursor
Lumen ships a native Cursor plugin bundle in this repository:
.cursor-plugin/plugin.json - plugin manifestmcp.json - local lumen MCP server wiringhooks/hooks-cursor.json - SessionStart hookskills/ - shared doctor and reindex skills
Use Cursor's plugin installation or distribution workflow with this bundle.
Detailed packaging notes: .cursor-plugin/INSTALL.md
Verify by opening a new Cursor agent session and asking it to use the doctor
skill or the Lumen semantic_search tool.
Codex
Quick install:
