Semble: A Local MCP Server for Claude Code with 98% Token Reduction

Semble is an MCP server that lets Claude Code search local codebases efficiently, returning only relevant code chunks instead of full files. It uses a hybrid of static embeddings, BM25, and a code-optimized reranking stack, all running locally on CPU — no API keys, no GPU, no heavy dependencies.

Installation

Install via uvx:

claude mcp add semble -s user -- uvx --from "semble[mcp]" semble

Once installed, Claude Code can search any repo — local or remote — directly.

Key Details

• Token reduction: Uses ~98% fewer tokens than the typical grep+read approach.
• Performance: Indexes any repo in ~250ms, answers queries in ~1.5ms (all on CPU).
• Quality: Reaches NDCG@10 of 0.854 — 99% of the best transformer hybrid tested, while being ~200x faster.
• Benchmarked against: grepai, probe, colgrep, and other existing methods.
• Open source: Available on GitHub under the MinishLab organization.

Who It's For

Developers using Claude Code on large codebases who want to reduce token burn and latency while getting high-quality code search results without external API calls.