OpenACE

AI-native Contextual Code Engine. Multi-signal semantic code search via MCP for Claude Code, Codex CLI, and any MCP-compatible client.

Install

npm install -g openace

Use with Claude Code

Add to your project's .mcp.json:

{
  "mcpServers": {
    "openace": {
      "command": "npx",
      "args": ["-y", "openace", "serve", ".", "--embedding", "siliconflow"],
      "env": {
        "OPENACE_EMBEDDING_API_KEY": "your-api-key"
      }
    }
  }
}

Use with Codex CLI

codex mcp add openace -- npx -y openace serve . --embedding siliconflow

Commands

# Start MCP server (default)
openace serve /path/to/project --embedding siliconflow

# Index a project
openace index /path/to/project --embedding siliconflow

# Search
openace search "user authentication" -p /path/to/project

MCP Tools

• semantic_search — Search code by natural language query with ranked results and snippets
• find_symbol — Look up symbols by exact name
• get_file_outline — Get structural overview of a file

How It Works

This npm package is a thin wrapper that delegates to the Python openace package via uvx. The Rust+Python engine provides:

• Multi-signal retrieval: BM25 + vector kNN + exact match + graph expansion + AST chunks
• Reciprocal Rank Fusion (RRF) for high-quality ranking
• CJK bigram tokenization for Chinese/Japanese/Korean queries
• Support for Python, TypeScript, JavaScript, Rust, Go, Java

Prerequisites

• uv must be installed (pip install uv or curl -LsSf https://astral.sh/uv/install.sh | sh)

Custom API Providers

Supports any OpenAI-compatible embedding/reranking API:

| Variable | Description | |----------|-------------| | OPENACE_EMBEDDING_API_KEY | API key for embedding provider | | OPENACE_EMBEDDING_BASE_URL | Custom base URL for embedding API | | OPENACE_RERANKER_API_KEY | API key for reranker provider | | OPENACE_RERANKER_BASE_URL | Custom base URL for reranker API |

License

MIT