ThreadBridge MCP Server for Zed

A Zed extension that provides persistent AI memory through the Model Context Protocol.

ThreadBridge remembers context across conversations using hybrid semantic search (Arctic Embed + BM25 + RRF) with a cognitive decay model (BLL).

Retrieval Benchmark

Runs entirely on local CPU with zero cloud dependency.

Config: Arctic Embed M (768d) + BM25 hybrid + RRF fusion + BLL reranker (30%). Top-20, threshold 0.15.

LoCoMo (Session-level, 1986 QA pairs)

LongMemEval (Session-level, 500 questions)

Per-question-type breakdown (LoCoMo)

Metric definitions

• Recall@K (fractional): fraction of correct sessions retrieved in top-K unique sessions. Standard IR recall.
• Recall_all@K (Ra@K): binary — 1.0 iff all correct sessions are in top-K, else 0.0. Used by MemGAS for direct comparability.
• NDCG@K: normalized discounted cumulative gain at session level.
• MRR: mean reciprocal rank of first correct session.

Notes

• LoCoMo dataset contains 10 conversations / 1986 QA pairs (Maharana et al. 2024).
• Baseline numbers from MemGAS Table 2&3 (recall_all definition confirmed via source code).
• LongMemEval baseline from Table 2&3 (ICLR 2025), using Stella V5 + dense retrieval.
• ThreadBridge reports both recall variants for transparency. The Ra@10 column is directly comparable to MemGAS.
• End-to-end LLM-Judge scores (Hindsight, MemR3, Zep, Mem0) evaluate a different pipeline and are not comparable to retrieval-layer metrics.

Installation

From Extension Marketplace

1. Open Zed
2. Go to Extensions (cmd+shift+x)
3. Search for "ThreadBridge"
4. Click Install

ThreadBridge is now available in the Zed Extension Marketplace. The extension will automatically download the appropriate binary for your platform.

Local Installation (Dev)

Dev extensions are compiled locally by Zed, so this installation method requires Rust via rustup. Rust is not required when installing ThreadBridge from the Zed Extension Marketplace.

1. Clone this repository:

   git clone https://github.com/dereklei12/zed-mcp-server-threadbridge.git
   

2. In Zed, open the command palette (cmd+shift+p) and run zed: install dev extension, then select the cloned directory.

3. The extension will automatically download the mcp-threadbridge binary from GitHub Releases on first use.

MCP Tools

Tool	Description
load_thread	Load saved conversation context for a project
save_thread	Save current conversation context
search_memory	Semantic search across project memory

Configuration

Optional settings in Zed:

• project_path — project directory for memory storage (default: current working directory)
• storage — where to store thread data:
  • "true" (default): local, at <project_path>/.threadbridge/
  • "false": global, at ~/.threadbridge/projects/
  • absolute path: custom location

Supported Platforms

• macOS (Apple Silicon)
• Linux (x86_64)
• Windows (x86_64)

License

MIT