Practical overview
When it fits
Use Longbow when an application needs a self-operated, clustered vector engine for agent memory or retrieval, particularly when Arrow Flight access, metadata filters or distributed membership matter.
Who it is for
- Teams building AI-agent applications that need shared vector memory.
- Engineers operating clustered vector retrieval for AI workloads.
- Developers integrating Arrow Flight-based vector search into a service.
Documented uses
- Store and retrieve dense or sparse vectors with HNSW search.
- Apply metadata predicates during searches and scans.
- Share vector-memory infrastructure across loosely coupled nodes.
- Use supported distance metrics and remove vectors through tombstones.
Requirements & limits
- The primary interface is Apache Arrow Flight over gRPC/HTTP2, with separate data and metadata servers.
- The README lists vector data types and dimensions from 128 through 3,072.
- Linux is recommended for best performance; GPU acceleration needs platform-specific builds.
- Storage options described include ephemeral in-memory storage, WAL and Parquet snapshots, with optional io_uring WAL support.
Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.
Build Longbow and start a local cluster
Prepare the Longbow binary and launch the documented local cluster.
Before you start
- Go 1.25 or later
- Linux or macOS; Linux is recommended for best performance
Steps
Clone the Longbow repository and change into its directory.
Build the standard binary with the command below.
go build -o bin/longbow ./cmd/longbowRun
./scripts/start_local_cluster.sh.
Expected outcome
A locally built Longbow binary and a started local cluster.
Guide limitations
- The README does not specify cluster topology, configuration values or a client-side test procedure in this setup sequence.
Compare options for Vector search
These projects document a common task and share a project role. This is a source-based comparison, not an execution benchmark or a guarantee of interchangeability.
| Project | Documented purpose | Platform | Access and requirements |
|---|---|---|---|
| Longbow | Store and retrieve dense or sparse vectors with HNSW search. | Server | |
| Kektordb | Save and retrieve semantic memories across agent sessions. | Self-hosted, Server | The README describes self-hosted use and displays an Apache 2.0 license badge. |
| Memento MCP | Add persistent knowledge-graph memory to an MCP-compatible client such as Claude Desktop, Cursor or GitHub Copilot. | Cloud, Self-hosted, Server |
Sources & review
Source record details
- Source availability
- Active
- Sources checked
- 17 October 2026
- Original website title
- 23skdu/longbow · Official homepage title · retained in its source language

