LanceDB Hybrid Search Memory Plugin

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name: memory-lancedb-hybrid description: LanceDB long-term memory plugin with BM25 + vector hybrid search (RRF or linear reranking).

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LanceDB Hybrid Search (Memory Plugin)

This skill packages a drop-in OpenClaw memory plugin that adds hybrid search to LanceDB memory:

Vector search (semantic)

BM25 full-text search (exact terms)

Configurable reranking:

- rrf (Reciprocal Rank Fusion, recommended) - linear (weighted combination)

It is based on (and credits) OpenClaw PR openclaw/openclaw#7636.

What you get

A local plugin (extension) located at:

plugin/ → overrides the built-in plugin id memory-lancedb (adds hybrid search)

Once enabled, it provides the same tools as the bundled LanceDB memory plugin:

memory_store

memory_recall

memory_forget

…but memory_recall/auto-recall/forget now use hybrid search when enabled.

Install / Enable

1) Ensure the skill folder exists (ClawHub install puts it under your workspace):

~/.openclaw/workspace/skills/memory-lancedb-hybrid/plugin

2) Install the plugin dependencies (once):

cd ~/.openclaw/workspace/skills/memory-lancedb-hybrid/plugin
npm install --omit=dev

3) Add the plugin to OpenClaw’s plugin load paths.

This plugin keeps the id memory-lancedb, so it will override the bundled memory-lancedb extension when discovered via plugins.load.paths (higher precedence than bundled).

Edit ~/.openclaw/openclaw.json:

{
  plugins: {
    load: {
      // Point at the plugin directory inside this skill
      paths: ["~/.openclaw/workspace/skills/memory-lancedb-hybrid/plugin"]
    },
    // Ensure the memory slot points at LanceDB memory
    slots: {
      memory: "memory-lancedb"
    },
    // Configure LanceDB memory (this override adds the hybrid config block)
    entries: {
      "memory-lancedb": {
        enabled: true,
        config: {
          embedding: {
            apiKey: "${OPENAI_API_KEY}",
            model: "text-embedding-3-small"
          },
          // Optional
          dbPath: "~/.openclaw/memory/lancedb",
          // Optional
          autoCapture: true,
          autoRecall: true,
          // Hybrid search options
          hybrid: {
            enabled: true,
            reranker: "rrf"
            // If using reranker: "linear", you can also set:
            // vectorWeight: 0.7,
            // textWeight: 0.3,
          }
        }
      }
    }
  }
}

4) Restart the Gateway.

Hybrid search needs an FTS index on the text column; the plugin will attempt to create it automatically. If FTS setup fails for any reason, the plugin logs a debug message and falls back to vector-only search.

Config reference

All config lives under plugins.entries.memory-lancedb.config.

hybrid.enabled (boolean, default true)

hybrid.reranker (rrf | linear, default rrf)

hybrid.vectorWeight (number 0–1, default 0.7, only used for linear)

hybrid.textWeight (number 0–1, default 0.3, only used for linear)

Notes / troubleshooting

This plugin does not modify OpenClaw’s install on disk; it overrides the bundled memory-lancedb at runtime (remove plugins.load.paths to revert).

If you already have LanceDB memory data on disk, you can keep using the same dbPath.

If you see no hybrid effect, make sure hybrid.enabled is true and that the FTS index was created (check Gateway logs).

Files

plugin/index.ts – plugin implementation (hybrid search)

plugin/config.ts – config parsing + UI hints

plugin/openclaw.plugin.json – manifest + JSON Schema (used for strict config validation)