Problem

OpenClaw's memory search uses node:sqlite (Node.js built-in SQLite). On Node.js v23.11.0, the built-in SQLite (v3.49.1) is not compiled with ENABLE_FTS5, causing FTS5-based keyword search to fail silently:

[memory] fts unavailable: no such module: fts5

This means the keyword/BM25 fallback in hybrid memory search is completely non-functional. Only vector search works (when an embedding provider is configured).

Environment

• OS: macOS (arm64, Darwin 25.3.0)
• Node.js: v23.11.0 (Homebrew)
• SQLite version: 3.49.1 (via node:sqlite)
• SQLite compile options: Missing ENABLE_FTS5 (verified via pragma compile_options)

Steps to Reproduce

1. Configure memorySearch.provider: "local" (or any provider)
2. Start gateway
3. Check logs: [memory] fts unavailable: no such module: fts5
4. memory_search returns mode: "hybrid" but FTS results are always empty

Suggestion

A few possible approaches:

1. Support better-sqlite3 as a fallback — it ships with a fully-compiled SQLite that includes FTS5 by default
2. Document the requirement — note that node:sqlite on some Node.js builds may lack FTS5, and suggest users compile Node.js with --sqlite-enable-fts5 (available since Node 23.x configure options)
3. Detect and warn more visibly — currently it logs a warning but the user may not notice; consider surfacing it in openclaw doctor

Workaround

Vector search (provider: "local" with embeddinggemma GGUF) works fine as the primary search mode. FTS5 is only needed for pure keyword matching fallback.