Silent-failure footgun in SearchKnowledge handler:
keyword := c.Query("keyword") // only "keyword" recognized
// empty keyword → service falls back to default listing (created_at DESC)
// → caller sees "all queries return the same N newest knowledges"
This is exactly what happened to a downstream agent (Support GPT) — it was
sending ?query=... (the parameter name every MCP / semantic-search tool
uses) and getting a constant 5-card listing back regardless of input. The
caller diagnosed it as "WeKnora embedding has degraded · vector channel
returns constant rankings", but actually the parameter was never read, the
search service got keyword="", and the SQL came back as a plain
list-by-created_at.
The handler stays a filename/title LIKE search (its real purpose is the
document-management UI). Two tweaks:
1. Accept ?query= as an alias for ?keyword= · this is what MCP / agent
integrations actually send. Cheap compatibility win, zero downside.
2. Empty keyword/query → 400 with a clear hint. Refusing the request is
strictly better than silently returning a default listing that looks
like "search results" but isn't query-driven.
Separately worth noting: callers who actually want semantic recall should
use POST /api/v1/knowledge-bases/{kb_id}/hybrid-search · which is the
real vector + BM25 endpoint. This handler was never the right tool for
RAG queries · the silent failure just made it look like one.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
toy0116
e76210a695