5. 400 - invalid vector mode

Vector topk has exactly two modes: fast (approximate, IVF-style) and high_recall (re-rank for accuracy). Any other string returns invalid_argument. The handler validates the enum before touching the index.

Any mode value other than the two legal ones.

curl -X POST "https://$OC_HOST/v1/tenants/$OC_TENANT/vector/products/topk" \
  -H "Authorization: Bearer $OC_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"query": [0.1, 0.2, 0.3], "k": 5, "mode": "warp_speed"}'

{
  "error": "invalid_argument",
  "message": "mode 'warp_speed' is not supported; valid values are 'fast' and 'high_recall'",
  "retry": false
}

• Use fast for online queries where p99 latency matters more than perfect recall.
• Use high_recall for batch jobs, evals, or when you need the re-rank pass.
• Omitting the field defaults to fast.
• retry: false - the same payload will fail the same way.