open-webui-embeddingslisted

Choose and wire open-weights embedding + reranker models into Open WebUI's RAG pipeline, across TEI, vLLM, OpenRouter or LiteLLM. Covers model selection on current MTEB data (quality, zero-shot contamination, and a FLOPs-based throughput model, since no leaderboard publishes speed), the query/document prefix strings each model needs and the PREFIX_FIELD_NAME mode switch that silently eats them, the exact wire shapes Open WebUI sends (URL auto-append on embed but NOT rerank; strict Cohere rerank shape), per-backend cliffs (LiteLLM encoding_format=null, TEI 422s, vLLM registry gaps and pooling fallbacks, OpenRouter's misreported rerank pricing), and copy-paste config per model.
air-gapped/skills · ★ 5 · AI & Automation · score 80

Install: claude install-skill air-gapped/skills

# Open WebUI RAG — embedding + reranking models and backends Target: operators choosing and wiring open-weights embedding and reranker models into Open WebUI. **Almost every failure mode here degrades quality silently** — right HTTP status, right vector dimension, worse answers — so this skill is built to catch them at config-time rather than by noticing that RAG "feels worse". **Two layers, kept separate:** - **Open WebUI's side is backend-agnostic.** `RAG_EMBEDDING_ENGINE=openai`, the `/v1/embeddings` payload, prefix handling, batching and concurrency are identical whether you serve with TEI, vLLM, OpenRouter, or OpenAI itself. That layer is this file plus `references/prefix-models.md`. - **The serving layer differs per backend** and lives in `references/backends.md` (+ the TEI-specific cliffs in `references/gotchas.md` §2-§6, §9). Verified against **v0.11.0** source (2026-07-29), re-checked through **v0.11.4**. The embed and rerank wire calls (`generate_openai_batch_embeddings`, `ExternalReranker.predict`) still send and parse the exact payloads below at v0.11.4 — only logging format and an internal header helper changed. v0.11.1–v0.11.4 instead shipped real retrieval-correctness fixes, a mandatory-external-embedding "slim" image, and new ingestion env vars — see §Slim image, the environment variable tables, and §Do not pin at exactly v0.11.0. One adjacent 0.11.0 change does affect ingestion verification: see §Verifying ingestion below. ## Start here | You want to… |