Three Modes, Three Strengths
SearchX offers three search modes. Each has a purpose. Here's when to use what.
Keyword Mode Best for: exact terms, code symbols, error messages, version numbers.
"kubernetes v1.31 pod restart policy" → exact match "TypeError: Cannot read property" → finds that exact error
Keyword search uses inverted text indexes. It's fast (<3ms) and precise. If your agent knows exactly what it's looking for, keyword mode is the answer.
Semantic Mode Best for: concepts, questions, vague queries, "find something like this."
"fast web framework for building APIs" → finds FastAPI (score 0.82) "how to manage containers in production" → finds Kubernetes (score 0.65)
Semantic search uses AI embeddings (Qwen3-Embedding) to understand meaning. It finds relevant results even when none of the keywords match. The tradeoff: it's slower (~300ms) because it requires an embedding API call.
Hybrid Mode (Default) Best for: everything else. The safe default.
Hybrid runs both keyword and semantic in parallel, then merges results using Reciprocal Rank Fusion (RRF). You get the precision of keywords with the intelligence of semantics.
Benchmark: Real Queries
| Query | Keyword | Semantic | Hybrid | |-------|---------|----------|--------| | "docker compose" | Docker Docs (#1) | Docker Docs (#3) | Docker Docs (#1) | | "fast reliable software" | Random results | Rust, Go (#1-2) | Rust (#1) | | "postgrsql tutoral" (typo) | 0 results | PostgreSQL (#1) | PostgreSQL (#1) |
Recommendation
- Default: Use mode=hybrid — it handles everything well
- Exact lookup: Use mode=keyword for code, errors, versions
- Conceptual: Use mode=semantic for research, discovery, exploration