SerpApi vs Valyu

SerpApi

Over 100 engines behind one GET URL, with json_restrictor field selection and output=md. 25 incidents on the status feed from July to 1 October 2026, including an outage across all APIs on 10 September.

Valyu

Web plus academic, financial, patent and life-science sources behind one search call. No published rate limits and no Retry-After or backoff guidance.

SerpApi

1. Use the MCP with Authorization: Bearer, not the key-in-path URL the README leads with
2. Read serpapi://engines/<engine> before calling a new engine, since params isn't typed
3. Add json_restrictor or output=md to cut tokens, and mode: compact on the MCP
4. A 429 means either the hourly limit or an empty balance. Check the account before retrying
5. Repeat a search within the hour and the cached copy is free. Set no_cache=true only when freshness matters

Valyu

1. Set max_price and max_num_results on every search to bound cost
2. Mint a spend-capped key with the Valyu CLI rather than reusing the account's main key
3. Call valyu_search. The legacy per-vertical MCP tools stop working on 2026-12-01
4. A 206 means some sources failed. Check which before treating results as complete
5. DeepResearch is async. Poll valyu_deepresearch_status rather than waiting in one call