Kagi Search API vs Tavily API + MCP

Kagi Search API

A public OpenAPI file, typed filters and API keys that can be limited by product and IP address make the API simple to call, at $12 per 1,000 searches. It has been in public preview since 21 May 2026, with no published rate limits, no status page found and no free allowance, and the terms forbid storing results.

Tavily API + MCP

Keyless search and extract, plus a free 1,000 credits a month with no card. x402 covers advanced search only, not extract, map, crawl or research.

Kagi Search API

1. Send POST https://kagi.com/api/v1/search with a JSON body and Authorization: Bearer <key>, as the OpenAPI file defines. Only query is required
2. Set limit to cap results returned. In the mixed search workflow the MCP tool applies the cap to each result category separately
3. Use extract.count (1 to 10) only when page text is needed. Extraction is billed at the Extract rate on top of the search
4. Do not store results. The API terms allow only the transient caching an application needs, and require deletion on termination
5. On 429 back off before retrying. The response covers both rate limiting and an exhausted usage limit, and no Retry-After header is documented

Tavily API + MCP

1. Try X-Tavily-Access-Mode: keyless first for search and extract. Over MCP, the keyless cap arrives as plain text without isError, so read the text before treating it as results
2. Send the key in Authorization: Bearer, not ?tavilyApiKey= in the MCP URL
3. On 429, wait for Retry-After. A 432 or 433 means a spend limit, and retrying won't help
4. Run /map before /crawl to bound the crawl, since crawl is billed as map plus extract
5. Research is async and runs 4 to 250 credits. Create the task, then poll /research/{request_id}