Fetch (MCP reference server) vs Tavily API + MCP

Fetch (MCP reference server)

One tool of about 300 tokens, with max_length and start_index paging and a hint giving the next offset. Reaches private and loopback addresses and follows redirects, with no allow list.

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.

Fetch (MCP reference server)

1. Fetch with the 5,000-character default and continue from the start_index the truncation note gives
2. Expect empty bodies from JavaScript-rendered sites and switch to a browser tool
3. Treat a robots.txt refusal as final for autonomous calls and tell the user
4. Use raw: true only for non-HTML content. It skips the Markdown conversion and returns the page as served

Tavily API + MCP

1. Try X-Tavily-Access-Mode: keyless first for search and extract, then switch to a key or x402 when the limit hits
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}