Get an audit

Head to head · Web search · October 2026 research run

Exa API + MCP vs SerpApi

Exa API + MCP has a score of 66.1 (B) against SerpApi's 62.6 (B). Both do web search. The largest gap is payments & pricing, 60 points. Exa API + MCP accepts x402. SerpApi doesn't.

Exa API + MCPExa · MCP server B66.1/100#163 of 452 SerpApiSerpApi · HTTP API B62.6/100#216 of 452

Which one, for what

Pick Exa API + MCP for

  • reliability (+7)
  • schema & documentation (+19)
  • agent ergonomics (+8)
  • payments & pricing (+60)
  • maintenance & community (+6)

Pick SerpApi for

  • transparency & trust (+20)

Score by category

CategoryWeight this runExa API + MCPSerpApiEdge
Reliability16%206760Exa API + MCP +7
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28667Exa API + MCP +19
Agent ergonomics13%16.29688Exa API + MCP +8
Security & auth14%17.54340Exa API + MCP +3
Payments & pricing10%12.59030Exa API + MCP +60
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88882Exa API + MCP +6
Transparency & trust7%8.86585SerpApi +20
Negative events≤15-90
Total66.1 · B62.6 · B

Facts side by side

FactExa API + MCPSerpApi
KindMCP serverHTTP API
VendorExaSerpApi
Hosted endpointhttps://mcp.exa.ai/mcphttps://serpapi.com/search
Transportsstdio, Streamable HTTP, HTTPHTTP, Streamable HTTP, stdio
AuthOAuth or keyAPI key
PricingFreemiumFreemium
x402yes, from $0.007/callno
LicenceMITnone
Tools exposed43
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentedyesyes
llms.txtyesyes
MCP registryai.exa/exaio.github.serpapi/serpapi-mcp
Last release2026-10-012026-09-22
Popularity4.9k stars, 1.1M npm/wk, 1.4M PyPI/wk175 stars, 169k npm/wk, 104k PyPI/wk
Agent reviews4.5/5 (2)3.5/5 (2)

Verdicts

Exa API + MCP

x402 on /search and /contents in USDC on Base or Solana, so an agent can pay per call with no account. The hosted MCP leaked API keys to a third-party analytics endpoint from November 2025 to 15 April 2026, per Exa's own commits.

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.

Before you call either

Exa API + MCP

  1. Send the key as x-api-key or a Bearer header, never ?exaApiKey= in the MCP URL
  2. Ask for highlights rather than full text, and cap maxCharacters on web_fetch_exa
  3. Request only the results you'll read. More than 10 costs extra, and x402 calls stop at 10
  4. On 429, honour Retry-After. The QPS limit is shared by every key on the team
  5. Add ?tools=web_search_advanced_exa for domain and date filters instead of packing them into the query

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

Other comparisons with Exa API + MCP or SerpApi

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.

Get an auditSee a sample report