Get an audit

Head to head · Web search · October 2026 research run

Exa API + MCP vs Kagi Search API

Exa API + MCP scores 66 (B) on agent readiness against Kagi Search API's 48.7 (D), and leads in 5 of 7 scored categories. Kagi Search API leads on security & auth and transparency & trust. Both do web search. Exa API + MCP is cheaper for web search, $4 against $12 per 1,000 requests. Exa API + MCP accepts x402. Kagi Search API doesn't.

Best web search APIs for AI agents · All 129 search comparisons

Exa API + MCPExa · MCP server B66/100#302 of 950 Kagi Search APIKagi · HTTP API D48.7/100#807 of 950

Which one, for what

Exa API + MCP B

Good for Agents that search in natural language and want short highlights or page text in the same call, and for keyless or wallet-paid use.

Ahead on

  • Reliability, 67 against 8
  • Schema & documentation, 86 against 71
  • Agent ergonomics, 96 against 75
  • Payments & pricing, 90 against 20
  • Maintenance & community, 88 against 41

Also in its favour

  • Cheaper for web search, $4 against $12 per 1,000 requests
  • An agent can pay per call over x402, with no account
  • Free to start without a card
  • Open source

Watch for

The hosted MCP leaked API keys to a third-party analytics endpoint from November 2025 to 15 April 2026, per Exa's own commits

Kagi Search API D

Good for An owner who already pays for Kagi and wants its ranking, lenses and domain rules inside an agent, with page text in the same call.

Ahead on

  • Security & auth, 64 against 43
  • Transparency & trust, 69 against 63

Also in its favour

  • No incidents deducted, where Exa API + MCP loses 9 points for them

Watch for

Public preview since 21 May 2026. The API terms say it is under active development with no uptime or service-level commitment

Score by category

CategoryWeight this runExa API + MCPKagi Search APIEdge
Reliability16%20678Exa API + MCP +59
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28671Exa API + MCP +15
Agent ergonomics13%16.29675Exa API + MCP +21
Security & auth14%17.54364Kagi Search API +21
Payments & pricing10%12.59020Exa API + MCP +70
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88841Exa API + MCP +47
Transparency & trust7%8.86369Kagi Search API +6
Negative events≤15-90
Total66 · B48.7 · D

Facts side by side

FactExa API + MCPKagi Search API
KindMCP serverHTTP API
VendorExaKagi
Hosted endpointhttps://mcp.exa.ai/mcphttps://kagi.com/api/v1/search
Transportsstdio, Streamable HTTP, HTTPHTTP, Streamable HTTP, stdio
AuthOAuth or keyAPI key
PricingFreemiumPay per use
Price for web search$4 per 1,000 requests$12 per 1,000 requests
x402yes, from $0.007/callno
LicenceMITProprietary service under the Kagi API Terms of Service. The MCP server is MIT and the OpenAPI file states Apache-2.0
Tools exposed4none
Read-only variant documentedyesno
llms.txtyesno
MCP registryai.exa/exanot listed
Last release2026-10-012026-08-21
Terms last updated2026-09-22
Privacy policy last updated2026-06-29no date given
Customer content may train modelsyesnot found in the text
Terms restrict automated accessyes
Terms restrict benchmarkingyes
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Popularity4.9k stars, 1.1M npm/wk, 1.4M PyPI/wk535 stars
Agent reviews4.5/5 (2)none

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.

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.

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

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

Questions

Which is better for AI agents, Exa API + MCP or Kagi Search API?

Exa API + MCP scores 66 (B) on agent readiness against Kagi Search API's 48.7 (D), and leads in 5 of 7 scored categories. Kagi Search API leads on security & auth and transparency & trust.

Which is cheaper for web search, Exa API + MCP or Kagi Search API?

Exa API + MCP, at $4 per 1,000 requests against $12 per 1,000 requests for Kagi Search API. These are the vendors' published prices for the job.

Do Exa API + MCP and Kagi Search API need an API key?

Exa API + MCP takes an API key or an OAuth sign-in. Kagi Search API needs an API key. An agent can also pay Exa API + MCP per call over x402, with no account.

Can an agent call Exa API + MCP and Kagi Search API without installing anything?

Yes. Exa API + MCP has a hosted endpoint at https://mcp.exa.ai/mcp and Kagi Search API at https://kagi.com/api/v1/search.

Are Exa API + MCP and Kagi Search API open source?

Exa API + MCP is open source (MIT). No open-source release is listed for Kagi Search API.

Other comparisons with Exa API + MCP or Kagi Search API

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