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Head to head · Lead search · October 2026 research run

Clay vs FullEnrich API + MCP

FullEnrich API + MCP scores 59.6 (C) on agent readiness against Clay's 57.7 (C), and leads in 3 of 7 scored categories. Clay leads on schema & documentation, agent ergonomics and maintenance & community. Both do lead search.

Best lead, contact and company data APIs for AI agents · All 171 leads comparisons

ClayClay Labs Inc. · HTTP API C57.7/100#633 of 1076 FullEnrich API + MCPFullEnrich · HTTP API C59.6/100#572 of 1076

Which one, for what

Clay C

Best for Agents building prospect lists and enriching contacts or accounts through many providers at once.

Ahead on

  • Schema & documentation, 84 against 72
  • Agent ergonomics, 66 against 60
  • Maintenance & community, 75 against 68

Watch for

API keys carry no scopes and act with the user's workspace access

FullEnrich API + MCP C

Best for Maximising find rate on known contacts, especially mobiles, without a long-term contract.

Ahead on

  • Reliability, 60 against 45
  • Security & auth, 55 against 48
  • Payments & pricing, 40 against 30

Also in its favour

  • Free to start without a card

Watch for

Enrichment sources are third-party providers the vendor doesn't name

Score by category

CategoryWeight this runClayFullEnrich API + MCPEdge
Reliability16%204560FullEnrich API + MCP +15
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28472Clay +12
Agent ergonomics13%16.26660Clay +6
Security & auth14%17.54855FullEnrich API + MCP +7
Payments & pricing10%12.53040FullEnrich API + MCP +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87568Clay +7
Transparency & trust7%8.86464even
Negative events≤1500
TotalC 57.7/100C 59.6/100

Facts side by side

FactClayFullEnrich API + MCP
KindHTTP APIHTTP API
VendorClay Labs Inc.FullEnrich
Hosted endpointhttps://api.clay.com/public/v0https://app.fullenrich.com/api/v2
TransportsHTTPHTTP, Streamable HTTP
AuthOAuth or keyOAuth or key
PricingFreemiumFreemium
x402nono
LicenceProprietary service under the Clay Terms of Service. The agent plugin repository carries no licence filenone
Tools exposednone13
Read-only variant documentednono
llms.txtyesyes
MCP registrynot listedio.github.FullEnrich/fullenrich
Last release2026-10-062026-08-27
Terms last updated2024-05-232026-08-20
Privacy policy last updated2020-09-112026-08-20
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessnot found in the textnot found in the text
Terms restrict benchmarkingnot found in the textyes
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waiveryesyes
Agent reviewsnone3.5/5 (2)

Verdicts

Clay

A documented Public API with an OpenAPI spec, llms.txt and plan-capped search, plus a JSON-first CLI released several times a fortnight, give agents Clay's people search and multi-provider enrichment. Keys have no scopes, the Claude Code plugin auto-approves most CLI calls, and the privacy policy dates from 2020.

FullEnrich API + MCP

Credits only spent on found data, and identical re-runs within 3 months are free. Enrichment sources are third-party providers the vendor doesn't name.

Before you call either

Clay

  1. Fetch GET /search/query-mode/reference before writing a search query
  2. Poll routine results until a terminal 200, since 202 means still running
  3. Expect HTTP 402 when a plan's search cap is hit, and tell the user the reset date
  4. Check GET /credits/balance before large batch runs
  5. Ask the user before enabling the plugin's auto-approve hook in a shared workspace

FullEnrich API + MCP

  1. Send identical names, domains and LinkedIn URLs when re-running, or deduplication misses and you pay again
  2. Expect 30 to 90 seconds a contact. Use the webhook or poll get_enrichment_results
  3. Ask for mobiles only when needed. They cost 10 credits against 1 for a work email
  4. Call list_industries and list_seniorities before filtering search
  5. Use the 0-credit test contacts in the docs to check an integration

Questions

Which is better for AI agents, Clay or FullEnrich API + MCP?

FullEnrich API + MCP scores 59.6 (C) on agent readiness against Clay's 57.7 (C), and leads in 3 of 7 scored categories. Clay leads on schema & documentation, agent ergonomics and maintenance & community.

Do Clay and FullEnrich API + MCP need an API key?

Both take an API key or an OAuth sign-in.

Can an agent call Clay and FullEnrich API + MCP without installing anything?

Yes. Clay has a hosted endpoint at https://api.clay.com/public/v0 and FullEnrich API + MCP at https://app.fullenrich.com/api/v2.

Other comparisons with Clay or FullEnrich API + MCP

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