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Head to head · Lead search · October 2026 research run

Clay vs ZoomInfo API + MCP

ZoomInfo API + MCP scores 72.2 (BB) on agent readiness against Clay's 57.7 (C), and leads in 6 of 7 scored categories. 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 ZoomInfo API + MCPZoomInfo Technologies LLC · HTTP API BB72.2/100#113 of 1076

Which one, for what

Clay C

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

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

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

ZoomInfo API + MCP BB

Best for Sales and marketing agents that need company, contact, intent and business-event data from one vendor, with free search before paid enrichment.

Ahead on

  • Reliability, 87 against 45
  • Agent ergonomics, 71 against 66
  • Security & auth, 65 against 48
  • Payments & pricing, 40 against 30
  • Transparency & trust, 75 against 64

Also in its favour

  • Agent-ready, a grade of BB or better

Watch for

The Licence Terms and Conditions bar disclosing benchmark results and automated access outside ZoomInfo's own tools without written approval

Score by category

CategoryWeight this runClayZoomInfo API + MCPEdge
Reliability16%204587ZoomInfo API + MCP +42
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28484even
Agent ergonomics13%16.26671ZoomInfo API + MCP +5
Security & auth14%17.54865ZoomInfo API + MCP +17
Payments & pricing10%12.53040ZoomInfo API + MCP +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.87576ZoomInfo API + MCP +1
Transparency & trust7%8.86475ZoomInfo API + MCP +11
Negative events≤1500
TotalC 57.7/100BB 72.2/100

Facts side by side

FactClayZoomInfo API + MCP
KindHTTP APIHTTP API
VendorClay Labs Inc.ZoomInfo Technologies LLC
Hosted endpointhttps://api.clay.com/public/v0https://api.zoominfo.com/gtm
TransportsHTTPHTTP, Streamable HTTP
AuthOAuth or keyOAuth
PricingFreemiumFreemium
x402nono
LicenceProprietary service under the Clay Terms of Service. The agent plugin repository carries no licence fileProprietary service under ZoomInfo's Licence Terms and Conditions. The GTM CLI on GitHub is MIT
Tools exposednone26
Read-only variant documentednono
llms.txtyesyes
Last release2026-10-062026-10-02
Terms last updated2024-05-23no date given
Privacy policy last updated2020-09-112025-10-13
Customer content may train modelsnot found in the textyes, with an opt-out
Terms restrict automated accessnot found in the textyes
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
Popularitynone534 npm/wk

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.

ZoomInfo API + MCP

Search, lookup and similar-record calls cost no credits, and a free account with 1,000 data and 1,000 AI credits needs no card. OAuth carries 20 scopes and limits are published per package. The Licence Terms and Conditions bar disclosing benchmark results, and the two documentation sites disagree on batch sizes and rate-limit headers.

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

ZoomInfo API + MCP

  1. Call Lookup first and pass the returned IDs to Search. Unknown industry, metro or topic strings are rejected with a 422
  2. Search before Enrich. Search is free, and each newly enriched record costs one data credit
  3. Request only the scopes the task needs in the scope parameter of the token call. Omitting it grants every scope configured on the app
  4. On 429 read X-RateLimit-Rejected-Bucket and wait for Retry-After. An exhausted hourly window can mean a wait of several hundred seconds
  5. Turn off model training in the AI client before connecting the MCP server. ZoomInfo prohibits MCP data being used for training

Questions

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

ZoomInfo API + MCP scores 72.2 (BB) on agent readiness against Clay's 57.7 (C), and leads in 6 of 7 scored categories.

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

Clay takes an API key or an OAuth sign-in. ZoomInfo API + MCP uses an OAuth sign-in.

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

Yes. Clay has a hosted endpoint at https://api.clay.com/public/v0 and ZoomInfo API + MCP at https://api.zoominfo.com/gtm.

Other comparisons with Clay or ZoomInfo API + MCP

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