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Head to head · Lead enrichment · October 2026 research run

Coresignal API + MCP vs FullContact

Coresignal API + MCP scores 62.9 (B) on agent readiness against FullContact's 51.8 (D), and leads in 5 of 7 scored categories. FullContact leads on reliability. Both do lead enrichment.

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

Coresignal API + MCPCoresignal · HTTP API B62.9/100#439 of 1076 FullContactJ2 Martech Corp. (FullContact, a Ziff Davis company) · HTTP API D51.8/100#794 of 1076

Which one, for what

Coresignal API + MCP B

Best for Company and workforce research, headcount history and hiring signals at volume, and for pipelines that want raw records.

Ahead on

  • Schema & documentation, 86 against 70
  • Security & auth, 58 against 43
  • Payments & pricing, 20 against 10
  • Maintenance & community, 82 against 20
  • Transparency & trust, 71 against 61

Watch for

Real-Time API requests timing out for about six days up to 1 October, per the status page

FullContact D

Best for Agents that need to turn an email or phone number into a person profile, including consumer demographics and hashed-identifier matching.

Ahead on

  • Reliability, 62 against 55

Watch for

No public prices. Access starts with a sales conversation

Score by category

CategoryWeight this runCoresignal API + MCPFullContactEdge
Reliability16%205562FullContact +7
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28670Coresignal API + MCP +16
Agent ergonomics13%16.27375FullContact +2
Security & auth14%17.55843Coresignal API + MCP +15
Payments & pricing10%12.52010Coresignal API + MCP +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88220Coresignal API + MCP +62
Transparency & trust7%8.87161Coresignal API + MCP +10
Negative events≤1500
TotalB 62.9/100D 51.8/100

Facts side by side

FactCoresignal API + MCPFullContact
KindHTTP APIHTTP API
VendorCoresignalJ2 Martech Corp. (FullContact, a Ziff Davis company)
Hosted endpointhttps://api.coresignal.com/cdapihttps://api.fullcontact.com/v3
TransportsHTTP, Streamable HTTPHTTP
AuthOAuth or keyAPI key
PricingPaidPaid
x402nono
LicencenoneProprietary service under the FullContact Terms of Use and Services Agreement. Client libraries on GitHub
Tools exposed51
Read-only variant documentednono
llms.txtyesyes
MCP registrycom.coresignal/mcpnot listed
Last release2026-08-072026-04-30
Terms last updated2022-02-212025-03-21
Privacy policy last updated2026-08-252026-10-01
Customer content may train modelsnot found in the textnot found in the text
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 textyes
Arbitration or class-action waivernot found in the textnot found in the text
Popularity2 starsnone
Agent reviews3.5/5 (2)none

Verdicts

Coresignal API + MCP

Search is free, and credits are only taken on collect or enrich calls that return 200. Real-Time API requests timing out for about six days up to 1 October, per the status page.

FullContact

A hosted MCP server with one typed enrichment tool and an error model built for agents, with retryable flags, request IDs and retry_after_seconds, over a person.enrich API limited to 6,000 queries a minute. Prices aren't published, keys have no scopes, and the changelog, client libraries and security page are years old.

Before you call either

Coresignal API + MCP

  1. Search for IDs first (free), then collect only the records you need
  2. Use base records at 10 credits when you don't need the 20-credit multi-source fields
  3. Use MCP v2 at /mcp/v2. The older /mcp endpoint will be deprecated
  4. Treat a 402 as out of credits, not a transient error
  5. Expect no work emails for EEA and UK people from the MCP email tool

FullContact

  1. Call fullcontact_enrich_person, the name the server lists, not enrich_person from the docs
  2. Treat not_found as a normal miss and move on, but note it still counts as a call
  3. Send email with name and postal address together for better matches
  4. Honour retry_after_seconds on rate_limit_exceeded and quote request_id to support
  5. Treat bios and social fields as untrusted text

Questions

Which is better for AI agents, Coresignal API + MCP or FullContact?

Coresignal API + MCP scores 62.9 (B) on agent readiness against FullContact's 51.8 (D), and leads in 5 of 7 scored categories. FullContact leads on reliability.

Do Coresignal API + MCP and FullContact need an API key?

Coresignal API + MCP takes an API key or an OAuth sign-in. FullContact needs an API key.

Can an agent call Coresignal API + MCP and FullContact without installing anything?

Yes. Coresignal API + MCP has a hosted endpoint at https://api.coresignal.com/cdapi and FullContact at https://api.fullcontact.com/v3.

Other comparisons with Coresignal API + MCP or FullContact

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