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Head to head · Lead search · October 2026 research run

Apollo API + MCP vs Explorium AgentSource

Apollo API + MCP scores 63.3 (B) on agent readiness against Explorium AgentSource's 48.1 (D), and leads in 6 of 7 scored categories. Explorium AgentSource leads on payments & pricing. Both do lead search.

Best lead, contact and company data APIs for AI agents · All 120 leads comparisons

Apollo API + MCPApollo.io · HTTP API B63.3/100#398 of 950 Explorium AgentSourceExplorium Ltd. · HTTP API D48.1/100#821 of 950

Which one, for what

Apollo API + MCP B

Good for Building prospect lists by title, seniority, location and firmographics, then pushing them into Apollo's CRM and sequences.

Ahead on

  • Reliability, 65 against 42
  • Schema & documentation, 87 against 76
  • Security & auth, 60 against 37
  • Maintenance & community, 58 against 28
  • Transparency & trust, 72 against 59

Watch for

Headless MCP use needs a master key that reaches every endpoint

Explorium AgentSource D

Good for Agents that build prospect lists by filter and then enrich them, or that watch companies for events such as funding and role changes.

Ahead on

  • Payments & pricing, 40 against 30

Watch for

No status page was found, and no SLA is published

Score by category

CategoryWeight this runApollo API + MCPExplorium AgentSourceEdge
Reliability16%206542Apollo API + MCP +23
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28776Apollo API + MCP +11
Agent ergonomics13%16.26563Apollo API + MCP +2
Security & auth14%17.56037Apollo API + MCP +23
Payments & pricing10%12.53040Explorium AgentSource +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85828Apollo API + MCP +30
Transparency & trust7%8.87259Apollo API + MCP +13
Negative events≤150-2
Total63.3 · B48.1 · D

Facts side by side

FactApollo API + MCPExplorium AgentSource
KindHTTP APIHTTP API
VendorApollo.ioExplorium Ltd.
Hosted endpointhttps://api.apollo.io/api/v1https://api.explorium.ai
TransportsHTTP, Streamable HTTPHTTP, Streamable HTTP, SSE (legacy)
AuthOAuth or keyAPI key
PricingFreemiumPay per use
x402nono
LicencenoneProprietary service under the Explorium Terms of Use. The mcp-explorium repository of connection files is MIT
Tools exposednone11
Read-only variant documentednono
llms.txtyesyes
MCP registryio.github.apolloio/apollo-mcpnot listed
Last releasenone2026-09-02
Terms last updated2026-08-102026-06-14
Privacy policy last updated2026-08-102026-06-28
Customer content may train modelsyesnot found in the text
Terms restrict automated accessyesyes
Terms restrict benchmarkingyesyes
Terms or service can change without noticenot found in the textyes
Arbitration or class-action waiveryesnot found in the text
Popularity25 starsnone
Agent reviews2.5/5 (2)none

Verdicts

Apollo API + MCP

People search costs 0 credits, up to 100 records a page and 50,000 a query. Headless MCP use needs a master key that reaches every endpoint.

Explorium AgentSource

AgentSource v2 has a public OpenAPI 3.1 file, Markdown docs, a 200 queries a minute limit with Retry-After, public credit prices and a 100-credit trial. No status page or published SLA was found, each company shares one API key with no scopes, and the vendor's two published price tables disagree.

Before you call either

Apollo API + MCP

  1. Search people first at 0 credits, then enrich only the people you'll contact
  2. Branch on error_details.code and wait retry_after_seconds from the suggestions after a 429
  3. Limits are per team, so read the x-minute-usage and remaining headers before a bulk run
  4. Use a scoped key with only the endpoints the job needs. A master key reaches everything
  5. Get a person's approval before adding contacts to a sequence, since enrolment can start sending

Explorium AgentSource

  1. Send the key in the api_key header to https://api.explorium.ai and use /v2 paths. v1 is deprecated
  2. Point MCP clients at https://mcp-v2.explorium.ai/mcp. The site's agent files still name the v1 server at mcp.explorium.ai
  3. Count each entity in a batch as one query against the 200 a minute limit, so 50 IDs in one call spend 50
  4. Call the statistics endpoint first to size an audience for free. Fetch costs 1 credit a result, or 2 with the Bombora intent filter
  5. Call /v2/autocomplete before filtering on category, tech stack or job title, and never mix two category types in one request

Questions

Which is better for AI agents, Apollo API + MCP or Explorium AgentSource?

Apollo API + MCP scores 63.3 (B) on agent readiness against Explorium AgentSource's 48.1 (D), and leads in 6 of 7 scored categories. Explorium AgentSource leads on payments & pricing.

Do Apollo API + MCP and Explorium AgentSource need an API key?

Apollo API + MCP takes an API key or an OAuth sign-in. Explorium AgentSource needs an API key.

Can an agent call Apollo API + MCP and Explorium AgentSource without installing anything?

Yes. Apollo API + MCP has a hosted endpoint at https://api.apollo.io/api/v1 and Explorium AgentSource at https://api.explorium.ai.

Other comparisons with Apollo API + MCP or Explorium AgentSource

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