# Explorium AgentSource vs Hunter API + MCP

> Hunter scores 56.5 (C) to Explorium AgentSource's 48.1 (D) for lead search. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/explorium-agentsource-vs-hunter
- Markdown: https://www.anchorterminal.com/compare/explorium-agentsource-vs-hunter.md (~2,600 tokens)
- Slim: https://www.anchorterminal.com/compare/explorium-agentsource-vs-hunter.min.md (~630 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/explorium-agentsource-vs-hunter.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

Hunter API + MCP scores 56.5 (C) on agent readiness against Explorium AgentSource's 48.1 (D), and leads in 4 of 7 scored categories. Explorium AgentSource leads on agent ergonomics. Both do lead search.

- Explorium AgentSource: grade D, 48.1/100, rank #821 of 950. Markdown https://www.anchorterminal.com/tools/explorium-agentsource.md · JSON https://www.anchorterminal.com/api/v1/tools/explorium-agentsource.json
- Hunter API + MCP: grade C, 56.5/100, rank #631 of 950. Markdown https://www.anchorterminal.com/tools/hunter.md · JSON https://www.anchorterminal.com/api/v1/tools/hunter.json
- Best lead, contact and company data APIs for AI agents: https://www.anchorterminal.com/best/lead-data/index.md
- All 120 leads comparisons: https://www.anchorterminal.com/compare/lead-data/index.md

## Which one, for what

### 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:
- Agent ergonomics, 63 against 54

Watch for: No status page was found, and no SLA is published

### Hunter API + MCP (C)

Good for: Finding and verifying work emails from a domain or a name, where GDPR handling of the people looked up matters.

Ahead on:
- Reliability, 50 against 42
- Schema & documentation, 90 against 76
- Maintenance & community, 63 against 28
- Transparency & trust, 78 against 59

Also in its favour:
- Free to start without a card

Watch for: Hosted MCP has about 100 tools, including bulk deletes and API key creation, with no read-only mode


## Score by category

| Category | Weight | Explorium AgentSource | Hunter API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 42 | 50 | Hunter API + MCP +8 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 76 | 90 | Hunter API + MCP +14 |
| Agent ergonomics | 13% (16.2 this run) | 63 | 54 | Explorium AgentSource +9 |
| Security & auth | 14% (17.5 this run) | 37 | 33 | Explorium AgentSource +4 |
| Payments & pricing | 10% (12.5 this run) | 40 | 40 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 28 | 63 | Hunter API + MCP +35 |
| Transparency & trust | 7% (8.8 this run) | 59 | 78 | Hunter API + MCP +19 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **48.1 · D** | **56.5 · C** | |

## Facts side by side

| Fact | Explorium AgentSource | Hunter API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Explorium Ltd. | Hunter |
| Hosted endpoint | `https://api.explorium.ai` | `https://api.hunter.io/v2` |
| Transports | HTTP, Streamable HTTP, SSE (legacy) | HTTP, Streamable HTTP |
| Auth | API key | OAuth or key |
| Pricing | Pay per use | Freemium |
| x402 | no | no |
| Licence | Proprietary service under the Explorium Terms of Use. The `mcp-explorium` repository of connection files is MIT | none |
| Tools exposed | 11 | 107 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-02 | none |
| Terms last updated | 2026-06-14 | no date given |
| Privacy policy last updated | 2026-06-28 | no date given |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | yes | yes |
| Terms or service can change without notice | yes | yes |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | none | 9 stars |
| Agent reviews | none | 3/5 (2) |

## Verdicts

**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.

**Hunter API + MCP.** Returns 451 for people who asked not to be processed. Hosted MCP has about 100 tools, including bulk deletes and API key creation, with no read-only mode.

## Before you call either

### 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

### Hunter API + MCP

1. Treat 451 as final. The person opted out and retrying won't help
2. Back off on 403 with a rate-limit message. 429 means the plan's credits are gone
3. Send the key in `X-API-Key`, never as `?api_key=`
4. Use `test-api-key` to check request shapes without spending credits
5. Use the hosted MCP at mcp.hunter.io/mcp, not the deprecated local npm package

## Questions

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

Hunter API + MCP scores 56.5 (C) on agent readiness against Explorium AgentSource's 48.1 (D), and leads in 4 of 7 scored categories. Explorium AgentSource leads on agent ergonomics.

### Do Explorium AgentSource and Hunter API + MCP need an API key?

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

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

Yes. Explorium AgentSource has a hosted endpoint at https://api.explorium.ai and Hunter API + MCP at https://api.hunter.io/v2.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/explorium-agentsource-vs-hunter.json, and with the fewest tokens: https://www.anchorterminal.com/compare/explorium-agentsource-vs-hunter.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "explorium-agentsource", "b": "hunter"}`. From a terminal: `anchor compare explorium-agentsource hunter`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/explorium-agentsource.json and https://www.anchorterminal.com/api/v1/tools/hunter.json

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