Hunter Automation

Power your outreach with Hunter.io -- discover email addresses by domain, find specific people's emails, verify deliverability, save leads, and track your API usage -- all through natural language commands.

Toolkit docs: composio.dev/toolkits/hunter

Setup

Add the Composio MCP server to your client configuration:
```
https://rube.app/mcp
```
Connect your Hunter.io account when prompted (API key authentication).
Start issuing natural language commands to find and verify emails.

Core Workflows

1. Search Domain for Email Addresses

Discover all publicly available email addresses for a given domain or company, with filtering by department, seniority, and type.

Tool: HUNTER_DOMAIN_SEARCH

Example prompt:

"Find all executive email addresses at stripe.com using Hunter"

Key parameters:

domain -- Domain to search (e.g., "stripe.com"). Required if company not provided.
company -- Company name to search (e.g., "Stripe"). Required if domain not provided.
type -- Filter by "personal" or "generic" emails
seniority -- Filter by levels: "junior", "senior", "executive" (array)
department -- Filter by departments: "executive", "it", "finance", "sales", etc. (array)
required_field -- Require specific fields: "full_name", "position", "phone_number" (array)
limit -- Max results per request (1-100, default 10; free/basic plans limited to 10)
offset -- Skip results for pagination (default 0)

2. Find a Specific Person's Email

Infer the most likely email address for a person given their name and domain or company.

Tool: HUNTER_EMAIL_FINDER

Example prompt:

"Find the email for Alexis Ohanian at reddit.com using Hunter"

Key parameters:

domain -- Target domain (e.g., "reddit.com"). Takes precedence over company.
company -- Company name (e.g., "Reddit"). Used if domain not provided.
Name (one of these combinations required):
- first_name + last_name (e.g., "Alexis" + "Ohanian")
- full_name (e.g., "Alexis Ohanian")
max_duration -- Max request duration in seconds (3-20, default 10). Longer durations yield more accurate results.

3. Verify Email Deliverability

Check whether an email address is valid, deliverable, and safe to send to.

Tool: HUNTER_EMAIL_VERIFIER

Example prompt:

"Verify if john.doe@example.com is a valid email address"

Key parameters:

email (required) -- The email address to verify (e.g., "john.doe@example.com")

Response includes: verification status, deliverability score, MX record validation, and risk assessment.

4. Get Email Volume Estimates

Check how many email addresses Hunter has for a domain or company -- this call is free and does not consume API credits.

Tool: HUNTER_EMAIL_COUNT

Example prompt:

"How many email addresses does Hunter have for stripe.com?"

Key parameters:

domain -- Domain to query (e.g., "stripe.com"). Required if company not provided.
company -- Company name (min 3 characters). Required if domain not provided.
type -- Filter count by "personal" or "generic" emails

Returns: Total count with breakdowns by type, department, and seniority level.

5. Save and Manage Leads

Create or update leads by email in a single upsert call -- no need to check existence first.

Tool: HUNTER_UPSERT_LEAD

Example prompt:

"Save john@stripe.com as a lead in Hunter with name John Doe, position CTO"

Key parameters:

email -- Lead's email address (primary identifier for upsert)
Name, position, company, and other lead metadata

6. Check Account Usage and Limits

Review your Hunter account plan details, remaining searches, and verification quotas before running bulk operations.

Tool: HUNTER_ACCOUNT_INFORMATION

Example prompt:

"How many Hunter API searches do I have left this month?"

Key parameters: None required.

Known Pitfalls

HTTP 401 means invalid credentials: authentication_failed errors indicate an invalid or expired API key. Fix before attempting bulk operations.
Email counts are estimates: HUNTER_EMAIL_COUNT returns approximate numbers for sizing and prioritization, not guaranteed retrievable email counts.
Domain search uses offset pagination: HUNTER_DOMAIN_SEARCH paginates via limit/offset. Do not assume the first page is complete -- continue fetching until results are empty or you hit a cap.
Empty results are not errors: HUNTER_DOMAIN_SEARCH can return emails: [] with no error. Treat as "no data found" and continue, rather than retrying as a failure.
Verification status nuances: accept_all or risky statuses from HUNTER_EMAIL_VERIFIER indicate uncertainty. Exclude these from strict deliverability workflows or handle them separately.
Free/basic plan limits: Free and basic plans limit HUNTER_DOMAIN_SEARCH to 10 results per request. Higher limits require a paid plan.
Domain format matters: Use bare domains like "stripe.com" -- do not include protocol ("https://") or "www." prefix.

Quick Reference

| Action | Tool Slug | Required Params | |---|---|---| | Search domain emails | HUNTER_DOMAIN_SEARCH | domain or company | | Find person's email | HUNTER_EMAIL_FINDER | Name + (domain or company) | | Verify email | HUNTER_EMAIL_VERIFIER | email | | Get email count | HUNTER_EMAIL_COUNT | domain or company | | Save/update lead | HUNTER_UPSERT_LEAD | email | | Check account | HUNTER_ACCOUNT_INFORMATION | None |