How to integrate Hunter MCP with Codex

Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With Hunter MCP integration, you can draft, triage, summarise emails, and much more, all without leaving the terminal or the app, whichever you prefer.

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Api Key

Hunter is an email marketing platform for lead generation and contact data enrichment. It helps you quickly find and verify professional email addresses to boost outreach.

26 Tools

Introduction

Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With Hunter MCP integration, you can draft, triage, summarise emails, and much more, all without leaving the terminal or the app, whichever you prefer.

Also integrate Hunter with

Why use Composio?

Apart from a managed and hosted MCP server, you will get:

  • CodeAct: A dedicated workbench that allows GPT to write its code to handle complex tool chaining. Reduces to-and-fro with LLMs for frequent tool calling.
  • Large tool responses: Handle them to minimise context rot.
  • Dynamic just-in-time access to 20,000 tools across 1000+ other Apps for cross-app workflows. It loads the tools you need, so GPTs aren't overwhelmed by tools you don't need.

How to install Hunter MCP in Codex

Run the setup command

Run this command in your terminal to add the Composio MCP server to Codex.

Terminal

It will initiate the authentication in a browser window, authorize Codex to access your Composio account.

Composio authentication page

(Optional) Authenticate with OAuth

To authenticate manually, run the login command to open a browser window and authorize Codex to access your Composio account.

bash
codex mcp login composio

Verify the connection

Run codex mcp list to confirm Composio appears as a registered MCP server.

bash
codex mcp list

Codex App

Codex App follows the same approach as VS Code.

  1. Click ⚙️ on the bottom left → MCP Servers → + Add servers → Streamable HTTP:
  2. Fill the header and Key fields with { "x-consumer-api-key" = "ck_*******" }.
  3. The Key is the Composio API key, that you can find on dashboard.composio.dev
  4. Click on Authenticate and authorize Codex to your Composio account and you're all set.
Codex App MCP setup
  1. Restart and verify if it's there in .codex/config.toml
bash
[mcp_servers.composio]
url = "https://connect.composio.dev/mcp"
http_headers = { "x-consumer-api-key" = "ck_*******" }

What is the Hunter MCP server, and what's possible with it?

The Hunter MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Hunter account. It provides structured and secure access to your lead generation and enrichment tools, so your agent can perform actions like finding emails, enriching company data, managing leads, and organizing leads lists on your behalf.

  • Email discovery and search: Instantly ask your agent to find all public email addresses for a given company or domain, complete with metadata to fuel your outreach and marketing campaigns.
  • Smart lead creation and management: Let your agent add new leads, update lead details, or delete outdated entries to keep your Hunter account organized and up-to-date.
  • Company and contact enrichment: Have the agent fetch detailed company profiles or use the Email Finder to infer the best contact email for a specific person at a target company.
  • Leads list organization: Direct your agent to create, update, or remove custom leads lists—making it easy to segment prospects for personalized marketing or sales workflows.
  • Custom attribute management: Empower your agent to create or delete custom lead attributes, tailoring your CRM data fields to match your unique business needs.

Conclusion

You've successfully integrated Hunter with Codex using Composio's MCP server. Now you can interact with Hunter directly from your terminal, VS Code, or the Codex App using natural language commands.

Key benefits of this setup:

  • Seamless integration across CLI, VS Code, and standalone app
  • Natural language commands for Hunter operations
  • Managed authentication through Composio
  • Access to 20,000+ tools across 1000+ apps for cross-app workflows
  • CodeAct workbench for complex tool chaining

Next steps:

  • Try asking Codex to perform various Hunter operations
  • Explore cross-app workflows by connecting more toolkits
  • Build automation scripts that leverage Codex's AI capabilities
TOOLS

Supported Tools

Every Hunter action and event your agent gets out of the box.

Account Information

Tool to retrieve information about your Hunter account.

Combined Enrichment

Tool to find both person and company information from an email address or LinkedIn handle in a single request.

Company Enrichment

Tool to get enrichment information for a company by its domain.

Create custom lead attribute

Tool to create a new custom lead attribute in your account.

Create Lead

Tool to create a new lead.

Create Leads List

Tool to create a new leads list.

Delete Custom Attribute

Tool to delete an existing custom attribute.

Delete Lead

Tool to delete a lead.

Delete Leads List

Tool to delete a leads list by its ID.

Discover Companies

Tool to search and retrieve companies matching specified criteria using filters or natural language queries.

Domain Search

Tool to search all email addresses for a given domain or company.

Email Count

Tool to get the total number of email addresses Hunter has for a domain or company with breakdowns by type, department, and seniority.

Email Finder

Tool to find the most likely email address for a person at a domain or company.

Email Verifier

Tool to verify the deliverability of an email address.

Get Custom Attribute

Tool to retrieve details of a specific custom attribute.

Get Lead

Tool to retrieve details of a specific lead by ID.

Get Leads List

Tool to retrieve details of a specific leads list by ID.

List Campaigns

Tool to get all email campaigns in your Hunter account.

List Custom Attributes

Tool to list all custom lead attributes in your account.

List Leads

Tool to list all leads saved in your account with optional filters.

List Leads Lists

Tool to list all leads lists in your account.

People Enrichment

Tool to find all information associated with an email address or LinkedIn profile including name, location, job title and social handles.

Update Custom Attribute

Tool to update an existing custom attribute's label.

Update Lead

Tool to update details of an existing lead by ID.

Update Leads List

Tool to update the name of a specific leads list.

Upsert Lead

Tool to create or update a lead by email in one call.

FAQ

Frequently asked questions

With a standalone Hunter MCP server, the agents and LLMs can only access a fixed set of Hunter tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Hunter and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. Codex fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Hunter tools.

Yes, absolutely. You can configure which Hunter scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Hunter data and credentials are handled as safely as possible.

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