apollo-io-mcp by thevgergroup - MCP Server

Apollo.io MCP Server

A Model Context Protocol (MCP) server for Apollo.io that integrates with Claude Desktop. This server provides access to Apollo's comprehensive B2B database for people and company search, enrichment, and insights.

Apollo.io MCP Server

Features

Apollo Org and People Search covering all major Apollo.io API endpoints
Claude Desktop optimized Simple ICP discovery
Advanced filtering with Apollo.io API parameter mapping

Claude Desktop Setup

This MCP server is designed to work seamlessly with Claude Desktop. Follow these steps to get started:

Claude Desktop MCP Configuration

Step 1: Get Your Apollo API Key

Before setting up the MCP server, you'll need an Apollo API key:

Launch Apollo and go to Settings > Integrations
Find the API option and click Connect
Click "API keys" to view or create new API keys, then click Create new key
Name your API key (e.g., "Claude Desktop Integration") and add a description
Select the endpoints you need access to, or toggle "Set as master key" for full access
Click "Create API key" and copy the key to a safe location

Important: Keep your API key secure. Anyone with access to this key can make API calls through your Apollo account.

Note: API access is dependent on your Apollo pricing plan. Check Apollo's pricing page for details on API limits and features available with your plan.

For more details, see the Apollo API Key Creation Guide.

Step 2: Configure Claude Desktop

Add this configuration to your Claude Desktop MCP settings:

Using npx (Recommended)

{
  "mcpServers": {
    "apollo": {
      "command": "npx",
      "args": ["@thevgergroup/apollo-io-mcp@latest"],
      "env": {
        "APOLLO_API_KEY": "your-actual-api-key-here",
        "APOLLO_BASE_URL": "https://api.apollo.io/api/v1"
      }
    }
  }
}

If using a Developer Installation (unlikely)

{
  "mcpServers": {
    "apollo": {
      "command": "node",
      "args": ["./node_modules/@thevgergroup/apollo-io-mcp/dist/server.js"],
      "env": {
        "APOLLO_API_KEY": "your-actual-api-key-here",
        "APOLLO_BASE_URL": "https://api.apollo.io/api/v1"
      }
    }
  }
}

Replace your-actual-api-key-here with the API key you created in Step 1.

Step 3: Test the Integration

Once configured, restart Claude Desktop and try asking:

"Search for software companies in California with 50-200 employees"
"Find C-level executives in the healthcare industry"
"Enrich the company data for google.com"

Manual Setup (For Developers)

If you prefer to install from source or need to modify the code:

Clone the repository:

git clone https://github.com/thevgergroup/apollo-io-mcp
cd apollo-io-mcp

Install dependencies:

npm install

Set up environment variables:

# Only if .env doesn't already exist
cp env.example .env

Edit .env and add your Apollo.io API key:

APOLLO_API_KEY=your-actual-api-key-here
APOLLO_BASE_URL=https://api.apollo.io/api/v1

Build the project:

npm run build

Claude Desktop Configuration for Source Installation

{
  "mcpServers": {
    "apollo": {
      "command": "node",
      "args": ["/path/to/apollo-io-mcp/dist/server.js"],
      "env": {
        "APOLLO_API_KEY": "your-actual-api-key-here",
        "APOLLO_BASE_URL": "https://api.apollo.io/api/v1"
      }
    }
  }
}

Available Tools

Search Tools

`apollo_search_people`

Search for people in Apollo's database with advanced filtering options. The tool provides comprehensive filter documentation to help target specific roles, locations, seniority levels, and companies.

Available Filters:

locations: Person locations (cities, states, countries)
seniority: Seniority levels (e.g., ["C-Level", "VP", "Director"])
titles: Job titles (e.g., ["CEO", "CTO", "Sales Manager"])
departments: Departments (e.g., ["Engineering", "Sales", "Marketing"])
company_domains: Company domains (e.g., ["google.com", "microsoft.com"])
industries: Industries (e.g., ["Software", "Healthcare", "Finance"])
technologies: Technologies they use (e.g., ["python", "react", "salesforce"])

Example:

{
  "query": "CEO",
  "filters": {
    "locations": ["California"],
    "seniority": ["C-Level"],
    "industries": ["Software", "SaaS"]
  },
  "per_page": 10
}

`apollo_search_companies`

Search for companies/organizations with comprehensive filtering options. The tool provides detailed documentation for all available filters to help target specific company types, locations, sizes, and industries.

Available Filters:

organization_locations: Company locations (most effective filter)
organization_not_locations: Exclude specific locations
q_organization_keyword_tags: Industry keywords (crucial for targeting)
organization_num_employees_ranges: Employee count ranges (very restrictive)
currently_using_any_of_technology_uids: Technologies companies use
revenue_range: Revenue range in dollars
latest_funding_amount_range: Latest funding round amount
total_funding_range: Total funding amount
q_organization_job_titles: Job titles in active postings

Example:

{
  "query": "education technology",
  "filters": {
    "organization_locations": ["Virginia", "Maryland", "Washington DC"],
    "q_organization_keyword_tags": ["edtech", "online learning", "education technology"],
    "organization_num_employees_ranges": ["11,20", "21,50", "51,100"]
  },
  "per_page": 25
}

Filter Best Practices:

Start with location filters - They're most effective at narrowing results
Use specific keywords - Generic terms return too many results
Combine multiple filters - Employee ranges + location + keywords work best
Use comma-separated employee ranges - Format as "11,20" not "11-20"
Employee range filters are very restrictive - If you get 0 results, try broader ranges or remove employee filters
Test filters incrementally - Start with location + keywords, then add employee ranges if needed

Enrichment Tools

`apollo_enrich_person`

Enrich a person's profile using email, LinkedIn URL, or name+company.

`apollo_enrich_company`

Enrich a company's profile using domain or name.

`apollo_bulk_enrich_people`

Bulk enrich multiple people profiles.

`apollo_bulk_enrich_organizations`

Bulk enrich multiple organization profiles.

Additional Tools

`apollo_get_organization_job_postings`

Get job postings for a specific organization.

`apollo_get_complete_organization_info`

Get complete information for a specific organization.

`apollo_search_news_articles`

Search for news articles related to companies.

Filter Reference

Company Search Filters

Filter	Type	Description	Example
`organization_num_employees_ranges`	array	Employee count ranges (comma-separated)	`["11,20", "21,50"]`
`organization_locations`	array	Company locations	`["Virginia", "Maryland"]`
`organization_not_locations`	array	Exclude locations	`["California"]`
`q_organization_keyword_tags`	array	Industry keywords	`["edtech", "saas"]`
`q_organization_name`	string	Company name filter	`"Google"`
`currently_using_any_of_technology_uids`	array	Technologies used	`["salesforce", "aws"]`
`revenue_range`	object	Revenue range (min/max)	`{"min": 1000000, "max": 10000000}`
`latest_funding_amount_range`	object	Latest funding range	`{"min": 5000000, "max": 50000000}`
`total_funding_range`	object	Total funding range	`{"min": 10000000, "max": 100000000}`

People Search Filters

Filter	Type	Description	Example
`locations`	array	Person locations	`["California", "New York"]`
`seniority`	array	Seniority levels	`["C-Level", "VP"]`
`departments`	array	Departments	`["Engineering", "Sales"]`
`titles`	array	Job titles	`["CEO", "CTO"]`

Claude Desktop Integration

This MCP server has been thoroughly tested and works seamlessly with Claude Desktop. All tests pass and the MCP protocol is fully implemented. The server includes 9 comprehensive tools covering all major Apollo.io API endpoints.

Optimized for Claude Desktop: Responses are simplified and optimized for Claude Desktop compatibility, reducing response size by up to 94% while preserving all essential information.

Testing

Run all tests:

npm test

Run CLI integration test:

node test-cli.js

Test specific filters:

node test-filters.js

Test MCP Inspector integration:

node test-inspector.js

Test with MCP Inspector (Visual Testing Tool)

The MCP Inspector provides a visual interface for testing and debugging MCP servers.

Setup Inspector:

# Install dependencies and setup inspector
npm install
./setup-inspector.sh

The setup script will automatically configure the MCP Inspector with your API key from the .env file.

MCP Inspector Configuration

The inspector uses this configuration (automatically set up by the script):

{
  "mcpServers": {
    "apollo": {
      "command": "node",
      "args": ["dist/server.js"],
      "env": {
        "APOLLO_API_KEY": "your-api-key-here",
        "APOLLO_BASE_URL": "https://api.apollo.io/api/v1"
      }
    }
  }
}

Run Inspector (UI Mode):

npm run inspector

This opens a web interface at http://localhost:6274 where you can:

Browse all available tools with their documentation
Test tools with form-based parameter input
View real-time responses and errors
Explore the MCP protocol implementation

Run Inspector (CLI Mode):

# List all available tools
npm run inspector:cli -- --method tools/list

# Test company search
npm run inspector:cli -- --method tools/call --tool-name apollo_search_companies --tool-arg query='education technology' --tool-arg per_page=5

# Test with filters
npm run inspector:cli -- --method tools/call --tool-name apollo_search_companies --tool-arg query='edtech' --tool-arg 'filters={"organization_locations":["Virginia"],"q_organization_keyword_tags":["edtech"]}' --tool-arg per_page=3

Inspector Features:

Visual Tool Testing: Form-based interface for all tools
Real-time Response Viewing: See API responses as they come in
Error Debugging: Visual error messages and stack traces
Protocol Inspection: View the underlying MCP protocol messages
Documentation Display: See all tool descriptions and parameter schemas

Environment Setup

The API key setup is covered in the Claude Desktop Setup section above. For reference:

For npx/npm users: Set environment variables in your Claude Desktop MCP configuration
For source users: Create a .env file in the project directory with your API key

Troubleshooting

Common Issues

"Unauthorized" errors: Check your APOLLO_API_KEY in the .env file or environment variables
"Rate limited" errors: You've hit Apollo's API rate limits. Check your Apollo API usage dashboard for current limits
Large result sets: Use more specific filters to narrow results
Empty company results: Try different filter combinations or check API limits
API access denied: Some endpoints require specific API key permissions. Ensure your key has access to the endpoints you're trying to use

Filter Best Practices

Start with location filters - They're most effective at narrowing results
Use specific keywords - Generic terms return too many results
Combine multiple filters - Employee ranges + location + keywords work best
Use comma-separated employee ranges - Format as "11,20" not "11-20"
Employee range filters are very restrictive - If you get 0 results, try broader ranges or remove employee filters
Test filters incrementally - Start with location + keywords, then add employee ranges if needed

API References

Contributing

Fork the repository
Create a feature branch
Make your changes
Add tests for new functionality
Submit a pull request

Releasing

This project uses semantic versioning and automated publishing. See for detailed instructions.

Quick release commands:

npm run release:patch  # Bug fixes
npm run release:minor  # New features
npm run release:major  # Breaking changes

License

This project is licensed under the MIT License - see the LICENSE file for details.