Harmonic MCP Server

Community MCP server for the Harmonic.ai API. Search and enrich companies and people for VC deal flow, with saved search monitoring.

Data & Enrichment by alludium (community) API Key active

GitHub Docs npm: @alludium/harmonic-mcp-server

Overview

Harmonic MCP Server is a community-built Model Context Protocol server (maintained by alludium) that exposes the Harmonic.ai API to AI agents. Harmonic.ai is a startup intelligence platform that tracks over 29M companies and 190M people, used primarily by venture capital, business development, and recruiting teams to discover early-stage startups, monitor funding events, and source talent.

The server provides 13 tools that cover company discovery (natural language search, typeahead autocomplete, similar company lookup), company enrichment (by domain, LinkedIn URL, or Harmonic ID), employee and network connection lookups, person enrichment, and management of Harmonic saved searches including net-new result monitoring. It implements automatic throttling and retry logic to stay within Harmonic's 10 requests-per-second rate limit.

Note that this is not an officially endorsed server from Harmonic.ai; it is a community wrapper around the public Harmonic API. A second community implementation (blue-yard/harmonic-mcp-server) exists with fewer tools. Both require a Harmonic API key, which is only available to paying Harmonic customers.

Tools

Tool	Description
`harmonic_search_companies`	Natural language search for companies in Harmonic's database.
`harmonic_search_typeahead`	Quick autocomplete-style search by company name or domain.
`harmonic_find_similar_companies`	Return companies similar to a given company.
`harmonic_lookup_company`	Look up a company by domain or LinkedIn URL.
`harmonic_get_company`	Retrieve full company details by Harmonic ID.
`harmonic_get_company_employees`	List employees of a company with role filters.
`harmonic_get_company_connections`	Identify network/team connections for a company.
`harmonic_lookup_person`	Look up a person by LinkedIn URL.
`harmonic_get_person`	Retrieve full person profile by Harmonic ID.
`harmonic_list_saved_searches`	List all saved searches on the account.
`harmonic_get_saved_search_results`	Retrieve results from a saved search.
`harmonic_get_saved_search_net_new_results`	Get newly matching results since last review.
`harmonic_clear_saved_search_net_new`	Mark net-new saved search results as reviewed.

Setup Guide

Prerequisites

A Harmonic.ai account with API access
A Harmonic API key from console.harmonic.ai/docs/dashboard
Node.js 18+ for the npx setup

Install

Run directly via npx (no install needed):

npx -y @alludium/harmonic-mcp-server

Or install globally:

npm install -g @alludium/harmonic-mcp-server

Claude Desktop / Cursor config

Add the following to claude_desktop_config.json (macOS path: ~/Library/Application Support/Claude/claude_desktop_config.json):

{
  "mcpServers": {
    "harmonic": {
      "command": "npx",
      "args": ["-y", "@alludium/harmonic-mcp-server"],
      "env": {
        "HARMONIC_API_KEY": "your_api_key_here"
      }
    }
  }
}

Restart Claude Desktop after saving. The server applies automatic throttling and retry to stay under Harmonic's 10 requests/second rate limit.

Use Cases

Build an AI sourcing agent that runs natural language queries like "seed-stage AI infra companies in Europe" against Harmonic, then enriches each hit with funding and team data.
Monitor saved searches for net-new matches and automatically draft outreach for founders who fit the investment thesis.
Enrich a target list of domains or LinkedIn URLs with Harmonic firmographics, headcount, and connection signals before a VC partner meeting.
Map out a company's team by pulling employees with role filters (e.g., engineering leadership) for recruiting or BD outreach.
Find lookalikes for a portfolio company using harmonic_find_similar_companies and rank them for competitive intelligence.

Example Prompts

"Search Harmonic for pre-seed AI agent companies founded in 2024 and return the top 20 with founders and total funding."
"Look up acme.com in Harmonic and list all engineering employees plus any warm connections from my network."
"Show me net-new results in my 'Vertical SaaS Seed' saved search and clear them after I review."
"Find 10 companies similar to Linear and summarize their headcount and last funding round."
"Get the full Harmonic profile for the founder at this LinkedIn URL and tell me their prior roles."

Pros

Comprehensive coverage of the Harmonic API: 13 tools across company search, enrichment, people, and saved searches.
Built-in rate-limit handling with automatic throttling and retry for Harmonic's 10 req/s cap.
Simple npx-based install with a single API key environment variable.
MIT licensed and runnable locally with no extra infrastructure.

Limitations

Community-maintained, not officially endorsed by Harmonic.ai; minimal stars/forks and limited release history.
Requires a paid Harmonic API key; there is no free tier.
Read-focused: no tools for creating or editing Harmonic lists, notes, or CRM-style records.

Alternatives

blue-yard/harmonic-mcp-server: A simpler community Harmonic MCP wrapper with ~6 tools covering company and people search.
Clearbit / Apollo / People Data Labs MCP servers: General-purpose company and contact enrichment alternatives if you do not need startup-specific signals.
Direct use of the Harmonic REST API via a custom function-calling tool if you want full control over endpoints and pagination.