How do I find my Harmonic API Key?

Log in to your Harmonic account, go to the **Console**, and navigate to the **API** section. You will be able to generate and copy your unique apikey from there.

What happens if a company is not found in the database?

If a company is not found, Harmonic will return a `201 Enrichment Triggered` status. This means a background update has been queued. You can check the status later using the `get_enrichment_status` tool.

Can I search for companies based on specific criteria?

Yes! Use the `search_startups` tool. You can provide a JSON string with filters like headcount, location, or industry to find companies that match your investment or sales criteria.

Is the integration secure?

Absolutely. The integration only accesses your data through your unique API key. Your credentials are encrypted and stored securely within the Vinkius Cloud infrastructure.

Harmonic MCP Server for LangChain 11 tools — connect in under 2 minutes

Name: Harmonic
Availability: InStock
Author: Vinkius

python.langchain.com/docs/integrations/tools/mcp

Built by Vinkius GDPR 11 Tools Framework

LangChain is the leading Python framework for composable LLM applications. Connect Harmonic through Vinkius and LangChain agents can call every tool natively. combine them with retrievers, memory, and output parsers for sophisticated AI pipelines.

Get MCP Server for AI Agents

ASK AI ABOUT THIS MCP SERVER

Open in ChatGPT Open in Claude Open in Perplexity

Vinkius supports streamable HTTP and SSE.

python

import asyncio
from langchain_mcp_adapters.client import MultiServerMCPClient
from langchain_openai import ChatOpenAI
from langgraph.prebuilt import create_react_agent

async def main():
    # Your Vinkius token. get it at cloud.vinkius.com
    async with MultiServerMCPClient({
        "harmonic": {
            "transport": "streamable_http",
            "url": "https://edge.vinkius.com/[YOUR_TOKEN_HERE]/mcp",
        }
    }) as client:
        tools = client.get_tools()
        agent = create_react_agent(
            ChatOpenAI(model="gpt-4o"),
            tools,
        )
        response = await agent.ainvoke({
            "messages": [{
                "role": "user",
                "content": "Using Harmonic, show me what tools are available.",
            }]
        })
        print(response["messages"][-1].content)

asyncio.run(main())

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Stream every event to Splunk, Datadog, or your own webhook in real-time

* Every MCP server runs on Vinkius-managed infrastructure inside AWS - a purpose-built runtime with per-request V8 isolates, Ed25519 signed audit chains, and sub-40ms cold starts optimized for native MCP execution. See our infrastructure

About Harmonic MCP Server

Connect your Harmonic.ai account to any AI agent and take full control of your startup discovery and investment research through natural conversation.

LangChain's ecosystem of 500+ components combines seamlessly with Harmonic through native MCP adapters. Connect 11 tools via Vinkius and use ReAct agents, Plan-and-Execute strategies, or custom agent architectures. with LangSmith tracing giving full visibility into every tool call, latency, and token cost.

What you can do

Company Enrichment — Instantly retrieve firmographics, funding history, and social traction signals for any domain.
Person Insights — Enrich professional profiles using LinkedIn URLs to get education and career history.
Startup Discovery — Search through over 35 million companies using advanced filters like headcount growth and industry.
Investor Research — Find investment firms and angels, and inspect their full portfolio history.
Funding Monitoring — List and retrieve details for funding rounds, including amounts and lead investors.
Enrichment Status — Track background data refresh requests to ensure you have the most up-to-date information.

The Harmonic MCP Server exposes 11 tools through the Vinkius. Connect it to LangChain in under two minutes — no API keys to rotate, no infrastructure to provision, no vendor lock-in. Your configuration, your data, your control.

How to Connect Harmonic to LangChain via MCP

Follow these steps to integrate the Harmonic MCP Server with LangChain.

Install dependencies

Run pip install langchain langchain-mcp-adapters langgraph langchain-openai

Replace the token

Replace [YOUR_TOKEN_HERE] with your Vinkius token

Run the agent

Save the code and run python agent.py

Explore tools

The agent discovers 11 tools from Harmonic via MCP

Why Use LangChain with the Harmonic MCP Server

LangChain provides unique advantages when paired with Harmonic through the Model Context Protocol.

The largest ecosystem of integrations, chains, and agents. combine Harmonic MCP tools with 500+ LangChain components

Agent architecture supports ReAct, Plan-and-Execute, and custom strategies with full MCP tool access at every step

LangSmith tracing gives you complete visibility into tool calls, latencies, and token usage for production debugging

Memory and conversation persistence let agents maintain context across Harmonic queries for multi-turn workflows

Harmonic + LangChain Use Cases

Practical scenarios where LangChain combined with the Harmonic MCP Server delivers measurable value.

RAG with live data: combine Harmonic tool results with vector store retrievals for answers grounded in both real-time and historical data

Autonomous research agents: LangChain agents query Harmonic, synthesize findings, and generate comprehensive research reports

Multi-tool orchestration: chain Harmonic tools with web scrapers, databases, and calculators in a single agent run

Production monitoring: use LangSmith to trace every Harmonic tool call, measure latency, and optimize your agent's performance

Harmonic MCP Tools for LangChain (11)

These 11 tools become available when you connect Harmonic to LangChain via MCP:

enrich_company

Enrich a company with firmographics, funding, and social signals

enrich_person

Enrich a person with professional history and social signals

get_api_profile

Get information about the current API user

get_company_stats

Get growth and headcount statistics for a company

get_enrichment_status

Check the status of a background enrichment request

get_investor_portfolio

Get the list of portfolio companies for an investor

list_company_news

List recent news and press releases for a company

list_funding_rounds

List funding rounds for a specific company

list_traction_signals

List social and web traction signals for a company

search_investors

Search for investment firms and angels

search_startups

Search for startups using filters like industry, location, and headcount

Example Prompts for Harmonic in LangChain

Ready-to-use prompts you can give your LangChain agent to start working with Harmonic immediately.

"Enrich the domain 'openai.com' and show funding rounds."

"Search for startups in 'Artificial Intelligence' with 50-200 employees."

"Show me the portfolio companies for 'Sequoia Capital'."

Troubleshooting Harmonic MCP Server with LangChain

Common issues when connecting Harmonic to LangChain through the Vinkius, and how to resolve them.

MultiServerMCPClient not found

Install: pip install langchain-mcp-adapters

Harmonic + LangChain FAQ

Common questions about integrating Harmonic MCP Server with LangChain.

How does LangChain connect to MCP servers?

Use langchain-mcp-adapters to create an MCP client. LangChain discovers all tools and wraps them as native LangChain tools compatible with any agent type.

Which LangChain agent types work with MCP?

All agent types including ReAct, OpenAI Functions, and custom agents work with MCP tools. The tools appear as standard LangChain tools after the adapter wraps them.