How to integrate Affinity MCP with Claude Agent SDK

This guide walks you through connecting Affinity to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Affinity agent that can list all companies added this week, show all opportunities in active pipeline, get recent contacts linked to acme corp through natural language commands. This guide will help you understand how to give your Claude Agent SDK agent real control over a Affinity account through Composio's Affinity MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Affinity is a relationship intelligence CRM that helps private capital investors find, manage, and close more deals. It streamlines deal flow and surfaces key connections to help you win opportunities.

20 Tools

Introduction

This guide walks you through connecting Affinity to the Claude Agent SDK using the Composio tool router. By the end, you'll have a working Affinity agent that can list all companies added this week, show all opportunities in active pipeline, get recent contacts linked to acme corp through natural language commands.

This guide will help you understand how to give your Claude Agent SDK agent real control over a Affinity account through Composio's Affinity MCP server.

Before we dive in, let's take a quick look at the key ideas and tools involved.

Also integrate Affinity with

OpenAI Agents SDKClaude CodeClaude CoworkCodexOpenClawHermesCLIGoogle ADKLangChainVercel AI SDKMastra AILlamaIndexCrewAI

TL;DR

Here's what you'll learn:
  • Get and set up your Claude/Anthropic and Composio API keys
  • Install the necessary dependencies
  • Initialize Composio and create a Tool Router session for Affinity
  • Configure an AI agent that can use Affinity as a tool
  • Run a live chat session where you can ask the agent to perform Affinity operations

What is Claude Agent SDK?

The Claude Agent SDK is Anthropic's official framework for building AI agents powered by Claude. It provides a streamlined interface for creating agents with MCP tool support and conversation management.

Key features include:

  • Native MCP Support: Built-in support for Model Context Protocol servers
  • Permission Modes: Control tool execution permissions
  • Streaming Responses: Real-time response streaming for interactive applications
  • Context Manager: Clean async context management for sessions

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

The Affinity MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Affinity account. It provides structured and secure access to your deal, company, and contact data, so your agent can analyze lists, fetch opportunity details, extract company insights, and organize people or organizations on your behalf.

  • Company data extraction and analysis: Let your agent retrieve detailed company profiles, summarize list entries, and pull custom field data for deeper insights and reporting.
  • Opportunity pipeline management: Automatically fetch and review all ongoing opportunities, track changes, and surface high-priority deals for follow-up.
  • List and view organization: Ask your agent to access entries across lists or saved views, aggregating metadata and field values for efficient CRM workflows.
  • Contact and relationship intelligence: Effortlessly browse, analyze, and summarize person records, including their list memberships, activity, and custom fields.
  • Automated CRM reporting: Generate summaries, export data, and monitor changes across companies, people, and opportunities to keep your pipeline up-to-date and actionable.

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

Composio's Composio SDK helps agents find the right tools for a task at runtime. You can plug in multiple toolkits (like Gmail, HubSpot, and GitHub), and the agent will identify the relevant app and action to complete multi-step workflows. This can reduce token usage and improve the reliability of tool calls. Read more here: Getting started with Composio SDK

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Composio SDK works

The Composio SDK follows a three-phase workflow:

  1. Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
  2. Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
  3. Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step09 STEPS
1

Prerequisites

Before starting, make sure you have:
  • Composio API Key and Claude/Anthropic API Key
  • Primary know-how of Claude Agents SDK
  • A Affinity account
  • Some knowledge of Python
2

Getting API Keys for Claude/Anthropic and Composio

Claude/Anthropic API Key
  • Go to the Anthropic Console and create an API key. You'll need credits to use the models.
  • Keep the API key safe.
Composio API Key
  • Log in to the Composio dashboard.
  • Navigate to your API settings and generate a new API key.
  • Store this key securely as you'll need it for authentication.
3

Install dependencies

npm install @anthropic-ai/claude-agent-sdk @composio/core dotenv

Install the Composio SDK and the Claude Agents SDK.

What's happening:

  • @composio/core provides Composio integration for Anthropic
  • @anthropic-ai/claude-agent-sdk is the core agent framework
  • dotenv/config loads environment variables
4

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
USER_ID=your_user_id_here
ANTHROPIC_API_KEY=your_anthropic_api_key_here

Create a .env file in your project root.

What's happening:

  • COMPOSIO_API_KEY authenticates with Composio
  • USER_ID identifies the user for session management
  • ANTHROPIC_API_KEY authenticates with Anthropic/Claude
5

Import dependencies

import 'dotenv/config';
import readline from 'node:readline';
import { Composio } from '@composio/core';
import { query, type Options } from "@anthropic-ai/claude-agent-sdk";

dotenv.config();
What's happening:
  • We're importing all necessary libraries including the Claude Agent SDK and Composio
  • The dotenv.config() function loads environment variables from your .env file
  • This setup prepares the foundation for connecting Claude with Affinity functionality
6

Create a Composio instance and Tool Router session

async function chat() {
  const { COMPOSIO_API_KEY, USER_ID } = process.env;
  if (!COMPOSIO_API_KEY || !USER_ID) {
    throw new Error('COMPOSIO_API_KEY and USER_ID required in .env');
  }

  const composio = new Composio({ apiKey: COMPOSIO_API_KEY });

  // Create Tool Router session for Affinity
  const session = await composio.create(USER_ID, {
    toolkits: ['affinity'],
  });
  const mcpUrl = session?.mcp.url;
What's happening:
  • The function checks for the required COMPOSIO_API_KEY environment variable
  • We're creating a Composio instance using our API key
  • The create method creates a Tool Router session for Affinity
  • The returned url is the MCP server URL that your agent will use
7

Configure Claude Agent with MCP

const options: Options = {
  permissionMode: 'bypassPermissions',
  mcpServers: {
    composio: {
      type: 'http',
      url: mcpUrl,
      headers: { 'x-api-key': COMPOSIO_API_KEY }
    }
  },
  systemPrompt: 'You are a helpful assistant with access to Affinity tools via Composio.',
  maxTurns: 10,
};
What's happening:
  • We're configuring the Claude Agent options with the MCP server URL
  • permissionMode: 'bypassPermissions' allows the agent to execute operations without asking for permission each time
  • The system prompt instructs the agent that it has access to Affinity
  • maxTurns: 10 limits the conversation length to prevent excessive API usage
8

Create client and start chat loop

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
  });

  console.log('\nChat started. Type "exit" to quit.\n');

  let isProcessing = false;

  async function ask(prompt: string) {
    isProcessing = true;
    rl.pause();

    process.stdout.write('Claude is thinking...');
    const stream = query({ prompt, options });

    let firstChunk = true;
    for await (const msg of stream) {
      const content = (msg as any).message?.content || (msg as any).content;
      if (Array.isArray(content)) {
        for (const block of content) {
          if (block.type === 'text' && block.text) {
            if (firstChunk) {
              process.stdout.write('\r\x1b[K');
              process.stdout.write('Claude: ');
              firstChunk = false;
            }
            process.stdout.write(block.text);
          }
        }
      }
    }
    process.stdout.write('\n\n');

    isProcessing = false;
    rl.resume();
    rl.prompt();
  }

  rl.on('line', async (line) => {
    if (isProcessing) return;

    const input = line.trim();
    if (input === 'exit') {
      rl.close();
      process.exit(0);
    }
    if (input) await ask(input);
    else rl.prompt();
  });

  await ask('What can you help me with?');
}
What's happening:
  • The readline interface is created to handle user input and output
  • The query function is used to send the user's input to the agent
  • The chat loop continues until the user types 'exit' or 'quit'
9

Run the application

try {
  await chat();
} catch (error) {
  console.error(error);
  process.exit(1);
}
What's happening:
  • The chat function is the entry point for the application
  • The try-catch block is used to handle any errors that occur

Complete Code

Here's the complete code to get you started with Affinity and Claude Agent SDK:

import 'dotenv/config';
import readline from 'node:readline';
import { Composio } from '@composio/core';
import { query, type Options } from "@anthropic-ai/claude-agent-sdk";

async function chat() {
  const { COMPOSIO_API_KEY, USER_ID } = process.env;
  if (!COMPOSIO_API_KEY || !USER_ID) {
    throw new Error('COMPOSIO_API_KEY and USER_ID required in .env');
  }

  const composio = new Composio({ apiKey: COMPOSIO_API_KEY });
  const session = await composio.create(USER_ID, {
    toolkits: ['affinity']
  });
  const mcp_url = session?.mcp.url;

  const options: Options = {
    permissionMode: 'bypassPermissions',
    mcpServers: {
      composio: {
        type: 'http',
        url: mcp_url,
        headers: { 'x-api-key': COMPOSIO_API_KEY }
      }
    },
    systemPrompt: 'You are a helpful assistant with access to Affinity tools via Composio.',
    maxTurns: 10,
  };

  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
  });

  console.log('\nChat started. Type "exit" to quit.\n');

  let isProcessing = false;

  async function ask(prompt: string) {
    isProcessing = true;
    rl.pause();

    process.stdout.write('Claude is thinking...');
    const stream = query({ prompt, options });

    let firstChunk = true;
    for await (const msg of stream) {
      const content = (msg as any).message?.content || (msg as any).content;
      if (Array.isArray(content)) {
        for (const block of content) {
          if (block.type === 'text' && block.text) {
            if (firstChunk) {
              process.stdout.write('\r\x1b[K');
              process.stdout.write('Claude: ');
              firstChunk = false;
            }
            process.stdout.write(block.text);
          }
        }
      }
    }
    process.stdout.write('\n\n');

    isProcessing = false;
    rl.resume();
    rl.prompt();
  }

  rl.on('line', async (line) => {
    if (isProcessing) return;

    const input = line.trim();
    if (input === 'exit') {
      rl.close();
      process.exit(0);
    }
    if (input) await ask(input);
    else rl.prompt();
  });

  await ask('What can you help me with?');
}

try {
  await chat();
} catch (error) {
  console.error(error);
  process.exit(1);
}

Conclusion

You've successfully built a Claude Agent SDK agent that can interact with Affinity through Composio's Tool Router.

Key features:

  • Native MCP support through Claude's agent framework
  • Streaming responses for real-time interaction
  • Permission bypass for smooth automated workflows
You can extend this by adding more toolkits, implementing custom business logic, or building a web interface around the agent.
TOOLS

Supported Tools

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

Get a company s list entries

Summarize company data across all lists, including list-specific fields and metadata like creation date and author.

Get a company s lists

Returns metadata for all the Lists on which the given Company appears.

Get all companies

Affinity API allows paginated access to company info and custom fields.

Get all list entries on a list

Access and export essential data and metadata for Companies, Persons, or Opportunities from a List, specifying data via `fieldIds` or `fieldTypes`.

Get all list entries on a saved view

Use the endpoint to access rows in a Saved View with specific filters and selected fields from a web app.

Get all opportunities

Pagination through Opportunities in Affinity yields basic info but excludes field data.

Get all persons

The Affinity API offers paginated access to Person data using `fieldIds` or `fieldTypes`.

Get a person s list entries

Summary: Browse rows for a Person in all Lists, showing field data and entry metadata like creation time and author.

Get a person s lists

Returns metadata for all the Lists on which the given Person appears.

Get a single company

Retrieve basic company info and specific field data by using `fieldIds` or `fieldTypes` parameters.

Get a single opportunity

Get basic details about an Opportunity without field data via provided endpoints.

Get a single person

Use GET `/v2/persons/fields` with `fieldIds` or `fieldTypes` for detailed data; basic info by default.

Get current user

Returns metadata about the current user.

Get metadata on all lists

Returns metadata on Lists.

Get metadata on a single list

Returns metadata on a single List.

Get metadata on a single list s fields

Returns metadata on the Fields available on a single List.

Get metadata on a single saved view

Returns metadata on a single Saved View.

Get metadata on company fields

Returns metadata on non-list-specific Company Fields.

Get metadata on person fields

Returns metadata on non-list-specific Person Fields.

Get metadata on saved views

Returns metadata on the Saved Views on a List.

FRAMEWORKS

How to build Affinity MCP Agent with another framework

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Affinity MCP with OpenAI Agents SDK

Claude Code logo

Claude Code

Use Affinity MCP with Claude Code

Claude Cowork logo

Claude Cowork

Use Affinity MCP with Claude Cowork

Codex logo

Codex

Use Affinity MCP with Codex

OpenClaw logo

OpenClaw

Use Affinity MCP with OpenClaw

Hermes logo

Hermes

Use Affinity MCP with Hermes

CLI logo

CLI

Use Affinity MCP with CLI

Google ADK logo

Google ADK

Use Affinity MCP with Google ADK

LangChain logo

LangChain

Use Affinity MCP with LangChain

Vercel AI SDK logo

Vercel AI SDK

Use Affinity MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Affinity MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Affinity MCP with LlamaIndex

CrewAI logo

CrewAI

Use Affinity MCP with CrewAI

FAQ

Frequently asked questions

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

Yes, you can. Claude Agent SDK 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 Affinity tools.

Yes, absolutely. You can configure which Affinity 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 Affinity data and credentials are handled as safely as possible.

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