How to integrate Polygon io MCP with Vercel AI SDK v6

This guide walks you through connecting Polygon io to Vercel AI SDK v6 using the Composio tool router. By the end, you'll have a working Polygon io agent that can get daily summary for aapl stock, retrieve latest news on tsla ticker, check if nyse market is open now through natural language commands. This guide will help you understand how to give your Vercel AI SDK agent real control over a Polygon io account through Composio's Polygon io MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Polygon io logoPolygon io
Api Key

Polygon io provides powerful APIs for real-time and historical market data—covering stocks, options, forex, and crypto. Instantly access reliable financial data to power your applications or trading strategies.

60 Tools

Introduction

This guide walks you through connecting Polygon io to Vercel AI SDK v6 using the Composio tool router. By the end, you'll have a working Polygon io agent that can get daily summary for aapl stock, retrieve latest news on tsla ticker, check if nyse market is open now through natural language commands.

This guide will help you understand how to give your Vercel AI SDK agent real control over a Polygon io account through Composio's Polygon io MCP server.

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

Also integrate Polygon io with

TL;DR

Here's what you'll learn:
  • How to set up and configure a Vercel AI SDK agent with Polygon io integration
  • Using Composio's Tool Router to dynamically load and access Polygon io tools
  • Creating an MCP client connection using HTTP transport
  • Building an interactive CLI chat interface with conversation history management
  • Handling tool calls and results within the Vercel AI SDK framework

What is Vercel AI SDK?

The Vercel AI SDK is a TypeScript library for building AI-powered applications. It provides tools for creating agents that can use external services and maintain conversation state.

Key features include:

  • streamText: Core function for streaming responses with real-time tool support
  • MCP Client: Built-in support for Model Context Protocol via @ai-sdk/mcp
  • Step Counting: Control multi-step tool execution with stopWhen: stepCountIs()
  • OpenAI Provider: Native integration with OpenAI models

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

The Polygon io MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Polygon io account. It provides structured and secure access to real-time and historical financial market data, so your agent can pull ticker lists, fetch stock summaries, analyze technical indicators, and surface news updates on your behalf.

  • Comprehensive ticker discovery and lookup: Instantly retrieve detailed lists of supported stock, forex, crypto, and option tickers to power your trading dashboards or research tools.
  • Daily summary and technical analysis: Ask your agent to fetch daily price summaries, calculate exponential moving averages, MACD, or RSI for any supported ticker and timeframe.
  • Financial events and dividend insights: Pull up historical dividend distributions, keep tabs on scheduled market holidays, and plan trading activities around real exchange calendars.
  • Up-to-date market status monitoring: Have your agent check real-time market open/close statuses and trading conditions across multiple exchanges and asset classes.
  • Automated news aggregation for securities: Let your agent gather the latest news articles, sentiment analysis, and headlines for specific tickers, helping you stay informed with minimal effort.

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 you begin, make sure you have:
  • Node.js and npm installed
  • A Composio account with API key
  • An OpenAI API key
2

Getting API Keys for OpenAI and Composio

OpenAI API Key
  • Go to the OpenAI dashboard and create an API key. You'll need credits to use the models, or you can connect to another model provider.
  • 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 required dependencies

bash
npm install @ai-sdk/openai @ai-sdk/mcp @composio/core ai dotenv

First, install the necessary packages for your project.

What you're installing:

  • @ai-sdk/openai: Vercel AI SDK's OpenAI provider
  • @ai-sdk/mcp: MCP client for Vercel AI SDK
  • @composio/core: Composio SDK for tool integration
  • ai: Core Vercel AI SDK
  • dotenv: Environment variable management
4

Set up environment variables

bash
OPENAI_API_KEY=your_openai_api_key_here
COMPOSIO_API_KEY=your_composio_api_key_here
COMPOSIO_USER_ID=your_user_id_here

Create a .env file in your project root.

What's needed:

  • OPENAI_API_KEY: Your OpenAI API key for GPT model access
  • COMPOSIO_API_KEY: Your Composio API key for tool access
  • COMPOSIO_USER_ID: A unique identifier for the user session
5

Import required modules and validate environment

typescript
import "dotenv/config";
import { openai } from "@ai-sdk/openai";
import { Composio } from "@composio/core";
import * as readline from "readline";
import { streamText, type ModelMessage, stepCountIs } from "ai";
import { createMCPClient } from "@ai-sdk/mcp";

const composioAPIKey = process.env.COMPOSIO_API_KEY;
const composioUserID = process.env.COMPOSIO_USER_ID;

if (!process.env.OPENAI_API_KEY) throw new Error("OPENAI_API_KEY is not set");
if (!composioAPIKey) throw new Error("COMPOSIO_API_KEY is not set");
if (!composioUserID) throw new Error("COMPOSIO_USER_ID is not set");

const composio = new Composio({
  apiKey: composioAPIKey,
});
What's happening:
  • We're importing all necessary libraries including Vercel AI SDK's OpenAI provider and Composio
  • The dotenv/config import automatically loads environment variables
  • The MCP client import enables connection to Composio's tool server
6

Create Tool Router session and initialize MCP client

typescript
async function main() {
  // Create a tool router session for the user
  const session = await composio.create(composioUserID!, {
    toolkits: ["polygon_io"],
  });

  const mcpUrl = session.mcp.url;
What's happening:
  • We're creating a Tool Router session that gives your agent access to Polygon io tools
  • The create method takes the user ID and specifies which toolkits should be available
  • The returned mcp object contains the URL and authentication headers needed to connect to the MCP server
  • This session provides access to all Polygon io-related tools through the MCP protocol
7

Connect to MCP server and retrieve tools

typescript
const mcpClient = await createMCPClient({
  transport: {
    type: "http",
    url: mcpUrl,
    headers: session.mcp.headers, // Authentication headers for the Composio MCP server
  },
});

const tools = await mcpClient.tools();
What's happening:
  • We're creating an MCP client that connects to our Composio Tool Router session via HTTP
  • The mcp.url provides the endpoint, and mcp.headers contains authentication credentials
  • The type: "http" is important - Composio requires HTTP transport
  • tools() retrieves all available Polygon io tools that the agent can use
8

Initialize conversation and CLI interface

typescript
let messages: ModelMessage[] = [];

console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
console.log(
  "Ask any questions related to polygon_io, like summarize my last 5 emails, send an email, etc... :)))\n",
);

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

rl.prompt();
What's happening:
  • We initialize an empty messages array to maintain conversation history
  • A readline interface is created to accept user input from the command line
  • Instructions are displayed to guide the user on how to interact with the agent
9

Handle user input and stream responses with real-time tool feedback

typescript
rl.on("line", async (userInput: string) => {
  const trimmedInput = userInput.trim();

  if (["exit", "quit", "bye"].includes(trimmedInput.toLowerCase())) {
    console.log("\nGoodbye!");
    rl.close();
    process.exit(0);
  }

  if (!trimmedInput) {
    rl.prompt();
    return;
  }

  messages.push({ role: "user", content: trimmedInput });
  console.log("\nAgent is thinking...\n");

  try {
    const stream = streamText({
      model: openai("gpt-5"),
      messages,
      tools,
      toolChoice: "auto",
      stopWhen: stepCountIs(10),
      onStepFinish: (step) => {
        for (const toolCall of step.toolCalls) {
          console.log(`[Using tool: ${toolCall.toolName}]`);
          }
          if (step.toolCalls.length > 0) {
            console.log(""); // Add space after tool calls
          }
        },
      });

      for await (const chunk of stream.textStream) {
        process.stdout.write(chunk);
      }

      console.log("\n\n---\n");

      // Get final result for message history
      const response = await stream.response;
      if (response?.messages?.length) {
        messages.push(...response.messages);
      }
    } catch (error) {
      console.error("\nAn error occurred while talking to the agent:");
      console.error(error);
      console.log(
        "\nYou can try again or restart the app if it keeps happening.\n",
      );
    } finally {
      rl.prompt();
    }
  });

  rl.on("close", async () => {
    await mcpClient.close();
    console.log("\n👋 Session ended.");
    process.exit(0);
  });
}

main().catch((err) => {
  console.error("Fatal error:", err);
  process.exit(1);
});
What's happening:
  • We use streamText instead of generateText to stream responses in real-time
  • toolChoice: "auto" allows the model to decide when to use Polygon io tools
  • stopWhen: stepCountIs(10) allows up to 10 steps for complex multi-tool operations
  • onStepFinish callback displays which tools are being used in real-time
  • We iterate through the text stream to create a typewriter effect as the agent responds
  • The complete response is added to conversation history to maintain context
  • Errors are caught and displayed with helpful retry suggestions

Complete Code

Here's the complete code to get you started with Polygon io and Vercel AI SDK:

typescript
import "dotenv/config";
import { openai } from "@ai-sdk/openai";
import { Composio } from "@composio/core";
import * as readline from "readline";
import { streamText, type ModelMessage, stepCountIs } from "ai";
import { createMCPClient } from "@ai-sdk/mcp";

const composioAPIKey = process.env.COMPOSIO_API_KEY;
const composioUserID = process.env.COMPOSIO_USER_ID;

if (!process.env.OPENAI_API_KEY) throw new Error("OPENAI_API_KEY is not set");
if (!composioAPIKey) throw new Error("COMPOSIO_API_KEY is not set");
if (!composioUserID) throw new Error("COMPOSIO_USER_ID is not set");

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

async function main() {
  // Create a tool router session for the user
  const session = await composio.create(composioUserID!, {
    toolkits: ["polygon_io"],
  });

  const mcpUrl = session.mcp.url;

  const mcpClient = await createMCPClient({
    transport: {
      type: "http",
      url: mcpUrl,
      headers: session.mcp.headers, // Authentication headers for the Composio MCP server
    },
  });

  const tools = await mcpClient.tools();

  let messages: ModelMessage[] = [];

  console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
  console.log(
    "Ask any questions related to polygon_io, like summarize my last 5 emails, send an email, etc... :)))\n",
  );

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

  rl.prompt();

  rl.on("line", async (userInput: string) => {
    const trimmedInput = userInput.trim();

    if (["exit", "quit", "bye"].includes(trimmedInput.toLowerCase())) {
      console.log("\nGoodbye!");
      rl.close();
      process.exit(0);
    }

    if (!trimmedInput) {
      rl.prompt();
      return;
    }

    messages.push({ role: "user", content: trimmedInput });
    console.log("\nAgent is thinking...\n");

    try {
      const stream = streamText({
        model: openai("gpt-5"),
        messages,
        tools,
        toolChoice: "auto",
        stopWhen: stepCountIs(10),
        onStepFinish: (step) => {
          for (const toolCall of step.toolCalls) {
            console.log(`[Using tool: ${toolCall.toolName}]`);
          }
          if (step.toolCalls.length > 0) {
            console.log(""); // Add space after tool calls
          }
        },
      });

      for await (const chunk of stream.textStream) {
        process.stdout.write(chunk);
      }

      console.log("\n\n---\n");

      // Get final result for message history
      const response = await stream.response;
      if (response?.messages?.length) {
        messages.push(...response.messages);
      }
    } catch (error) {
      console.error("\nAn error occurred while talking to the agent:");
      console.error(error);
      console.log(
        "\nYou can try again or restart the app if it keeps happening.\n",
      );
    } finally {
      rl.prompt();
    }
  });

  rl.on("close", async () => {
    await mcpClient.close();
    console.log("\n👋 Session ended.");
    process.exit(0);
  });
}

main().catch((err) => {
  console.error("Fatal error:", err);
  process.exit(1);
});

Conclusion

You've successfully built a Polygon io agent using the Vercel AI SDK with streaming capabilities! This implementation provides a powerful foundation for building AI applications with natural language interfaces and real-time feedback.

Key features of this implementation:

  • Real-time streaming responses for a better user experience with typewriter effect
  • Live tool execution feedback showing which tools are being used as the agent works
  • Dynamic tool loading through Composio's Tool Router with secure authentication
  • Multi-step tool execution with configurable step limits (up to 10 steps)
  • Comprehensive error handling for robust agent execution
  • Conversation history maintenance for context-aware responses

You can extend this further by adding custom error handling, implementing specific business logic, or integrating additional Composio toolkits to create multi-app workflows.
TOOLS

Supported Tools

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

Get All Tickers

Tool to retrieve a comprehensive list of supported ticker symbols across all asset classes.

Get Condition Codes

Tool to retrieve a unified list of trade and quote condition codes and their definitions.

Get Crypto EMA

Tool to calculate Exponential Moving Average (EMA) technical indicator for a crypto ticker.

Get Crypto MACD

Tool to calculate Moving Average Convergence/Divergence (MACD) technical indicator for a crypto ticker.

Get Crypto Open/Close

Tool to get the open, close, high, low, and volume for a cryptocurrency pair on a specific date.

Get Crypto RSI

Tool to calculate the Relative Strength Index (RSI) for a cryptocurrency ticker.

Get Crypto SMA

Tool to calculate Simple Moving Average (SMA) technical indicator for a cryptocurrency ticker.

Get Daily Open/Close

Tool to get the daily open, close, after-hours, and pre-market prices for a stock on a specific date.

Get Dividends

Tool to retrieve a historical record of cash dividend distributions for a given ticker.

Get Economy Inflation Indicators (Enhanced)

Tool to retrieve key indicators of realized inflation including CPI and PCE price indexes with comprehensive date filtering.

Get Exponential Moving Average

Tool to retrieve the Exponential Moving Average for a stock ticker.

Get SEC Filing

Tool to retrieve detailed information about a specific SEC filing by filing ID.

Get SEC Filing File

Tool to download a specific file from an SEC filing.

Get Forex EMA

Tool to calculate Exponential Moving Average (EMA) technical indicator for a forex pair.

Get Forex MACD

Tool to calculate Moving Average Convergence/Divergence (MACD) technical indicator for a forex pair.

Get Forex Real-Time Currency Conversion

Tool to convert amounts between currency pairs using real-time forex rates.

Get Forex RSI

Tool to calculate the Relative Strength Index (RSI) technical indicator for a forex pair.

Get Forex SMA

Tool to calculate Simple Moving Average (SMA) technical indicator for a forex pair.

Get Futures Quotes

Tool to get real-time quote information for futures contracts with bid/ask prices, sizes, and timestamps.

Get Grouped Daily Market Summary

Tool to retrieve daily OHLCV data for the entire market for a given date.

Get Historic Forex Ticks

Tool to get historic ticks for a currency pair on a specific date.

Get Inflation Expectations

Tool to retrieve inflation expectations data from the Federal Reserve, including market-based rates and Cleveland Fed model estimates.

Get IPO Data

Tool to retrieve comprehensive information on Initial Public Offerings (IPOs), including upcoming and historical events.

Get Labor Market Data

Tool to retrieve labor market data including unemployment rate, labor force participation rate, average hourly earnings, and job openings.

Get MACD

Tool to retrieve the Moving Average Convergence/Divergence (MACD) for a stock ticker.

Get Market Holidays

Tool to retrieve upcoming market holidays and their corresponding open/close times.

Get Market Status

Tool to retrieve the current trading status across major exchanges and currency markets.

Get News

Tool to retrieve the most recent news articles for a specified ticker.

Get Options Contract Overview

Tool to retrieve comprehensive details about a specific options contract including contract type, exercise style, expiration date, strike price, and underlying ticker.

Get Options EMA

Tool to calculate Exponential Moving Average (EMA) technical indicator for an options ticker.

Get Options MACD

Tool to calculate Moving Average Convergence/Divergence (MACD) technical indicator for an options ticker.

Get Options RSI

Tool to calculate Relative Strength Index (RSI) technical indicator for an options ticker.

Get Options SMA

Tool to calculate Simple Moving Average (SMA) technical indicator for an options ticker.

Get Related Companies

Tool to retrieve tickers related to a given ticker based on similar business or market characteristics.

Get RSI

Tool to retrieve the Relative Strength Index (RSI) for a stock ticker.

Get Simple Moving Average

Tool to retrieve the Simple Moving Average (SMA) for any ticker (stocks, forex, crypto).

Get Splits

Tool to retrieve historical stock split events for a given ticker.

Get Stocks Custom Bars

Tool to retrieve aggregated historical OHLC and volume data for a stock over custom date ranges with configurable time windows.

Get Stocks Daily Market Summary

Tool to retrieve daily OHLC, volume, and VWAP data for all U.

Get Stocks Filings Risk Factors

Tool to retrieve risk factors identified in companies' 10K filings.

Get Stocks Filings Sections

Tool to retrieve raw text content from specific sections of SEC filings (10-K, 10-Q, etc.

Get Stocks Free Float

Tool to retrieve free float data for US-listed securities showing the most recent available number of shares available for public trading and the percentage of total shares outstanding.

Get Stocks Full Market Snapshot

Tool to retrieve a comprehensive snapshot of the entire U.

Get Stocks Income Statements

Tool to retrieve comprehensive income statement data including revenue, expenses, and net income from company SEC filings.

Get Stocks Previous Day Bar

Tool to retrieve the previous trading day's open, high, low, close (OHLC), and volume data for a stock ticker.

Get Stocks Risk Factor Taxonomies

Tool to retrieve the complete list of risk factor classifications used in the risk factors endpoint.

Get Stocks V1 Dividends

Tool to retrieve historical dividend payment records for US stocks with split-adjusted amounts and historical adjustment factors.

Get Short Interest Data

Tool to retrieve comprehensive FINRA short interest data that tracks the short selling metrics for securities on a specific settlement date.

Get Short Volume Data

Tool to retrieve short selling volume data for stock tickers.

Get Stocks V1 Splits

Tool to retrieve historical stock split and reverse split events for US equities with historical adjustment factors for price normalization.

Get Ticker Events

Tool to retrieve timeline of ticker change events such as symbol renaming or rebranding.

Get Ticker Overview

Tool to retrieve comprehensive details for a single ticker, including identifiers, industry, and branding assets.

Get Ticker Types

Tool to retrieve a list of all ticker types supported by Polygon.

Get Treasury Yields

Tool to retrieve daily market yields for US Treasury securities across standard maturities (1-month to 30-year).

List Exchanges

Tool to retrieve all exchanges supported by Polygon.

List Filing Files

Tool to retrieve files associated with an SEC filing by filing ID.

List SEC Filings

Tool to retrieve SEC filings from the Polygon.

List Options Contracts

Tool to list and filter options contracts by underlying ticker, type, expiration, strike, and more.

Last Quote for a Symbol

Tool to retrieve the last quote tick for a given stock symbol.

Last Trade for a Currency Pair

Tool to retrieve the last trade tick for a currency pair in the forex market.

FAQ

Frequently asked questions

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

Yes, you can. Vercel AI SDK v6 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 Polygon io tools.

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

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