The Polygon.io MCP Server provides an LLM-friendly interface to access comprehensive financial market data through Polygon.io API endpoints as MCP tools. Key capabilities include:
• Market Data & Trading: OHLC aggregates/bars for stocks, options, forex, and crypto; real-time and historical trades and quotes; daily open/close data with customizable time windows • Market Snapshots: Current snapshots for individual tickers, option contracts, crypto order books, entire markets, and gainers/losers across all asset types • Reference Data: Ticker details, supported symbols and types, company information, exchanges, and market conditions • Corporate Actions & Fundamentals: Historical dividends, stock splits, earnings data, financial statements, and fundamental company metrics • Economic & Alternative Data: Treasury yields, inflation data, economic indicators, short interest, and short volume metrics • Benzinga Integration: Analyst ratings, insights, earnings estimates, consensus data, firm details, guidance, and market commentary • Futures Markets: Contracts, quotes, trades, products, trading schedules, market status, and snapshots for futures • News & Research: Ticker-specific news articles, market research, and IPO information (upcoming and historical) • Market Operations: Trading hours, market holidays, and current exchange operating status
The server supports filtering by date ranges, tickers, market types, and various parameters, making it suitable for both real-time market monitoring and historical financial analysis.
Provides access to comprehensive financial market data from Polygon.io, including stock/options/forex/crypto aggregates, real-time and historical trades, market snapshots, ticker details, dividends data, and financial fundamentals.
Click on "Install Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type
@followed by the MCP server name and your instructions, e.g., "@Polygon-io MCP Serverget the latest price for AAPL stock"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
:test_tube: This project is experimental and could be subject to breaking changes.
Massive.com MCP Server
A Model Context Protocol (MCP) server that provides access to the full Massive.com financial data API through an LLM-friendly interface.
Rather than exposing one tool per endpoint, this server gives the LLM four composable tools — search, docs, call, and query — that cover the entire Massive.com API surface. Data can be stored in-memory as DataFrames, queried with SQL, and enriched with built-in financial functions.
Tools
Tool | Description |
| Search for API endpoints and built-in functions by natural language query. Returns names, URL patterns, and descriptions. Supports scoping to |
| Get parameter documentation for a specific endpoint. Pass the docs URL from |
| Call any Massive.com REST API endpoint. Supports storing results as an in-memory DataFrame ( |
| Run SQL against stored DataFrames using SQLite. Supports |
Built-in Functions
Functions can be applied to API results or query output via the apply parameter on call_api and query_data. Use search_endpoints with scope="functions" to discover them.
Category | Functions |
Greeks |
|
Returns |
|
Technical |
|
Data Coverage
The server dynamically indexes all Massive.com API endpoints at startup from llms.txt, so it automatically stays in sync with the API. Coverage includes:
Stock, options, forex, crypto, and futures aggregates
Real-time and historical trades and quotes
Market snapshots, gainers/losers
Ticker details and reference data
Dividends, splits, IPOs
Financial fundamentals
Analyst ratings and news (Benzinga)
Treasury yields, inflation data
Market status and holidays
Related MCP server: Dingo MCP Server
Installation
Prerequisites
Python 3.10+
A Massive.com API key
Astral UV (v0.4.0+)
Claude Code
First, install Claude Code
Install the MCP server, then register it with Claude Code:
To upgrade to a new version later:
Upgrading from Previous versions recommended uvx --from ... mcp_massive or uv run --with. These commands download dependencies on every cold start, which can cause the server to exceed Claude's 30-second connection timeout. Switch to uv tool install as shown above — it downloads dependencies once and starts instantly after that.
This command will install the MCP server in your current project.
If you want to install it globally, you can run the command with -s <scope> flag.
See claude mcp add --help for more options.
To start Claude Code, run claude in your terminal.
If this is your first time using, follow the setup prompts to authenticate
You can also run claude mcp add-from-claude-desktop if the MCP server is installed already for Claude Desktop.
Claude Desktop
Follow the Claude Desktop MCP installation instructions to complete the initial installation and find your configuration file.
Install the server:
Find the installed binary path:
Add the server to your Claude Desktop config. Replace
<path_to_mcp_massive>with the output from the previous step, and fill in the remaining fields.
Configuration
Environment Variables
Variable | Required | Default | Description |
| Yes | — | Your Massive.com API key |
| No | — | Deprecated alias for |
| No |
| Transport protocol: |
| No |
| Base URL for API requests |
| No |
| URL for the endpoint index |
| No |
| Maximum number of in-memory DataFrames |
| No |
| Maximum rows per stored DataFrame |
Transport
By default, STDIO transport is used. The transport can be set via the --transport CLI argument or the MCP_TRANSPORT environment variable (CLI argument takes precedence).
Usage Examples
Once integrated, you can prompt Claude to access Massive.com data:
Development
Running Locally
Check to ensure you have the Prerequisites installed.
Install from your local checkout, then reference the binary directly:
Debugging
For debugging and testing, we recommend using the MCP Inspector:
This will launch a browser interface where you can interact with your MCP server directly and see input/output for each tool.
Code Linting
This project uses just for common development tasks. To lint your code before submitting a PR:
This will run ruff format and ruff check --fix to automatically format your code and fix linting issues.
Links
Privacy Policy
This MCP server interacts with Massive.com's API to fetch market data. All data requests are subject to Massive.com's privacy policy and terms of service.
Massive.com Privacy Policy: https://massive.com/legal/privacy
Data Handling: This server does not store or cache any user data. All requests are proxied directly to Massive.com's API.
API Key: Your Massive.com API key is used only for authenticating requests to their API.
Contributing
If you found a bug or have an idea for a new feature, please first discuss it with us by submitting a new issue. We will respond to issues within at most 3 weeks. We're also open to volunteers if you want to submit a PR for any open issues but please discuss it with us beforehand. PRs that aren't linked to an existing issue or discussed with us ahead of time will generally be declined.