Polygon.io MCP Server

An MCP server for Polygon.io Financial Market Data

→ polygon-io/mcp_polygon · listed on mcp_so

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// key findings

✅

3 tools verified — handlers match their declared behaviour

3 read-only tools verified — handlers contain no write/delete/exec

✅

No credential exfiltration, no sensitive file access, no obfuscation

Static analysis found nothing flowing your secrets to unexpected places.

✅

Open source with a license and README

Anyone can audit the code, the license is declared, and the publisher documents what it does.

🔐

You'll be asked for 2 credentials: MASSIVE_API_KEY, POLYGON_API_KEY

These are read from process.env at runtime. Make sure you trust where they’ll be sent.

// required environment variables

This server reads these from process.env. You'll be asked to provide them before it can run.

configMCP_TRANSPORT— No stdio Transport protocol: stdio, sse, or streamable-http

🔐 secretMASSIVE_API_KEY— claude mcp add massive -e =your_api_key_here -- mcp_massive

🔐 secretPOLYGON_API_KEY— No — Deprecated alias for MASSIVE_API_KEY

configMASSIVE_API_BASE_URL— No https://api.massive.com Base URL for API requests

configMASSIVE_LLMS_TXT_URL— No https://massive.com/docs/rest/llms.txt URL for the endpoint index

configMASSIVE_MAX_TABLES— No 50 Maximum number of in-memory tables

configMASSIVE_MAX_ROWS— No 50000 Maximum rows per stored tables

// full audit trail

The full breakdown of what we checked, the deductions that landed, the network hosts, the dependency advisories, and concrete fix guidance is available to verified publishers.

// improvement guidance — verified publishers only

We have 3 concrete improvements we can share with the publisher of this MCP. Each comes with specific guidance to raise the trust score.

// embed badge in your README

[![M8ven Score](https://m8ven.ai/badge/mcp/polygon-io-mcp-polygon-b1lkv4)](https://m8ven.ai/mcp/polygon-io-mcp-polygon-b1lkv4)

commit: c58ec7e4df7482c53fc4adeb2de0e979f77f3a23

code hash: 51d5c1bb79b667ce83f0fec410c97196d4cefe37709d3e0f9d6a52e520994876

verified: 6/16/2026, 1:05:17 PM

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