Massive API (formerly Polygon.io)

by massive.com

Finance Added on November 9th, 2026

What it does

The Massive API, formerly Polygon.io, gives stock, options, forex and crypto market data, for example the previous day's prices for a share. Requests are GET calls with an apiKey parameter or a Bearer header, and the answers are JSON. Free with a free API key for 5 requests a minute. An official MCP server (github.com/massive-com/mcp_massive) lets AI agents read the market data.

API
HTTP-GET
JSON
MCP
REST

At a glance

API key: Needed, free · More APIs with a free key
Pricing: Free with a free API key for 5 requests a minute.
From the browser: Yes (CORS)
Formats: JSON
Interface: REST, HTTP-GET, MCP
Provider: massive.com

More information: https://massive.com/docs/rest/quickstart

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HTML

<a href="https://free-web-services.com/web-services/unit-convertors/fiinance/massive-api.html"><img src="https://free-web-services.com/badge.svg" width="208" height="44" alt="Listed on Free Web Services" /></a>

Markdown

[![Listed on Free Web Services](https://free-web-services.com/badge.svg)](https://free-web-services.com/web-services/unit-convertors/fiinance/massive-api.html)

Example request

curl

curl 'https://api.massive.com/v2/aggs/ticker/AAPL/prev?apiKey=YOUR_API_KEY'

JavaScript

const response = await fetch("https://api.massive.com/v2/aggs/ticker/AAPL/prev?apiKey=YOUR_API_KEY");
const data = await response.json();
console.log(data);

Python

import requests

response = requests.get(
    "https://api.massive.com/v2/aggs/ticker/AAPL/prev?apiKey=YOUR_API_KEY",
    timeout=30,
)
print(response.json())

Replace YOUR_API_KEY with your own key. The JavaScript works in a web page as well as in Node.js 18 or newer.