polygon-api-client
Official Polygon.io REST and Websocket client.
Decision gist · record as of 2026-08-14
Yes. The package has low install friction, active maintenance, no known vulnerabilities, permissive licensing, and broad Python version support. It is the official client for a widely-used financial data API, making it the natural choice if you need Massive market data in Python. The main constraint is needing a valid API key and accepting the free tier's rate limits.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires a Massive API key.
- API free tier has usage limitations and may trigger rate limits.
- Low install friction with only three runtime dependencies (urllib3, websockets, certifi).
License · maintenance · safety
MIT (permissive) — MIT license permits commercial and private use with minimal restrictions, making it suitable for most projects.
last release 2025-10-30 (288 days) · last repo commit 2026-07-09 · 1,496 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 793,154 downloads/mo, #5,043 on PyPI
Alternatives
Verify before relying
pip install -U massive
from polygon_api_client import RESTClient
client = RESTClient(api_key="<API_KEY>")
trades = [t for t in client.list_trades(ticker="AAPL", timestamp="2022-01-04")]- Exact rate limit thresholds and behavior under free tier usage.
- WebSocket reconnection and error handling behavior in production scenarios.
- Performance characteristics when fetching very large historical datasets.
- Whether import path is 'polygon_api_client' or 'massive' in current version.
What it is and what it does
This is the official Python client for Massive (rebranded from Polygon.io on October 30, 2025), providing both REST and WebSocket interfaces to financial market data. The REST client handles stock trades, quotes, aggregates (OHLCV bars), and options chains with automatic pagination by default, while the WebSocket client streams real-time tick data for subscribed symbols. The library abstracts away connection management, pagination logic, and API authentication, letting you focus on data retrieval.
The package depends on urllib3 for HTTP requests, websockets for real-time connections, and certifi for SSL certificate validation. It supports Python 3.9 and newer, with no system-level compiled dependencies. Pagination is enabled by default for list endpoints, meaning the limit parameter controls page size rather than total results—you can disable this if you need a fixed result count. The client includes debug mode for inspecting request and response details.
Use it for
- Fetch historical stock trades and quotes for backtesting trading strategies or analyzing market microstructure.
- Stream real-time tick data via WebSocket for live trading systems or market monitoring dashboards.
- Query options chains with filter parameters for options analysis and research.
- Build data pipelines that aggregate OHLCV bars at various timeframes for technical analysis.
- Retrieve last trade and quote snapshots for current market price lookups in applications.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
The package has low install friction, active maintenance, no known vulnerabilities, permissive licensing, and broad Python version support. It is the official client for a widely-used financial data API, making it the natural choice if you need Massive market data in Python. The main constraint is needing a valid API key and accepting the free tier's rate limits.
Install
polygon-api-client on PyPI
Before you install
Low install friction with only three runtime dependencies (urllib3, websockets, certifi). Actively maintained with recent commits and 1496 repository stars. Supports Python 3.9 through 3.14.
Requires a Massive API key. API free tier has usage limitations and may trigger rate limits.
License in practice
MIT license permits commercial and private use with minimal restrictions, making it suitable for most projects.
Quickstart
pip install -U massive
from polygon_api_client import RESTClient
client = RESTClient(api_key="<API_KEY>")
trades = [t for t in client.list_trades(ticker="AAPL", timestamp="2022-01-04")]Verify before relying
- Exact rate limit thresholds and behavior under free tier usage.
- WebSocket reconnection and error handling behavior in production scenarios.
- Performance characteristics when fetching very large historical datasets.
- Whether import path is 'polygon_api_client' or 'massive' in current version.
Package facts
| License | MIT permissive |
| Python support | Supports the current Python release <4.0,>=3.9 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 3 packagesurllib3websocketscertifi |
| Maintenance | Actively maintained 288 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 793,154 / month, #5,043 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | License :: OSI Approved :: MIT LicenseProgramming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: 3.9 |
Evidence: polygon_api_client-1.16.3-py3-none-any.whl
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See also massive · longbridge · coinbase-advanced-py · python-kraken-sdk · py-clob-client · sec-api · finnhub-python · binance-connector · yfinance · yahooquery