Python SDK

Package: yfin on PyPI

pip install yfin

yfinance-Compatible Import

Use this path when you want existing yfinance-style code to keep its shape.

import yfin as yf

ticker = yf.Ticker("AAPL", contact="[email protected]")

history = ticker.history(period="1mo", interval="1d")
fast_info = dict(ticker.fast_info)
info = ticker.info
chain = ticker.option_chain()

Common supported calls include Ticker, download, history, fast_info, info, options, option_chain, corporate actions, financial statements, analyst data, holders, insider data, calendar data, SEC filings, sustainability, shares, valuation, and live quote helpers.

For a migration table, see Migrate from yfinance. For data behavior, see Symbols, Historical Prices, and Missing Data.

Return Shapes

The compatibility layer returns Python objects that existing yfinance code usually expects: pandas DataFrame and Series objects for tabular/time-series data, dictionaries for quote and metadata objects, and lists for collection responses such as news.

The low-level Client returns JSON-compatible Python dictionaries that match the REST API response bodies.

Low-Level Client

Use Client when you want direct access to the hosted REST API from Python.

import yfin

client = yfin.Client(contact="[email protected]")

quote = client.quote(["AAPL", "MSFT"])
history = client.history("NVDA", range="5d", interval="1h")
fundamentals = client.fundamentals("AAPL", modules=["price", "summaryDetail"])

Configuration

Pass configuration directly:

client = yfin.Client(
    contact="[email protected]",
    api_key="yfin_...",
    timeout=10,
)

Or use environment variables:

export [email protected]
export YFIN_API_KEY=yfin_...
export YFIN_BASE_URL=https://api.yfin.dev

YFIN_BASE_URL is useful for tests and alternate API origins.

Errors

The SDK raises YfinRateLimitError for HTTP 429 and YfinError for other API or transport failures.

import yfin
from yfin import YfinRateLimitError

client = yfin.Client(contact="[email protected]")

try:
    print(client.history("AAPL", range="1mo", interval="1d"))
except YfinRateLimitError as exc:
    print("rate limited", exc)

Live Quotes

The Python package also exposes yfinance-style live quote helpers:

import yfin as yf

ws = yf.WebSocket()
ws.subscribe(["AAPL", "MSFT"])

For direct REST endpoint shapes, use the API Reference.