yfin 0.1.4

Python SDK for the hosted yfin Yahoo Finance API, with yfinance-compatible data access.

yfin Python SDK

yfin is a yfinance-compatible Python SDK backed by the hosted api.yfin.dev Yahoo Finance API. The hosted API handles Yahoo Finance contracts, crumb bootstrap, caching, request coalescing, and origin budgets. The SDK adds pandas/yfinance-shaped access on top.

Use yfinance for a mature local-only notebook dependency. Use yfin when you want the same Python shape plus a hosted REST API, shared caching, OpenAPI, explicit rate limits, and infrastructure that absorbs Yahoo cookie/crumb/TLS and rate-limit churn.

pip install yfin

Quickstart

import yfin as yf

aapl = yf.Ticker("AAPL")

print(aapl.history(period="5d", interval="1d"))
print(aapl.fast_info)
print(aapl.info)
print(aapl.option_chain())
print(aapl.funds_data.top_holdings)
print(aapl.valuation)
print(yf.download(["AAPL", "MSFT"], period="5d"))

ws = yf.WebSocket(verbose=False)
ws.subscribe("BTC-USD")

Low-Level Hosted API Client

import yfin

client = yfin.Client(contact="[e-mail]")
print(client.quote(["AAPL", "MSFT"]))
print(client.history("NVDA", range="5d", interval="1h"))

Set YFIN_BASE_URL to override the hosted API URL.

What yfin Ships

• yfinance-compatible Ticker, Tickers, download, WebSocket, and AsyncWebSocket APIs.
• 45 CP2-confirmed Yahoo REST contracts behind https://api.yfin.dev.
• OpenAPI schema at https://api.yfin.dev/v1/openapi.json.
• Machine-readable endpoint manifest at https://api.yfin.dev/v1/endpoints.
• Cache metadata and explicit typed rate-limit errors.

Honest Performance Position

yfin is not guaranteed to beat yfinance on cold one-off notebook calls. A cold miss goes through yfin and then Yahoo. The hosted path is designed to win when requests are repeated, concurrent, cacheable, or run from services/agents that benefit from managed Yahoo access.

Recent live checks:

Probe	Result
Anonymous forced history misses	25/25 HTTP 200, no 429
17 forced history misses	1.4s wall time
Same 17 warm hosted reads	117ms wall time, 76ms median
Python SDK 17-accessor warm pass	637ms wall time
Local yfinance matching 16-accessor pass	1330ms wall time

See the benchmark notes.

Trust And Docs

• Source
• Changelog
• yfin vs yfinance
• Compatibility matrix
• Rate limits
• Privacy policy
• LLM/crawler summary

Rate Limits

Identity	Total requests/minute	Yahoo-origin misses/minute
Anonymous IP	1200	120
X-Yfin-Contact / SDK contact=	6000	600
Manual API key	30000	3000

High-volume users can email [e-mail] for an API key.