yahoo-finance-fetcher

Yahoo Finance Fetcher

Download and validate historical market data using Yahoo Finance (yfinance). Clean the output into standard CSV/OHLCV format.

Overview

This skill allows AI Agents compliant with the Agent Skills specification to download historical stock, crypto, forex, and commodity prices, performing basic Data Science Quality Assurance (QA) before saving to disk.

Requirements

• Python 3.10+
• Dependencies listed in requirements.txt

[!WARNING] Security Notice: This skill executes a local Python script (scripts/download_yahoo.py). Agents using this skill must be granted permission to execute commands in the user's terminal. Ensure you review the source code of the script to understand the operations being performed on your local machine.

Installation

Clone this repository into your agent's skills directory. The paths vary by runtime:

git clone https://github.com/felipemillar/yahoo-finance-fetcher.git <target-directory>
cd <target-directory>
python install.py

Schema & Validation

The output is a CSV with the following columns: datetime, asset, open, high, low, close, volume, timezone

In --audit mode no row is dropped; invalid rows are flagged instead, and the schema is extended with two columns: is_valid, invalid_reason.

A companion JSON file (*_report.json) is also generated containing a Data Quality diagnostic (rows dropped due to NaNs, duplicates, invalid prices, or extreme outliers) and execution metadata.

Legal Disclaimer & Non-Affiliation

Disclaimer: This project is for personal and research use only. It is not affiliated with, endorsed, or sponsored by Yahoo! Inc. or Verizon Media. The yfinance library relies on a public, undocumented API which may change at any time.

Users are solely responsible for ensuring that their usage complies with the Yahoo Terms of Service. This software does not provide financial advice, and no guarantees are made regarding the accuracy, completeness, or timeliness of the data obtained.

Created and maintained by QRT Solutions.