> For the complete documentation index, see [llms.txt](https://qi-blockchain.gitbook.io/qie-oracle/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://qi-blockchain.gitbook.io/qie-oracle/how-qie-oracle-works/data-sourcing-off-chain-price-feeds-on-chain.md).

# 📡 Data Sourcing (Off-Chain Price Feeds → On-Chain)

The first step in the QIE Oracle system is **data collection from external sources**. To ensure accuracy and reliability, QIE Oracle sources price data from **trusted and reputable providers**, including:

* **Cryptocurrency exchanges**\
  → *e.g., Binance, Coinbase, Kraken*
* **Financial market data providers**\
  → *e.g., XAUt (Tether Gold) and other real-world asset feeds*

***

#### 🔄 Data Flow Overview

The Oracle follows a standardized process to collect, process, and publish asset prices:

1. **Fetch price data**\
   A backend service regularly queries external APIs to retrieve the latest price information.
2. **Transform data**\
   The raw data is normalized to match the required precision and format used by the blockchain (e.g., converting float values to fixed-point integers).
3. **Submit to Oracle contract**\
   The processed data is submitted to QIE Oracle smart contracts via **signed transactions**, ensuring authenticity and data integrity.

***

#### ✅ Key Benefits

* **Structured** — Data is consistently formatted for easy consumption by smart contracts
* **Accurate** — Pulled from trusted, high-liquidity sources
* **Tamper-proof** — Signed and verified before being published on-chain

This system ensures that all on-chain price feeds are reliable, secure, and compatible with QIE-based applications.