> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hadron.fi/llms.txt
> Use this file to discover all available pages before exploring further.

# Crank

Hadron pools are designed for active management. Unlike passive AMMs (like Uniswap), the pool **does not update the midprice based on reserves**. You, the operator, must push price updates from your own price engine. This is the crank.

The crank loop is the heartbeat of a live Hadron pool. A typical production crank:

1. Fetches the latest market price from your price source (CEX feed, oracle, internal model)
2. Computes the new midprice and optionally a new spread
3. Builds an `update_midprice_and_base_spread` instruction
4. Sends and confirms the transaction
5. Waits for the next tick, then repeats

```rust theme={null}
Example coming soon
```