> For the complete documentation index, see [llms.txt](https://uroborosdefi.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://uroborosdefi.gitbook.io/docs/routing-protocol/concepts/index.md).

# Index

### How it works?

    To get up-to-date prices market prices, we need to constantly listen to market updates. Fortunately, most DEX's provide a simple way to do that - using *Ethereum events*.

We introduced a service called **Index** to monitor this events and convert raw blockchain data into markets and tokens. ***It's now for internal use only, but later can become public.***

For example: when swap occurs on uniswap v2, this event is emitted:

```solidity
event Sync(uint112 reserve0, uint112 reserve1);
```

Index service takes this event, loads tokens at event's address and creates an entry in database:

```json
{
    "address": "...",
    "token0": "...",
    "token1": "...",
    "reserve0": "...",
    "reserve1": "...",
    "blockNumber": "...",
    "chainId": "..."
    // ...
}
```

Later, those markets and tokens are loaded by **routing** service.