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

# Deployment Requirements

> Requirements and configuration for deploying the CoW Protocol Watch Tower

# Deployment Requirements

Requirements and configuration for deploying the CoW Protocol Watch Tower.

## Prerequisites

To run your own watch-tower instance, you'll need:

* An RPC node connected to one or more supported networks:
  * Ethereum mainnet
  * Arbitrum One
  * Gnosis Chain
  * Base
  * Sepolia (testnet)
  * Avalanche
  * Polygon
  * Linea
  * Plasma
  * Ink
* Internet access to the CoW Protocol OrderBook API

<Warning>
  Programmatic order types may consume considerable RPC calls. Ensure your RPC provider can handle the load, or consider running your own node.
</Warning>

## Deployment block numbers

The `deployment-block` parameter references the block number where the ComposableCoW contract deployed to each chain. Watch-tower optimization relies on this to fetch events only after deployment.

Refer to [Deployed Contracts](https://github.com/cowprotocol/composable-cow#deployed-contracts) for deployment blocks on each chain.

### Example deployment blocks

| Network      | Deployment Block |
| ------------ | ---------------- |
| Mainnet      | 17883049         |
| Sepolia      | 8468184          |
| Arbitrum One | 343493668        |
| Base         | 31084679         |
| Gnosis Chain | 40394915         |
| Avalanche    | 63235114         |
| Polygon      | 72315184         |
| Linea        | 25028604         |
| Plasma       | 4810535          |
| Ink          | 37142449         |

<Note>
  These block numbers are examples from the config file. Always verify the latest deployment blocks in the Composable CoW repository.
</Note>

## Page size configuration

The `pageSize` option specifies how many blocks to fetch when querying historical events via `eth_getLogs`.

### Default setting

The default is `5000`, which represents the maximum blocks fetchable in a single Infura request.

### Custom RPC nodes

When running against your own RPC node, set `pageSize` to `0` to retrieve all blocks in one request instead of multiple paginated requests.

```json theme={null}
{
  "networks": [
    {
      "name": "mainnet",
      "rpc": "https://your-rpc-endpoint.com",
      "deploymentBlock": 17883049,
      "pageSize": 0
    }
  ]
}
```

<Note>
  Adjust `pageSize` based on your provider's limits. Some providers enforce stricter limits than Infura's 5000-block threshold.
</Note>

## Configuration file

The watch-tower requires a JSON configuration file specifying:

* Network configurations
* RPC endpoints
* Deployment blocks
* Filter policies (optional)

See the `config.json.example` file in the repository for a complete configuration template with all supported networks.