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The Watch Tower monitors multiple blockchain networks simultaneously. Each network is configured in the networks array in your config.json file.

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Networks array structure

The configuration file contains a networks array where each element defines a blockchain network to monitor:
config.json
{
  "networks": [
    {
      "name": "mainnet",
      "rpc": "https://mainnet.infura.io/v3/YOUR_API_KEY",
      "deploymentBlock": 17883049,
      "filterPolicy": {
        "defaultAction": "ACCEPT"
      }
    }
  ]
}

​
Per-network settings

Each network configuration supports the following fields:

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name

Required - String identifier for the network. 
"name": "mainnet"
Supported network names:
  • mainnet - Ethereum Mainnet
  • sepolia - Ethereum Sepolia testnet
  • arbitrum_one - Arbitrum One
  • avalanche - Avalanche C-Chain
  • base - Base
  • gnosis_chain - Gnosis Chain
  • polygon - Polygon PoS
  • linea - Linea
  • plasma - Plasma
  • ink - Ink

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rpc

Required - RPC endpoint URL for connecting to the blockchain. Supports both HTTP(S) and WebSocket protocols. 
"rpc": "https://mainnet.infura.io/v3/YOUR_API_KEY"
Conditional order types may consume considerable RPC calls. Ensure your RPC provider has sufficient rate limits.

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deploymentBlock

Required - Block number at which the ComposableCoW contract was deployed on the network. This optimizes the watch-tower by only fetching events from the blockchain after this block number. 
"deploymentBlock": 17883049
Refer to Deployed Contracts for the correct deployment block for each chain.

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watchdogTimeout

Optional - Timeout in milliseconds for the watchdog timer. If the watch-tower doesn’t process a block within this time, it will restart. 
"watchdogTimeout": 300000

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processEveryNumBlocks

Optional - Throttle block processing to only process blocks every N blocks. Default is 1 (process every block). 
"processEveryNumBlocks": 1

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orderBookApi

Optional - Custom URL for the CoW Protocol OrderBook API. If not specified, uses the default API for the network. 
"orderBookApi": "https://api.cow.fi/mainnet/api/v1"

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pageSize

Optional - Number of blocks to fetch when querying historical events (eth_getLogs). Default is 5000, which is the maximum number of blocks that can be fetched in a single request from Infura. 
"pageSize": 5000
If running against your own RPC node, you may set pageSize to 0 to fetch all blocks in one request instead of paging.

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filterPolicy

Required - Defines filtering rules for conditional orders. See Filter policy configuration for details.

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Supported chains

{
  "name": "mainnet",
  "rpc": "https://mainnet.infura.io/v3/YOUR_API_KEY",
  "deploymentBlock": 17883049
}

​
Example configuration

Complete example with multiple networks:
config.json
{
  "networks": [
    {
      "name": "mainnet",
      "rpc": "ws://172.20.0.5:8546",
      "deploymentBlock": 17883049,
      "pageSize": 5000,
      "processEveryNumBlocks": 1,
      "filterPolicy": {
        "defaultAction": "ACCEPT"
      }
    },
    {
      "name": "arbitrum_one",
      "rpc": "https://arb1.arbitrum.io/rpc",
      "deploymentBlock": 343493668,
      "filterPolicy": {
        "defaultAction": "ACCEPT"
      }
    }
  ]
}

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