​
1. Create a transformation

For this use case, we’re going to track Uniswap v2, v3, and v4 swap events. Notably, this will also pick up any protocols that have forked from Uniswap. Here’s a transformation function to pull out all of those events from an EVM block: 
function blockSwaps(block) {
  const swaps = [];

  for (const tx of block.transactions || []) {
    for (const log of tx.receipt?.logs || []) {
      const decodedWithMetadata = utils.evmDecodeLogWithMetadata(log, [
        'event Swap(address indexed sender, uint256 amount0In, uint256 amount1In, uint256 amount0Out, uint256 amount1Out, address indexed to)', // V2
        'event Swap(address sender, address recipient, int256 amount0, int256 amount1, uint160 sqrtPriceX96, uint128 liquidity, int24 tick)', // V3
        'event Swap(PoolId indexed id, address indexed sender, int128 amount0, int128 amount1, uint160 sqrtPriceX96, uint128 liquidity, int24 tick, uint24 fee)',
      ]);

      if (decodedWithMetadata) {
        swaps.push({
          chain: block._network,
	        transaction_hash: tx.hash,
	        log_index: log.logIndex,
	        pool_address: log.address?.toLowerCase(),
	        decoded: decodedWithMetadata.decoded,
	      });
      }
    }
  }

	return swaps;
}
If we save the above code as swaps.js, then we can leverage it to test against any EVM network + block using the test endpoint. Here’s how we could do it as a CURL request: 
curl "https://app.indexing.co/dw/transformations/test?network=base&beat=25000000" \
	-H "X-API-KEY: <API_KEY>" \
	-F code=@./swaps.js \
	| jq
Once we’re happy with the results, we can commit the transformation using the create endpoint like this: 
curl "https://app.indexing.co/dw/transformations/block_swaps" \
	-H "X-API-KEY: <API_KEY>" \
	-d code=@./swaps.js \
	| jq

​
2. Deploy the pipeline

The second, and final step, is simply deploying the pipeline! Use an existing webhook or head over to webhook.site to get a temporary one. You can create the pipeline with the following payload: 
{
	"name": "block_swaps",
	"transformation": "block_swaps",
	"networks": ["base"],
	"delivery": {
		"adapter": "HTTP",
		"connection": {
			"host": "<WEBHOOK ENDPOINT>"
		}
	}
}
And as a CURL request: 
curl https://app.indexing.co/dw/pipelines \
	-H "Content-Type: application/json" \
	-H "X-API-KEY: <API KEY>" \
	-d '{
		"name": "block_swaps",
		"transformation": "block_swaps",
		"networks": ["base"],
		"delivery": {
			"adapter": "HTTP",
			"connection": {
				"host": "<WEBHOOK ENDPOINT>"
			}
		}
	}' \
	| jq
You can add any of the supported networks to the pipeline during creation - the more the merrier!
It should only take a few seconds to begin seeing data flow. Once you’re done expirementing, make sure to disable the pipeline with enabled: false: 
curl https://app.indexing.co/dw/pipelines \
	-H "Content-Type: application/json" \
	-H "X-API-KEY: <API KEY>" \
	-d '{
    "enabled": false,
		"name": "block_swaps",
		"transformation": "block_swaps",
		"networks": ["base"],
		"delivery": {
			"adapter": "HTTP",
			"connection": {
				"host": "<WEBHOOK ENDPOINT>"
			}
		}
	}' \
	| jq