Package Exports
- evm-translator
- evm-translator/lib/index.js
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Readme
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evm-translator
a library for making EVM-based blockchain data more human-readable
If you're looking to contribute to evm-translator, click here.
If a transaction interacts with 5 addresses, there will be 5 different interpretations, each from the perspective of each address. When interpreting a transaction, if an address is not provided, the interpretation will default to using the from address of the transaction.
Logical Layout
- Raw data fetcher
- Decoder
- Interpreter
- Contract-specific interpreters
- Generic Interpreters
- transfers
- tokens
- fallback
Contractor-specific Interpreter Maps
The long-term vision is that every contract creator (or their community) writes one of these JSON maps for their contract and adds the IPFS/Arweave/API URL to the JSON in their contract as a read function that we can query and index.
The mid-term vision is we store these maps in a openly accessible database. When we interpret a transaction, we query the DB.
The current state is that we have a folder of JSON files in the repo.
An example of an Interpreter Map
{
"contractAddress": "0x7a250d5630b4cf539739df2c5dacb4c659f2488d",
"contractOfficialName": "UniswapV2Router02",
"contractName": "Uniswap V2",
"writeFunctions": {
"addLiquidity": {
"action": "added liquidity",
"keywords": {
"token_0": {
"key": "contractSymbol",
"filters": {
"eventName": "Transfer",
"from": "{userAddress}"
},
"defaultValue": "unknown"
},
"token_1": {
"key": "contractSymbol",
"filters": {
"eventName": "Transfer",
"from": "{userAddress}"
},
"index": 1,
"defaultValue": "unknown"
}
},
"exampleDescriptionTemplate": "{userName} added liquidity to the {token_0}-{token_1} {contractName} pool",
"exampleDescription": "0xf1a9 added liquidity to the SUPER-WETH Uniswap V2 pool"
},
"addLiquidityETH": {
"action": "added liquidity",
"keywords": {
"token_0": {
"key": "contractSymbol",
"filters": {
"eventName": "Transfer",
"from": "{userAddress}"
},
"defaultValue": "unknown"
}
},
"exampleDescriptionTemplate": "{userName} {action} to the {token_0}-{chainSymbol} {contractName} pool",
"exampleDescription": "0xf1a9 added liquidity to the ACYC-ETH Uniswap V2 pool"
}
}
}If you want to add your own contract specific interpretation, click here.
This is an example of the decoded event logs when the addLiquidity function gets called.
{
"txHash": "0x0e6388e80a6023cfc8e7b9fb2ff94e3bf5d34cdc8bb348d124e2385e29d5bcf8",
"txType": "contract interaction",
"nativeValueSent": "0",
"chainSymbol": "ETH",
"txIndex": 191,
"reverted": false,
"gasUsed": "142824",
"effectiveGasPrice": "176081789506",
"fromAddress": "0xf1a935a3588d20994e02848c93b107000a60110d",
"toAddress": "0x7a250d5630b4cf539739df2c5dacb4c659f2488d",
"interactions": [
{
"contractName": "Uniswap V2",
"contractSymbol": "UNI-V2",
"contractAddress": "0x25647e01bd0967c1b9599fa3521939871d1d0888",
"events": [
{
"eventName": "Mint",
"logIndex": 300,
"params": {
"sender": "0x7a250d5630b4cf539739df2c5dacb4c659f2488d",
"amount0": "1373338329117707188",
"amount1": "3432476292290743708413"
}
},
{
"eventName": "Sync",
"logIndex": 299,
"params": {
"reserve0": "4747953991459041932832",
"reserve1": "11866878806943684115024747"
}
},
{
"eventName": "Transfer",
"logIndex": 298,
"params": {
"from": "0x0000000000000000000000000000000000000000",
"to": "0xf1a935a3588d20994e02848c93b107000a60110d",
"value": "40.512792305770100502"
}
}
]
},
{
"contractName": "SuperFarm",
"contractSymbol": "SUPER",
"contractAddress": "0xe53ec727dbdeb9e2d5456c3be40cff031ab40a55",
"events": [
{
"eventName": "Approval",
"logIndex": 297,
"params": {
"owner": "0xf1a935a3588d20994e02848c93b107000a60110d",
"spender": "0x7a250d5630b4cf539739df2c5dacb4c659f2488d",
"value": "115792089237316195423570985008687907853269984665640564036025.107715622385931522"
}
},
{
"eventName": "Transfer",
"logIndex": 296,
"params": {
"from": "0xf1a935a3588d20994e02848c93b107000a60110d",
"to": "0x25647e01bd0967c1b9599fa3521939871d1d0888",
"value": "3432.476292290743708413"
}
}
]
},
{
"contractName": "Wrapped Ether",
"contractSymbol": "WETH",
"contractAddress": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
"events": [
{
"eventName": "Transfer",
"logIndex": 295,
"params": {
"from": "0xf1a935a3588d20994e02848c93b107000a60110d",
"to": "0x25647e01bd0967c1b9599fa3521939871d1d0888",
"value": "1.373338329117707188"
}
}
]
}
],
"contractType": "OTHER",
"methodCall": {
"name": "addLiquidity",
"arguments": {...}
},
"traceCalls": [
{
"name": "getPair",
"params": {}
}
...
],
"timestamp": "2021-12-01T00:06:38Z",
"officialContractName": "UniswapV2Router02"
}When the above map is applied to above decoded event logs, this is the interpretation that it will generate.
{
"txHash": "0x0e6388e80a6023cfc8e7b9fb2ff94e3bf5d34cdc8bb348d124e2385e29d5bcf8",
"userAddress": "0xf1a935a3588d20994e02848c93b107000a60110d",
"userName": "0xf1a9",
"contractName": "Uniswap V2",
"contractOfficialName": "UniswapV2Router02",
"action": ["added liquidity"],
"exampleDescription": "0xf1a9 added liquidity to the SUPER-WETH Uniswap V2 pool",
"nativeValueSent": "0",
"nativeValueReceived": "0",
"chainSymbol": "ETH",
"tokensReceived": [
{
"type": "LPToken",
"name": "Uniswap V2",
"symbol": "UNI-V2",
"address": "0x25647e01bd0967c1b9599fa3521939871d1d0888",
"amount": "40.512792305770100502"
}
],
"tokensSent": [
{
"type": "ERC20",
"name": "SuperFarm",
"symbol": "SUPER",
"address": "0xe53ec727dbdeb9e2d5456c3be40cff031ab40a55",
"amount": "3432.476292290743708413"
},
{
"type": "ERC20",
"name": "Wrapped Ether",
"symbol": "WETH",
"address": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
"amount": "1.373338329117707188"
}
],
"gasPaid": "0.025148705504404944",
"extra": {
"token_0": "SUPER",
"token_1": "WETH"
}
}The Interpreter Map supplies contractName, action, extra, and a more specific exampleDescription.
All other values come from generic interpretations.
Handling special transactions
Double-sided transactions
Some transactions like an NFT sale should have very different interpretations based on the perspective we view it from. The getActionFromInterpretation function within /src/core/DoubleSidedInterpreter.ts uses the tokensSent and tokensReceived fields from the interpretation to deduce the action.
Within the contract specific interpreter JSON files that handle such transactions, the "action": "__NFTSALE__" is used to denote an action that varies on the perspective of the user. Also {__NATIVEVALUETRANSFERRED__} denotes the selling price of the NFT when we are unsure if we should use nativeValueSent or nativeValueReceived.
See 0xc814cb6b61222beda8a9bcc359e776e72ae732a1c29df572099ecef27c8461e4 as an example of such a transaction.
Multicall transactions
Some transactions like a Uniswap V3 multicall are really multiple transactions disguised as one. During the decoding process, the decodeRawTxTrace function within /src/core/MulticallTxInterpreter.ts grabs the "second-level" method calls and put those into the traceCalls field within the DecodedTx. We keep track of multicall method names and contract addresses within /src/interfaces/utils.ts and when we identify a transaction falling into this category, we use the second-level methods to populate the action array within the Interpretation object.
See 0xb38f55471c5a8539a605287b4116a4bf83a58261b3cfe00bc53337298003b9ae as an example of such a transaction.