paulperegud / ethtxd

Ethereum Tx Decoder

ethtxd

Lightweight Ethereum Tx Decoder with a built in REST API.

Whats this?

A simple tool with an API to extract out Ethereum call traces.

Install from Source

Unfortunately due to some low-level functions in glibc, this can't be compiled into a static binary. It requires to be built from source for the time being.

sh <(curl -L https://nixos.org/nix/install) --daemon

make build

cp dist-newstyle/<...>/ethtxd ~/.local/bin/ethtxd

Usage

# Terminal 1
ethtxd -p 3000 -r https://mainnet.infura.io/v3/<PROJECT_ID>

# Terminal 2
curl localhost:3000/tx/<TX_HASH>

Example Return

Note that you can compose this tool with 4byte.directory or abi-decoder to decode the function signatures and event topics.

{
  "tag": "SuccessResponse",
  "txHash": "0xc7963f40f6e62de89ca32e4b39d4a26e354ed743e0e922ad1917e3d90b6bbc2e",
  "traces": [
    {
      "tag": "TxCall",
      "callTarget": "0x95c4b6c7cff608c0ca048df8b81a484aa377172b",
      "callSigBytes": "0xa9059cbb",
      "callData": "0x0000000000000000000000009389e143dff86096766cd9ff82198857745a8d7b00000000000000000000000000000000000000000000000863a750c3291ed23b",
      "callTrace": [
        {
          "tag": "TxEvent",
          "eventBytes": "0x00000000000000000000000000000000000000000000000863a750c3291ed23b",
          "eventTopics": [
            "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
            "0x3a22df48d84957f907e67f4313e3d43179040d6e",
            "0x9389e143dff86096766cd9ff82198857745a8d7b"
          ]
        },
        {
          "tag": "TxReturn",
          "returnData": "0x0000000000000000000000000000000000000000000000000000000000000001"
        }
      ]
    },
    {
      "tag": "TxEvent",
      "eventBytes": "0x00000000000000000000000000000000000000000000000863a750c3291ed23b",
      "eventTopics": [
        "0x7084f5476618d8e60b11ef0d7d3f06914655adb8793e28ff7f018d4c76d505d5",
        "0x9389e143dff86096766cd9ff82198857745a8d7b"
      ]
    }
  ]
}

Build

# Install Nix
sh <(curl -L https://nixos.org/nix/install) --daemon

# Get Cachix
nix-env -iA cachix -f https://cachix.org/api/v1/install

# Use cachis
cachix use dapp

make build

Development

We're using VSCode with the vscode-haskell plugin. The supplied nix-shell should have all the dependencies installed by default.

git clone [email protected]:kendricktan/ethtxd.git
cd ethtxd
nix-shell
code .

# Alternatively
make repl # For a ghci repl

Upgrading Packages

To upgrade packages, use niv.

rm nix/sources.*

niv init # To update nix pkgs
niv drop nixpkgs
niv drop niv
niv add nixos/nixpkgs
niv add dapptools/dapptools
make build