Jb Decode

Juicebox V5 Transaction Decoder

Decode and analyze Juicebox V5 transaction calldata.

Common Function Selectors

JBMultiTerminal

pay(uint256,address,uint256,address,uint256,string,bytes)
  Selector: 0x...
  - Pay into a project

cashOutTokensOf(address,uint256,uint256,address,uint256,address,bytes)
  Selector: 0x...
  - Cash out tokens for funds

sendPayoutsOf(uint256,address,uint256,uint256,uint256)
  Selector: 0x...
  - Distribute payouts to splits

useAllowanceOf(uint256,address,uint256,uint256,uint256,address,address,string)
  Selector: 0x...
  - Use surplus allowance

JBController

launchProjectFor(address,string,(uint256,uint256,uint256,uint256,address,(uint256,uint256,uint256,bool,bool,bool,bool,bool,bool,bool,bool,bool,bool,bool,bool,bool,bool,address,uint256),(uint256,(bool,uint256,uint256,address,uint256,address)[])[],(address,address,(uint256,uint32)[],(uint256,uint32)[])[])[],(address,(address,uint8,uint32)[])[],string)
  - Launch a new project

queueRulesetsOf(uint256,(uint256,uint256,uint256,uint256,address,(uint256,uint256,uint256,bool,bool,bool,bool,bool,bool,bool,bool,bool,bool,bool,bool,bool,bool,address,uint256),(uint256,(bool,uint256,uint256,address,uint256,address)[])[],(address,address,(uint256,uint32)[],(uint256,uint32)[])[])[],string)
  - Queue new rulesets

mintTokensOf(uint256,uint256,address,string,bool)
  - Mint tokens

burnTokensOf(address,uint256,uint256,string)
  - Burn tokens

Decoding with Cast

Decode Calldata

# Get the function signature
cast 4byte <first-4-bytes-of-calldata>

# Decode full calldata (need ABI)
cast calldata-decode "pay(uint256,address,uint256,address,uint256,string,bytes)" <calldata>

Decode Transaction

# Get transaction details
cast tx <txhash> --rpc-url $RPC_URL

# Decode the input
cast tx <txhash> --rpc-url $RPC_URL | grep input

Example: Decode a Pay Transaction

# Assuming calldata starts with pay() selector
cast calldata-decode \
    "pay(uint256,address,uint256,address,uint256,string,bytes)" \
    "0x..." \
    # Returns:
    # projectId: 123
    # token: 0x0000...0000 (native)
    # amount: 1000000000000000000
    # beneficiary: 0x...
    # minReturnedTokens: 0
    # memo: "Supporting the project"
    # metadata: 0x...

Decoding with ethers.js

Setup

import { ethers } from 'ethers';

// Terminal ABI fragment
const TERMINAL_ABI = [
    'function pay(uint256 projectId, address token, uint256 amount, address beneficiary, uint256 minReturnedTokens, string memo, bytes metadata) payable returns (uint256)',
    'function cashOutTokensOf(address holder, uint256 projectId, uint256 cashOutCount, address tokenToReclaim, uint256 minTokensReclaimed, address beneficiary, bytes metadata) returns (uint256)',
    'function sendPayoutsOf(uint256 projectId, address token, uint256 amount, uint256 currency, uint256 minTokensPaidOut) returns (uint256)',
];

const iface = new ethers.Interface(TERMINAL_ABI);

Decode Calldata

function decodeCalldata(calldata: string) {
    try {
        const decoded = iface.parseTransaction({ data: calldata });
        return {
            name: decoded.name,
            args: decoded.args,
            signature: decoded.signature,
        };
    } catch (e) {
        return null;
    }
}

Decode Transaction from Hash

async function decodeTransaction(txHash: string) {
    const provider = new ethers.JsonRpcProvider(process.env.RPC_URL);
    const tx = await provider.getTransaction(txHash);

    if (!tx) throw new Error('Transaction not found');

    const decoded = iface.parseTransaction({ data: tx.data });

    return {
        from: tx.from,
        to: tx.to,
        value: ethers.formatEther(tx.value),
        function: decoded?.name,
        args: decoded?.args,
    };
}

Transaction Analysis Examples

Pay Transaction

Function: pay(uint256,address,uint256,address,uint256,string,bytes)
Parameters:
  projectId: 123          → Paying into project #123
  token: 0x000...000      → Using native currency (ETH)
  amount: 1e18            → Paying 1 ETH
  beneficiary: 0xABC...   → Tokens go to this address
  minReturnedTokens: 0    → No minimum (accepts any amount)
  memo: "Great project!"  → Payment memo
  metadata: 0x...         → Optional hook metadata

Effect: Sends 1 ETH to project #123, mints tokens to 0xABC...

Cash Out Transaction

Function: cashOutTokensOf(...)
Parameters:
  holder: 0xABC...        → Token holder cashing out
  projectId: 123          → From project #123
  cashOutCount: 1000e18   → Cashing out 1000 tokens
  tokenToReclaim: 0x0...  → Reclaiming ETH
  minTokensReclaimed: 0   → No minimum
  beneficiary: 0xABC...   → ETH goes here
  metadata: 0x...         → Optional hook metadata

Effect: Burns 1000 tokens, sends proportional ETH to 0xABC...

Queue Rulesets Transaction

Function: queueRulesetsOf(...)
Parameters:
  projectId: 123
  rulesetConfigs: [...]   → New ruleset configurations
  memo: "Update params"

Effect: Queues new ruleset(s) that activate when current ends

Decoding Hook Metadata

Hook metadata is ABI-encoded. Common patterns:

Buyback Hook Metadata

// Encode
bytes memory metadata = abi.encode(amountToSwapWith, minimumSwapAmountOut);

// Decode
(uint256 amountToSwapWith, uint256 minimumSwapAmountOut) = abi.decode(metadata, (uint256, uint256));

721 Hook Metadata

// Encode tier IDs to mint
bytes memory metadata = abi.encode(tierIds);

// Decode
uint256[] memory tierIds = abi.decode(metadata, (uint256[]));

Generation Guidelines

1. Identify the contract from the to address
2. Extract function selector (first 4 bytes)
3. Decode parameters using the appropriate ABI
4. Explain the effect in plain language
5. Decode nested metadata if present

Example Prompts

• "What does this transaction do? 0x..."
• "Decode this calldata for JBMultiTerminal"
• "Explain what happened in transaction 0xabc..."
• "What parameters were used in this pay() call?"