Pod Bridge SDK

TypeScript SDK for bridging tokens between POD and EVM chains (e.g., ETH Mainnet).

Architecture

ETH -> Pod: Deposit on ETH, AUTO-CLAIM on Pod (no claim TX needed)
Pod -> ETH: Deposit on Pod, claim on ETH with proof from pod_getBridgeClaimProof RPC

Key points:

• ERC20 and native token bridging supported
• Token addresses differ between chains (e.g., USDC on ETH maps to native 0xEeee...EEeE on Pod)
• Use ETH-side decimals for amounts (e.g., 1e6 for 1 USDC, not 1e18)
• Pod transactions require EIP-1559 (type 2) gas params, not legacy gasPrice

Features

• Bridge Deposits: Deposit ERC20 or native tokens to the bridge
• Claim with Proof: Claim on ETH using pod_getBridgeClaimProof RPC
• Track Bridge Requests: Query deposits sent/received by any address
• Claim Status Tracking: Monitor claim status and finality
• Transaction Building: Generate unsigned transactions ready for signing

Installation

npm install @tapforce/pod-bridge-sdk
# or
yarn add @tapforce/pod-bridge-sdk
# or
pnpm add @tapforce/pod-bridge-sdk

Quick Start

import {
  SourceChainToPodActionClient,
  PodToSourceChainActionClient,
  PodBridgeTrackerClient,
  getBridgeClaimProof,
  SOURCE_CHAIN_BRIDGE_ABI,
  POD_BRIDGE_ABI,
} from '@tapforce/pod-bridge-sdk';

Configuration

For Action Clients (creating transactions)

import { PodBridgeActionsClientConfig } from '@tapforce/pod-bridge-sdk';

const actionConfig: PodBridgeActionsClientConfig = {
  sourceChain: {
    contractAddress: '0x...' // BridgeDepositWithdraw on ETH
  },
  pod: {
    contractAddress: '0x0000000000000000000000000000000000B41D9E' // BridgeMintBurn on Pod
  }
};

For Tracker Client (querying events)

import { PodBridgeConfig } from '@tapforce/pod-bridge-sdk';
import { ethers } from 'ethers';

const trackerConfig: PodBridgeConfig = {
  sourceChain: {
    provider: new ethers.JsonRpcProvider('https://eth-mainnet.rpc.example'),
    contractAddress: '0x...',
    deploymentBlock: 12345678 // Optional: avoids indexing empty blocks
  },
  pod: {
    provider: new ethers.JsonRpcProvider('https://rpc.pod.network'),
    contractAddress: '0x0000000000000000000000000000000000B41D9E',
    deploymentBlock: 0
  }
};

Usage

ETH -> Pod (Auto-claim)

Deposits on ETH are automatically claimed on Pod after block finalization.

const client = new SourceChainToPodActionClient(actionConfig);

// Create deposit transaction (with optional permit for gasless approval)
const depositTx = client.deposit({
  token: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48', // USDC on ETH
  amount: ethers.parseUnits('1', 6),  // 1 USDC (use ETH-side decimals)
  destinationWalletAddress: '0x...',
  from: '0x...',
  // permit: '0x...' // Optional: ERC20 permit bytes
});

// Don't forget to approve the bridge contract first for ERC20 tokens
const tx = await signer.sendTransaction(depositTx);
const receipt = await tx.wait();

// No claim needed - balance auto-credited on Pod after finalization

Pod -> ETH (Claim with proof)

Deposits on Pod require claiming on ETH with a proof from pod_getBridgeClaimProof.

import {
  PodToSourceChainActionClient,
  getBridgeClaimProof,
  ClaimProofData,
} from '@tapforce/pod-bridge-sdk';

const client = new PodToSourceChainActionClient(actionConfig);

// Step 1: Deposit on Pod
const depositTx = client.deposit({
  token: '0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE', // Native token on Pod
  amount: ethers.parseUnits('1', 6),  // Use ETH-side decimals (1 USDC = 1e6)
  destinationWalletAddress: '0x...',
  from: '0x...',
});

// Pod requires EIP-1559 gas params (all zeros for free transactions)
const tx = await podSigner.sendTransaction({
  ...depositTx,
  maxFeePerGas: 0n,
  maxPriorityFeePerGas: 0n,
  gasLimit: 0n,
});

// Step 2: Get claim proof from Pod RPC
const { proof, auxTxSuffix } = await getBridgeClaimProof(podProvider, tx.hash);

// Step 3: Claim on ETH
const claimData: ClaimProofData = {
  ethTokenAddress: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48', // USDC on ETH
  amount: ethers.parseUnits('1', 6),  // Must match deposited amount
  to: '0x...',
  proof,
  auxTxSuffix,
};

const claimTx = client.claim({ claimData, from: '0x...' });
const claim = await ethSigner.sendTransaction(claimTx);

Tracking Deposits

const tracker = new PodBridgeTrackerClient(trackerConfig);

// Get all deposits for an address
const deposits = await tracker.getAllDepositsFor('0x...');

for (const deposit of deposits) {
  console.log('Request ID:', deposit.requestId);
  console.log('Direction:', deposit.deposit.chain === 'sourceChain' ? 'ETH -> Pod' : 'Pod -> ETH');
  console.log('Token:', deposit.deposit.token);
  console.log('Amount:', deposit.deposit.amount);
  console.log('Timestamp:', new Date(deposit.deposit.timestamp * 1000).toISOString());
  console.log('Status:', deposit.isClaimed ? 'Claimed' : (deposit.isClaimable ? 'Claimable' : 'Pending'));
}

// Get deposits sent/received by address
const sent = await tracker.getDepositsSentBy('0x...');
const received = await tracker.getDepositsReceivedBy('0x...');

// Check if deposit can be claimed
const canClaim = await tracker.canBeClaimed(deposit);

// Batch check processed status
const statuses = await tracker.areRequestsProcessed(deposits);

API Reference

SourceChainToPodActionClient

For ETH -> Pod deposits (auto-claim on Pod).

deposit(args: {
  token: string;
  amount: string | bigint;
  destinationWalletAddress: string;
  from?: string;
  permit?: string;          // Optional ERC20 permit bytes (default: '0x')
}): UnsignedTransaction

PodToSourceChainActionClient

For Pod -> ETH deposits and claims.

// Deposit tokens on Pod
deposit(args: {
  token: string;            // Use 0xEeee...EEeE for native token
  amount: string | bigint;  // Use ETH-side decimals
  destinationWalletAddress: string;
  from?: string;
}): UnsignedTransaction

// Claim on ETH with proof
claim(args: {
  claimData: ClaimProofData;
  from?: string;
}): UnsignedTransaction

getBridgeClaimProof

Helper to call pod_getBridgeClaimProof RPC and format the result.

import { getBridgeClaimProof } from '@tapforce/pod-bridge-sdk';

const { proof, committeeEpoch, auxTxSuffix } = await getBridgeClaimProof(
  podProvider,      // ethers.JsonRpcProvider connected to Pod RPC
  depositTxHash     // TX hash of the deposit on Pod
);

PodBridgeTrackerClient

getDepositsSentBy(address: string, fromBlock?: number): Promise<BridgeRequest[]>
getDepositsReceivedBy(address: string, fromBlock?: number): Promise<BridgeRequest[]>
getAllDepositsFor(address: string, fromBlock?: number): Promise<BridgeRequestWithType[]>
canBeClaimed(deposit: BridgeRequest): Promise<boolean>
areRequestsProcessed(deposits: BridgeRequest[]): Promise<boolean[]>

Types

ClaimProofData

interface ClaimProofData {
  ethTokenAddress: string;  // Token address on ETH (different from Pod)
  amount: string | bigint;  // Must match deposited amount
  to: string;               // Recipient address
  proof: string;            // Hex bytes from pod_getBridgeClaimProof
  auxTxSuffix: string;      // Hex bytes from pod_getBridgeClaimProof
}

BridgeRequest

interface BridgeRequest {
  requestId: string;

  deposit: {
    chain: 'sourceChain' | 'pod';
    txHash: string;
    depositor: string;
    destination: string;
    token: string;
    amount: string;
    chainId: number;
    blockNumber: number;
    timestamp: number;       // Unix timestamp (seconds)
  };

  claim?: {
    chain: 'sourceChain' | 'pod';
    txHash: string;
    claimer: string;
    chainId: number;
    blockNumber: number;
    timestamp: number;
  };

  isClaimed: boolean;
  isClaimable: boolean;
}

Events

The bridge contracts emit different events per chain:

// ETH (Source Chain)
event Deposit(uint256 indexed id, address indexed from, address indexed to, address token, uint256 amount);
event Claim(bytes32 indexed txHash, address token, address mirrorToken, uint256 amount, address indexed to);

// Pod
event Deposit(bytes32 indexed id, address indexed from, address indexed to, address token, uint256 amount);

ABIs

The SDK exports separate ABIs for each chain:

• SOURCE_CHAIN_BRIDGE_ABI - ETH bridge (deposit with permit, claim with proof)
• POD_BRIDGE_ABI - Pod bridge (3-param deposit)
• BRIDGE_ABI - Alias for SOURCE_CHAIN_BRIDGE_ABI

Pod-specific Notes

• Pod system contract address: 0x0000000000000000000000000000000000B41D9E
• Pod transactions are free: use maxFeePerGas: 0, maxPriorityFeePerGas: 0, gasLimit: 0
• Must use EIP-1559 (type 2) transactions, not legacy gasPrice
• Pod does NOT need value set for native token deposits - the system contract handles balance internally
• Pod returns blockNumber as a Unix timestamp in receipts

Development

npm run build   # Build
npm run clean   # Clean

Dependencies

• ethers: ^6.15.0

License

ISC

Repository

• GitHub
• Issues