Blockchain Integration

Smart Contract Requirements

The payment channel MUST be implemented as a smart contract on the target blockchain. The contract MUST provide three functions:

open_channel

Creates a new payment channel.

• Parameters: leecher, seeder, deposit_amount, timeout_period, channel_id, memo
• Actions:
  • Transfer tokens from Leecher to escrow account
  • Create channel state record
  • Store channel metadata
• Returns: Transaction signature

close_channel

Closes channel with the final payment check (cooperative close).

• Parameters: channel_id, amount, nonce, signature
• Actions:
  • Verify payment check signature
  • Verify nonce exceeds last_nonce
  • Transfer amount to Seeder
  • Refund deposited - amount to Leecher
  • Mark channel as closed
• Returns: Transaction signature

timeout_close

Closes channel after timeout (force-close by Leecher).

• Parameters: channel_id
• Actions:
  • Verify current_time exceeds channel.timeout
  • Refund entire deposit to Leecher
  • Mark channel as timed out
• Returns: Transaction signature

Account / State Structure

The contract MUST use deterministic account addressing (e.g. Program Derived Addresses on Solana, CREATE2 on Ethereum) to ensure channel accounts can be computed from parameters.

Transaction Construction

transaction = {
  instructions: [
    token_transfer(leecher -> escrow, amount),
    create_channel_state(
      leecher: leecher_wallet,
      seeder: seeder_wallet,
      escrow: escrow_account,
      deposited: amount,
      channel_id: channel_id,
      created_at: current_timestamp,
      timeout: current_timestamp + timeout_period,
      last_nonce: 0,
      status: "Open"
    ),
    attach_memo({
      protocol: "seedpay",
      version: "1.0",
      session_hash: session_hash,
      nonce: nonce
    })
  ],
  signers: [leecher_private_key]
}

Token Program Requirements

The blockchain MUST support:

• Token transfers (fungible tokens, e.g. USDC)
• Escrow accounts controlled by smart contracts
• Memo/note attachment to transactions

RPC Provider Requirements

Minimum Requirements

RPC Operations

Implement retry logic with exponential backoff and cache channel state to reduce RPC dependency.

Confirmation Requirements

• Confirmed: Transaction included in block, may be reverted
• Finalized: Transaction cannot be reverted (chain-specific finality)