Transfer          Airdrop           Stream            Stream to Role
────────────────────────────────────────────────────────────────────
Single recipient  Many recipients   Single recipient  Role holders
One-time          One-time (batch)  Continuous        Continuous
Immediate         Immediate         Over duration     Auto-managed
Manual            Manual            Manual            Automatic

Best for:         Best for:         Best for:         Best for:
• Invoices        • Rewards         • Salaries        • Committees
• Grants          • Airdrops        • Grants          • Working groups
• Expenses        • Rebates         • Vesting         • Recurring roles

interface IPayments {
    /// @notice Simple transfer from treasury
    function transfer(
        address token,
        address to,
        uint256 amount,
        string calldata memo
    ) external;

    /// @notice Batch transfer to multiple recipients
    function airdrop(
        address token,
        address[] calldata recipients,
        uint256[] calldata amounts
    ) external;

    /// @notice Create a payment stream
    function createStream(
        address token,
        address recipient,
        uint256 totalAmount,
        uint256 startTime,
        uint256 duration,
        uint256 cliffDuration
    ) external returns (uint256 streamId);

    /// @notice Create streams for all role holders
    function streamToRole(
        bytes32 roleId,
        address token,
        uint256 amountPerHolder,
        uint256 duration
    ) external returns (uint256[] memory streamIds);

    /// @notice Withdraw from a stream
    function withdrawFromStream(uint256 streamId) external;

    /// @notice Cancel a stream
    function cancelStream(uint256 streamId) external;
}

Proposal: "Q1 Contributor Payments"

Description: |
  This proposal executes Q1 payments for approved contributors.

Actions:
  # Immediate transfer for completed work
  - type: transfer
    token: USDC
    to: 0x1234...
    amount: 5000
    memo: "Q1 Development Milestone"

  # Stream for ongoing work
  - type: create_stream
    token: USDC
    recipient: 0x5678...
    total: 12000
    duration: 90 days
    cliff: 0

  # Airdrop rewards to participants
  - type: airdrop
    token: DAO
    recipients: [0xAAA..., 0xBBB..., 0xCCC...]
    amounts: [1000, 1000, 1000]

import { PaymentsClient } from '@lux/dao-sdk';

const payments = new PaymentsClient(signer);

// Simple transfer (requires TREASURER_ROLE)
await payments.transfer(
  usdc.address,
  recipientAddress,
  ethers.parseUnits('5000', 6),
  'Invoice #1234'
);

Payment Approval Matrix:

< $1,000:
  - Single Lead signature
  - No proposal required

$1,000 - $10,000:
  - 2 Lead signatures
  - Logged in treasury report

$10,000 - $50,000:
  - Committee proposal
  - 3-day voting period

> $50,000:
  - Full DAO proposal
  - 7-day voting period
  - Standard timelock

┌─────────────────────────────────────────────────────────────┐
│ Treasury Payments                                            │
├─────────────────────────────────────────────────────────────┤
│                                                              │
│  Recent Transfers                                            │
│  ──────────────────────────────────────────────────────     │
│  Jan 15  0x1234...  5,000 USDC   "Q1 Development"           │
│  Jan 14  0x5678...  2,500 USDC   "Design Work"              │
│  Jan 10  0xABCD...  1,000 USDC   "Community Event"          │
│                                                              │
│  Active Streams (3)                              Total/mo   │
│  ──────────────────────────────────────────────────────     │
│  Research Lead     1,000 USDC/mo   ████████░░  80%          │
│  Dev Contributor     500 USDC/mo   ██████░░░░  60%          │
│  Community Mgr       750 USDC/mo   ████░░░░░░  40%          │
│                                                              │
│  Pending Airdrops (1)                                       │
│  ──────────────────────────────────────────────────────     │
│  Governance Rewards  500 recipients  50,000 DAO tokens      │
│  Status: Awaiting execution                                  │
│                                                              │
└─────────────────────────────────────────────────────────────┘

import { PaymentsClient } from '@lux/dao-sdk';

const payments = new PaymentsClient(provider);

// Track all payment events
payments.on('Transfer', (token, to, amount, memo) => {
  console.log(`Transfer: ${amount} to ${to}`);
});

payments.on('StreamCreated', (streamId, recipient, total, duration) => {
  console.log(`Stream ${streamId}: ${total} over ${duration}s`);
});

payments.on('AirdropExecuted', (token, recipientCount, totalAmount) => {
  console.log(`Airdrop: ${totalAmount} to ${recipientCount} addresses`);
});

Multi-sig thresholds:
  - < $10K: 2-of-3 signers
  - $10K-$50K: 3-of-5 signers
  - > $50K: 4-of-7 signers + timelock

// Validate address before payment
function validateRecipient(address: string): boolean {
  // Check format
  if (!ethers.isAddress(address)) return false;

  // Check against known addresses (optional)
  const known = knownAddresses.get(address);
  if (!known) {
    console.warn('Unknown address - verify manually');
  }

  return true;
}

// In treasury contract
uint256 public constant MAX_SINGLE_PAYMENT = 100_000e6; // 100K USDC
uint256 public constant DAILY_LIMIT = 250_000e6;        // 250K USDC

// Good
await payments.transfer(usdc, recipient, amount,
  'Invoice #1234 - Q1 Development Milestone 2');

// Bad
await payments.transfer(usdc, recipient, amount, '');

// Instead of 10 separate transfers
const recipients = [...];
const amounts = [...];
await payments.airdrop(token, recipients, amounts);