DRAIN

Decentralized Runtime for AI Networks

An open protocol for trustless, streaming micropayments between AI consumers and providers.

ERC-8190: This protocol is being formalized as an Ethereum standard — Payment Channels with Signed Vouchers. The ERC defines the minimal interface for unidirectional payment channels using EIP-712 signed vouchers, complementary to ERC-8183 (Agentic Commerce).

╔══════════════════════════════════════════════════════════════════════════════╗
║                           1000 AI REQUESTS                                   ║
╠══════════════════════════════════════════════════════════════════════════════╣
║                                                                              ║
║   DRAIN              │  Per-Request Payments (x402, etc.)                    ║
║   ─────              │  ────────────────────────────────                     ║
║   2 transactions     │  1000 transactions                                    ║
║   ~$0.04 gas         │  ~$20+ gas                                            ║
║   0ms latency        │  2-5 sec per request                                  ║
║   1 wallet popup     │  1000 wallet popups (or API key)                      ║
║                                                                              ║
╚══════════════════════════════════════════════════════════════════════════════╝

Why DRAIN?

Existing decentralized AI protocols require holding volatile tokens, creating speculation dynamics that overwhelm utility. Meanwhile, 78% of the world lacks credit cards, and AI agents can't have bank accounts.

DRAIN fills this gap: stablecoin micropayments without tokens, complexity, or intermediaries.

Overview

DRAIN enables permissionless, pay-per-token AI inference without intermediaries. Users open payment channels with USDC, stream requests to any compatible provider, and settle on-chain only when needed.

Core Principles:

• Minimal – The protocol defines only what's necessary
• Permissionless – Anyone can be a provider or consumer
• Trustless – Cryptography replaces trust
• Immutable – No admin keys, no upgrades, no fees

How It Works

DRAIN is like a prepaid card for AI: deposit USDC, use it across requests, withdraw the remainder.

┌──────────────────────────────────────────────────────────────────┐
│                        Off-Chain (Fast & Free)                   │
│                                                                  │
│    Consumer                                      Provider        │
│        │                                             │           │
│        │───────── Request + Voucher ────────────────►│           │
│        │◄──────── AI Response ───────────────────────│           │
│        │───────── Request + Voucher ────────────────►│           │
│        │◄──────── AI Response ───────────────────────│           │
│        │                    ...                      │           │
│                                                                  │
└────────┼─────────────────────────────────────────────┼───────────┘
         │                                             │
         │              On-Chain (Rare)                │
         ▼                                             ▼
┌──────────────────────────────────────────────────────────────────┐
│                        DRAIN Contract                            │
│                                                                  │
│     open(provider, amount, duration)    →  Lock USDC             │
│     claim(channelId, amount, signature) →  Pay provider          │
│     close(channelId)                    →  Refund remainder      │
└──────────────────────────────────────────────────────────────────┘

The Two Roles

Consumer Flow

1. Open Channel: Deposit USDC for a specific provider and duration (~$0.02 gas, ~5 sec finality)
2. Use Service: Send requests with signed vouchers (free, off-chain, $0.000005 per request)
3. Close Channel: Withdraw unused USDC after expiry (~$0.02 gas, ~5 sec finality)

Provider Flow

1. Receive Request: Validate voucher signature and amount
2. Deliver Service: Return AI response
3. Claim Payment: Submit highest voucher to get paid (~$0.02 gas, ~5 sec finality)

Channel Duration & Provider Protection

The consumer sets the channel duration when opening (e.g., 24h). But providers control their requirements:

Key insight: Even after channel expiry, the provider can claim as long as the consumer hasn't closed. The consumer must actively call close() – it's not automatic.

Vouchers Are Cumulative

Each voucher contains the total amount spent, not the increment:

Request 1: voucher.amount = $0.10  (total spent so far)
Request 2: voucher.amount = $0.25  (total, not $0.15 increment)
Request 3: voucher.amount = $0.40  (total, not $0.15 increment)

Provider only needs to claim the last voucher to receive full payment.

Payment Currency

USDC on Polygon can be bridged from Ethereum, Base, Arbitrum via Circle CCTP.

Handshake58 Marketplace

The official DRAIN marketplace is Handshake58 - a provider directory where AI agents can discover and pay for AI inference.

For AI Agents

Install the MCP Server and start using AI with crypto payments:

npm install -g drain-mcp

Configure in Claude Desktop or Cursor:

{
  "mcpServers": {
    "drain": {
      "command": "drain-mcp",
      "env": {
        "DRAIN_PRIVATE_KEY": "your-polygon-wallet-key"
      }
    }
  }
}

That's it! The MCP server auto-discovers providers from Handshake58.

Agent-Oriented Endpoints

Protocol Specification (ERC-8190)

DRAIN implements ERC-8190: Payment Channels with Signed Vouchers — an Ethereum standard for streaming micropayments via EIP-712 signed vouchers.

The protocol intentionally excludes provider discovery, reputation systems, dispute resolution, and governance. See ERC-8183 (Agentic Commerce) and ERC-8004 (Trustless Agents) for complementary standards.

Full specification: See contracts/ for the Solidity implementation and the ERC-8190 draft for the formal standard.

Security Model