IATP-D402: Inter-Agent Transfer Protocol with Payment Support

IATP-D402 enables AI agents and APIs to charge for their services using the D402 payment protocol (HTTP 402 Payment Required). Build payment-enabled:

🌐 APIs and web servers
🔧 MCP (Model Context Protocol) servers
🤖 A2A utility agents
🤝 CrewAI tools and agents

🚀 Quick Start

Installation

pip install traia-iatp

Add D402 to Your FastAPI Server (5 lines)

from fastapi import FastAPI
from traia_iatp.d402.servers.fastapi import D402FastAPIMiddleware
from traia_iatp.d402.price_builder import D402PriceBuilder

app = FastAPI()

# Add D402 (5 lines)
price_builder = D402PriceBuilder(network="sepolia")
d402 = D402FastAPIMiddleware(server_address="0x...", facilitator_url="https://test-facilitator.d402.net")
price = price_builder.create_price(0.01)  # $0.01 USD
d402.register_endpoint("/api/analyze", price_wei=price.amount, token_address=price.asset.address, network="sepolia", description="Analysis")
d402.add_to_app(app)

# Your endpoint (unchanged!)
@app.post("/api/analyze")
async def analyze(request: Request):
    return {"result": "done"}

Call D402-Protected Servers (2 lines)

from traia_iatp.d402.clients.httpx import d402HttpxClient
from eth_account import Account

async with d402HttpxClient(
    operator_account=Account.from_key("0x..."),
    wallet_address="0x...",
    max_value=100000,
    base_url="http://localhost:8000"
) as client:
    # Payment automatic!
    response = await client.post("/api/analyze", json={"text": "test"})

📚 Documentation

Full documentation: docs.d402.net

Quick Links

Complete Examples - Step-by-step integration examples (0-6)
Server Integration - Add D402 to existing servers
Client Integration - Call D402-protected APIs
MCP Servers - Build payment-enabled MCP servers
Utility Agents - Build A2A utility agents
CrewAI Integration - Use D402 tools in CrewAI

Complete Integration Examples

The examples section provides complete, working code for:

Wallet Creation & Funding - Setup wallets, get testnet USDC
Existing Server → D402 - Add payments to your API (before/after)
Calling D402 Servers - Build payment-enabled client
API → MCP Server - Convert REST to MCP tools
CrewAI + MCP - Use MCP server in crews
MCP → Utility Agent - Wrap MCP as A2A agent
CrewAI + Utility Agent - Use agents in crews

🌟 Key Features

D402 Payment Protocol

✅ HTTP 402 Payment Required - Standard payment protocol
✅ EIP-712 Signatures - Secure payment authorization
✅ On-Chain Settlement - Smart contract-based settlements
✅ Hosted Facilitators - No infrastructure setup required

Server Integration

✅ FastAPI - D402FastAPIMiddleware
✅ Starlette - D402PaymentMiddleware
✅ Any ASGI Framework - D402ASGIWrapper (Flask, Django, Quart, etc.)
✅ 5-line integration - Minimal code changes

Client Integration

✅ HTTPX (Async) - d402HttpxClient with automatic payment
✅ Requests (Sync) - Wrapper for synchronous apps
✅ 2-line integration - Just make requests normally

MCP & A2A

✅ MCP Servers - Payment-enabled tool servers
✅ Utility Agents - A2A protocol with D402
✅ CrewAI Integration - A2AToolkit for paid tools
✅ Template Generation - Auto-generate server code

🔧 What's in the Package

Core Components (IN pip package)

src/traia_iatp/
├── d402/                     # D402 payment protocol
│   ├── servers/             # Server middleware (FastAPI, Starlette, MCP)
│   ├── clients/             # Client libraries (HTTPX, base client)
│   ├── asgi_wrapper.py      # Universal ASGI wrapper
│   ├── price_builder.py     # USD-based pricing
│   └── facilitator.py       # Facilitator client
│
├── mcp/                      # MCP server templates & tools
├── server/                   # Utility agent templates
├── client/                   # A2A client & CrewAI tools
├── contracts/                # Smart contract integration
└── registry/                 # Agent discovery & search

Examples (NOT in pip package)

examples/                     # Integration examples
├── servers/                 # FastAPI, Starlette, ASGI examples
└── clients/                 # HTTPX, Requests examples

Documentation (NOT in pip package)

docs/                         # GitBook documentation
├── getting-started/         # Installation, quick start
├── examples/                # Complete integration examples (0-6)
├── wallet-setup/            # Wallet creation & CLI
├── d402-servers/            # Server integration guides
├── d402-clients/            # Client integration guides
├── mcp-servers/             # MCP server guides
├── utility-agents/          # Utility agent guides
└── crewai-integration/      # CrewAI guides

🏗 Architecture

┌────────────────────────────────────────────────────────────┐
│                    Your Application                         │
│      (API / MCP Server / Utility Agent / CrewAI Crew)      │
└────────────────────────────────────────────────────────────┘
                           │
                           ▼
┌────────────────────────────────────────────────────────────┐
│                  IATP-D402 Framework                        │
│  • Server Middleware  • Client Libraries  • Templates      │
└────────────────────────────────────────────────────────────┘
                           │
                           ▼
┌────────────────────────────────────────────────────────────┐
│                  D402 Payment Protocol                      │
│  • HTTP 402  • EIP-712 Signing  • Facilitator Service      │
└────────────────────────────────────────────────────────────┘
                           │
                           ▼
┌────────────────────────────────────────────────────────────┐
│               Smart Contracts (On-Chain)                    │
│         • IATPWallet  • Settlement  • Tokens                │
└────────────────────────────────────────────────────────────┘

🌐 Facilitators (No Setup Required)

You don't need to run your own facilitator!

All Testnets: https://test-facilitator.d402.net (currently: Sepolia)
All Mainnets: https://facilitator.d402.net (currently: Arbitrum)

See Facilitator URLs for details.

🔐 Wallet Creation

# Create IATP wallet (owner creates their own wallet)
traia-iatp create-iatp-wallet \
  --owner-key 0x... \
  --create-operator \
  --wallet-name "My Server" \
  --wallet-type MCP_SERVER \
  --network sepolia

See Creating Wallets for complete guide.

📦 Use Cases

1. Monetize Your API

# Add payment to any endpoint
d402.register_endpoint("/api/analyze", price_usd=0.01)

2. Build Payment-Enabled MCP Servers

@mcp.tool()
@require_payment_for_tool(price=price_builder.create_price(0.01))
def analyze(text: str) -> dict:
    return analyze_sentiment(text)

3. Use Paid Tools in CrewAI

toolkit = A2AToolkit.create_from_endpoint(
    endpoint="http://localhost:9001",
    payment_private_key="0x...",
    wallet_address="0x...",
    max_payment_usd=1.0
)

agent = Agent(role="Analyst", tools=toolkit.tools)

🛠 CLI Commands

# Create IATP wallet
traia-iatp create-iatp-wallet --owner-key 0x... --create-operator

# Create utility agency from MCP server
traia-iatp create-agency --name "My Agent" --mcp-name "Trading MCP"

# List available agencies
traia-iatp list-agencies

# Search for tools
traia-iatp find-tools --query "sentiment analysis"

🔗 Links

Documentation: docs.d402.net
PyPI: pypi.org/project/traia-iatp
GitHub: github.com/Traia-IO/IATP
Examples: docs/examples/

📄 License

MIT License - see LICENSE file for details.

🤝 Support

📖 Documentation: docs.d402.net
🐛 Issues: GitHub Issues
💬 Website: traia.io
📧 Email: support@traia.io

Made with ❤️ by the Traia Team

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