ATP: Agent Trade Protocol

The premier agent-to-agent payment protocol and foundational framework to empower the agent economy.

Overview

ATP (Agent Trade Protocol) is the premier agent-to-agent payment protocol that will be the foundational framework to empower the agent economy. Designed to overcome x402's issues and make agent-to-agent payments dynamic and simple, ATP enables automatic payment processing for agent services on the Solana blockchain. The protocol provides a middleware layer that automatically deducts payments from user wallets based on token usage, ensuring secure and transparent transactions.

Key Features

• Security: Response encryption ensures users cannot access output until payment is confirmed on-chain
• Automation: Zero-configuration payment processing through middleware integration
• Decentralization: All payments executed on Solana blockchain with full transaction visibility
• Format Flexibility: Supports multiple usage formats (OpenAI, Anthropic, Google, etc.) automatically
• Transparency: Automatic payment splitting between treasury and recipient wallets

Architecture

ATP Protocol operates through three main components:

1. Settlement Service (Facilitator): Centralized service handling all settlement logic, usage parsing, payment calculation, and blockchain transaction execution
2. Middleware: FastAPI middleware that intercepts API responses, extracts usage data, encrypts responses, executes payments, and decrypts responses only after payment confirmation
3. Client: User-facing client that simplifies making requests to ATP-protected endpoints and interacting with the settlement service

Request Flow

sequenceDiagram
    participant Client
    participant Server
    participant Middleware
    participant SettlementService
    participant Solana

    Client->>Server: POST /v1/chat<br/>(with wallet key)
    Server->>Server: Process request
    Server->>Middleware: Response with usage data
    Middleware->>Middleware: Encrypt response
    Middleware->>SettlementService: Parse usage & calculate payment
    SettlementService->>SettlementService: Calculate payment amount
    SettlementService->>Solana: Create & sign transaction
    Solana-->>SettlementService: Transaction confirmed
    SettlementService-->>Middleware: Payment confirmed (tx signature)
    Middleware->>Middleware: Decrypt response
    Middleware->>Client: Return decrypted response<br/>(with settlement details)

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Quick Start

Installation

pip install atp-protocol

Server Setup (5 minutes)

Add ATP middleware to your FastAPI server:

from fastapi import FastAPI
from fastapi.responses import JSONResponse
from atp.middleware import ATPSettlementMiddleware
from atp.schemas import PaymentToken

app = FastAPI(title="My ATP-Protected API")

# Add ATP Settlement Middleware
app.add_middleware(
    ATPSettlementMiddleware,
    allowed_endpoints=["/v1/chat", "/v1/completions"],
    input_cost_per_million_usd=10.0,  # $10 per million input tokens
    output_cost_per_million_usd=30.0,  # $30 per million output tokens
    recipient_pubkey="YourSolanaWalletPublicKeyHere",  # Your wallet
    payment_token=PaymentToken.SOL,  # SOL or USDC
    wallet_private_key_header="x-wallet-private-key",
    require_wallet=True,
)

@app.post("/v1/chat")
async def chat(request: dict):
    """Agent endpoint with automatic payment processing."""
    message = request.get("message", "")
    
    # Agent logic implementation
    response_text = "Agent response here"
    
    # Return response with usage data
    # Middleware handles payment processing automatically
    return JSONResponse(content={
        "response": response_text,
        "usage": {
            "input_tokens": 100,
            "output_tokens": 50,
            "total_tokens": 150
        }
    })

Client Usage

from atp.client import ATPClient

# Initialize client with wallet
client = ATPClient(
    wallet_private_key="[1,2,3,...]",  # Your wallet private key
    settlement_service_url="https://facilitator.swarms.world"
)

# Make request with automatic payment processing
response = await client.post(
    url="https://api.example.com/v1/chat",
    json={"message": "Hello!"}
)

print(response["response"])  # Agent output
print(response["atp_settlement"])  # Payment details

Examples

Below is a comprehensive table of example integrations and usage:

Framework Integrations

Category	Example Link	Description
Framework Integration	Swarms Framework	Enterprise multi-agent orchestration
Framework Integration	LangChain	Popular Python LLM framework
Framework Integration	AutoGen	Microsoft's multi-agent framework
Framework Integration	CrewAI	Multi-agent orchestration
Framework Integration	Anthropic	Claude API integration

Client & Server Example Scripts

Category	Example Link	Description
Client Example	Health Check	Check settlement service status
Client Example	Parse Usage	Parse usage from various formats
Client Example	Calculate Payment	Calculate payment without executing
Client Example	Execute Settlement	Direct settlement execution
Client Example	Make Request	Request ATP-protected endpoints
Server Example	Basic Example	Simple middleware setup
Server Example	Full Flow	Complete payment flow
Server Example	Settlement Service	Direct service usage

See examples/README.md for complete documentation.

Security Features

Feature	Description
Response Encryption	Agent responses are encrypted before payment verification, ensuring users cannot see output until payment is confirmed on-chain.
Payment Verification	Responses are only decrypted after successful blockchain transaction confirmation (status="paid" with valid transaction signature).
Error Handling	Failed payments result in encrypted responses with error details, preventing unauthorized access to agent output.

Payment Structure

Payments are automatically split between:

• Treasury: Receives processing fee (default 5%, configured on settlement service)
• Recipient: Receives remainder (95% by default) - your wallet specified via recipient_pubkey

Supported Payment Tokens

• SOL (Solana native token)
• USDC (USD Coin on Solana)

Usage Data Formats

The middleware automatically supports multiple usage formats:

OpenAI Format

{
  "usage": {
    "prompt_tokens": 100,
    "completion_tokens": 50,
    "total_tokens": 150
  }
}

Anthropic Format

{
  "usage": {
    "input_tokens": 100,
    "output_tokens": 50
  }
}

Google/Gemini Format

{
  "usageMetadata": {
    "promptTokenCount": 100,
    "candidatesTokenCount": 50,
    "totalTokenCount": 150
  }
}

The settlement service automatically detects and parses these formats, so you can use any format your agent API returns.

Configuration

Environment Variables

# Settlement Service
ATP_SETTLEMENT_URL="https://facilitator.swarms.world"  # Default
ATP_SETTLEMENT_TIMEOUT=300.0  # 5 minutes (default)

# Encryption (optional - generates new key if not set)
ATP_ENCRYPTION_KEY="base64-encoded-fernet-key"

Middleware Configuration

app.add_middleware(
    ATPSettlementMiddleware,
    allowed_endpoints=["/v1/chat"],  # Endpoints to protect
    input_cost_per_million_usd=10.0,  # Pricing
    output_cost_per_million_usd=30.0,
    recipient_pubkey="YourWalletPublicKey",  # Required
    payment_token=PaymentToken.SOL,  # SOL or USDC
    wallet_private_key_header="x-wallet-private-key",
    require_wallet=True,  # Require wallet for payment
    settlement_service_url="https://facilitator.swarms.world",
    settlement_timeout=300.0,
    fail_on_settlement_error=False,  # Graceful error handling
)

API Reference

Middleware

The ATPSettlementMiddleware class provides automatic payment processing for FastAPI endpoints.

Key Features:

• Automatic usage parsing from multiple formats
• Response encryption before payment
• Payment execution via settlement service
• Response decryption after payment confirmation

See Middleware Documentation for complete API reference.

Client

The ATPClient class provides a simple interface for:

• Making requests to ATP-protected endpoints
• Interacting with the settlement service directly
• Parsing usage data
• Calculating payments
• Executing settlements

See Client Documentation for complete API reference.

Settlement Service

The settlement service (facilitator) handles:

• Usage parsing from various formats
• Payment calculation
• Blockchain transaction creation and execution
• Transaction confirmation

See Settlement Service Documentation for complete API reference.

Error Handling

Missing Wallet Key

If wallet private key is missing and require_wallet=True:

{
  "detail": "Missing wallet private key in header: x-wallet-private-key"
}

Status: 401 Unauthorized

Payment Failure

If payment fails and fail_on_settlement_error=False (default):

{
  "response": "encrypted_data_here",
  "response_encrypted": true,
  "atp_settlement": {
    "error": "Settlement failed",
    "detail": "Insufficient funds",
    "status_code": 400
  },
  "atp_settlement_status": "failed",
  "atp_message": "Agent response is encrypted. Payment required to decrypt."
}

The response remains encrypted until payment succeeds.

Best Practices

1. Wallet Security: Never log or persist wallet private keys. Use them only in-memory for transaction signing.

2. Error Handling: Use fail_on_settlement_error=False for graceful degradation. Check atp_settlement_status in responses to handle payment failures appropriately.

3. Timeout Configuration: Increase settlement_timeout if you experience timeout errors. Blockchain confirmation can take time depending on network conditions.

4. Usage Data: Always include accurate token counts in your responses. Middleware skips settlement if usage data cannot be parsed.

5. Testing: Use testnet wallets and small amounts for testing. Verify transactions on Solana explorer before production deployment.

6. Monitoring: Monitor atp_settlement_status in responses to track payment success rates and identify potential issues.

Resources

Resource	Description
Full Documentation	Complete API documentation
Settlement Service API	Facilitator API reference
Middleware Reference	Middleware configuration
Client Reference	Client API reference
ATP Vision	Protocol vision and roadmap

Contributing

Contributions are welcome. Please read our contributing guidelines and submit pull requests for review.

Development

Requirements

• Python 3.10+
• FastAPI (for middleware)
• Solana wallet (for payments)

Installation from Source

git clone https://github.com/The-Swarm-Corporation/ATP-Protocol.git
cd ATP-Protocol
pip install -e .

Running Tests

pytest tests/

Code Quality

# Format code
black .

# Lint code
ruff check .

License

This project is licensed under the MIT License. See the LICENSE file for details.

Citation

If you use ATP (Agent Trade Protocol) in your research or software, please cite The Swarm Corporation:

@software{atp_protocol,
  title = {ATP: Agent Trade Protocol},
  author = {{The Swarm Corporation}},
  year = {2025},
  url = {https://github.com/The-Swarm-Corporation/ATP-Protocol},
  note = {Agent-to-agent payment protocol for the agent economy}
}

The Swarm Corporation. ATP: Agent Trade Protocol. https://github.com/The-Swarm-Corporation/ATP-Protocol

Acknowledgments

Built by The Swarm Corporation to enable agent-to-agent commerce on the blockchain.

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For additional information, see the examples directory or the complete documentation.