x402-policy 0.2.0

Policy engine for autonomous AI agent x402 micro-payments with ERC-8004 trust scoring

x402 Policy Engine

Python SDK for autonomous AI agent micro-payments.

pip install x402-policy

---

What is this?

x402 Policy Engine gives AI agents the ability to pay for APIs, data, and compute without human approval.

• Session keys — user signs once, agent transacts freely (no 5-15s approval wall)
• ERC-8004 trust scoring — cross-chain reputation via TAP resolver
• Policy guardrails — daily caps, per-tx limits, allowlists, kill-switch
• Gasless relayer — sponsor transactions, earn 0.1% on settled volume

Built on Coinbase's x402 protocol + Ethereum's ERC-8004 Trustless Agents.

---

Quick Start

from x402_policy import (
    PolicyConfig,
    SessionKeyManager,
    TAPResolver,
    create_policy,
    TimeWindow
)
import asyncio

async def main():
    # 1. Create a session key (user signs once)
    manager = SessionKeyManager(
        wallet_private_key=os.environ["WALLET_PRIVATE_KEY"],
        chain_id=8453  # Base
    )
    session = await manager.create_session(
        daily_limit=5.0,
        per_tx_limit=0.10,
        window_hours=24,
        allowed_recipients=["api.coinbase.com", "api.coingecko.com"]
    )

    # 2. Check agent trust score (cross-chain ERC-8004)
    resolver = TAPResolver()
    tap = await resolver.verify("0xAgentId...", chain_id=8453)
    
    if not tap["payment_approved"]:
        print(f"Agent not trusted: {tap['payment_reason']}")
        return

    # 3. Execute autonomous payment
    result = await manager.execute_payment(
        session=session,
        recipient="api.coinbase.com/v1/prices",
        amount=0.05,
        description="ETH price feed"
    )
    print(f"✅ Paid ${result['amount_usd']} — tx: {result['tx_hash'][:16]}...")

asyncio.run(main())

---

Core Components

Policy Engine

from x402_policy import create_policy, TimeWindow

policy = create_policy(
    daily_budget=5.0,
    per_tx_max=0.10,
    allowlist=["api.coinbase.com", "api.openai.com"],
    time_windows=[TimeWindow(start_hour=6, end_hour=22)]
)

result = policy.approve_payment(
    recipient="api.coinbase.com",
    amount=0.02,
    description="ETH price feed"
)
# ✅ Auto-approved under policy

TAP Resolver (ERC-8004 Cross-Chain Reputation)

from x402_policy import TAPResolver

resolver = TAPResolver()
trust = await resolver.score("0xAgentId...", chain_id=8453)

print(f"Trust score: {trust.overall_score}/5.0 ({trust.trust_level.value})")
print(f"Recommendation: {trust.recommendation}")

Session Keys (Gasless Payments)

from x402_policy import SessionKeyManager

manager = SessionKeyManager(wallet_private_key="0x...")
session = await manager.create_session(daily_limit=10.0, per_tx_limit=0.50)

# Agent pays without further approval
result = await manager.execute_payment(
    session=session,
    recipient="api.openai.com",
    amount=0.05
)

x402 Policy Client

from x402_policy import x402PolicyClient, PolicyConfig

client = x402PolicyClient(
    wallet_private_key="0x...",
    policy_config=PolicyConfig(daily_budget=5.0, per_tx_max=0.10)
)

result = await client.pay("api.coinbase.com", 0.05, "Price feed")

---

Architecture

User signs session (one-time)
        ↓
SessionKeyManager issues session key
        ↓
TAPResolver checks cross-chain ERC-8004 trust score
        ↓
PolicyEngine enforces spending limits
        ↓
x402 client executes USDC payment
        ↓
RelayerService sponsors gas + takes 0.1% fee

---

Supported Chains

• Ethereum (chain ID: 1)
• Base (chain ID: 8453)
• Arbitrum One (chain ID: 42161)
• Optimism (chain ID: 10)
• BSC (chain ID: 56)
• Polygon (chain ID: 137)
• Avalanche (chain ID: 43114)
• Moonbeam (chain ID: 1284)

---

Dashboard

Run the FastAPI dashboard for policy management:

uvicorn x402_policy.dashboard:app --reload --port 8000

Open http://localhost:8000/docs for the interactive API docs.

---

Use Cases

1. AI trading agents — pay for price feeds, market data, exchange APIs
2. AI research agents — pay for web searches, data APIs, LLM calls
3. AI content agents — pay for media APIs, stock photos, transcription
4. AI automation agents — pay for infrastructure, compute, storage

---

Revenue Model

Tier	Price	Includes
Open Source	Free	SDK, session keys, TAP resolver
Pro	$49/mo	Hosted dashboard, webhook alerts, relayer service
Enterprise	$499/mo	Multi-agent management, SLA, white-label

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Hackathon Targets

• ETHGlobal Cannes 2026
• Consensus Miami 2026
• DoraHacks x402

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Links

• x402 Protocol
• ERC-8004 (Trustless Agents)
• Agent.market
• x402 Foundation

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License

MIT