← Back to AsterPay

Documentation

The trust layer for AI agent payments. 8 security checks. Trust Score 0-100. Fiat in seconds.

Quick Start

Get started in under 2 minutes. The Trust Score API is free — no signup needed.

1. Check an agent's trust score (free, no auth)

# Check any agent wallet — no API key, no payment
curl https://x402.asterpay.io/v1/agent/trust-score/0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045

# Response:
# { "trustScore": 34, "tier": "verified", "maxPerTx": 1000, ... }

2. Create an account & get API keys

Sign up at app.asterpay.io and create a sandbox API key from the dashboard.

3. Test with the API Playground

Use the built-in API Playground to make test requests instantly — no code required.

4. Make your first x402 request

# The x402 flow: request → 402 → pay USDC → retry → 200

# Step 1: Request a paid endpoint (returns 402 + payment requirements)
curl https://x402.asterpay.io/v1/market/price/bitcoin

# Step 2: Use @x402/fetch to handle payment automatically
npm install @x402/fetch

5. Submit KYB for production fiat settlement

When you're ready to receive EUR, submit a KYB application from the dashboard. Approval enables stablecoin → fiat settlement to your bank account.

How x402 Works

x402r: Escrow & Refund Protection

API Reference

Know Your Agent (KYA) — FREE

Agent Deep Analysis — PREMIUM (x402)

Market Data

AI Tools

Crypto Analytics

Utilities

Settlement

Facilitator (x402 v2)

x402r — Escrow & Refunds

Discovery & System

Authentication

x402 Payment (primary)

All paid endpoints use the x402 protocol. No API key needed — payment is the authentication. Your client signs a USDC transaction and includes it in the request header.

API Keys (optional, for tracking)

Create API keys in the dashboard to track usage, set rate limits, and view analytics.

curl -H "Authorization: Bearer sk_sand_your_key" \
     https://x402.asterpay.io/v1/market/price/bitcoin

Key Prefix	Environment	Description
sk_sand_	Sandbox	Testing, no real payments
sk_live_	Production	Real USDC payments + EUR settlement

Supported Chains

Chain	Stablecoins	Status
Base	USDC, EURC	✅ Primary
Base Sepolia	USDC	✅ Testnet
Ethereum	USDC, EURC, EURCV	✅ Supported
Polygon	USDC	✅ Supported
Solana	USDC	✅ Supported
XRPL	EURCV	✅ Supported
BNB Chain	USDC	🚧 Q2 2026
Monad	USDC	🚧 Roadmap

Fiat Settlement

AsterPay converts your stablecoin earnings to fiat and sends them to your bank account.

• EUR: SEPA Instant — in your bank in seconds
• GBP: Faster Payments (Q2 2026)
• USD: ACH (Q3 2026)
• Stablecoins: USDC, EURC (Circle), EURCV (SG-FORGE / Société Générale)
• Requirements: Approved KYB + bank account on file
• MiCA: Fully compliant with EU MiCA regulation (effective July 2026)

Agent Trust Score

Every agent that interacts with AsterPay receives a Trust Score (0-100) based on 8 security checks:

Component	Max Points	Source
Wallet Age	15	On-chain (first tx)
Wallet Activity	15	Transaction count
Sanctions Screening	20	Chainalysis Oracle (OFAC/EU/UN)
Agent Identity	20	ERC-8004 on-chain registry
Operator KYB	20	Off-chain verification
Payment History	5	AsterPay track record
Trust Bond	5	Staked collateral

Scores map to access tiers:

Tier	Score	Max Per Tx	Max Daily
Open	0–19	$1	$10
Verified	20–49	$1,000	$5,000
Trusted	50–79	$10,000	$50,000
Enterprise	80–100	Unlimited	Unlimited

SDKs

@asterpay/x402 (TypeScript/JavaScript)

x402 protocol client with AI Agent Wallet and LangChain integration.

# Install
npm install @asterpay/x402

# Usage
import { createX402Client, createAgentWallet } from '@asterpay/x402';

const wallet = createAgentWallet({
  privateKey: process.env.AGENT_KEY,
  network: 'base',
  spendingLimits: { daily: 10 }
});

const client = createX402Client({ wallet });
const response = await client.fetch('https://x402.asterpay.io/v1/market/price/bitcoin');

asterpay (Python)

Full Python SDK with async support. CrewAI and LangChain integrations included.

# Install
pip install asterpay

# Usage
from asterpay import AsterPay

client = AsterPay(api_key="sk_live_...")
score = client.discovery.trust_score("0xd8dA...96045")
print(score.trust_score, score.tier)  # 34, "verified"

# Async
import asyncio
from asterpay import AsyncAsterPay

async def main():
    client = AsyncAsterPay(api_key="sk_live_...")
    price = await client.market.get_price("bitcoin")
    print(price)

asterpay-openai-agents (Python)

Payment tools for OpenAI Agents SDK — give your AI agents the ability to pay.

# Install
pip install asterpay-openai-agents

# Usage
from agents import Agent
from asterpay_agents import get_asterpay_tools, AsterPayWallet

wallet = AsterPayWallet(
    private_key=os.environ["AGENT_KEY"],
    network="base",
    daily_limit=10.0
)

agent = Agent(
    name="Shopping Assistant",
    tools=get_asterpay_tools(wallet)
)

@asterpay/attest (CLI & SDK — EU AI Act)

Scan your TypeScript project for AI SDK imports, run compliance signal checks, and generate EU AI Act documentation. August 2, 2026 deadline.

# Zero install — try now
npx @asterpay/attest scan

# Check compliance signals
npx @asterpay/attest check

# Generate Annex IV docs
npx @asterpay/attest docs -o ./compliance

GitHub · npm · MIT License

Agent-to-Agent Payments (Payment Rail Propagation)

AsterPay's MCP server includes two tools for the x402 "virus machine" pattern — payment rails that propagate automatically between agents:

agent_pay — Pre-payment trust gate

Before paying another agent, call agent_pay to verify they're not sanctioned and check their trust tier. Returns payment instructions if safe, blocks if sanctioned.

# Via MCP: agent checks trust before sending USDC
# → Returns: trust score, sanctions status, payment instructions
# → Blocks sanctioned addresses automatically
# → Recommends escrow for low-trust agents (score < 30)

get_payment_rail — JSON-LD rail for propagation

Returns AsterPay's payment rail as a JSON-LD document. Install this rail to pay any AsterPay-connected agent, then forward it to every agent you interact with.

# Returns JSON-LD payment rail with:
{
  "@context": { "x402": "https://x402.org/schema/" },
  "x402:signatureScheme": "ECDSA-SHA256",
  "x402:supportedNetworks": ["Base", "Ethereum", "Polygon", ...],
  "asterpay:trustScoring": { "scoreRange": "0-100" },
  "asterpay:settlement": { "currencies": ["EUR", "USD", "GBP"] }
}

Discovery: .well-known/x402.json (JSON-LD) · Signature: ECDSA-SHA256

Code Examples

Trust Score — cURL (free)

# Get full trust assessment for any wallet
curl https://x402.asterpay.io/v1/agent/trust-score/0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045

# Quick tier check
curl https://x402.asterpay.io/v1/agent/tier/0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045

# Batch check 10 agents at once
curl -X POST https://x402.asterpay.io/v1/agent/trust-score/batch \
  -H "Content-Type: application/json" \
  -d '{"addresses": ["0xd8dA...", "0xABC..."]}'

Trust Score — Python

from asterpay import AsterPay

client = AsterPay()
result = client.discovery.trust_score("0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045")

if result.tier in ("trusted", "enterprise"):
    process_payment(result.wallet)
elif result.screening.sanctioned:
    block_wallet(result.wallet)
else:
    require_additional_verification(result.wallet)

Node.js — Fetch with x402 payment

import { fetchWithPayment } from '@x402/fetch';

const response = await fetchWithPayment(
  'https://x402.asterpay.io/v1/ai/summarize',
  {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ text: 'Your text here...' })
  },
  wallet
);

Python — Market data

import requests

# Free endpoint (no payment needed)
r = requests.get("https://x402.asterpay.io/v1/settlement/estimate",
    params={"amount": "100"})
print(r.json())  # { "eur": "92.50", "rate": 0.925, ... }

cURL — Check supported networks

curl https://x402.asterpay.io/v2/x402/supported

Webhooks

Configure webhooks in the dashboard to receive real-time notifications.

// Webhook payload example
{
  "event": "settlement.completed",
  "transaction_id": "txn_abc123",
  "amount_usdc": "100.00",
  "amount_eur": "92.50",
  "status": "settled",
  "sepa_reference": "ASTER-2026-0213"
}

Dashboard

The AsterPay Dashboard gives you full control:

• API Keys — Create and manage sandbox & production keys
• Playground — Test all endpoints interactively (including Trust Score)
• Usage Analytics — Real-time charts for requests, revenue, and latency
• Transactions — Track stablecoin payments and fiat settlements
• Budgets — Set daily/weekly/monthly spending limits for AI agents
• CRM — Lead pipeline and outreach tracking
• Webhooks — Configure event notifications
• Team — Invite team members with role-based access
• KYB — Submit your business verification for production fiat settlement

Infrastructure Partners

• Drip — Usage metering, anomaly detection, and real-time webhooks. Every API call is tracked via Drip for usage analytics and billing intelligence. Critical events (anomalies, charge failures) are forwarded to ops in real-time.
• InsumerAPI — On-chain attestation provider across 32 chains. Powers the credential and activity layers of our KYA Trust Score.

Support

We're here to help you integrate fast.

• Email: [email protected]
• Community: t.me/asterpaycommunity
• Interactive API docs: Swagger UI