Payment infrastructure for autonomous AI agents, premium APIs, data products, and machine-to-machine commerce.

AiFinPay AIFP-1 turns HTTP 402 Payment Required into a production-grade payment handshake for AI agents. A merchant can price any API action, content object, data query, or compute job. An agent can discover the price, pay automatically within policy, receive a cryptographic receipt, and retry the original request without a human checkout screen.

flowchart LR
    Agent["AI Agent"] -->|1. Request protected resource| Merchant["Merchant API"]
    Merchant -->|2. HTTP 402 payment challenge| Agent
    Agent -->|3. Quote + pay| AIFP["AiFinPay Control Plane"]
    AIFP -->|4. Wallet policy + settlement| Wallet["Agent Wallet"]
    AIFP -->|5. Signed receipt token| Agent
    Agent -->|6. Retry with receipt| Merchant
    Merchant -->|7. Verify locally + grant access| Agent

x402 established a practical model for using HTTP 402 Payment Required as a payment interaction between clients and protected resources. AIFP-1 uses the same HTTP foundation and extends it into a broader protocol surface for autonomous AI agents, merchant APIs, wallets, receipts, policy controls, and machine-to-machine commerce. The intent is compatibility and specialization, not replacement.

• x402 standardized HTTP 402 Payment Required payment interactions for web resources.
• AIFP adopts the same foundation while expanding the protocol for autonomous AI agents.
• AIFP introduces quote negotiation, receipt lifecycle, wallet policies, merchant-side verification, governance, SDKs, and protocol specifications.
• AIFP targets machine-to-machine commerce where software can discover, purchase, and access digital resources autonomously.
• The two approaches are complementary, and AIFP can coexist with x402-based ecosystems.

AiFinPay charges a 1% protocol fee on successful transactions. The remaining 99% settles to the merchant, excluding any applicable payment-network, gas, processor, or settlement costs.

Learn more in Protocol Economics.

flowchart TB
    subgraph AgentLayer["Agent Layer"]
        AgentSDK["Agent SDK"]
        Passport["Agent Passport"]
        Budget["Budget Policy"]
    end
    subgraph MerchantPlane["Merchant Data Plane"]
        Middleware["Merchant Middleware"]
        Pricing["Pricing Engine"]
        Verifier["Local Receipt Verifier"]
        Resource["Protected API / Data / Compute"]
    end
    subgraph ControlPlane["AiFinPay Control Plane"]
        Quote["Quote Service"]
        Pay["Payment Orchestrator"]
        Receipt["Receipt Authority"]
        Ledger["Ledger + Webhooks"]
        JWKS["JWKS + Key Rotation"]
    end
    subgraph Settlement["Settlement Layer"]
        Assets["USDC / USDT / PYUSD"]
        Networks["Supported Networks"]
        Fiat["Fiat + Hybrid Rails"]
    end
    AgentSDK --> Passport
    AgentSDK --> Budget
    AgentSDK --> Middleware
    Middleware --> Pricing
    Pricing --> AgentSDK
    AgentSDK --> Quote
    Quote --> Pay
    Pay --> Assets
    Pay --> Fiat
    Assets --> Networks
    Pay --> Receipt
    Receipt --> AgentSDK
    AgentSDK --> Verifier
    Verifier --> JWKS
    Verifier --> Resource
    Receipt --> Ledger
    Ledger --> MerchantPlane

AiFinPay separates the control plane from the merchant data plane. Merchants verify receipt tokens locally, so access checks remain fast and resilient. The control plane handles quotes, wallet authorization, settlement, receipts, key rotation, and webhooks.

sequenceDiagram
    autonumber
    participant A as AI Agent
    participant M as Merchant API
    participant P as AiFinPay
    participant W as Wallet
    A->>M: GET /premium-data<br/>Accept-Payment: aifp/1.0
    M-->>A: 402 Payment Required<br/>Payment Challenge
    A->>P: POST /v1/quote
    P-->>A: quote_id, amount, currency, nonce, expiry
    A->>P: POST /v1/pay<br/>Idempotency-Key
    P->>W: Check policy + debit approved wallet
    W-->>P: Settlement reference
    P-->>A: Ed25519 receipt token
    A->>M: Retry request<br/>Payment-Receipt: JWT
    M->>M: Verify signature, audience, resource, amount, expiry, nonce
    M-->>A: 200 OK + protected response

{
  "payment_challenge": {
    "version": "1.0",
    "scheme": "aifp",
    "merchant_id": "mrch_9f3a1c2b",
    "resource": "/api/data",
    "pricing_tier": "standard",
    "estimated_amount": "0.00001",
    "currency": "USD",
    "accepted_assets": ["USDC", "USDT", "PYUSD"],
    "accepted_chains": ["polygon", "base", "solana"],
    "quote_endpoint": "https://api.aifinpay.io/v1/quote",
    "nonce": "b7e2c91a",
    "expires_at": "2026-07-01T12:34:56Z"
  }
}

npm install @aifinpay/merchant

import { aifpPaywall } from "@aifinpay/merchant";

app.use(aifpPaywall({
  merchantId: "mrch_...",
  pricing: {
    "/api/data": { tier: "standard" },
    "/api/search": { tier: "complex" },
    "/api/inference": { tier: "premium" }
  }
}));

npm install @aifinpay/agent

import { AIFPAgent } from "@aifinpay/agent";

const agent = new AIFPAgent({
  apiKey: process.env.AIFP_AGENT_KEY,
  walletId: "wlt_...",
  budget: { dailyUsd: 5 }
});

const response = await agent.fetch("https://merchant.example.com/api/data");

curl https://api.aifinpay.io/v1/quote \
  -H "Authorization: Bearer $AIFP_AGENT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"merchant_id":"mrch_9f3a1c2b","resource":"/api/data","pricing_tier":"standard"}'

Every canonical source document lives in docs/aifp. Every important document is reachable within two clicks from this README.

This repository is organized as a public protocol foundation project:

• Canonical RFC/specification set in docs/aifp/.
• Human-readable documentation portal in docs/.
• Machine-readable OpenAPI and JSON Schema contracts.
• Postman collection for API exploration.
• SDK design surface for TypeScript, Python, and Go.
• Examples for merchant, agent, wallet, webhook, and raw HTTP flows.
• GitHub issue forms, PR template, workflows, code ownership, roadmap, security, and support policy.

Code, examples, schemas, scripts, tests, GitHub workflows, and machine-readable artifacts are licensed under Apache-2.0. Documentation, prose specifications, diagrams, and governance documents are licensed under CC BY 4.0 unless a file states otherwise. See LICENSE.

AiFinPay is designed to become a foundational standard for the AI web: a neutral payment layer where autonomous software can discover priced resources, reason about budgets, pay safely, carry reputation, and access the machine-readable economy without subscriptions or human checkout.