AiFinPay — Payment Rail for AI Agents

Stripe for autonomous AI agents. One line of code — agent.pay(url) — and your agent settles a real on-chain payment on Polygon or Solana mainnet, then receives the gated response. Non-custodial. Live since 2026. Polygon facilitator compatible.

# Python
pip install aifinpay-agent --pre

# Node / TypeScript
npm install @aifinpay/agent@alpha

# MCP server (Claude Desktop, Cursor, Windsurf, Continue)
npx @aifinpay/mcp

One-click MCP for Claude Desktop / Cursor

Drop this block into your client config — claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/claude_desktop_config.json) or Cursor's ~/.cursor/mcp.json:

{
  "mcpServers": {
    "aifinpay": {
      "command": "npx",
      "args": ["@aifinpay/mcp"]
    }
  }
}

Restart the client. Your model now has five payment tools (payable_fetch, agent_address, agent_quote, pay_with_split, quote_split) and can autonomously settle any x402-gated API.

Full client matrix (Claude Desktop, Cursor, Windsurf, Continue, LobeChat, Cline) lives in MCP_CONFIG.md.

Packages

Package	Path	Install	Latest
aifinpay-agent (Python)	./python	pip install aifinpay-agent --pre	0.2.0a2 (alpha)
@aifinpay/agent (Node / TypeScript)	./node	npm install @aifinpay/agent@alpha	0.3.0-alpha.0 (alpha)
@aifinpay/mcp (MCP server)	./mcp	npx @aifinpay/mcp	0.1.0-alpha.2 (alpha)
Go SDK	—	go get github.com/AiFinPay/sdk/go	soon
Rust SDK	—	cargo add aifinpay-sdk	soon

What this is

agent.pay(url) — one line of Python or TypeScript that pays any x402-protected URL on behalf of an autonomous AI agent. The SDK auto-detects the facilitator flavor (AiFinPay native, Coinbase x402, …), signs an Ed25519 challenge, retries the request, and returns the response.

Same agent, drop into Claude Desktop's MCP config and the LLM gets five tools (payable_fetch, agent_address, agent_quote, pay_with_split, quote_split) for autonomous payment loops.

Quick start

Python

from aifinpay import Agent
agent = Agent.new()
print("Fund this address with MATIC:", agent.address)
print("Save this secret:", agent.secret_b58)

# Pay any x402-protected URL
resp = agent.pay("https://api.example.com/v1/data")

# Direct fee-on-top split — merchant gets 100% of merchant_amount;
# AiFinPay 1% on top.
invoice = agent.pay_with_split_invoice(
    chain="polygon",
    merchant_wallet="0xMerchant...",
    merchant_amount=10**18,
    order_id="search-1",
)

Node.js / TypeScript

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

const agent = Agent.new();
console.log("Fund this address:", agent.address);

const res = await agent.pay("https://api.example.com/v1/data");

const invoice = await agent.payWithSplitInvoice({
  chain: "polygon",
  merchantWallet: "0xMerchant...",
  merchantAmount: 10n ** 18n,
  orderId: "search-1",
});

MCP (Claude Desktop)

{
  "mcpServers": {
    "aifinpay": {
      "command": "npx",
      "args": ["@aifinpay/mcp"],
      "env": {
        "AIFINPAY_AGENT_SECRET": "<base58 secret>",
        "AIFINPAY_MAX_USD": "0.50"
      }
    }
  }
}

Restart Claude Desktop. The model now has five payment tools — payable_fetch(url) lets it autonomously call any x402-gated API.

How it works

sequenceDiagram
    Agent->>Server: GET /api/...
    Server-->>Agent: 402 + manifest + nonce
    Agent->>Agent: sign SHA256("AiFinPay-x402:{nonce}:{pubkey}")
    Agent->>Server: GET /api/... + 3 auth headers
    Server-->>Agent: 200 + payload

Loading

For a partner who wants to accept AiFinPay payments, the simplest integration is a single HTTP call to aifinpay.company/api/seat/<pubkey> inside their existing API — no wallet, no chain library, no KYC. See examples/echo-x402-server for a working ~70-line reference.

For full autonomy via fee-on-top atomic split (merchant gets 100% of their quoted price, agent pays the fee on top), agents call b2bPayWithSplit() on the AiFinPaySplitter Polygon contract: 0xE34Fc0E6694821c600Fa0955C0F74720ea6d8440 — owned by Gnosis Safe 0xD31d82c4b35DABaA2ad7023C89A78A052D1f3c8e (4-of-N).

Live contract addresses

All verified on Polygonscan.

	Polygon (mainnet)
AiFinPayCore	0x24Bee0df…1C7b
AgentPassport	0xB385Cc32…662a
MSECCOToken	0x1Fe20213…1d55
AiFinPaySplitter	0xE34Fc0E6…8440
Gnosis Safe (multisig owner)	0xD31d82c4…3c8e

Solana program (Anchor): 5g9zWHF1Vv6GiGpA2ZbJQbSCDZd5hAk9AyvabRJvKFx2.

Framework integrations

Drop-in adapters for popular agent frameworks live under ./examples/. Each is a working, paste-and-run example.

Framework	Example	What it shows
OpenAI Agents SDK	examples/openai-agent	Tool-style integration: GPT-4 calls a tool that pays an x402 endpoint and returns the response
Claude (MCP)	examples/claude-mcp	Zero-code: just install the MCP server, talk to Claude
LangChain	examples/langchain	BaseTool wrapping agent.pay()
CrewAI	examples/crewai	A research crew that buys inference and search calls as it works
Flowise	examples/flowise	Custom node JSON + import instructions
AutoGPT / AutoGen	examples/autogpt	Headless agent loop that funds itself once, then runs unattended
Reference partner server	examples/echo-x402-server	~70-line Node server that accepts AiFinPay payments
Live bridges	examples/io-net-x402-bridge, exa-x402-bridge, venice-x402-bridge	Production bridges in front of io.net / Exa / Venice

Verified mainnet payments

Two on-chain proofs that the full stack works end-to-end:

Provider	Asset	What was bought	Tx
Exa Search	POL	First SDK call via Exa	0xeb13c5ed…59c8700
io.net	POL	Llama-3.3-70B inference, $0.025	0x7c6ca0ff…129f0a

Repo layout

sdk/
├── python/                  aifinpay-agent (PyPI)
├── node/                    @aifinpay/agent (npm)
├── mcp/                     @aifinpay/mcp (npm)
├── docs/                    QUICKSTART.md, MCP_CONFIG.md, integrations
└── examples/
    ├── openai-agent/        OpenAI Agents SDK tool
    ├── claude-mcp/          Claude Desktop MCP config + walkthrough
    ├── langchain/           LangChain BaseTool wrapper
    ├── crewai/              CrewAI multi-agent crew that pays
    ├── flowise/             Flowise custom node
    ├── autogpt/             Headless self-funding agent loop
    ├── echo-x402-server/    reference partner integration (~70 lines)
    ├── io-net-x402-bridge/  live io.net bridge
    ├── exa-x402-bridge/     live Exa bridge
    └── venice-x402-bridge/  live Venice bridge

Releasing

Each package version-bumps independently. Both registries get prerelease tags so production users only see stable when explicitly opt-in.

# Python
cd python
python -m build
python -m twine upload --repository pypi dist/*

# Node
cd ../node
npm run build
npm publish --tag alpha

# MCP
cd ../mcp
npm install                 # so it can resolve @aifinpay/agent
npm run build
npm publish --tag alpha

Contributing

Issues and PRs welcome. For protocol-level changes, please open an issue first to discuss.

License

MIT — see LICENSE.

Links

• Site: https://aifinpay.company
• Docs: https://aifinpay.company/docs
• Manifesto: https://aifinpay.company/manifesto.json
• x402 protocol: https://www.x402.org
• MCP spec: https://modelcontextprotocol.io