paypack-langchain 0.1.5

langchain-paypack: x402 (Coinbase) + AP2 (Google) dual-protocol Agent payments. One agent.pay() for USDC/ETH on-chain (Base/Ethereum/Polygon/Arbitrum) + Alipay/WeChat CNY via Cloud. Auto-routes by currency. Dify Tool Plugin available.

langchain-paypack: x402 + AP2 dual-protocol for LangChain Agents

🌐 Dual-channel · Neutral — the only Agent payment middleware supporting Alipay + WeChat Pay.

x402 (Coinbase) + AP2 (Google) dual-protocol. One agent.pay() for USDC/ETH across Base/Ethereum/Polygon/Arbitrum, plus Alipay/WeChat CNY. Dify Tool Plugin also available.

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Installation

pip install paypack-langchain

Requires Python 3.10+.

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Quick Start

1. Get your API Key

curl -X POST https://rhcjw.com/pay/v1/register \
  -H "Content-Type: application/json" \
  -d '{"name": "my_agent", "email": "[e-mail]"}'

Returns:

{"api_key": "ppk_your_api_key_here"}

Save this key — you'll use it in every call.

2. Create a payment in 3 lines

from paypack_langchain import PayPackTool

tool = PayPackTool(
    api_key="ppk_your_api_key_here",
    base_url="https://rhcjw.com/pay",
)

result = tool.run(amount=0.01, subject="AI data query")
print(result)

Output:

支付订单已创建
订单号: PP20260710120000ABC12345
金额: ¥0.01
状态: pending
支付链接: https://openapi.alipay.com/...
二维码: https://...

3. Verify it worked

Check order status:

from paypack_langchain import PayPackQueryTool

query = PayPackQueryTool(
    api_key="ppk_your_api_key_here",
    base_url="https://rhcjw.com/pay",
)

print(query.run(order_id="PP20260710120000ABC12345"))

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Use in a LangChain Agent

from langchain.agents import create_react_agent, AgentExecutor
from langchain_openai import ChatOpenAI
from paypack_langchain import PayPackTool, PayPackQueryTool

llm = ChatOpenAI(model="gpt-4")
tools = [
    PayPackTool(api_key="ppk_xxx", base_url="https://rhcjw.com/pay"),
    PayPackQueryTool(api_key="ppk_xxx", base_url="https://rhcjw.com/pay"),
]

agent = create_react_agent(llm, tools, ...)
agent_executor = AgentExecutor(agent=agent, tools=tools)

# Agent now handles payments and order queries automatically

When your Agent calls a metered API and receives an HTTP 402 response, it can use PayPackTool to settle the payment and retry the request — fully autonomous.

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Supported Currencies & Routing

Currency	Route	Networks	Status
CNY	PayPack Cloud API	Alipay / WeChat Pay	✅ Production (¥0.10 / ¥0.05 verified)
USDC	On-chain (local signer)	Base / Ethereum / Polygon / Arbitrum	✅ Live
ETH	On-chain (local signer)	Base / Ethereum / Polygon / Arbitrum	✅ Live

Auto-routed by currency parameter — one tool, three currencies.

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API Reference

PayPackTool

Parameter	Type	Required	Description
api_key	string	for CNY	PayPack Cloud API key (ppk_...)
base_url	string	for CNY	PayPack Cloud endpoint: https://rhcjw.com/pay
private_key	string	for USDC/ETH	Wallet private key (0x...) or set PRIVATE_KEY env
network	string	for USDC/ETH	Blockchain: base-sepolia (default), base-mainnet, ethereum-mainnet, polygon-mainnet, arbitrum-mainnet
broadcast	bool	❌	True to broadcast to chain, False (default) to dry-run sign only
amount	float	✅	Payment amount (e.g. 0.01 for ¥0.01 or 0.01 USDC)
subject	string	✅	Description shown on payment page
currency	string	❌	CNY (default, via Cloud), USDC or ETH (on-chain)
to	string	for USDC/ETH	Recipient wallet address (0x...), required for on-chain
callback_url	string	❌	Webhook URL for payment notification (Cloud mode)

PayPackQueryTool

Parameter	Type	Required	Description
api_key	string	✅	Your PayPack Cloud API key
base_url	string	✅	PayPack Cloud endpoint
order_id	string	✅	Order ID from PayPackTool response

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Links

• Cloud API: https://rhcjw.com/pay
• PyPI: https://pypi.org/project/paypack-langchain/
• GitHub: https://github.com/rhcjw/paypack
• Dify Plugin: PR #2693 (in review)
• Issues: https://github.com/rhcjw/paypack/issues