moltspay 0.4.0

Python SDK for MoltsPay - Agent-to-Agent Payments. LangChain compatible.

MoltsPay Python SDK

Python SDK for MoltsPay - Agent-to-Agent Payments.

MoltsPay enables AI agents to pay each other for services using the x402 protocol - HTTP-native payments with USDC stablecoins. No gas fees, no complex wallet management.

What is MoltsPay?

MoltsPay is blockchain payment infrastructure designed for AI agents. It solves a fundamental problem: how do autonomous AI agents pay for services?

• 🤖 Agent-to-Agent Commerce - AI agents can autonomously discover, pay for, and use services
• 💨 Gasless Payments - Uses EIP-2612 permits, no ETH needed
• 🔗 x402 Protocol - HTTP 402 Payment Required - payments as native HTTP flow
• 🔒 Spending Limits - Set per-transaction and daily limits for safety
• 🌐 Multi-Chain - Base and Polygon supported
• 🦜 LangChain Ready - Drop-in tools for LangChain agents

Installation

pip install moltspay

For LangChain integration:

pip install moltspay[langchain]

Quick Start

from moltspay import MoltsPay

# Initialize (auto-creates wallet if not exists)
client = MoltsPay()
print(f"Wallet address: {client.address}")

# Discover services from a provider
services = client.discover("https://juai8.com/zen7")
for svc in services:
    print(f"{svc.id}: {svc.price} {svc.currency}")

# Pay for a service
result = client.pay(
    "https://juai8.com/zen7",
    "text-to-video",
    prompt="a cat dancing on the beach"
)
print(result.result)

Features

Auto Wallet Management

Wallet is automatically created on first run and stored at ~/.moltspay/wallet.json. Compatible with Node.js CLI.

from moltspay import MoltsPay

client = MoltsPay()
print(f"Address: {client.address}")
print(f"Balance: {client.balance()} USDC")

Spending Limits

Control your agent's spending with built-in limits:

from moltspay import MoltsPay

client = MoltsPay()

# Check current limits
limits = client.limits()
print(f"Max per tx: {limits.max_per_tx}")
print(f"Max per day: {limits.max_per_day}")
print(f"Spent today: {limits.spent_today}")

# Update limits
client.set_limits(max_per_tx=20, max_per_day=200)

Multi-Chain Support

MoltsPay supports multiple chains. Default is Base, but you can use Polygon:

from moltspay import MoltsPay

# Default: Base
client = MoltsPay()

# Use Polygon
client = MoltsPay(chain='polygon')

# Pay on Polygon
result = client.pay(
    "https://juai8.com/zen7",
    "text-to-video",
    prompt="a cat dancing"
)

Supported Chains:

Chain	Network ID	Token
Base	eip155:8453	USDC
Polygon	eip155:137	USDC

Both chains are gasless - the CDP facilitator handles all on-chain settlement.

Async Support

Full async/await support for high-performance applications:

import asyncio
from moltspay import AsyncMoltsPay

async def main():
    async with AsyncMoltsPay() as client:
        result = await client.pay(
            "https://juai8.com/zen7",
            "text-to-video",
            prompt="a cat dancing"
        )
        print(result.result)

asyncio.run(main())

Error Handling

Comprehensive exception types for robust error handling:

from moltspay import MoltsPay, InsufficientFunds, LimitExceeded, PaymentError

client = MoltsPay()

try:
    result = client.pay(...)
except InsufficientFunds as e:
    print(f"Need {e.required} USDC, have {e.balance}")
except LimitExceeded as e:
    print(f"Exceeds {e.limit_type} limit: {e.amount} > {e.limit}")
except PaymentError as e:
    print(f"Payment failed: {e}")

LangChain Integration

Use MoltsPay as tools in your LangChain agents - let your AI autonomously pay for services!

from langchain.agents import initialize_agent, AgentType
from langchain_openai import ChatOpenAI
from moltspay.integrations.langchain import MoltsPayTool

llm = ChatOpenAI(model="gpt-4")
tools = [MoltsPayTool()]

agent = initialize_agent(
    tools, 
    llm, 
    agent=AgentType.OPENAI_FUNCTIONS,
    verbose=True
)

# Agent can now pay for AI services!
result = agent.run("Generate a video of a cat dancing on the beach")

Available Tools

Two tools available for different use cases:

from moltspay.integrations.langchain import get_moltspay_tools

tools = get_moltspay_tools()  # Returns both tools

Tool	Description
MoltsPayTool	Pay for and execute services
MoltsPayDiscoverTool	Discover available services and prices

CLI Compatibility

Wallet format is fully compatible with the Node.js CLI:

# Create wallet with Node CLI
npx moltspay init --chain base

# Use same wallet in Python
python -c "from moltspay import MoltsPay; print(MoltsPay().address)"

How x402 Works

Your Agent                     Service Provider              Blockchain
    │                               │                           │
    │ Request service               │                           │
    │ ──────────────────────────>   │                           │
    │                               │                           │
    │ 402 + price + wallet          │                           │
    │ <──────────────────────────   │                           │
    │                               │                           │
    │ [Sign payment - NO GAS]       │                           │
    │                               │                           │
    │ Request + signed payment      │                           │
    │ ──────────────────────────>   │ Verify & settle           │
    │                               │ ─────────────────────────>│
    │                               │                           │
    │ 200 OK + result               │                           │
    │ <──────────────────────────   │                           │

Your agent never pays gas - the CDP facilitator handles all on-chain settlement.

Use Cases

• AI Assistants - Let your assistant pay for premium APIs
• Autonomous Agents - Agents that can spend within limits
• Multi-Agent Systems - Agents paying other agents for services
• AI Pipelines - Pay-per-use for expensive compute steps

Running a Server (Accepting Payments)

Want to accept payments for your AI services? See the Server Guide.

Quick start:

# Install
pip install moltspay

# Create skill structure
mkdir my_skill && cd my_skill
# Add moltspay.services.json and __init__.py (see docs)

# Start server
moltspay-server ./my_skill --port 8402

Related Projects

• moltspay (Node.js) - Node.js SDK and CLI
• x402 Protocol - The HTTP payment standard

Links

• Website: https://moltspay.com
• PyPI: https://pypi.org/project/moltspay/
• npm (Node.js): https://www.npmjs.com/package/moltspay
• GitHub: https://github.com/Yaqing2023/moltspay-python

License

MIT