Blocks402

from fastapi import FastAPI
from block402_fastapi import payment_required

app = FastAPI()

@app.get("/premium-data")
@payment_required(
    amount="0.10",                     # amount in USDC
    payment_address="YOUR_WALLET_ADDRESS",
    token_mint="USDC_MINT_ADDRESS"
)
async def get_premium_data():
    return {"data": "Premium content"}

from block402_client import X402AutoClient
from bnb.keypair import Keypair

client = X402AutoClient(wallet_keypair=Keypair())

# Automatically handles 402 and pays
response = await client.fetch(
    "https://api.example.com/premium-data"
)
data = response.json()

from langchain.chat_models import ChatOpenAI
from block402_langchain import create_x402_agent
from bnb.keypair import Keypair

# Load wallet
keypair = Keypair()

# Create agent with X402 support
agent = create_x402_agent(
    wallet_keypair=keypair,
    llm=ChatOpenAI(),
    max_payment="5.0"   # USD-equivalent cap for a single task
)

# Agent can now autonomously pay for API access
response = agent.run(
    "Get the latest market data from https://api.example.com/premium-data "
    "and summarize the key trends"
)

from typing import TypedDict
from langgraph.graph import StateGraph, END
from block402_langgraph import payment_node, check_payment_required
from bnb.keypair import Keypair

class AgentState(TypedDict):
    api_url: str
    api_response: str
    payment_required: bool
    payment_completed: bool
    wallet_keypair: Keypair

# Build workflow
workflow = StateGraph(AgentState)

def fetch_data(state: AgentState) -> AgentState:
    # call the API; if it returns 402, mark it
    required = check_payment_required(state["api_url"])
    return {**state, "payment_required": required}

# Nodes
workflow.add_node("fetch_data", fetch_data)
workflow.add_node("pay", payment_node)   # handles x402 payment & receipt

# Edges
workflow.set_entry_point("fetch_data")
workflow.add_conditional_edges(
    "fetch_data",
    lambda s: "pay" if s["payment_required"] else END,
    {"pay": "fetch_data", END: END}
)

graph = workflow.compile()