Python SDK

Gate any HTTP route for stablecoin payments with solana-pay-kit — one package, FastAPI / Flask / Django shims over a framework-agnostic core.

solana-pay-kit (the solana_pay_kit package) is stablecoin payment gating for HTTP services in Python. Pick a currency, give it your wallet address, and gate a route in two lines — an unpaid request gets a 402 Payment Required advertising both x402 and MPP, and the client settles with either. FastAPI, Flask, and Django ride on a framework-agnostic core.

Install

pip install "solana-pay-kit[flask]"   # or [fastapi] / [django]

The base install carries no web-framework dependency; the framework shims live in optional extras imported on demand.

Quick start

Configure and gate a route

solana_pay_kit.configure(...) builds the process-wide config once at boot. With no operator it uses a published demo signer and the Surfpool sandbox — enough to run locally. @require_payment(gate) answers a 402 when no valid proof was sent, or runs the view when one was.

import solana_pay_kit
from flask import Flask, jsonify
from solana_pay_kit import Gate, usd
from solana_pay_kit.flask import payment, require_payment

solana_pay_kit.configure(network="solana_localnet")gate = Gate.build(    name="quote",    amount=usd("0.01"),    description="Stock quote",    default_pay_to=solana_pay_kit.config().effective_recipient(),    accept_default=solana_pay_kit.config().accept,)app = Flask(__name__)# @require_payment settles the 402 (MPP or x402, the client's choice) before# the view runs; the verified proof is readable via solana_pay_kit.flask.payment().@app.get("/quote")@require_payment(gate)def quote():    return jsonify(ok=True, protocol=payment().protocol.value)

Run it

python app.py

Make a paid call

Hit the route with the pay CLI — it walks the user through approval and pays in USDC:

pay curl http://127.0.0.1:8000/quote

The same surface works in FastAPI and Django — see Frameworks.

Python also ships the paying side for x402. x402_async_client returns an httpx.AsyncClient that turns any 402 into a signed PAYMENT-SIGNATURE payment and replays the request:

from solana_pay_kit import Signer
from solana_pay_kit.protocols.x402.client import SolanaRpc, x402_async_client

# x402_async_client returns an httpx.AsyncClient that turns any 402 into a# signed PAYMENT-SIGNATURE payment and replays the request — transparently.async with x402_async_client(signer, rpc) as http:    resp = await http.get("https://api.example.com/quote")    print(resp.status_code, resp.headers.get("payment-response"))

See Client for the low-level building blocks.

No Python at all — the pay CLI is a client for any 402-gated route, handling wallet, signing, and the payment retry for you:

brew install pay     # or: npm install -g @solana/pay
pay --sandbox curl https://debugger.pay.sh/mpp/quote/AAPL

Next steps

Payment schemes — fixed charge, metered usage (upto), and session.
Frameworks — Flask, FastAPI, and Django shims.
Pricing — the gate DSL, registries, fees, and dynamic pricing.
Client — the paying side.
Signers — local keys and fee sponsorship.
Errors — the exception types and the boot-time safety rails.