Algorand X402 Python

x402 on Algorand - Python

Build x402 HTTP-native payment applications on Algorand with Python. Use the reference files below for detailed guidance on each component.

Python Quick Start

The x402-avm package on PyPI bundles core protocol, AVM mechanism, HTTP clients, and server middleware. Pick the extras you need:

# AVM only (no HTTP client/server)
pip install "x402-avm[avm]"

# Server middleware (pick one)
pip install "x402-avm[fastapi,avm]"    # FastAPI async
pip install "x402-avm[flask,avm]"      # Flask sync

# HTTP clients (pick one)
pip install "x402-avm[httpx,avm]"      # Async with httpx
pip install "x402-avm[requests,avm]"   # Sync with requests

# Bazaar discovery extension
pip install "x402-avm[extensions,avm]"

# Everything
pip install "x402-avm[all]"

> Distribution name is x402-avm but the import root is x402 (not x402_avm).

Register AVM Scheme

Every component registers the AVM exact scheme unconditionally — no environment variable guards:

# Client
from x402 import x402Client
from x402.mechanisms.avm.exact import ExactAvmScheme

client = x402Client()
client.register("algorand:*", ExactAvmScheme(signer=my_signer))

# Server
from x402.server import x402ResourceServer
from x402.mechanisms.avm.exact import ExactAvmServerScheme

server = x402ResourceServer()
server.register("algorand:*", ExactAvmServerScheme())

# Facilitator
from x402 import x402Facilitator
from x402.mechanisms.avm.exact import ExactAvmFacilitatorScheme

facilitator = x402Facilitator()
facilitator.register("algorand:*", ExactAvmFacilitatorScheme(signer=my_signer))

The register_exact_avm_client/server/facilitator helpers from x402.mechanisms.avm.exact are also valid.

Python algosdk Encoding

Python algosdk's msgpack_decode() expects base64 strings, msgpack_encode() returns base64 strings. Boundary conversion: msgpack_decode(base64.b64encode(raw_bytes).decode()) / base64.b64decode(msgpack_encode(obj)).

Reference Guide

Navigate to the appropriate reference based on your task. Each topic has three files:

• {name}.md — Step-by-step implementation guide
• {name}-reference.md — API details and type signatures
• {name}-examples.md — Complete, runnable code samples

Explaining x402 for Python

Understand the x402-avm Python package structure, extras installation ([avm], [fastapi], [flask], [httpx], [requests], [extensions], [all]), signer protocols, async vs sync variants, and algosdk encoding boundaries.

• [explain-algorand-x402-python.md](./references/explain-algorand-x402-python.md) — Package ecosystem explanation
• [explain-algorand-x402-python-reference.md](./references/explain-algorand-x402-python-reference.md) — API reference for the x402-avm package
• [explain-algorand-x402-python-examples.md](./references/explain-algorand-x402-python-examples.md) — Python pattern examples

Building Clients

Build HTTP clients with httpx (async) or requests (sync) that automatically handle 402 payments. Covers wrapHttpxWithPayment, wrapRequestsWithPayment, ClientAvmSigner for payment signing.

• [create-python-x402-client.md](./references/create-python-x402-client.md) — Client creation guide
• [create-python-x402-client-reference.md](./references/create-python-x402-client-reference.md) — httpx/requests API reference
• [create-python-x402-client-examples.md](./references/create-python-x402-client-examples.md) — Client code examples

Building Servers

Build payment-protected servers with FastAPI (async) or Flask (sync) middleware. Covers route pricing, PaymentMiddlewareASGI, Flask PaymentMiddleware, and multi-network support.

• [create-python-x402-server.md](./references/create-python-x402-server.md) — Server creation guide
• [create-python-x402-server-reference.md](./references/create-python-x402-server-reference.md) — FastAPI/Flask middleware API reference
• [create-python-x402-server-examples.md](./references/create-python-x402-server-examples.md) — Server code examples

Building Facilitators and Bazaar Discovery

Build facilitator services that verify and settle Algorand payments on-chain. Covers FacilitatorAvmSigner protocol, registerexactavmfacilitator, FastAPI facilitator endpoints (/verify, /settle, /supported), and Bazaar discovery extension for automatic cataloging and indexing of payment-gated APIs (declarediscoveryextension, extractdiscoveryinfo, bazaarresourceserverextension).

• [create-python-x402-facilitator.md](./references/create-python-x402-facilitator.md) — Facilitator creation guide (includes Bazaar setup in Steps 6-10)
• [create-python-x402-facilitator-reference.md](./references/create-python-x402-facilitator-reference.md) — Facilitator + Bazaar API reference
• [create-python-x402-facilitator-examples.md](./references/create-python-x402-facilitator-examples.md) — Facilitator + Bazaar code examples

Low-Level SDK Usage

Use x402-avm core components and AVM mechanism directly for custom integrations. Covers x402Client, x402ResourceServer, x402Facilitator, AVM signer protocols, constants, utilities, transaction encoding, and fee abstraction.

• [use-python-x402-core-avm.md](./references/use-python-x402-core-avm.md) — Core SDK usage guide
• [use-python-x402-core-avm-reference.md](./references/use-python-x402-core-avm-reference.md) — Core/AVM API reference
• [use-python-x402-core-avm-examples.md](./references/use-python-x402-core-avm-examples.md) — Core SDK code examples

Python Package Quick Reference

One PyPI distribution (x402-avm) provides everything via extras. Import root is x402.

| Install spec | Purpose | | ------------ | ------- | | x402-avm[avm] | Core protocol + Algorand SDK (py-algorand-sdk) | | x402-avm[httpx,avm] | Async HTTP client wrapper (httpx) with automatic 402 payment handling | | x402-avm[requests,avm] | Sync HTTP client wrapper (requests) with automatic 402 payment handling | | x402-avm[fastapi,avm] | FastAPI async payment middleware | | x402-avm[flask,avm] | Flask sync payment middleware | | x402-avm[extensions,avm] | Bazaar discovery extension | | x402-avm[all] | All extras (EVM, SVM, AVM, all servers and clients, extensions) |

How to Use This Skill

1. Start here to understand which reference you need
2. Read the {name}.md file for step-by-step implementation guidance
3. Consult {name}-reference.md for API details
4. Use {name}-examples.md for complete, runnable code samples

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: algorand-devrel
• Source: algorand-devrel/algorand-agent-skills
• License: MIT

Install and usage instructions live in the source repository linked above.