ProBex

Explain the x402-avm Python package for Algorand payment protocol integration. Use when developers ask about x402 Python package structure, extras installation ([avm], [evm], [svm], [fastapi], [flask], [httpx], [requests], [all]), signer protocols (ClientAvmSigner, FacilitatorAvmSigner), async vs sync variants, registration patterns, or algosdk encoding boundaries. Strong triggers include "how does x402 work in Python?", "explain x402-avm Python package", "what extras do I install?", "ClientAvmSigner vs FacilitatorAvmSigner", "algosdk encoding in x402", "async vs sync x402 Python", "how do I sign Algorand transactions in x402?", "msgpack_decode expects base64".

Explain x402-avm for TypeScript/JavaScript developers. Use when explaining @x402-avm/* package structure, signer interfaces (ClientAvmSigner, FacilitatorAvmSigner), registration patterns (registerExactAvmScheme), builder patterns, constants, utilities, and TypeScript-specific integration patterns. Strong triggers include "how do I use @x402-avm", "explain the TypeScript packages", "what is ClientAvmSigner", "what is FacilitatorAvmSigner", "how to register AVM scheme", "TypeScript x402 signer", "x402 avm package structure", "how does @x402-avm/avm work", "@x402-avm/core imports".

Teach the x402 protocol with Algorand (AVM) integration. Use when explaining what x402 is, how Algorand integrates as a first-class citizen alongside EVM/SVM, the HTTP 402 payment flow, architecture of the three components (client, server, facilitator), CAIP-2 network identifiers, fee abstraction, ASA support, and both TypeScript and Python package ecosystems. Strong triggers include "what is x402", "how does x402 work with Algorand", "explain the payment flow", "what are the three components", "how do client server and facilitator interact", "x402 architecture", "teach me about x402-avm", "how does fee abstraction work".

Use the x402-avm Python package core and AVM mechanism directly for custom integrations. Use when working with x402 core components (x402Client, x402ResourceServer, x402Facilitator), implementing AVM signer protocols, using constants (ALGORAND_TESTNET_CAIP2, USDC ASA IDs), calling utility functions (address validation, amount conversion, transaction encoding), building custom payment flows, creating transaction groups, or understanding fee abstraction. Strong triggers include "use x402 Python SDK directly", "x402 core components", "AVM signer protocol", "Algorand constants", "transaction encoding", "fee abstraction", "custom x402 integration", "ExactAvmScheme", "to_atomic_amount", "decode_transaction_bytes".

Use @x402-avm/core and @x402-avm/avm TypeScript packages directly for custom x402 payment integrations. Use when building custom clients, resource servers, or facilitators with the x402 protocol on Algorand, implementing payment policies, creating AVM signer interfaces, handling transaction groups, or integrating fee abstraction. Strong triggers include "use x402 core package", "create x402 client", "implement facilitator signer", "x402 payment verification", "fee abstraction on Algorand", "register AVM scheme", "transaction group signing", "x402ResourceServer", "x402Client", "x402Facilitator", "ClientAvmSigner", "FacilitatorAvmSigner".

Create x402 HTTP clients with httpx (async) or requests (sync) that automatically handle 402 payments on Algorand. Use when building Python HTTP clients that pay for API access, setting up automatic 402 payment handling, implementing ClientAvmSigner for payment signing, or choosing between httpx and requests for x402. Strong triggers include "create a Python x402 client", "httpx with x402 payments", "requests with x402 Algorand", "automatic 402 payment handling in Python", "wrapHttpxWithPayment", "wrapRequestsWithPayment", "x402HttpxClient setup", "x402_requests setup", "how do I pay for API access with Algorand in Python?", "ClientAvmSigner implementation".

Create Python x402 facilitator with Bazaar discovery extension for API cataloging. Use when adding Bazaar discovery to x402 resource servers, declaring discovery extensions on payment-gated routes, extracting discovery info on the facilitator side, validating extensions, building API catalogs for paid services, or integrating Bazaar with FastAPI/Flask servers. Strong triggers include "Bazaar discovery extension", "declare_discovery_extension", "API catalog for x402", "resource discovery", "bazaar_resource_server_extension", "extract_discovery_info", "paid API catalog", "machine-readable API menu", "x402 discovery".

Create Python x402 facilitator services that verify and settle payments on-chain. Use when building a FastAPI-based facilitator, implementing the FacilitatorAvmSigner protocol (sign_transaction, sign_group, simulate_group, send_group, confirm_transaction), registering with register_exact_avm_facilitator, creating multi-network facilitators (EVM+SVM+AVM), or setting up facilitator API endpoints (/verify, /settle, /supported). Strong triggers include "create a Python facilitator", "build a payment facilitator service", "implement FacilitatorAvmSigner", "set up facilitator endpoints", "verify and settle Algorand payments", "fee payer service".

Create x402 payment-protected servers with FastAPI (async) or Flask (sync) for Algorand. Use when building resource servers that require USDC payments, setting up payment middleware, configuring route pricing, or protecting API endpoints with x402. Strong triggers include "create a FastAPI server with x402 payments", "add payment middleware to Flask", "protect my API endpoint with Algorand USDC", "set up x402 resource server in Python", "PaymentMiddlewareASGI setup", "Flask PaymentMiddleware", "how do I accept Algorand payments on my API?", "multi-network payment server", "x402 route configuration".

Create x402 HTTP clients with Fetch and Axios that automatically handle 402 payments on Algorand. Use when building applications that consume x402-protected APIs, setting up automatic payment handling with wrapFetchWithPayment or wrapAxiosWithPayment, implementing ClientAvmSigner for browser wallets or Node.js private keys, configuring payment policies, or handling 402 payment flows. Strong triggers include "create x402 client", "wrap fetch with payment", "wrap axios with payment", "automatic 402 payment", "ClientAvmSigner", "pay for API with USDC", "x402 fetch", "x402 axios".

Create x402 facilitator services that verify and settle Algorand payments, with optional Bazaar discovery extension for API cataloging. Use when building a facilitator that verifies payment transactions, settles on-chain, implements FacilitatorAvmSigner, creates Express.js facilitator servers, integrates Bazaar discovery for indexing paid resources, or extracts discovery metadata from payment flows. Strong triggers include "create x402 facilitator", "FacilitatorAvmSigner", "verify and settle payment", "facilitator server", "Bazaar discovery", "x402Facilitator", "payment settlement", "facilitator signer", "catalog paid APIs".

Create fullstack Next.js apps with x402 payment protection using paymentProxy and withX402. Use when building Next.js applications with payment-gated routes, setting up x402 middleware for API protection, creating paywalls with Algorand payments, or integrating x402 with App Router. Strong triggers include "Next.js x402 paywall", "payment proxy middleware", "withX402 route handler", "paymentProxyFromConfig", "protect Next.js routes with payments", "x402 middleware.ts", "payment-gated API", "Next.js Algorand payments", "@x402-avm/next".

Create paywall UIs for x402-protected endpoints on Algorand and multi-chain. Use when building payment-gated content with server-side middleware and client-side wallet integration, setting up PaywallBuilder with network handlers, integrating with Express/Hono/Next.js, configuring wallet discovery (Pera, Defly, Lute), or building multi-network paywalls (AVM+EVM+SVM). Strong triggers include "create x402 paywall", "PaywallBuilder", "avmPaywall", "payment wall", "paywall middleware", "402 payment page", "paywall HTML", "payment-gated content".

Create x402 payment-protected servers with Express.js and Hono. Use when building a resource server that returns 402 Payment Required, setting up payment middleware, configuring protected routes, implementing multi-network support (AVM+EVM+SVM), integrating paywall UI, building facilitator servers, or implementing dynamic pricing. Strong triggers include "create an x402 server", "add payment middleware to Express", "protect routes with x402", "set up payment-gated API", "hono payment middleware", "402 payment required server", "x402 express server", "x402 hono server", "build a facilitator server", "fee abstraction server".