"Understanding OAuth 2.0 Protocol" matching MCP servers:

Model Context Protocol (MCP) server for Mexican Electronic Invoicing (CFDI 4.0, Complemento de Pagos 2.0). Provide tools to validate, generate, and explore API specifications for SAT/PAC interoperability.

Enables LLM agents to manage QuickBooks Online invoices, customers, and payments via typed tools with OAuth 2.1 authentication, rate limiting, and retries, plus read-only resources for company and receivables summaries.

Mercury Banking MCP server with full Invoicing API support. Read accounts/transactions and create/manage recurring invoices via Model Context Protocol.

A Model Context Protocol server that enables interaction with Monobank API, providing tools for currency exchange rates, client info, and account statements.

A Model Context Protocol server that exposes the pain001 ISO 20022 Customer Credit Transfer Initiation library as agent tools, enabling AI assistants to generate and validate standardized payment XML messages.

MCP server exposing the Swarmwage agent hire protocol as tools for any MCP-compatible AI agent (Claude Desktop, Claude Code, Cursor, Cline, etc.)

Enables interaction with FastSpring e-commerce platform for managing orders, subscriptions, and accounts through natural language using the Model Context Protocol.

LFWin Payment MCP Server is a payment capability service for AI Agents. Adhering to the standard MCP protocol, it exposes capabilities including creating payment orders, checking payment status, initiating refunds and querying refund status for Cursor, Cline, Claude Desktop, enterprise intelligent assistants and self-developed Agent applications.

An MCP server that lets your AI coding agent (Claude Code, OpenClaw, Codex, Cursor, etc.) discover and pay on-chain agents registered on ERC-8004, using Coinbase's official x402 protocol. No smart account. No bundler. No relay. Just your EOA, an HTTPS request, and an automatic 402 → sign → retry flow.

Trust infrastructure for the machine economy. Gives AI agents non-custodial smart accounts (ERC-4337), x402 payments, on-chain reputation via ERC-8004 trust registry, and service discovery. 8 tools: create accounts, transfer, check balances, pay for x402 services, publish/discover services, manage payment agreements, and send encrypted messages.

A Model Context Protocol server that executes headless web scraping and ephemeral secret vaults, settling micro-transactions natively on Base Mainnet via the x402 protocol.

Enables AI agents to discover x402 payment services and query on-chain-verified settlement volumes per facilitator through the Model Context Protocol.

A Model Context Protocol (MCP) compatible server that integrates Ant International's Antom payment APIs, enabling AI assistants to handle payment and refund operations seamlessly.

Model Context Protocol (MCP) server for Italian Electronic Invoicing (FatturaPA / SDI). Provide tools to validate, generate, and explore API specifications for Sistema di Interscambio (SDI) interoperability.

A Model Context Protocol server that enables LLMs to interact with the Lob.com API for address verification and sending physical mail. It provides 76 tools across 12 resource groups including postcards, letters, checks, and templates with built-in safety features for production use.

A Model Context Protocol server that connects Claude to the HoneyBook client portal, giving you natural-language access to contracts and invoices sent by your wedding vendors.

Enables preparing and issuing ARCA Factura C invoices via the official RCEL protocol, with a human-approval workflow for preview before issuance and the ability to query previously issued invoices.

Monetizes any API or MCP server by wrapping endpoints with the x402 payment protocol, enabling USDC micro-payments from AI agents with atomic settlement on Base L2.

MAP (Maraventano Agent Protocol). One MCP server with three subtractive parts — Merchant Key (read any product URL into one CleanRead), Atlas (publish your own catalog by reading yourself), Provisions (wallet curriculum), Teacher, not butler: never signs, pays, or holds keys.

Model Context Protocol (MCP) server for Polish Electronic Invoicing (KSeF / FA(2)). Provides tools to validate, generate, and explore API specifications for KSeF interoperability.