"How to create an MCP tool" matching MCP servers:

A minimal demo of the x402 payment protocol protecting an MCP tool endpoint, showing how to charge for MCP tools using real 402 rejections and testnet payments.

A local, read-only stdio MCP server that lets a Grok Build CLI agent check how much of its weekly SuperGrok / Grok Build usage pool is left, when the period resets, and its Extra Usage cap via tools like get_budget. It reads the existing grok login session and returns per-product figures as JSON, mirroring the TUI /usage screen, so agents can pause before expensive work when quota runs low.

An MCP server for the SmartBill Cloud API. It lets an MCP client issue and manage Romanian invoices, proformas and payments, download document PDFs, and read VAT rates, series and stock levels.

A read-only MCP server for the open-banking.io PSD2 API that lets AI agents query personal bank balances and transactions via natural language, with zero-knowledge encryption ensuring all sensitive data is decrypted in-process and never exposed to third parties.

Enables AI agents to create and manage sellable listings, handle orders, and integrate Stripe payments through natural language using ListBee's API.

MCP server for NovaPay that enables AI agents to create payment links, poll payment status, manage session lifecycle, and generate merchant keys.

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

Enables running a local MCP server for Poland's KSeF (Krajowy System e-Faktur) e-invoicing system, so invoice data stays on the user's own machine rather than passing through an intermediary service. It currently exposes only a diagnostic server_info tool, with invoice search and retrieval tools still to come.

Create free, no-signup invoices from your AI assistant — the create_invoice tool returns a link that opens blankinvoicemaker.com pre-filled, ready to download as a watermark-free PDF.

Enables coding agents to create and look up crypto payments over stdio, returning checkout links, payment statuses, paged payment lists, and receivable currencies, with real payments gated behind an explicit opt-in environment flag.

Enables MCP clients to access all endpoints of an x402 gateway by paying real-time microtransactions (USDC on Base) per API call, with automatic tool discovery and spend guardrails.

Unofficial MCP server for Oblio.eu accounting software enabling natural language interaction to create invoices, manage documents, collect payments, query nomenclatures, and submit e-Factura to Romania's SPV system.

MCP server for creating and fiscalizing invoices via solo.com.hr API. Enables AI agents to generate invoices, retrieve invoice details, list invoices, and check next invoice number.

Create invoices from any MCP client via the Invovate API — compute totals and generate PDF, JSON, or UBL invoices in 11 languages. Exposes four tools: calculate_invoice_totals (no API key needed), generate_invoice_pdf, generate_invoice_ubl, and get_invoice_capabilities.

Enables MCP hosts like Claude, VS Code, Cursor, and others to discover payment methods, create payment links, verify payments, inspect invoices, and manage refunds through focused tools, with a guided safe payment workflow and a restricted generic API escape hatch.

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.

Enables AI agents to search merchant catalogs, verify product prices and stock, and create purchases with budget limits and human-in-the-loop approval in Russian specialty stores.

AI-powered invoice automation. Create PDF invoices, predict late payment risk 0-100, auto-send reminders, reconcile Stripe/PayPal payments, track cash flow. 10 MCP tools, 4 resources.

MCP server that gives Claude/GPT agents commerce tools — each tool call pays an upstream x402 endpoint and returns its artifact.