"How to create a sandbox environment" matching MCP servers:

Enables AI agents to pay with crypto (XSGD) via EIP-3009 and receive single-use virtual Visa cards from the StraitsX sandbox or production environment.

A paid MCP server that lets AI agents send SMS messages to US phone numbers via x402 micropayments, with automatic compliance and opt-out handling.

Keyless crypto payments for AI agents. One MCP call turns any wallet address into a non-custodial crypto payment link or tip jar, no API key and no account, with funds settling straight to your wallet at a 0% platform fee (USDC/USDT, BTC, LTC, DASH, DOGE, ZCASH).

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

x402-trust gives AI agents a "check before you pay" layer for the x402 ecosystem.

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.

A template for building MCP servers with a built-in paywall gate that offers free local execution and premium server-side execution via Stripe and x402 payment lanes.

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.

MCP server exposing a fictional payment domain as tools, resources, and prompts, enabling reasoning over transactions, payment hubs, services, and system health.

Enables AI agents to scan payment endpoints for safety, returning a letter grade (A–F) and verdict before authorizing payments.

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

Enables AI agents to manage a fictional B2B workspace SaaS (Tessera) with tools for ticketing, invoicing, customer management, and trial extensions, featuring a human-in-the-loop confirm pattern for safety.

Enables AI agents to discover, inspect, and pay for paid HTTP and MCP services using USDC on Solana with a self-custodial wallet.

Connects Claude to the customer side of Housecall Pro, letting you view estimates and invoices, check company details, and decline estimate options using the link your contractor sent.

MCP server for the PayPay Open Payment API, enabling QR code creation, payment tracking, refunds, and cancellations with sandbox and production support.

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.

Exactly-once execution for irreversible agent actions: an agent claims the right to run an effect, and a retry after a lost response returns the sealed result instead of charging again. 12 tools over stdio, including a gateway mode where the agent holds a single-use ticket and never the provider key.

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.