"Free and Easy-to-Use Minecraft Protocol Servers for Proof of Concept Projects" matching MCP servers:

Enables MCP agents to verify email addresses using prepaid credits, with balance checks and receipt retrieval via a Streamable HTTP endpoint.

MCP server for e-commerce operations including product catalog management, cart/checkout, and Stripe integration, with built-in EU AI Act compliance.

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.

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.

Credit and payments for AI agent developers — over MCP. No crypto required

Enables AI agents to discover, query, and pay for HTTP endpoints and MCP tools using Stellar USDC/SEP-41 stablecoins through a federated P2P bazaar catalog and x402 payment facilitator.

AI payment router for routing across 300+ LLM models with per-request USDC settlement on Base and Tempo, session budgets, and x402 payments via the MCP protocol.

Free x402 endpoint checker plus paid report and metadata tools. Remote MCP server for agents. Written by AI named Nock, not a human.

Streamable HTTP MCP server that exposes user and billing management tools, resources, and prompts through a REST API, enabling natural language interaction with user profiles, bills, and sharing features.

Pay-per-call USDC payment proxy for AI agents. Issue scoped Pay Tokens with hard spending caps and auto-journal every charge to freee / Money Forward / QuickBooks.

MCP server that gates API calls to AI agents using proof-of-work (free) or Lightning payment (3 sats), providing challenge, verify, and status tools for per-call authentication without accounts.

Provision KYC-free, crypto-paid Nordic VPS and dedicated servers from any AI agent. Enables natural language hosting workflows including comparison, top-up, and provisioning of anonymous servers.

Enables agents to discover, sample, and pay per call in USDC for live threat intelligence, ZK proof generation, and arbitrage signals via the x402 protocol.

Provides a three-layer payment firewall for AI agents, enabling identity verification, risk screening, and execution authorization with on-chain policy enforcement for secure and auditable transactions.

A proof of concept MCP server that gives AI agents business context for e-commerce operations including orders, inventory, logistics, returns, claims, and payments.

Enables interaction with UCO Bank APIs through the Model Context Protocol, supporting banking operations such as account lookup, transaction history, and more.

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.

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 for real FDM 3D-printing slicing, quoting, and design-for-manufacturability analysis via the FabTally API, supporting 12 printer profiles and 12 materials. Includes free discovery/printability tools and paid slice/quote/orientation tools settled via x402 (USDC on Base).

Read-only MCP server for Easy Pay Direct / NMI payment gateway, enabling natural language queries of transactions, subscriptions, and customer vault records.