"User interface design or related topics" matching MCP servers:

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.

MCP server that lets a chatbot browse eSIM plans, sign in, prepare quotes, and execute wallet or card purchases on an existing eSIM platform, with safe typed tools.

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.

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).

MCP Server for AI agents to discover and call pay-per-request APIs via EntRoute. Give Claude, Cursor, Windsurf, or any MCP-compatible agent access to 350+ verified x402 API endpoints across 110+ capabilities — DeFi prices, web search, prediction markets, news, and more.

Generate crypto QR codes (BTC, ETH, SOL, USDC, USDT, EURC) and manage payment sessions from Claude Desktop or any MCP client. Non-custodial, free.

A local MCP server that integrates ProofJSON to assess invoices before payment, providing allow/review/block decisions with confidence scores and verification capabilities.

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.

Lets AI agents discover, pay for, and call any HTTP API per request using USDC, with gasless nanopayments and no API keys or accounts needed.

Enables AI agents to autonomously pay for Xiaohongshu note details, user notes, and wholesale pricing data using USDC micropayments on Base via x402, with automatic payment signing, retries, and configurable spending limits.

Enables AI agents to browse the giftcardshop catalog and purchase gift cards using Lightning payments, with no account or signup required.

The MCP gateway that lets any AI agent discover and pay metered APIs on Base or Solana — without the user wiring payments themselves.

A Model Context Protocol server for the EuroDNS User API — domains, DNS zones, contacts, subscriptions, SSL, invoices and orders.

Enables agents to request payment authorization against signed human mandates, enforcing policy-as-code limits and returning a decision (authorize, challenge, or deny) without moving funds.

Read-only MCP server for the Swiss eBill portal, enabling users to list bills and download invoice PDFs via an authenticated browser session. It cannot approve, release, or pay anything.

Connect Peil to Claude (or any MCP client): log hours, draft invoices from unbilled hours, and check where you stand — from a prompt.

Enables building client statements of account from existing invoices, credit notes, and deposits, with aged outstanding balances, PDF/plain-text output, and drafted payment chasers at friendly, firm, or final levels.

Spending limits for AI agents. Create budgets, enforce limits, track spend across x402, cards, MPP, or any payment rail.

Enables AI assistants to search real products, purchase with user approval, track deliveries, and run a seller business end to end via the Firestarter commerce platform.

Enables conversational AI assistants to help users discover movies, find showtimes, book seats, and process payments for AMC Theatres through a simple API interface.