"Using PostgreSQL with n8n Workflow Automation" matching MCP servers:

Enables billing automation via natural language by creating a Composio MCP server that connects to Gmail, Google Sheets, Xero, and more for invoice generation, expense tracking, and payment processing.

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.

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

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.

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.

Enables MCP clients to access Monobank's open API for exchange rates, account and jar balances, and statements, as well as set webhooks, using natural language tools.

MCP server providing Polymarket weather-market bucket-transition signals for AI agents, with free city/signal inspection tools and paid signal bundles via USDC on Base using x402.

Provides currency conversion using the Wise API, supporting real-time and historical rates with caching and cross-rate calculation.

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

Enables natural-language interaction with Splitwise to explain balances, find missing or duplicate expenses, plan settlements, and safely add expenses with confirmation.

Enables issuing credit notes and credit memos against an invoice or standalone as revisable drafts that can be finalized into frozen numbered documents, then rendered as Markdown or printable HTML with totals broken down by currency, reason and month. All amounts are handled as integer minor units and all data stays local, so nothing is sent anywhere.

Budget, approval, and receipt layer that agents call when they buy on a human's behalf. MCP server with dry-run by default.

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

Automates Spectrum/Charter ISP account management tasks such as viewing account overview, paying bills, checking outages, and scheduling technician visits via browser automation.

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

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.

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.

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.

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.