"An overview or guide to Search Engine Optimization (SEO)" matching MCP servers:

A standard MCP server for discovering AI agents and negotiating signed skill contracts. Buyer-seller payments are settled directly outside the platform; Agent Economy Engine collects only a platform fee after both parties attest completion.

Pay-per-use semantic web search for AI agents. Powered by SearxNG, agents pay in sats via Lightning Network micropayments — no API keys required.

A locally runnable stdio MCP server for Fortrip hotel search, live room rates, hotel details, trip planning and booking payment links. Uses a Fortrip CLI token or saved CLI login; payments are completed by the user on Fortrip and Stripe.

Enables MCP-capable agents to retrieve a tamper-evident decomposition of x402 network growth on Base and to place $399 human-reviewed endpoint or wallet audits paid over the x402 rail, without moving funds itself.

PayCheck is an MCP server that checks a planned payment before an agent pays.

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).

Keyless MCP exchanger for AI agents — pay an exact amount to one deposit address, EMC delivered to any address. USDT(Tron) > EMC. Live at https://swap.emercoin.com/mcp

MCP server for the Gravv payments API that lets AI assistants onboard customers, run KYC, open accounts, move money, issue cards, and exchange currency, with built-in documentation search and safety confirmations for money-moving operations.

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.

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.

Official Dodo Payments MCP servers - dodopayments-api for live payments, subscriptions, customers, products, refunds, license keys, and usage-based billing (browser OAuth, no API key needed) and dodo-knowledge for semantic search over Dodo Payments documentation.

Enables agents to grade and repair the Bazaar discovery metadata of x402 services through native tools, itemizing defects or returning a validator-passed discovery package inferred from one real sample output. Calls are paid in USDC on Base via the x402 protocol, with no accounts or API keys required.

Unified gateway for ISO 20022 message families, providing meta-tools to search, describe, validate, generate, and parse financial messages.

Enables agents and developers to check x402 endpoints, assess scores and wallet risks, authorize payments with spending rules, and report outcomes before an agent pays.

Universal x402 buyer agent — discover, pay for, and call any x402 paid API endpoint from Claude Desktop, Cursor, or Claude Code with automatic USDC payment via AgentCash.

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.

Enables AI agents to search marketplace listings, place escrow-protected purchases paid in Nano, track orders, and retrieve signed receipts.

Enables AI agents to call paid APIs and settle HTTP 402 payment challenges with USDC on Base, without private keys ever being involved.

Enables MCP-wired agents to fetch live, historical, or proof-backed Base-mainnet asset prices signed with ML-DSA-65 and anchored to Hedera, automatically handling x402 USDC payments; it also lists the provider's available x402 services.

Official MCP server for PushNotif.biz.id. Enables AI agents to register websites, generate one-line SDK snippets, and broadcast or schedule Web Push (VAPID), Android FCM, iOS APNs, In-App Popups, Live Activity Toasts, and automated RSS push notifications with real-time CTR analytics.

Enables AI agents to draft AP-style press releases from a product URL and publish them to a public newsroom page, or distribute them across a newswire to hundreds of news, TV and radio sites, with status tracking for wire orders. Paid calls are settled per request in USDC on Base via x402 from the user's own wallet, defaulting to quote-only mode with spend caps and confirmation tokens.

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.

Hand a secret to another agent as an encrypted, pay-per-read token delivered exactly once, leaving no copy behind. Also pre-flights an x402 endpoint before your agent pays it. Runs locally over stdio and encrypts in your own process, so there is no hosted version to hand your plaintext to.

Enables MCP-capable agents to search the curated gold-402 directory of x402 services, probe any endpoint for valid 402 payment terms, and optionally purchase a human editorial verdict for a resource.

This is an MCP server for the BillingServ API. Once it's set up, your AI assistant can look up customers, invoices, orders, packages, and reports straight from your BillingServ installation

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.

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.

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.

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

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