"Web search services that don't require an API key" matching MCP servers:

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

Enables AI agents to access DDG's payable services including checkout/payment conformance, MCP/tool security audits, agent-discovery repair, and buyer-agent smoke probes, with structured payment challenges.

Enables agents to access production-grade paid MCP tools with real on-chain x402 v2 settlement, including EVM wallet risk scoring, payload normalization, and facilitator discovery, all discoverable via Bazaar-compatible metadata.

Provides current weather conditions and 7-day forecasts for any location worldwide, covering temperature, humidity, wind, and precipitation, with pay-per-call micropayments via x402.

MCP Server for the LINE Shopping API, enabling AI agents and tools to interact with LINE Shopping data and operations via the Model Context Protocol.

A comprehensive Model Context Protocol (MCP) server that provides complete access to the Recharge Storefront API endpoints. Enables AI assistants to manage subscriptions, customers, orders, and billing through a standardized interface.

Read-only MCP server that performs deterministic local preflights of agent-payment boundary documents and x402 v2 PaymentRequired JSON, and prepares unsubmitted public quote-request drafts without network calls or fund movement.

An MCP server for Nexi POS payment operations, enabling creation of purchases and refunds, polling payment states, confirming transactions, and recovering unconfirmed transactions.

Buy at cash-only or unsupported shops by paying crypto (BTC signet, USDC) to a proxy shopper through a 2-of-3 escrow with timelocks over Nostr, or earn as a proxy shopper. Tools that move money act only with confirm: true.

Connects AI assistants to Quaderno's tax compliance engine, enabling tax calculation, tax ID validation, and invoice creation via natural language.

Enables MCP clients such as Claude Desktop and Cursor to obtain Base L2 payment instructions and extract clean, token-estimated Markdown from web pages after on-chain verification of a 0.05 USDC payment.

Enables AI assistants to manage an online store for honey and beekeeping products, including order tracking, inventory updates, sales stats, and invoice resending via the Model Context Protocol.

Provides AI models with authoritative knowledge and code generation for Kapital Bank's payment gateway, including endpoint specifications, payment flows, code samples in multiple languages, error code lookup, and sandbox test credentials. It enables integration without requiring merchant credentials or live bank execution.

The first commercial implementation of HTTP 402 Payment Required for creator content. AI agents discover music, video, and text catalogs as pre-indexed Pockets (list_pockets, search_pockets — free, no key) and pull licensed content per-use through a 402 paywall. Tiered per-pull pricing by content type; 85% of every pull pays the rights holder instantly, with attribution and an audit trail.

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

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).

An MCP server that wraps the Check Payroll API, providing 263 tools for managing companies, employees, contractors, payrolls, tax configuration, and more.

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.

Reads and validates any European e-invoice a business receives — XRechnung, UBL, CII, ZUGFeRD/Factur-X PDF, Peppol BIS 3, FatturaPA, KSeF FA(3) — into canonical EN 16931 JSON with plain-language fix hints in EN/DE/PL/IT/FR, plus PDF, CSV and DATEV export. Nothing is stored; works without a key on a small daily quota.