"Finding alternatives to REF and MCP for APIs" matching MCP servers:

Discover audio and LLM services, compare seven voices, and check prices for free. Generate speech, transcribe audio and request LLM text with optional capped USDC payments on Base; voice-cloning requirements are also available.

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

Connects MCP clients to a telephony account so users can manage phone numbers, SIP accounts, routing, SMS, calls, and billing in plain language. It exposes search, schema lookup, and execute tools to run permitted API operations, with confirmation required for paid or destructive actions.

Enables AI agents to create and manage contract-guarded USDC wallets on Base with enforceable per-payment, daily, and monthly caps, vendor allowlists, escalation thresholds, and freeze controls. It provides read-only policy checks plus unsigned transaction proposals for payments, funding, vendor management, wallet creation, and module deployment without holding keys or broadcasting.

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

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.

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.

Enables AI agents to discover and pay for x402-gated HTTP APIs, handling 402 Payment Required flows with local signing. Supports EVM and Solana with non-custodial wallet management.

MCP server for NovaPay that enables AI agents to create payment links, poll payment status, manage session lifecycle, and generate merchant keys.

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

Enables AI agents to call LLM APIs via x402 micropayments in USDC on Base network, manage a local wallet, and query consumption records.

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

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 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 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).

Enables AI agents to scan payment endpoints for safety, returning a letter grade (A–F) and verdict before authorizing payments.

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 creating and tracking payment invoices and retrieving watchlist net-worth and source data via the FinCobra Checkout and Watchlist APIs.

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 manage a fictional B2B workspace SaaS (Tessera) with tools for ticketing, invoicing, customer management, and trial extensions, featuring a human-in-the-loop confirm pattern for safety.