"Popular MCP tools commonly used by programmers" matching MCP servers:

Enables agents to call paid utilities for DNS/SSL checks, site status, summarization, keyphrase extraction, decision advice, data cleanup, claim verification, and grounding via per-call USDC payments over x402, with free discovery tools and no signup or API key.

MCP server for Brazilian data lookups (Pix codes, CEP, CNPJ) and web rendering tasks (Markdown, screenshots, PDFs) via a paid HTTP API with x402 billing.

MCP server for deterministic financial transactions, providing tools to fetch account balances, check blocked PIX keys, and execute atomic PIX transfers with integer-cent precision.

A Model Context Protocol (MCP) server that provides testing and debugging tools for Stripe integrations, including test clock management, customer and product management, and subscription testing.

Deposit by Ouroboros Apps (https://ouroborosapps.com). Freelance deposit and payment schedule: approved deposits, payment dates, and client wording; deposit waivers and date changes need approval. Connect by pasting https://deposit-continuity2.vercel.app/mcp into Claude, Cursor, Grok, or ChatGPT developer mode (OAuth). Docs: https://ouroborosapps.com/docs/deposit

Lets agents discover and health-check a directory of live x402 pay-per-call endpoints, probe an individual URL with one unpaid request to see whether it returns a payment challenge and at what price, and read on-chain settlement demand for crawled sellers. It also serves reproducible, solver-verified sudoku puzzles and the pricing, network, and payment details of the studio's paid pay-per-call routes.

Connects AI agents to Uber Conta by Digio via Open Finance Brazil, enabling read-only queries on balances, transactions, credit card bills, and investments.

Invoice by Ouroboros Apps (https://ouroborosapps.com). Freelance invoice records: approved invoice line items, quantities, agreed rates, due dates, and late terms; invoice changes need explicit approval. Connect by pasting https://invoice-continuity2.vercel.app/mcp into Claude, Cursor, Grok, or ChatGPT developer mode (OAuth). Docs: https://ouroborosapps.com/docs/invoice

Wise balances, card payments, transfers and recipients in Claude, ChatGPT & co. Transfers you approve twice.

Enables AI agents to interact with the BulkClix platform for SMS, OTP, airtime, mobile money, bank transfers, data bundles, KYC, contacts, and account management via natural language.

Marketplace of MCP servers and APIs that agents pay for per call in USDC over x402 on Base; connect anonymously, pay only when you call

Enables AI agents to access real-time financial data, news, and web reading through a single MCP endpoint with zero installation.

Enables AI agents to pay for services in DigiByte/DigiDollar on testnet via the x402 pay-and-retry pattern, with spend limits and security policies.

Enables AI assistants to build PayRetailers cross-border payment integrations accurately by providing official documentation, endpoint specs, country-specific payload validation, webhook guidance, and integration prompts as MCP resources, tools, and prompts.

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 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.

Enables querying OpenCode Go subscription quota (rolling, weekly, and monthly usage) and Zen prepaid balance as MCP tools.

MCP server exposing a fictional payment domain as tools, resources, and prompts, enabling reasoning over transactions, payment hubs, services, and system health.

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.

A Model Context Protocol server that enables interaction with Monobank API, providing tools for currency exchange rates, client info, and account statements.