"Exploring Gemini Services or Tools That Don’t Require an API Key" matching MCP servers:

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.

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.

Enables AI agents to convert PDFs and images into validated, structured JSON for invoices, receipts, contracts, and resumes, or into any caller-supplied JSON Schema, through five extraction tools. Each tool call pays per use in USDC over x402 from a wallet the caller supplies, with no signup or API key required.

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.

Enables AI assistants to compute VAT, selling prices, quotations, VietQR transfer content, multi-level referral commissions, and industry workflows for Vietnamese businesses through a free remote MCP endpoint.

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.

Per-customer API usage analytics and billing exports for small B2B APIs. Agents can sign up, get ingest snippets and read usage by customer, endpoint and plan.

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.

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.

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.

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.

MCP server for decoding and inspecting x402 payment headers and requests. Remote endpoint: https://lumenworks-x402-decoder.onrender.com/mcp

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.

Enables AI agents to use pay-per-call web-to-Markdown, structured extraction, crawling, Base token and wallet data, FX rates, and crypto alert tools via USDC payments on Base.

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

Open-source registry of structured API specs for African providers: payments (Wave, Paycard, ...), SMS and WhatsApp (Africa's Talking, Infobip, ...), identity, delivery and speech. AI agents read the real endpoints, parameters and gotchas and write the integration. Each capability is marked verified (tested against the live API) or ready (written from the docs, not yet tested).

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

Provides trust and commerce checks for agent operators through HTTP x402 and a remote MCP endpoint, enabling clients to inspect x402 quotes, MCP handshakes, and A2A cards and to run paid verification and data tools.

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 LLMs to interact with ParaBank financial services, including retrieving accounts and transactions, transferring funds, and paying bills via natural language.

Enables AI agents and scripts to manage bookings, provider assignment, rescheduling, cancellations, customers, quotes, invoices, and dashboard data through a self-hosted API and MCP interface using your own Chrome session.

Enables AI agents to read and change jobs, job status, customers, quotes with line items, invoices, quote and invoice email, payments, and Scheduler bookings in an account by reusing the user's own signed-in Chrome session, with no official API keys needed. Ships read-only hints and confirmation prompts for tools that reach other people, and can be run over stdio or streamable HTTP.

Daily market-regime context for trading agents: is the market risk-on or risk-off? Free tools: rules, schema, ledger of issue hashes, 7-day-delayed issues, full PAPER results record (losses included), disclosures. Paid tool: today's issue via x402, 0.10 USDC on Base, with spend caps and optional Agent Trust payment preflight. No track record; not investment advice.

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

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.

Enables AI agents and scripts to access clients, estimates, invoices, payments, and reports from a user's own Joist account through their Chrome session, over MCP or a local REST API.

MCP server for the Stripe API with 10 tools covering payments, customers, invoices, and subscriptions. Generated with MCPForge. Destructive and financial operations require human approval.

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