"Building OpenAI Agents SDK Using Official Documentation" matching MCP connectors:

ManaBuy MCP Server is a stdio-based Model Context Protocol server for integrating ManaBuy product and order APIs with MCP clients. It exposes tools for product search, product detail retrieval, SKU and order-field inspection, order quotation, authenticated order creation, order status lookup, and order detail retrieval, with explicit confirmation required before any order-creation workflow.

The Apiosk MCP lets AI agents discover, pay for, execute, and publish APIs through the Apiosk gateway. It is a machine endpoint, not a website, so connect it from an MCP client (Claude, Cursor, ChatGPT, and others) rather than browsing it here.

Pay-per-use tool API for AI agents. Free tier, x402 USDC micropayments, or API key.

A general store for AI agents. Pay in USDC via x402; every purchase gets a signed certificate.

Pre-payout IBAN screening for AI agents: validation, sanctions (OFAC), Swiss clearing, risk

European payment QR — SPAYD (CZ/SK) & EPC/GiroCode (SEPA), plus text/WiFi/vCard. Local, free.

AgisHub — pay-per-call tools for AI agents over x402 (USDC on Base). No API key.

Pass messages between AI agents with cleaning, metadata enrichment, and metered billing.

DAG manifold, property leads, GPU inference, and signal feed for AI agents.

Non-custodial USDC <-> bank for AI agents via x402 + Transak. Own funds only; PT + EU/EEA; 18+.

Website monetization for AI agents: apply, integrate ads, reporting, and payouts — all over MCP.

Pay-per-call x402 gateway: agent tools, OpenAI-compatible LLM, market data, RPC, security audits.

Marketplace where AI agents buy datasets and API access, pay per call in USDC over x402.

Pre-signature x402 payment-risk oracle. AI agents call forecast_payment before paying a counterparty and get a GO / HOLD / STOP verdict from settlement reputation, price-anomaly (quoted vs the payee's own median), and OFAC sanctions screening — plus a third-party-verifiable Ed25519 signed receipt. Verdict only; never takes custody. Free under $10 at risk; returns an x402 payment challenge over that.

Singapore property & financial data APIs for AI agents. 27 MCP tools. x402 micropayments.

Keyless non-custodial crypto payments for AI agents: payment links and tip jars, no API key.

Prepaid virtual cards for AI agents: one-time cards, spend caps, human approvals.

Pre-signature x402 payment verdict (GO/HOLD/STOP) for AI agents, with a verifiable signed receipt.

EUR settlement + trust for AI agent commerce: budgets, KYA, merchant discovery. 22 tools.

x402-gated agentic vending stack for AI agents — dynamic-priced payload vending, Ghost Layer decision-notarization resale, and a real multi-seller marketplace for x402-payable APIs. Base/USDC + XRPL/RLUSD settlement.