"Resources to Become an Expert in LangChain" matching MCP connectors:

The agentic layer of letters. Agents send real printed mail worldwide, German compliance built in.

Ready for a new way to bill pay? Pay any US bill in a snap, right from your AI assistant. Describe or snap a photo of your bill (electric, water, gas, internet, phone, medical, credit card, rent, parking tickets, traffic violations and more) and Papaya reads it, then hands you a secure link to pay by card. Fast, secure, and no juggling twelve logins, with full or partial payments and status updates. Available in the US only. Powered by Papaya (papayapay.com).

Pay any US bill in a snap, right from your chat — utilities, medical, rent, parking tickets & more.

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.

Agent-to-business commerce sandbox: intents, offers, bookings. Demo data, ed25519-signed calls.

Payments and pricing math sellers do weekly, computed deterministically over MCP: processor_fees breaks down payment costs with editable presets, charge_to_net answers what to charge to net a target amount, invoice_total validates and totals line items, with discount_stack, proration, and installment_plan in the premium tier.

Split shared expenses in a group — no account needed. See who owes whom and settle up.

Non-custodial USDC checkout on Solana for AI agents and humans. Six tools inspect a public checkout, prepare one-time or recurring payments under a hard USDC ceiling, and read payment or subscription status, always returning unsigned transactions for the caller's own wallet to sign so Rendben never holds funds or keys.

Payment-rail-independent intent-to-effect integrity for consequential agent actions.

Monetization gateway for MCP servers. Agents call a tool, receive an x402 v2 payment challenge, sign a USDC transfer on Base, and get the result. Payment is verified before the tool runs and settled only after it returns, so failed calls are never charged. Discovery and tool listing are free.

Monetize any MCP server: x402 paywall, pay-per-call billing in USDC on Base, agent marketplace.

Verify x402 payment endpoints before an AI agent pays: scam scan, on-chain checks, trust scores.

Looks up the full data of an electronic invoice (NFe) from the access key. Platform-hosted, no crede

Pay-per-request webpage-to-Markdown extraction for AI agents. $0.005 USDC via x402 on Solana.

MCP marketplace: agents pay per call in USDC via x402. Plus Base chain data and a USDC<->bank ramp.

A machine-to-machine agent superstore -- paid API services for autonomous agents via x402 on Base.

Pay for HTTP APIs and charge for your own: x402 micropayments in USDC on Base.

Incorporate a German GmbH or UG in chat, then finish and pay on a secure link.

Checks reputation and transaction evidence to flag counterparty risk before autonomous payments.

Agent-to-agent marketplace: AI agents list and buy data, services and compute. Signed receipts.