x402-native payment rail for AI agents

Monetize your MCP in minutes. Agents pay on their own.

Paste a URL. Set a price. Buyers prepay by card.
Agents call with spend-capped Pay Tokens — no human in the loop.

$ npx create-lemon-mcp # → live in 5 min, 97% to you
Start for free Watch demo
Pay Token lc_pay ········ 3f8a
$3.18 / $5.00
318 calls left
Exp 07 / 26
verified · $0.01 charged
14:21:08 paid_call +$0.0097
14:19:55 paid_call +$0.0097
14:15:02 cap_exceeded blocked
97% to sellers
3,000 free calls (lifetime)
$0.005 minimum per call
0 crypto wallets
How it works

Every cent moves automatically.

Buyer prepays → agent calls within cap → 97% lands with you. That's the whole model.

1

Buyer prepays by card

Opens the buy link, pays $5 – $50 with a card. Stripe Connect Direct Charge. No crypto.

2

Agent pays per call

AI agent calls with a Pay Token. Hard cap enforced at the gateway — never exceeds budget.

3

Revenue splits automatically

3% to LemonCake. 97% via Stripe direct payout to your account. Budget zero → auto-stop with 402.

The payment flow
Buyer prepay $5.00 card
LemonCake gateway + ledger
Your API $0.01 / call
cap reached → 402 agent self-funds, continues
Why developers choose LemonCake

Sub-cent pricing

Charge $0.005 per call. Stripe's $0.30 floor makes sub-cent structurally impossible — we built from scratch for AI-native billing.

MCP-native middleware

Drop-in for any MCP server. Works with Claude, OpenAI, LangChain, CrewAI, or scaffold from scratch in one CLI command.

No API-key management

Pay Tokens replace secret keys. Buyers authenticate once at install — you never touch their credentials, no reset tickets.

Hard spend caps

A $5 Pay Token can never spend $5.01. No approvals, no monitoring. A runaway agent hits the wall instantly — your API never sees it.

Per-agent kill switch

Bind Pay Tokens to agent IDs. If one goes rogue, pause or revoke — the gateway blocks it on the next call, budget remaining or not.

Stripe-backed payouts

Buyers fund Pay Tokens by card. Sellers receive via Stripe Connect Direct Charge. LemonCake never pools or holds funds.

Open core — like Supabase & Clerk
MIT What you can fork
  • @lemon-cake/mcp-sdk
  • @lemon-cake/x402-server
  • agent-payment-mcp
  • MCP adapters (Claude, Cursor, LangChain)
  • All docs & migration guides
Hosted What we run as a service
  • Billing engine (settlement, ledger)
  • Revenue routing & Stripe payouts
  • Dashboard (analytics, payouts, abuse)
  • Compliance (tax, invoicing, reporting)
  • Fraud / abuse detection

If we ever shut down, your integration keeps working.

Stripe is for humans.
Orb & Metronome are for SaaS.
LemonCake is for AI.

When the buyer is an AI agent, billing infrastructure looks different.
We built the stack that matches that shape.

Start for free — 3,000 calls on us
No credit card. No crypto wallet. Live in 5 minutes.