⚡️ 60-second quickstart

# 1. Register at https://lemoncake.xyz, grab a BUYER_JWT

# 2. Issue a Pay Token (scoped, expiring, revocable)
curl -X POST https://lemoncake.xyz/api/tokens \
  -H "Authorization: Bearer $BUYER_JWT" \
  -H "Content-Type: application/json" \
  -d '{"serviceId":"svc_xxx","limitUsdc":"2.00","sandbox":true}'
# → { "jwt": "<pay_token>", ... }

# 3. Hand it to your agent. Done.
#    Claude / Cursor:
npx agent-payment-mcp
#    Eliza v2:
npm install eliza-plugin-lemoncake
#    Anything else:
curl -X POST https://lemoncake.xyz/api/proxy/svc_xxx/your/endpoint \
  -H "Authorization: Bearer <pay_token>" \
  -H "Idempotency-Key: $(uuidgen)"

Budget exhausted? 402. Token revoked? 422. No runaway agents. No stolen keys.

What is LemonCake?

LLM agents are getting powerful — but they still can't pay for things autonomously.

LemonCake solves this with Pay Tokens: short-lived JWTs that give an agent a scoped spending limit. The agent calls paid APIs through our proxy, gets charged per call in USDC, and stops automatically when the budget runs out.

You                    Agent                   Paid API
 │                       │                        │
 ├─ issue Pay Token ──▶  │                        │
 │   limit: $2.00        │                        │
 │                       ├─ call /api/proxy ────▶ │
 │                       │   Authorization: Bearer <pay_token>
 │                       │                        │
 │                       │  ◀─ response + charge ─┤
 │                       │    X-Charge-Id: ch_...  │
 │                       │    X-Amount-Usdc: 0.001 │
 │                       │                        │
 │                       ├─ (budget exhausted)     │
 │                       │   402 Payment Required  │
 │                       ✗   agent stops cleanly   │

🔌 Integrations

MCP サーバー —

... View full README on GitHub