# LVL LTD — How To (machine summary)

Site: https://lvlltd.com  
HTML hub: https://lvlltd.com/how-to/  
JSON: https://lvlltd.com/how-to/index.json  

## What this is

x402 AI agent skill marketplace on Base USDC. Free outlines before pay. One-time unlock. Sealed pack re-download with the same payment. Public proof ledger never invents volume.

## Pages

| Page | URL |
|------|-----|
| Hub | https://lvlltd.com/how-to/ |
| Human path | https://lvlltd.com/how-to/human/ |
| Agent setup | https://lvlltd.com/how-to/agent-setup/ |
| Agent shopping flow | https://lvlltd.com/how-to/agent-shopping/ |
| Quick reference | https://lvlltd.com/how-to/quick-reference/ |

## Canary (recommended first buy)

- skill_id: `agent-x402-first-buy`
- price: $0.05 USDC (atomic `50000`)
- outline: https://lvlltd.com/skills/agent-x402-first-buy/outline.json
- challenge: https://lvlltd.com/api/pay?skill=agent-x402-first-buy
- human: https://lvlltd.com/first-unlock/

## Agent sequence (canonical)

1. `GET https://lvlltd.com/api/shop` (or `/catalog.json`)
2. `GET https://lvlltd.com/skills/{id}/outline.json`
3. `GET https://lvlltd.com/api/pay?skill={id}` → HTTP 402
4. Transfer exact `maxAmountRequired` USDC on Base (8453) to `payTo`
5. `POST https://lvlltd.com/api/pay` with header `X-PAYMENT: {"txHash":"0x…","skill":"{id}"}`
6. Receive `sealed_pack.files`
7. Optional: `GET https://lvlltd.com/api/proof`

## Key endpoints

- Health: `/api/health`
- Shop: `/api/shop`
- Catalog: `/catalog.json`
- Pay: `/api/pay`
- Proof: `/api/proof`
- Recover: `/api/recover`
- llms: `/llms.txt`
- Agent card: `/agent.json`
- Fleet: `/fleet.json`
- JS SDK: `/sdk/agent-shop.mjs`

## Payment constants

- Network: Base, chain_id 8453
- USDC: `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`
- Apex challenges declare `x402Version: 2` and `x402_version: "2"`
- Always trust live challenge fields over cached payTo

## Honesty

- Confirmed unlocks only on `/api/proof`
- Zeros / low volume are valid
- Swarm smoke_demo_not_ledger is not GMV

## Human first unlock

1. Outline → 2. MetaMask + Base + USDC → 3. `/first-unlock/` $0.05 → 4. Download sealed pack  
Wallet help: https://lvlltd.com/get-started/

## Recover after paid failure

`POST /api/recover` or `POST /api/pay` with same `txHash` + `skill` (idempotent). UI: https://lvlltd.com/recover/