How To · Quick reference
Quick reference cards
Scannable paths and endpoints. Full prose lives on sibling How-To pages.
Human first unlock (< 3 minutes if wallet ready)
1 · Outline
2 · Wallet
MetaMask · Base 8453 · USDC · /get-started/
3 · Pay $0.05
/first-unlock/ or marketplace buy canary
4 · Download
Sealed pack · save tx · re-download anytime
Open first unlock Buy canary now
Agent first purchase (canary)
GET /api/shop
next_action + inventory
GET outline
/skills/agent-x402-first-buy/outline.json
GET 402
/api/pay?skill=agent-x402-first-buy
POST unlock
X-PAYMENT: {txHash, skill}
curl -si "https://lvlltd.com/api/pay?skill=agent-x402-first-buy" | head -20
# pay atomic 50000 USDC on Base to payTo from body
curl -sS -X POST "https://lvlltd.com/api/pay" \
-H "Content-Type: application/json" \
-H 'X-PAYMENT: {"txHash":"0x…","skill":"agent-x402-first-buy"}' \
-d '{"txHash":"0x…","skill":"agent-x402-first-buy"}'
Key machine endpoints
| Endpoint | Purpose |
|---|---|
/api/health | Liveness |
/api/shop | Agent entry + next_action |
/catalog.json | Full catalog |
/api/catalog | Search |
/skills/{id}/outline.json | Free eval |
/api/pay?skill={id} | 402 challenge |
POST /api/pay | Unlock |
/api/proof | Confirmed ledger |
/api/recover | Re-deliver after paid failure |
/llms.txt | Agent map |
/fleet.json | Multi-domain fleet |
/how-to/index.json | This guide set |
/agent.json | Agent discovery |
/sdk/agent-shop.mjs | JS SDK |
Common failure modes & fixes
402 on GET — Expected challenge. Parse body; do not abort the shop loop.
Wrong network — Must be Base mainnet (8453), not Ethereum mainnet.
Wrong amount — Use exact atomic
maxAmountRequired (not rounded human dollars only).Wrong payTo — Always from live challenge, not a cached address from weeks ago.
Paid, no files — Wait 2–5s;
POST /api/recover with same txHash; check BaseScan.Empty activity — Ledger honesty. Not a UI bug if
/api/proof also shows zero/low.Outline-only skill — Prefer Deep / Execution Verified before large spends.
Swarm proof_tx — Smoke only if nested under
proof.kind=smoke_demo_not_ledger; use apex /api/proof for sales.Depth badges (human)
Deep Standard Outline-only · filter: marketplace?depth=deep