LahamuPrepare the test environment
Use an up-to-date Chrome browser with MetaMask. If needed, obtain free Base Sepolia test USDC from Circle Faucet. Do not buy or bridge real funds.
ORDERBOOK AUDIT / DEMO MODE
ORDERBOOK AUDIT / TESTNET GUIDE
Check the calculation. Then test the flow.
Estimate fills, fees and unfilled quantity from an orderbook snapshot you supply. Inspect the synthetic example before trying the separate 0.01 test USDC API payment on Base Sepolia.
This instance runs in demo mode. Orderbook calculations are free, and the wallet payment page is unavailable. Inspect the synthetic example, then try the calculation through the API docs.
Testnet only. Test tokens have no real dollar value. Mainnet payments are not enabled. This audit does not fetch prices, accept orderbook screenshots or execute trades.
01
A small, exact example.
Buy 0.03 BTC: 0.01 BTC at 100,000 USD, then 0.02 BTC at 100,100 USD. The taker fee is 5 basis points (0.05%). All prices below are synthetic USD values.
SYNTHETIC / REQUEST
{
"base": "BTC",
"quote": "USD",
"snapshot_at": "2026-09-05T02:00:00Z",
"side": "buy",
"amount_base": "0.03",
"taker_fee_bps": "5",
"max_age_ms": 10000,
"bids": [
{
"price": "99900",
"size": "0.1"
}
],
"asks": [
{
"price": "100000",
"size": "0.01"
},
{
"price": "100100",
"size": "0.04"
}
]
}Principal: 1000 + 2002 = 3002 USD. Fee: 3002 × 5 / 10000 = 1.501 USD. Total cash: 3003.501 USD.
SYNTHETIC / EXPECTED ECONOMIC FIELDS
{
"requested_base": "0.03",
"filled_base": "0.03",
"unfilled_base": "0",
"fully_fillable": true,
"levels_used": 2,
"gross_quote_for_filled": "3002",
"fee_quote_for_filled": "1.501",
"cash_quote_for_filled": "3003.501",
"cash_direction": "pay"
}Decimal amounts are JSON strings to preserve precision. The estimated USD trade cost is separate from the API fee of 0.01 test USDC. No trade is placed.
Decimal amounts are JSON strings to preserve precision. These USD amounts describe a synthetic trade estimate, not a payment request. No order is placed.
The stored example uses analysis time 2026-09-05T02:00:01Z: snapshot age is 1000 ms and freshness is fresh. Reusing that old timestamp now can return stale. The payment page refreshes the synthetic timestamp before its quote; actual processing time still determines age.
02
You control every wallet step.
Connect, then request a quote
Open the payment page, click Connect wallet and review the Base Sepolia network request. Then request the free quote. Wallet connection alone does not submit the analysis.
Review the quote and sign yourself
Check the recipient, synthetic input and 0.01 test USDC amount. Only click Sign & pay when ready, then approve the MetaMask signature yourself.
Compare the result and receipt
Compare the calculation fields above. A completed test returns a calculation and a settlement response with success: true on eip155:84532. This response is not independent onchain verification.
The free host can take about a minute to wake. Let the page load before starting. This guide never opens a wallet prompt.
02
Try the free demo calculation.
Open the API docs and use POST /v1/orderbook-audit with the example input. Valid requests in this demo return a calculation without a 402 payment quote or settlement receipt. Do not attach a payment signature.
The same calculation limits apply: supplied snapshot only, no FX or transfer costs, no exchange lot-size rounding, and no trade execution. Demo use is not a completed payment trial or customer revenue.
03
An unclear payment needs review.
If submission has an unclear outcome, preserve the result, receipt and transaction hash. Check that transaction before any retry; do not sign again simply because a response was lost. The payment page keeps a local lock after submission.
That lock is limited to the same browser profile and origin. It is not shared across another browser or the old and new domains. An earlier payment must still be checked before a new attempt.
The estimate excludes FX, transfers and exchange lot-size rounding. It cannot guarantee execution and is not intended for latency-critical trading. Valid unpaid POST /v1/orderbook-audit requests return HTTP 402 payment requirements.
04
Keep the trial evidence useful.
An audit trial records your calculation and settlement response, or the exact step where you stopped. Example reading, wallet connection and faucet tokens alone do not complete it. This is separate from a free-data trial, independent chain verification and customer revenue.
FEEDBACK TEMPLATE
Lahamu trial: audit_payment
Run date / completed step:
Calculation received: yes / no
Settlement response received: yes / no
Expected amounts matched: yes / no / not checked
Error or discrepancy (no signature):
My workflow / hosted API or local library preference:
Assistance received: yes / noCopy and complete the template locally. This page does not submit it. Share errors rather than wallet screenshots; omit seed phrases, private keys, signatures, exchange credentials and confidential orderbooks.