Venue
Certified againstthe venue, on aproduction key
Spot and futures each passed an eight-part certification on a real key, including the branch everyone skips: the venue accepted the order and the response was lost. No orders left behind, and the wallet did not move.
What "certified" meant, concretely
The signature, against the real endpoint
Signed reads and writes against the production API rather than a mock — because the interesting failures are in the parts a mock is written from the same misunderstanding as the client.
The instrument filters
Tick size, step size, minimum notional, and what the venue does with an order that violates each. Rounding happens against the venue’s own numbers, fetched from the venue, and always downward.
The error taxonomy
Which failures are retryable, which are permanent, and which mean "your order may exist". A connector that maps everything to a generic error turns the third category into the first, and retries a live order.
The lost response
Exercised for real: submit, lose the answer, resolve it into exactly one order. This is the branch that costs money when it is wrong, and it is the one that cannot be tested by reading the documentation.
The stream, past its own expiry
The private user stream was soaked well past the session time-to-live it advertises, because a stream that silently stops delivering fills after N hours is indistinguishable from a quiet market until you reconcile.
- MEXC spotLive orders, certified. Signed reads, private stream, attached protective exits.
- MEXC futuresLive orders, certified separately — a resting perp order creates leveraged exposure, so it was its own decision and its own eight checks.
- BinanceMarket data, screening, derivatives feeds. Order placement is not certified there and the platform does not pretend otherwise.
- PaperA simulated book with fees, slippage and depth, borrowing its instrument specs from the venue it is standing in for.
What the platform does with each venue today. Read markets are everywhere; placing orders is a deliberate, separately certified act.
Questions about MEXC
Do you hold my API key?
A live venue needs a credential and it is yours, provided by you. The architecture keeps a credential that moves money out of any process serving other customers — that constraint is the reason live accounts are provisioned deliberately rather than at sign-up.
What permissions should the key have?
Trading and reading. Not withdrawal. Nothing here has any use for a withdrawal permission, and a key that has one is a key whose compromise is unrecoverable.
Are MEXC’s published fees the fees?
No, and this is worth knowing before you compute an edge. The published schedule for the market we trade says zero while the fills say about 14 basis points round trip. The platform uses the rate your own fills show.
Can I test against MEXC without a key?
Yes — the paper venue borrows MEXC’s instrument specifications, so rounding, minimum sizes and filters behave the way they will when the orders are real.
Rehearse the venue before you fund it
Paper runs against the same instrument rules, so what fits there fits here.