Testnet

Testnet uses the same public API endpoints and request formats as live integrations. Only the mode-specific parameters change.

Keep the endpoint path and request body shape the same as the corresponding API reference.

Request Parameters

Field	Required	Default	Description
X-API-Key	Yes	None	Use a test API key, for example mk_test_your_api_key.
X-App-Client	Yes	None	Use merchant-client-testnet.
Content-Type	Required for JSON requests	None	Use application/json when sending a JSON request body.

merchant-client-testnet tells Stafiel that the request belongs to testnet. It must be used with mk_test_ keys. A test key with merchant-client, or a live key with merchant-client-testnet, is rejected with 401 AUTH_FAILED.

Data Isolation

Testnet and live data are separate. Keep testnet activity isolated from live customer payments, accounting, reconciliation, webhook handling, and operational records in your own system.

Do not treat a successful testnet payment as a real customer payment.

Chain Labels

Testnet chain names use explicit labels:

Chain Label	Testnet	Chain ID
eth-sepolia	Ethereum Sepolia	11155111
base-sepolia	Base Sepolia	84532
bsc-testnet	BNB Smart Chain Testnet	97
polygon-amoy	Polygon Amoy	80002
solana-devnet	Solana Devnet	103
tron-nile	Tron Nile	3448148188

Use the chain and token options shown in your Merchant Dashboard as the source of truth for what your account can create.

Webhooks

Use separate webhook configuration for testnet. Treat testnet event IDs, signing secrets, and delivery logs as separate from live deliveries.

Go-Live Checklist

Before going live, replace:

• Merchant ID: use your live merchant ID in API requests.
• API key: use a live API key with the mk_live_ prefix.
• X-App-Client: change merchant-client-testnet to merchant-client.
• Chain labels: switch from testnet labels to mainnet chain labels.
• Webhook configuration: use the live webhook endpoint and signing secret.