Testing and sandbox

This page covers practical testing strategies without implying a separate undocumented public sandbox hostname.

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Testnet currencies

For integration testing, use invoiceCurrency and paymentCurrency values that map to Sepolia test tokens:

• fUSDC-sepolia

• fUSDT-sepolia

These values are part of the allowed enum in server-side validation alongside mainnet and Polygon mainnet identifiers.

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Webhook testing

• Expose your local listener with a tunnel (ngrok, Cloudflare Tunnel, etc.).

• Register the HTTPS tunnel URL as webhookUrl in the profile webhook API.

• Trigger a test payment and observe POST delivery and X-Kollect-Signature.

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Deposit wallet

Even in test configurations, the merchant record must have a deposit wallet resolved for payout initiation. Missing configuration typically surfaces as a business error mapped to PAYMENT_PROCESSING_FAILED during create-payment / initiate flow.

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Idempotency testing

1

Call create-payment

Call create-payment with a fixed X-Idempotency-Key and body A; expect 200.

2

Repeat the same request

Repeat with the same key and body A; expect the same successful payload (cached).

3

Change the body

Repeat with the same key and body B; expect 409 (IDEMPOTENCY_CONFLICT).

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Related pages

• Create payment URL

• Idempotency