This document walks you through the complete onboarding flow for the NUSDpay platform.

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Integration Overview

We recommend integrating in the following order. The phases differ in call frequency: phase 1 is one-time setup, phase 2 results are cacheable, and only phase 3 is called on every transaction.
Integration overview: one-time setup, initial fetch, per transaction

Integration overview (click to enlarge)

Results of phases 1–2 can be stored long-term: the wallet_id and keys are fixed, and enum/fee configuration rarely changes. Only phase 3 is on the per-transaction path.
1

Contact us and create an account

Before using any API, you need to contact us to create an account and obtain a wallet_id.
  1. Send an email to [email protected] with your company/project name, contact information, and a brief description of your business scenario
  2. We will create a wallet for you, bind your project information, and assign administrator permissions
  3. Once complete, you will receive a dedicated wallet_id
wallet_id is a fixed, project-level value: each project corresponds to one wallet_id, assigned by us. Store it in your configuration and pass the same value on every API call; you do not need to create wallets for end users or maintain a user-to-wallet_id mapping (end-user collection is handled by generating a per-user deposit address). When a new project is launched, we will assign it a new wallet_id.
For detailed instructions, see the Wallet ID Application and Configuration Guide.
2

Generate API keys

After obtaining your wallet_id, generate an API key pair for interface authentication.
  1. Follow the instructions to generate an Ed25519 key pair (the public key serves as API_KEY, the private key as API_SECRET)
  2. Provide the public key to us for binding
For key generation, see Generate public and private keys.
3

Platform configuration

Based on your business needs, confirm the following configuration items:Chains and tokens — Select the chains and tokens to enable. See Supported Tokens and Chains.Webhook callback — Provide a callback URL to receive transaction status updates in real time. See Webhook Overview.Payout configuration — If you need the payout function, confirm that Payout permissions are enabled for the relevant chain.
For configuration changes, please contact technical support. Do not modify settings yourself to avoid impacting business operations.
4

Understand the request specification

Before calling the interfaces, please read the following:

Request Specification

Request headers and authentication

API Signature

Signature calculation method

Transaction Status

Meaning and transitions of each status

Error Codes

Error codes and troubleshooting guide
5

Integration development

After completing the preparations above, choose the corresponding module based on your business scenario:

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Payin (Deposit)

Deposit integration flow

Deposit integration flow (click to enlarge)

Main interfaces:

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Payout (Withdrawal)

Main interfaces:

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Checkout (Optional)

If you want to provide a ready-made payment page to end users, you can integrate the Checkout H5 page. See Integrate H5 Page.
If you only use the API for wallet management and asset operations and do not need to integrate Checkout, you can skip this section.

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Next Steps

Product Overview

Learn about the full capabilities of NUSDpay.

Sandbox Testing

Validate your integration in the test environment.