APIs

Public REST APIs for accessing USDD protocol data — no authentication required.

Base URL: https://openapi.usdd.io

---

Endpoints

Method	Endpoint	Description
GET	/totalSupply	True total supply of USDD: USDD in circulation + sUSDD
GET	/circulatingSupply	True circulating supply of USDD: USDD in circulation + sUSDD
GET	/api/v1/external/earn-apy	USDD saving yield across all chains
GET	/api/v1/external/total-supply/usdd	USDD circulating supply per chain
GET	/api/v1/external/total-supply/susdd	sUSDD circulating supply per chain

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GET USDD Total Supply

Returns the true total supply of USDD across all chains as a plain numeric value.

When users stake USDD, they receive sUSDD — a yield-bearing token deployed in on-chain investment strategies. The staked USDD is no longer in circulation. This endpoint returns USDD in circulation + sUSDD, which is the correct figure for total supply tracking.

GET /totalSupply

Parameters: None

Response

Returns a single numeric value (no JSON wrapper).

Example Request

curl https://openapi.usdd.io/totalSupply

Example Response

1010300157

---

GET USDD Circulating Supply

Returns the true circulating supply of USDD across all chains as a plain numeric value. Equals USDD in circulation + sUSDD.

GET /circulatingSupply

Parameters: None

Response

Returns a single numeric value (no JSON wrapper).

Example Request

curl https://openapi.usdd.io/circulatingSupply

Example Response

1010300157

---

GET Earn APY

Returns the current USDD savings annual yield for each supported chain.

GET /api/v1/external/earn-apy

Parameters: None

Response Parameters

Field	Type	Description
tronApy	String	Annual yield on TRON, 4 decimal places
ethApy	String	Annual yield on Ethereum, 4 decimal places
bscApy	String	Annual yield on BNB Chain, 4 decimal places

Example Request

curl "https://openapi.usdd.io/api/v1/external/earn-apy"

Example Response

{
  "code": 0,
  "data": {
    "tronApy": "0.0800",
    "ethApy": "0.1200",
    "bscApy": "0.1200"
  },
  "message": "SUCCESS"
}

Error Codes

Code	Description
0	Success
500	Internal server error

---

GET USDD Supply

Returns the current USDD supply in circulation across all chains, excluding sUSDD. Updated every 5 minutes.

Note: When users stake USDD, they receive sUSDD — a yield-bearing token deployed in on-chain investment strategies. This endpoint only reflects USDD tokens currently in circulation, not the USDD value staked as sUSDD. To get the true total supply of USDD (including the portion staked as sUSDD), use /totalSupply.

GET /api/v1/external/total-supply/usdd

Parameters: None

Response Parameters

Field	Type	Description
symbol	String	Token identifier, always "USDD"
totalSupply	Number	USDD in circulation across all chains (excludes sUSDD)
tron	Number	USDD in circulation on TRON
eth	Number	USDD in circulation on Ethereum
bsc	Number	USDD in circulation on BNB Chain

Example Request

curl "https://openapi.usdd.io/api/v1/external/total-supply/usdd"

Example Response

{
  "code": 0,
  "data": {
    "symbol": "USDD",
    "totalSupply": 210785566.7,
    "tron": 48992362.03,
    "eth": 138316391.29,
    "bsc": 23476813.38
  },
  "message": "SUCCESS"
}

Error Codes

Code	Description
0	Success
500	Internal server error

---

GET sUSDD Supply

Returns the current sUSDD circulating supply across all chains. Updated every 5 minutes.

sUSDD is a yield-bearing token received when staking USDD. Its value grows over time as the underlying USDD is deployed in on-chain investment strategies. sUSDD can be redeemed for USDD at any time.

GET /api/v1/external/total-supply/susdd

Parameters: None

Response Parameters

Field	Type	Description
symbol	String	Token identifier, always "sUSDD"
totalSupply	Number	sUSDD supply across all chains
tron	Number	sUSDD supply on TRON
eth	Number	sUSDD supply on Ethereum
bsc	Number	sUSDD supply on BNB Chain

Example Request

curl "https://openapi.usdd.io/api/v1/external/total-supply/susdd"

Example Response

{
  "code": 0,
  "data": {
    "symbol": "sUSDD",
    "totalSupply": 1890027.46,
    "tron": 0,
    "eth": 1201916.02,
    "bsc": 688111.44
  },
  "message": "SUCCESS"
}

Error Codes

Code	Description
0	Success
500	Internal server error

---

Quick Start

JavaScript

// Get USDD Total Supply
const res = await fetch('https://openapi.usdd.io/api/v1/external/total-supply/usdd');
const { data } = await res.json();
console.log('Total Supply:', data.totalSupply);
// → Total Supply: 210785566.7

Python