API Reference

Complete reference for the WDK Indexer REST API

Base URL

API Base URL
https://wdk-api.tether.io

Authentication

All requests require a valid API key in the x-api-key header:

Authentication Header
x-api-key: your-api-key-here

Don't have an API key yet? Request one by following the steps in our Get Started guide.


Rate Limiting

Endpoint
Limit

GET /api/v1/:blockchain/:token/:address/token-balances

4 req / 10s

GET /api/v1/:blockchain/:token/:address/token-transfers

8 req / 10s


API Endpoints

Health check endpoint

get

Check if the API server is running

Responses
200

Success

application/json
get
/api/v1/health
GET /api/v1/health HTTP/1.1
Host: wdk-api.tether.io
Accept: */*
200

Success

{
  "status": "ok",
  "timestamp": "2025-10-25T15:45:16.836Z"
}

Get token transfers for an address

get

Retrieve the token transfer history for a specific address on a given blockchain

Path parameters
blockchainstring · enumRequiredPossible values:
tokenstring · enumRequiredPossible values:
addressstring · min: 1Required
Query parameters
limitinteger · min: 1 · max: 1000OptionalDefault: 10
fromTsintegerOptionalDefault: 0
toTsintegerOptional
sortstring · enumOptionalDefault: descPossible values:
Header parameters
x-api-keystringRequired

API Key for authentication

Responses
200

Success

application/json
get
/api/v1/{blockchain}/{token}/{address}/token-transfers
GET /api/v1/{blockchain}/{token}/{address}/token-transfers HTTP/1.1
Host: wdk-api.tether.io
x-api-key: text
Accept: */*
{
  "transfers": [
    {
      "blockchain": "text",
      "blockNumber": 1,
      "transactionHash": "text",
      "transferIndex": 1,
      "token": "text",
      "amount": "text",
      "timestamp": 1,
      "transactionIndex": 1,
      "logIndex": 1,
      "from": "text",
      "to": "text"
    }
  ]
}

Get token balance for an address

get

Retrieve the current token balance for a specific address on a given blockchain

Path parameters
blockchainstring · enumRequiredPossible values:
tokenstring · enumRequiredPossible values:
addressstring · min: 1Required
Header parameters
x-api-keystringRequired

API Key for authentication

Responses
200

Success

application/json
get
/api/v1/{blockchain}/{token}/{address}/token-balances
GET /api/v1/{blockchain}/{token}/{address}/token-balances HTTP/1.1
Host: wdk-api.tether.io
x-api-key: text
Accept: */*
{
  "tokenBalance": {
    "blockchain": "text",
    "token": "text",
    "amount": "text"
  }
}

Error Handling

The API returns standard HTTP error codes:

Status Code
Description

400

Bad Request - Invalid parameters

401

Unauthorized - Invalid API key

404

Not Found - Resource not found

429

Too Many Requests - Rate limit exceeded

500

Internal Server Error

Error Response Format

Error Response
{
  "error": "error_type",
  "message": "Detailed error message"
}

Next Steps


Need Help?