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POST /auth/authenticate-client

Creates a JWT token for a Steam user, allowing them to access client endpoints (inventory, market, trading). Authentication: API Key (api-key header, requires CORE_ACCESS scope)

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Request

POST https://api.assetpay.co/auth/authenticate-client
Content-Type: application/json
api-key: YOUR_API_KEY

{
  "clientSteamId": "76561198012345678",
  "clientTradeUrl": "https://steamcommunity.com/tradeoffer/new/?partner=12345678&token=AbCdEfGh",
  "clientId": "user-123",
  "clientData": {
    "totalWager": 5000,
    "kycLevel": 2,
    "fiatDeposits": true,
    "cryptoDeposits": false
  }
}

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Body Parameters

ParameterTypeRequiredDescription
clientSteamIdstringYesSteam ID 64 (must match 76561XXXXXXXXXXXX format, 17 digits)
clientTradeUrlstringYesSteam trade offer URL
clientIdstringNoYour own user identifier (max 128 chars). Stored on every trade as externalClientUserId.
clientDataobjectNoUser context for collateral calculations. See clientData fields below.

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clientData Fields

These fields feed into the risk model that determines instant deposit collateral. All are optional and default to 0/false if omitted.
FieldTypeDescription
totalWagernumberTotal USD amount the user has wagered on your platform. Higher values increase external trust score.
kycLevelnumberUser’s KYC verification level on your platform (0-3). Level 3 unlocks higher collateral thresholds.
fiatDepositsbooleanUser has made fiat deposits on your platform.
cryptoDepositsbooleanUser has made crypto deposits on your platform.
Having both fiatDeposits and cryptoDeposits as true combined with kycLevel: 3 gives the highest collateral multiplier. The clientData is updated on every authentication call, so pass current values each time.

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Response

{
  "requestId": "...",
  "success": true,
  "data": {
    "token": "eyJhbGciOiJIUzI1NiIsInVzZXJJZCI6Im1lcmNoYW50LXV1aWQifQ..."
  }
}

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Response Fields

FieldTypeDescription
tokenstringJWT signed with your API secret (HS256). Valid for 24 hours.

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Token Structure

The generated JWT contains: Header: 
{
  "alg": "HS256",
  "userId": "your-merchant-id"
}
Payload: 
{
  "client": {
    "steamID": "76561198012345678",
    "tradeUrl": "https://steamcommunity.com/tradeoffer/new/?partner=...",
    "clientId": "user-123",
    "clientData": { "totalWager": 5000, "kycLevel": 2, "fiatDeposits": true, "cryptoDeposits": false }
  },
  "iat": 1709550000,
  "exp": 1741086000
}

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Rate Limits

Merchant StatusLimit
Verified1,000,000 requests / hour
Unverified100 requests / hour

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Errors

CodeKeyWhen
1001VALIDATION_FAILEDInvalid Steam ID format, missing trade URL, etc.
1400MISSING_API_KEYNo api-key header provided
1401INVALID_API_KEYAPI key not found or invalid
1403API_KEY_SCOPE_DENIEDKey doesn’t have CORE_ACCESS scope