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Every SDK method returns an ApiResponse<T>. The SDK does not throw on API failures. Check status before you use data. On success, data holds the resource. On failure, status and message describe what went wrong. error holds structured Core error details when available. data may hold Core’s raw error JSON or be null.
Do not wrap SDK calls in try/catch for API failures. Only BlnkInit throws when baseUrl is missing.

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Parse the response

Read the envelope first. Use status to classify the failure, then read the field that carries detail for that type. 
interface ApiResponse<T> {
  status: number;
  message: string;
  data: T;
  error?: {
    code: string;
    message: string;
    details?: unknown;
  } | null;
}
PropertyContains
statusHTTP-style codes: 2xx success, 4xx client error, etc.
dataSuccess body, or Core error JSON on rejection. May be null.
errorStructured error parsed from Core’s error_detail. Use error.code for logic.
messageHuman-readable description. For logs and UI only. Do not use for logic.

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How to handle errors

1

Check status

Confirm success before you use data. On every call, check that status is in the 2xx range for the method you called.
Error handling
const response = await blnk.Transactions.get('txn_f482a1b3-6c2d-4e89-a17b-3d5e8f2a1c94');

if (response.status < 200 || response.status >= 300) {
  const errorCode = response.error?.code;

  switch (response.status) {
    case 404:
      // Resource not found: check errorCode (e.g. TXN_NOT_FOUND)
      break;
    case 401:
    case 403:
      // Auth or scope failure: check the API key
      break;
    default:
      // Log status, errorCode, and response.message
      break;
  }
  return;
}

// Use response.data
2

Read the error detail

Use the field that matches the failure type:
  • Core rejection (status is a Core HTTP error and data is set): read response.error?.code for the code Core returned.
  • SDK validation (status === 400 and data is null): read response.message and fix the payload before retrying.
Route on response.status when you do not need code-level logic (401, 404, 409, 5xx).
3

Configure transport handling

When the SDK cannot reach Core or the request times out, you get status: 500 and data: null.Configure timeout and logging in your SDK client to investigate these failures.

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Core errors

When Core rejects a request, the SDK wraps the failure in an ApiResponse. It sets status to Core’s HTTP status, message to the error message, data to Core’s JSON error body, and error to structured details parsed from error_detail. On Core 0.15.0 and later, a rejected request looks like this:
404 Not Found
const response = await blnk.Transactions.get('txn_missing');

// response:
{
  status: 404,
  message: 'transaction not found',
  data: {
    error: 'transaction not found',
    error_detail: {
      code: 'TXN_NOT_FOUND',
      message: 'transaction not found',
      details: {}
    }
  },
  error: {
    code: 'TXN_NOT_FOUND',
    message: 'transaction not found',
    details: {}
  }
}
Read the failure from response.error?.code. Use response.status to choose a broad response. Treat response.error?.message as display text; Core may change wording between releases. On older Core versions, response.error?.code may be UNKNOWN.
StatusWhen it happensWhat to do
404Resource ID or path does not existCheck response.error?.code (e.g. TXN_NOT_FOUND, IDT_NOT_FOUND)
401 or 403API key, scope, or permission failureCheck the key, scopes, and whether the method requires the master key
409Conflict (duplicate reference, lock, or in-progress job)Retry only if the operation is safe to repeat
400Core rejected the payloadFix the request body before retrying
5xxCore or upstream failureRetry later and check Core logs
Do not match exact error strings in application logic. Message text can change. Prefer response.error?.code for routing and response.error?.message for user-facing messages only. See the 0.15.0 migration guide and API error codes.

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Client-side validation

Some methods validate input before sending a request. When validation fails, Core never receives the call.
FieldValue
status400
messageValidation error string, e.g. reference field must be a valid string
datanull
errornull
Each Core API lists required fields for that call.

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Transport failures

When the SDK cannot reach Core or the request times out, you get status: 500, data: null, and a message describing the failure. Configure timeout and logging in Using the SDK. When debugging transport failures, log status, message, and the endpoint you called.

Using the SDK

Timeouts, retries, and logging.

0.15.0 migration

Error codes, inflight queuing, and reconciliation changes.

Quick start

Install the SDK and create your first transaction.

Changelog

TypeScript SDK releases and version history.

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Need help?

We are very happy to help you make the most of Blnk, regardless of whether it is your first time or you are switching from another tool. To ask questions or discuss issues, please contact us or join our Discord community.