> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bolta.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Developer Tools

> An overview of the developer tools Bolta provides, including the sandbox environment, API documentation, and debugging tools.

<Note>
  Some links point to the service guide, which is in Korean.
</Note>

# Developer Tools

## API documentation

Detailed documentation for every endpoint, along with code samples in multiple programming languages.

Supported languages: Shell, HTTP, JavaScript, Ruby, Python, PHP, Java, Go

## Sandbox environment

Test the API with a test key.

* **Test keys** (`test_` prefix): Bolta simulates every issuance request and sends nothing to the NTS.
* **Live keys** (`live_` prefix): These operate in the production environment, and Bolta sends issuance requests to the NTS.

> Create test keys and live keys under [Developer Center > API Keys](/docs/developer-center/api-key).

[Business Registration Status](/en/docs/api-introduction/business-registration-status) returns mock results only for the fixed numbers listed in its guide when you use a test key. A number outside that list is rejected with `400`, and a bulk lookup that includes any such number is rejected as a whole.

[Revenue and Expense](/en/docs/api-introduction/revenue-expense) returns fixed sample revenue and expenses for a test key, regardless of your subscription. Sync requests do not collect anything.

[Bank Account Transactions](/en/docs/api-introduction/bank-account-transactions) returns fixed sample accounts and transactions for a test key, regardless of your subscription.

[Bank Account Holder](/en/docs/api-introduction/bank-account-holder) returns mock results only for the fixed account numbers listed in its guide when you use a test key. It deducts no points, and an account number outside that list is rejected with `400`.

[Tax Invoice PDF](/en/docs/api-introduction/tax-invoice-pdf) returns a sample PDF URL right away for issuances made with a test key. Check the `202` polling flow with a live key.

## Logging

Check the webhook delivery history.

* **Webhook logs**: Monitor the delivery history of events such as issuance completion and failure.

> For webhook setup, see the [Webhook connection](/docs/developer-center/webhook-connection) guide, and for checking logs, see the [Webhook logs](/docs/developer-center/webhook-log) guide.