# Fundamentals

> Get to know the ETG API basics — authorization, requests, responses, errors, security features, and the sandbox environment.

URL: https://docs.emergingtravel.com/docs/fundamentals/

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The sections share with you the fundamentals of the ETG API:

* [Authorization](/docs/fundamentals/authorization/).
* [Requests](/docs/fundamentals/requests/).
* [Responses](/docs/fundamentals/responses/).
* [Errors](/docs/fundamentals/errors/).
* [Security features](/docs/fundamentals/security-features/).
* [Sandbox](/docs/fundamentals/sandbox/).




## Pages

- [Authorization](/docs/fundamentals/authorization/)
- [Requests](/docs/fundamentals/requests/)
- [Responses](/docs/fundamentals/responses/)
- [Errors](/docs/fundamentals/errors/)
- [Security features](/docs/fundamentals/security-features/)
- [Sandbox](/docs/fundamentals/sandbox/)