---
title: "API Fundamentals in Insider One"
slug: "api-reference-fundamentals"
description: "Learn the fundamentals of Insider One APIs: authentication, rate limits, status and error codes, request anatomy, Postman setup, and OAuth 2.0 credentials."
updated: 2026-07-06T13:27:20Z
published: 2026-07-06T13:27:24Z
canonical: "academy.insiderone.com/api-reference-fundamentals"
---

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

# API Fundamentals

This section provides the foundational resources for integrating with Insider One’s API infrastructure. You’ll find detailed guidance on authentication methods, rate-limiting policies, standardized error responses, and environment setup in Postman.

Use these references to establish secure, efficient, and scalable API connections tailored to your use case:

- [Insider One APIs](/docs/api-reference-insider-apis)
- [Anatomy of an API Request](/docs/anatomy-of-an-api-request)
- [API Authentication Tokens](/docs/api-authentication-tokens)
- [API Rate Limits](/docs/api-rate-limits)
- [API Status and Error Codes](/docs/api-status-and-error-codes)
- [Insider One APIs in Postman](/docs/insider-apis-in-postman)
- [OAuth 2.0 Credentials](/v1/docs/oauth-20-credentials)