---
title: "Custom Scopes in OAuth: Step-by-Step Guide"
description: "Learn how to create and manage custom OAuth scopes for precise API access control, enhancing security and improving usability."
canonicalUrl: "https://zuplo.com/learning-center/custom-scopes-in-oauth-guide"
pageType: "learning-center"
authors: "adrian"
tags: "OAuth, Tutorial"
image: "https://zuplo.com/og?text=Custom%20Scopes%20in%20OAuth%3A%20Step-by-Step%20Guide"
---
**[OAuth](https://en.wikipedia.org/wiki/OAuth) custom scopes allow you to
control API access with precision.** They define specific permissions for API
actions, enhancing security, guiding developers, and organizing resources
effectively. Here's what you need to know:

- **What are OAuth Scopes?** Permissions that determine what parts of an API an
  app can access.
- **Why Use Custom Scopes?** Tailor access, improve security, and align
  permissions with your API structure.
- **Examples:**
  - `users.read`: View user profiles.
  - `transactions.create`: Initiate financial transfers.
  - `articles.publish`: Publish content.
- **How to Plan Scopes:** Use clear naming conventions (e.g.,
  `resource.action`), define access levels, and document thoroughly.
- **Implementation Steps:**
  1. Configure your authorization server with scope details.
  2. Link scopes to API endpoints (e.g., `GET` requests require `read` scopes).
  3. Validate scopes during the OAuth flow.
- **Key Tips:** Test thoroughly, monitor usage, and manage scope updates
  carefully to maintain security and performance.

Custom scopes improve API security and usability by granting only the necessary
permissions for specific operations. Now, let’s dive deeper into how to plan,
implement, and manage them.

## Planning Custom Scopes

When planning custom scopes, focus on creating consistent names, defining clear
boundaries, and providing thorough documentation. This approach ensures OAuth
remains secure and easy to manage.

### Scope Naming Rules

Choose a naming convention that clearly conveys the purpose and access level of
each scope. A common and effective method uses dot notation to pair resources
with actions:

- **Resource.Action Format**: Use lowercase letters separated by dots (e.g.,
  `users.read`, `documents.write`).
- **Versioning**: Add version indicators when needed (e.g.,
  `api.v1.users.manage`).
- **Action Hierarchy**: Arrange actions from least to most privileged (e.g.,
  `files.list`, `files.read`, `files.write`, `files.delete`).

### Setting Scope Boundaries

Design scope boundaries that strike a balance between security and usability.
Each scope should grant only the permissions necessary for its intended
function.

| Access Level | Example Scope    | Usage Purpose            |
| ------------ | ---------------- | ------------------------ |
| Read-only    | `reports.view`   | Data retrieval           |
| Write        | `reports.create` | Creating resources       |
| Manage       | `reports.manage` | Full CRUD operations     |
| Admin        | `reports.admin`  | Administrative functions |

- Group related actions to align with your API’s structure and minimize
  complexity.
- Isolate high-risk operations into separate scopes for added security.

Once scope names and boundaries are established, document their purpose and
usage in detail.

### Scope Documentation

Clear documentation helps developers use and implement scopes correctly. Include
the following in your documentation:

- A detailed explanation of each scope's purpose
- Required permission levels
- Example scenarios and implementation guidance
- Dependencies or relationships between scopes
- Any rate limits or usage restrictions

Using [OpenAPI](https://en.wikipedia.org/wiki/OpenAPI_Specification)
specifications can keep your API documentation aligned with its actual
implementation. This minimizes inconsistencies and ensures your API gateway
setup matches what developers see in the documentation (you can use tools like
Zuplo and Zudoku for this).

## Setting Up Custom Scopes

This section explains how to implement custom scopes within the OAuth flow,
building on your scope planning.

### Auth Server Setup

To integrate custom scopes into your authentication flow, configure your
authorization server with the following steps:

- **Define Scope Details**: Specify each scope's resource, permitted actions,
  permission levels, and usage limits in the server configuration.
- **Set Validation Rules**: Ensure requested scopes match predefined patterns to
  block invalid or unauthorized combinations.
- **Token Configuration**: Include approved scopes in access tokens for
  downstream verification.

### Connecting Scopes to APIs

Once your authorization server is set up, link the appropriate scopes to secure
your API endpoints.

| Endpoint Type     | Example Scope   | Required Configuration       |
| ----------------- | --------------- | ---------------------------- |
| Read Operations   | `users.read`    | Validate GET requests        |
| Write Operations  | `users.write`   | Verify POST, PUT, or PATCH   |
| Admin Functions   | `users.admin`   | Ensure full CRUD permissions |
| System Operations | `system.manage` | Validate special privileges  |

Your API gateway should validate every incoming request against these scopes
before granting access to protected endpoints. Check out our full guide on
[securing your API with OAuth](/learning-center/securing-your-api-with-oauth) to
learn more.

### Scope Request Flow

After defining and connecting scopes, manage them effectively during the OAuth
flow:

1. The client requests specific scopes during the authorization process.
2. The authorization server checks these requests against the allowed scopes.
3. The user reviews and consents to the requested permissions.
4. Tokens containing the approved scopes are issued.
5. The API gateway enforces permission checks for protected endpoints.

This process ensures developers have clear guidance on the required scopes for
accessing each endpoint.

## Scope Management

Once you've set up custom scopes and integrated them with your API, managing
them effectively is key to maintaining security and performance. This involves
handling updates, monitoring usage, and managing scope changes to keep your API
running smoothly.

### Scope Updates and Versions

When updating scopes, aim to minimize disruptions. For smaller updates, you can
simply add new permissions. Larger changes, however, may call for creating a new
version of a scope. Maintaining backward compatibility during this transition
ensures developers have time to adjust without breaking their integrations. This
phased approach aligns with your initial token configuration, keeping security
consistent as your API evolves.

### Tracking Scope Usage

Monitoring scope usage helps you understand how your API is accessed and can
guide permission settings. Use an
[API monitoring tool](/learning-center/8-api-monitoring-tools-every-developer-should-know)
to track metrics like scope request frequency and access patterns. Sharing this
data through a [developer portal](https://zudoku.dev) allows your clients to
better manage their API keys and improve their integrations.

### Scope Changes and Removal

When retiring or modifying scopes, clear communication is critical. Notify
developers well in advance and provide detailed instructions for making updates.
During the transition period, support both the old and new scope formats to
ensure a seamless migration and avoid disruptions to your API's functionality.

## Testing Custom Scopes

Once your custom scopes are set up and integrated, it's crucial to thoroughly
test their performance and reliability. Testing ensures your OAuth scopes work
as intended, maintain API security, and help you catch issues before they affect
users.

### Scope Setup Tests

Run automated tests to confirm your scope configurations. Focus on:

- Token generation and refresh processes using various scope combinations
- Validating scopes against protected endpoints
- Ensuring proper error handling for invalid or missing scopes

This approach ensures your scope configurations remain consistent and functional
through deployments and updates. We have an
[end-to-end API testing guide](/learning-center/end-to-end-api-testing-guide)
that you might find useful for getting set up.

### Common Scope Problems

When working with custom scopes, certain problems tend to crop up. Addressing
these early can save time and prevent headaches:

- **Scope Bloat**: Overly detailed scopes can complicate token management. Keep
  scope definitions concise and group related permissions where possible.
- **Missing Validations**: Ensure your authorization server correctly validates
  all scope combinations. Test edge cases to catch potential conflicts.
- **Permission Gaps**: Double-check that scope hierarchies don't unintentionally
  grant access. Carefully document and test scope relationships to avoid
  oversights.

Once you've tackled these common issues, assess performance to confirm
everything runs smoothly.

### Speed and Efficiency

Keep an eye on key performance metrics:

- Time taken to generate tokens with complex scope combinations
- Speed of scope validation
- Authorization response times
- Token refresh efficiency

Your API gateway's monitoring tools can help track these metrics. For instance,
Zuplo offers
[real-time analytics](/blog/analytics-for-developers-using-your-api) to pinpoint
performance bottlenecks in your scope setup.

To boost performance:

- Cache validation results and keep scope strings short
- Use fast, efficient algorithms for parsing scopes
- Optimize token storage and retrieval processes

These steps will help ensure your custom scopes are both secure and efficient.

## Summary

We've covered the planning, setup, and management of custom OAuth scopes. Here's
a quick recap with practical tips.

### Benefits of Custom Scopes

Custom OAuth scopes improve API security by offering detailed access control,
reducing unnecessary permissions, and ensuring users only access the resources
they need.

Key benefits include:

- **Improved Security**: Restricts access to specific endpoints, lowering the
  risk of unauthorized actions.
- **Streamlined User Experience**: Users interact only with what’s necessary,
  reducing confusion and potential errors.

These benefits lay the groundwork for successful implementation.

### Tips for Implementation

- **Designing Scopes**  
  Create a clear hierarchy that matches your API's functionality. Use concise,
  descriptive, and consistent naming conventions.
- **Documentation and Tracking**  
  Clearly document each scope's purpose, associated permissions, related API
  endpoints, and any dependencies.
- **Managing Scopes**  
  Implement a system to monitor usage, track adoption, identify redundant
  scopes, and plan updates effectively.

Zuplo's API gateway and real-time analytics can help you manage custom scopes,
address bottlenecks, and strengthen security.
[Try it today for free!](https://portal.zuplo.com/signup?utm_source=blog)