Modify Metadata Through Metadata API Functions Permission

Users must have the Customize Application permission to create, update, and delete metadata records. Thereafter, users with the Modify Metadata Through Metadata API Functions permission can edit metadata (including Apex) through Metadata API even if they don’t also have the Modify All Data permission. Metadata API is used for deployments using change sets, the Ant Migration Tool, or the Salesforce CLI. Users must have the permission that enables use of the feature supported by the metadata they’re trying to modify. They must also have the permission that enables their deployment tool.

The Modify Metadata Through Metadata API Functions permission doesn’t impact direct customization of metadata using Setup UI pages, because those pages don’t use Metadata API for updates.

Along with the Manage Prompts user permission, the Modify Metadata Through Metadata API Functions permission grants users the ability to manage In-App Guidance in Lightning Experience.

Some metadata, such as Apex, executes in system context, so be careful how you delegate the Modify Metadata Through Metadata API Functions permission. Modify Metadata Through Metadata API Functions allows deployment of Apex metadata, but it doesn’t allow some Apex development and debugging features that still require the Modify All Data permission.

Modify Metadata Through Metadata API Functions is enabled automatically when either the Deploy Change Sets or the Author Apex permission is selected.

Metadata API Developer Guide

Modify Metadata Through Metadata API Functions Permission