Validates a post without creating one.
This endpoint applies the same validation rules as POST /posts,
including social-account resolution, platform-specific validation, and
media validation for referenced media library items.
Bearer authentication header of the form Bearer <token>, where <token> is your auth token.
Post content expressed as thread items.
The array exists for future thread support. Currently exactly one item is supported.
1 elementSocial-account targets for this post.
All referenced social accounts must belong to the same project.
Duplicate socialAccountId values are invalid.
1