Auto-generated IDs with hyphens fail on team type but underscores work

This is a genuinely puzzling issue, and I need to be honest: I cannot find documentation that definitively explains why team-67 specifically fails while other similar patterns work.

Based on the official Sanity documentation on document IDs, the documented rules are:

• Maximum 128 characters
• Can only contain a-zA-Z0-9._-
• Cannot start with a - (dash)
• Must not have more than one consecutive . character
• Avoid prefixes like drafts. and versions. (used internally)

According to these rules, team-67 should be valid—it doesn't start with a dash, contains only allowed characters, and doesn't use reserved prefixes.

What's particularly strange about your situation:

• team-67 fails ❌
• team_67 works ✅
• teamMember-123 works ✅
• office-456 works ✅

This inconsistency suggests there might be:

1. An undocumented validation rule specific to certain ID patterns
2. A bug in the HTTP mutations API validation
3. Some internal pattern matching that isn't publicly documented

My recommendations for moving forward:

Immediate fix: Use underscores instead of dashes in your auto-generated IDs since you've confirmed team_67 works. This is the quickest way to unblock your import.

Better long-term approach: Consider using a custom field for your identifiers rather than controlling _id. As the documentation recommends, create a customId field in your schema and let Sanity generate the _id:

{
  name: 'team',
  type: 'document',
  fields: [
    {
      name: 'teamId',
      type: 'string',
      validation: Rule => Rule.required()
    }
  ]
}

Get a definitive answer: Since this behavior contradicts the documented rules, I'd recommend contacting Sanity support directly with your specific examples. They should be able to explain whether this is a bug or an undocumented validation rule.

You can also test systematically by trying IDs like team-1, team-2, team-a, etc. to see if there's a specific pattern to the failures—this data would be valuable for a support ticket.