Feature request: Extend options for Relationship or Select fields (support async/dynamic options)

[dev387]

Description

Currently, both relationship and select fields in Payload CMS rely on static options or on existing relationTo collections.
However, in many real-world cases — especially in multi-tenant or dynamic systems — it would be extremely useful if these options could be asynchronous or dynamically generated, e.g. from an API, user context, or runtime data.

Example use cases

• Relationship field

{
  name: 'tenant',
  type: 'select',
  hasMany: false,
  admin: {
    description: 'Select a tenant or choose All Tenants',
    options: async () => {
      const tenants = await fetch('/api/tenants').then(res => res.json());
      return [
        { label: 'All Tenants', value: 'all' }, // or value: null
        ...tenants.map(t => ({ label: t.name, value: t.id })),
      ];
    },
  },
}

• Select field (with async options)

{
  name: 'tenant',
  type: 'select',
  hasMany: false,
  admin: {
    description: 'Select a tenant or choose All Tenants',
    options: async () => {
      const tenants = await fetch('/api/tenants').then(res => res.json());
      return [
        { label: 'All Tenants', value: 'all' },
        ...tenants.map(t => ({ label: t.name, value: t.id })),
      ];
    },
  },
}

Proposed enhancement

Add support for async or dynamic options for:

• select fields (admin.options could accept a function returning a Promise)
• relationship fields (via an optional loadOptions callback or similar mechanism)

Benefits

• Greatly increases flexibility for admin UI configuration
• Enables conditional loading based on the current user, tenant, or external data
• Reduces need for hardcoded lists, custom components, or backend preprocessing
• Keeps field definitions declarative and intuitive

Example scenarios

• Multi-tenant systems where options depend on logged-in user's tenant
• Integration with external services to fetch option lists dynamically
• Providing virtual options like "All Tenants" alongside database-driven ones

Question

Would the Payload team be open to adding async/dynamic support for options (or a loadOptions callback) for select and/or relationship fields in the admin UI?