Describe the Bug

Context

While removing as any assertions in app/src/composables/use-collab.ts, we discovered that the SDK client isn't receiving

the schema generic it needs for proper type inference.

How SDK Generics Work

The Directus SDK is designed around a Schema generic that flows through the entire type system:

// The SDK client accepts a Schema generic
DirectusClient

// Which propagates to queries
readUsers<Schema, Query>()

// Which determines what fields are valid
Query<Schema, Item>.fields → QueryFields<Schema, Item>

When you provide a proper Schema, the SDK can:

1. Know which collections exist (directus_users, directus_files, etc.)
2. Know field types for each collection
3. Detect relational fields by checking if a field's type exists in the Schema
4. Allow nested object syntax for those relational fields: { avatar: ['id', 'modified_on'] }

The Problem

The app passes unknown as the Schema generic:

// app/src/sdk.ts
export type SdkClient = DirectusClient & AuthenticationClient & RestClient;

With unknown, the SDK's type inference chain breaks:

// SDK internals (simplified)
type RelationalFields<Schema, Item> = {
[Key in keyof Item]: Extract<Item[Key], ItemType> extends never ? never : Key;
}[keyof Item];

type ItemType = Schema[keyof Schema]; // With unknown → never

ItemType = unknown[keyof unknown] = unknown[never] = never

RelationalFields<unknown, User> = never (no fields match never)

Object syntax { avatar: [...] } is excluded from valid field types

This forces us to use as any:

fields: ['id', 'first_name', 'last_name', { avatar: ['id', 'modified_on'] }] as any

Possible solution

The SDK exports CoreSchema - a pre-defined generic that describes all system collections:

User extends the CoreSchema with the expected data structure hierarchy.

To Reproduce

• Open IDE
• Query the SDK with a nested field
• Run vue-tsc

Directus Version

v15.0.0

Hosting Strategy

Self-Hosted (Docker Image)

Database

No response