Populate & Type Inference

One of the most powerful features of strapi-typed-client is automatic type inference based on your populate parameter. The TypeScript return type changes depending on which relations you populate.

Without Populate

When you call find() or findOne() without a populate parameter, relations are returned as minimal reference objects:

const result = await strapi.articles.find()

// result[0] has:
// {
//   id: number
//   documentId: string
//   title: string
//   content: string
//   category: { id: number; documentId: string } | null
//   tags: { id: number; documentId: string }[]
//   createdAt: string
//   updatedAt: string
// }

Relations only include id and documentId by default. To get the full related object, you need to populate.

With Populate

Boolean Populate

Pass true for any relation to include its full data:

const result = await strapi.articles.find({
    populate: {
        category: true,
    },
})

// Now category is fully typed:
// result[0].category is:
// {
//   id: number
//   documentId: string
//   name: string
//   slug: string
//   ...
// } | null

TypeScript knows the exact shape of the populated relation. You get full autocomplete on category.name, category.slug, etc.

Nested Populate

Populate relations of relations by passing a nested object:

const result = await strapi.articles.find({
    populate: {
        category: {
            populate: {
                parentCategory: true,
            },
        },
    },
})

// result[0].category.parentCategory is now fully typed

You can nest as deeply as your schema requires:

const result = await strapi.articles.find({
    populate: {
        author: {
            populate: {
                avatar: true,
                organization: {
                    populate: {
                        logo: true,
                    },
                },
            },
        },
    },
})

How Type Inference Works

The generated types include conditional type definitions that map populate parameters to return types. When you write:

const result = await strapi.articles.find({
    populate: { category: true },
})

TypeScript evaluates the populate parameter at compile time and produces a return type where category is the full Category interface instead of just { id: number; documentId: string }.

INFO

This means you get compile-time errors if you try to access a field on an unpopulated relation:

const result = await strapi.articles.find()

// Type error: Property 'name' does not exist
result[0].category.name 

Payload Types

For advanced use cases, you can use the generated payload types directly to describe the shape of a response with specific populate options:

import type { ArticleGetPayload } from '@/strapi'

type ArticleWithCategory = ArticleGetPayload<{
    populate: {
        category: true
    }
}>

// Use it as a function parameter type
function renderArticle(article: ArticleWithCategory) {
    console.log(article.title)
    console.log(article.category.name) // fully typed
}

This is especially useful when you need to pass fetched data between functions and want to preserve the populated type information.

Use as const when extracting populate to a variable

If you define your populate object outside the method call, you must use as const. Without it, TypeScript widens true to boolean and GetPayload cannot infer the populated fields:

// ❌ Type inference broken — `true` widens to `boolean`
const populate = { category: true, tags: true }
type Result = ArticleGetPayload<{ populate: typeof populate }>
// Result has no populated fields

// ✅ Correct — `as const` preserves literal types
const populate = { category: true, tags: true } as const
type Result = ArticleGetPayload<{ populate: typeof populate }>
// Result includes full Category and Tag[] fields

This also applies when passing populate to client methods via a variable:

const POPULATE = { category: true, author: true } as const

// Type inference works correctly
const result = await strapi.articles.find({ populate: POPULATE })
result[0].category.name // ✅ fully typed

When you pass the object inline, as const is not needed — TypeScript infers literal types automatically.

Populating Media

Media fields work the same way:

const result = await strapi.articles.find({
    populate: {
        coverImage: true,
    },
})

// result[0].coverImage is:
// {
//   id: number
//   name: string
//   url: string
//   width: number | null
//   height: number | null
//   formats: Record<string, any> | null
//   ...
// } | null

Populating Components

Components that are part of a content type can also be populated:

const result = await strapi.articles.find({
    populate: {
        seo: true, // component field
    },
})

// result[0].seo is the full component type
// { metaTitle: string, metaDescription: string, ... }

TIP

Populate only what you need. Each populated relation adds to the response size and query time. The type system helps you here — you only get typed access to fields you explicitly populate.