Should there be a way to set the default to currentSchema.parse({})?

[mrft]

Let me try to explain what behavior I'd like to implement

Consider this schema:

const schema = z.strictObject({
  constants: z.object({
    a: z.string().default("defaultA"),
    b: z.number().default(0),
  }),
});

This would parse { constants: { } } as { constants: { a: "defaultA", b: 0 } }.

But if constants is empty, you might as well leave out constants entirely. Neveretheless, parsing {} will yield an error (as is expected), but if none of the properties on the lower level are defined, requiring the user to pass an empty object does not make a lot of sense.

What you don't want to do is repeating all the defaults, while setting a default on the constants object.

Repeating yourself can be avoided if you define your constantsSchema first:

const constantsSchema = z.object({
  a: z.string().default("defaultA"),
  b: z.number().default(0),
});

const schema = z.strictObject({
  constants: constantsSchema.default(constantsSchema.parse({})),
});

which to me lacks readability.

So I created a helper function

function zOptionalWithDefaults<T extends z.ZodRawShape>(schema: z.ZodObject<T>) {
  return schema.default(schema.parse({}));
}

that can be used like this:

const schema = z.strictObject({
  constants: zOptionalWithDefaults(z.object({
    a: z.string().default("defaultA"),
    b: z.number().default(0),
  })),
});

but since method chaining is how zod works, I was hoping that maybe in a future version, something like this could be possible (there is probably a way better name):

const schema = z.strictObject({
  constants: z.object({
    a: z.string().default("defaultA"),
    b: z.number().default(0),
  }).defaultSelf(),
});

[inkeep-ai-assistant[bot]]

Zod (v4) does not provide a built-in method like .defaultSelf() to automatically set a default value of an object schema to its own .parse({}) result. The approach you described—using a helper function to parse the schema with an empty object and then setting that as the default—is currently the most direct way to achieve this pattern(1).

For example:

const constantsSchema = z.object({
  a: z.string().default("defaultA"),
  b: z.number().default(0),
});

const schema = z.strictObject({
  constants: constantsSchema.default(constantsSchema.parse({})),
});

This will ensure that if constants is omitted, its default will be an object with all nested defaults applied(1).

There is no native method chaining alternative (such as .defaultSelf()) in Zod (v4) to perform this automatically. You must explicitly provide the default value, typically by parsing the inner schema as you’ve shown(1).

📚 Sources:

1. Defining schemas

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Have another question? Just tag @inkeep.

[mrft]

There is no native method chaining alternative (such as .defaultSelf()) in Zod (v4) to perform this automatically. You must explicitly provide the default value, typically by parsing the inner schema as you’ve shown

The whole point of opening the discussion was to discuss whether it would be a good idea to have a native solution for this.