---
layout: default
title: Attributes
parent: Deriving JsonSchema
nav_order: 1
---

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# Attributes

You can add attributes to your types to customize Schemars's derived `JsonSchema` implementation.

Serde also allows setting `#[serde(...)]` attributes which change how types are serialized, and Schemars will generally respect these attributes to ensure that generated schemas will match how the type is serialized by serde_json. `#[serde(...)]` attributes can be overriden using `#[schemars(...)]` attributes, which behave identically (e.g. `#[schemars(rename_all = "camelCase")]`). You may find this useful if you want to change the generated schema without affecting Serde's behaviour, or if you're just not using Serde.

## Table of Contents
1. [Supported Serde Attributes](#supported-serde-attributes)
    1. [`rename`](#rename)
    1. [`rename_all`](#rename_all)
    1. [`tag` / `untagged`](#tag)
    1. [`default`](#default)
    1. [`skip`](#skip)
    1. [`skip_serializing`](#skip_serializing)
    1. [`skip_deserializing`](#skip_deserializing)
    1. [`flatten`](#flatten)
    1. [`with`](#with)
1. [Other Attributes](#other-attributes)
    1. [Doc Comments (`doc`)](#doc)

## Supported Serde Attributes

<div class="indented">

<h3 id="rename">

`#[serde(rename = "name")]` / `#[schemars(rename = "name")]`
</h3>

Set on a struct, enum, field or variant to use the given name in the generated schema instead of the Rust name. When used on a struct or enum, the given name will be used as the title for root schemas, and as the schema identifier for schemas referenced from another schema's `$ref` property.

Serde docs: [container](https://serde.rs/container-attrs.html#rename) / [variant](https://serde.rs/variant-attrs.html#rename) / [field](https://serde.rs/field-attrs.html#rename)

<h3 id="rename_all">

`#[serde(rename_all = "...")]` / `#[schemars(rename_all = "...")]`
</h3>

Set on a struct, enum or variant to rename all fields according to the given case convention (see the Serde docs for details).

Serde docs: [container](https://serde.rs/container-attrs.html#rename_all) / [variant](https://serde.rs/variant-attrs.html#rename_all)

<h3 id="tag">

`#[serde(tag = "type")]` / `#[schemars(tag = "type")]` / `#[serde(untagged)]` / `#[schemars(untagged)]`
</h3>

Set on an enum to generate the schema for the [internally tagged](https://serde.rs/enum-representations.html#internally-tagged) or [untagged](https://serde.rs/enum-representations.html#untagged) representation of this enum. Schemars does not currently support the adjacently tagged representation ([#4](https://github.com/GREsau/schemars/issues/4)).

Serde docs: [`tag`](https://serde.rs/container-attrs.html#tag) / [`untagged`](https://serde.rs/container-attrs.html#untagged)

<h3 id="default">

`#[serde(default)]` / `#[schemars(default)]` / `#[serde(default = "path")]` / `#[schemars(default = "path")]`
</h3>

Set on a struct or field to give fields a default value, which excludes them from the schema's `required` properties. The default will also be set on the field's schema's `default` property, unless it is skipped by a [`#[serde(skip_serializing_if = "..."]`](https://serde.rs/field-attrs.html#skip_serializing_if) attribute on the field. If the field also has a [`#[serde(serialize_with = "..."]`](https://serde.rs/field-attrs.html#serialize_with) property set, then it will be used to serialize the default value.

Serde docs: [container](https://serde.rs/container-attrs.html#default) / [field](https://serde.rs/field-attrs.html#default)

<h3 id="skip">

`#[serde(skip)]` / `#[schemars(skip)]`
</h3>

Set on a variant or field to prevent it from appearing in any generated schema.

Serde docs: [variant](https://serde.rs/variant-attrs.html#skip) / [field](https://serde.rs/field-attrs.html#skip)

<h3 id="skip_serializing">

`#[serde(skip_serializing)]` / `#[schemars(skip_serializing)]`
</h3>

Set on a field of a (non-tuple) struct to set the `writeOnly` property on that field's schema. Serde also allows this attribute on variants or tuple struct fields, but this will have no effect on generated schemas.

Serde docs: [field](https://serde.rs/field-attrs.html#skip_deserializing)

<h3 id="skip_deserializing">

`#[serde(skip_deserializing)]` / `#[schemars(skip_deserializing)]`
</h3>

Set on a variant or field. When set on a field of a (non-tuple) struct, that field's schema will have the `readOnly` property set. When set on a variant or tuple struct field Schemars will treat this the same as a [`skip`](#skip) attribute.

Serde docs: [variant](https://serde.rs/variant-attrs.html#skip_deserializing) / [field](https://serde.rs/field-attrs.html#skip_deserializing)

<h3 id="flatten">

`#[serde(flatten)]` / `#[schemars(flatten)]`
</h3>

<h3 id="with">

`#[serde(with = "module")]` / `#[schemars(with = "module")]`
</h3>

</div>

## Other Attributes

<h3 id="doc">

Doc Comments (`#[doc = "..."]`)
</h3>

TODO!