diff --git a/.changeset/slimy-knives-decide.md b/.changeset/slimy-knives-decide.md
new file mode 100644
index 000000000..9149be0d7
--- /dev/null
+++ b/.changeset/slimy-knives-decide.md
@@ -0,0 +1,5 @@
+---
+'@shopify/ui-extensions': minor
+---
+
+Add discount function settings api
diff --git a/packages/ui-extensions/src/surfaces/admin/api.ts b/packages/ui-extensions/src/surfaces/admin/api.ts
index 995aeb523..0fca4d204 100644
--- a/packages/ui-extensions/src/surfaces/admin/api.ts
+++ b/packages/ui-extensions/src/surfaces/admin/api.ts
@@ -9,3 +9,4 @@ export type {ProductDetailsConfigurationApi} from './api/product-configuration/p
 export type {ProductVariantDetailsConfigurationApi} from './api/product-configuration/product-variant-details-configuration';
 export type {OrderRoutingRuleApi} from './api/order-routing-rule/order-routing-rule';
 export type {ValidationSettingsApi} from './api/checkout-rules/validation-settings';
+export type {DiscountFunctionSettingsApi} from './api/discount-function-settings/discount-function-settings';
diff --git a/packages/ui-extensions/src/surfaces/admin/api/checkout-rules/launch-options.ts b/packages/ui-extensions/src/surfaces/admin/api/checkout-rules/launch-options.ts
index 13ceb98fb..700f72a92 100644
--- a/packages/ui-extensions/src/surfaces/admin/api/checkout-rules/launch-options.ts
+++ b/packages/ui-extensions/src/surfaces/admin/api/checkout-rules/launch-options.ts
@@ -6,7 +6,6 @@ interface Metafield {
   value: string;
   type: string;
 }
-
 interface Validation {
   /**
    * the validation's gid when active in a shop
diff --git a/packages/ui-extensions/src/surfaces/admin/api/checkout-rules/metafields.ts b/packages/ui-extensions/src/surfaces/admin/api/checkout-rules/metafields.ts
index d96e6693c..a93e9be79 100644
--- a/packages/ui-extensions/src/surfaces/admin/api/checkout-rules/metafields.ts
+++ b/packages/ui-extensions/src/surfaces/admin/api/checkout-rules/metafields.ts
@@ -1,49 +1,4 @@
-const supportedDefinitionTypes = [
-  'boolean',
-  'collection_reference',
-  'color',
-  'date',
-  'date_time',
-  'dimension',
-  'file_reference',
-  'json',
-  'metaobject_reference',
-  'mixed_reference',
-  'money',
-  'multi_line_text_field',
-  'number_decimal',
-  'number_integer',
-  'page_reference',
-  'product_reference',
-  'rating',
-  'rich_text_field',
-  'single_line_text_field',
-  'product_taxonomy_value_reference',
-  'url',
-  'variant_reference',
-  'volume',
-  'weight',
-  'list.collection_reference',
-  'list.color',
-  'list.date',
-  'list.date_time',
-  'list.dimension',
-  'list.file_reference',
-  'list.metaobject_reference',
-  'list.mixed_reference',
-  'list.number_decimal',
-  'list.number_integer',
-  'list.page_reference',
-  'list.product_reference',
-  'list.rating',
-  'list.single_line_text_field',
-  'list.url',
-  'list.variant_reference',
-  'list.volume',
-  'list.weight',
-] as const;
-
-export type SupportedDefinitionType = (typeof supportedDefinitionTypes)[number];
+import {SupportedDefinitionType} from '../shared';
 
 interface MetafieldUpdateChange {
   type: 'updateMetafield';
diff --git a/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/discount-function-settings.doc.ts b/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/discount-function-settings.doc.ts
new file mode 100644
index 000000000..4c2c8ec44
--- /dev/null
+++ b/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/discount-function-settings.doc.ts
@@ -0,0 +1,27 @@
+import {ReferenceEntityTemplateSchema} from '@shopify/generate-docs';
+
+const data: ReferenceEntityTemplateSchema = {
+  name: 'Discount Function Settings API',
+  description:
+    'This API is available to Discount Function Settings extensions. Refer to the [tutorial](/docs/apps/build/discounts/build-ui-extension) for more information. Note that the [`FunctionSettings`](/docs/api/admin-extensions/components/forms/functionsettings) component is required to build Discount Function Settings extensions.',
+  isVisualComponent: false,
+  type: 'API',
+  definitions: [
+    {
+      title: 'applyMetafieldChange',
+      description: 'Applies a change to the discount function settings.',
+      type: 'ApplyMetafieldChange',
+    },
+    {
+      title: 'data',
+      description:
+        'The object exposed to the extension that contains the discount function settings.',
+      type: 'DiscountFunctionSettingsData',
+    },
+  ],
+  category: 'API',
+  subCategory: 'Target APIs',
+  related: [],
+};
+
+export default data;
diff --git a/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/discount-function-settings.ts b/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/discount-function-settings.ts
new file mode 100644
index 000000000..0df7f6e79
--- /dev/null
+++ b/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/discount-function-settings.ts
@@ -0,0 +1,15 @@
+import type {StandardApi} from '../standard/standard';
+import type {ExtensionTarget as AnyExtensionTarget} from '../../extension-targets';
+
+import {ApplyMetafieldChange} from './metafields';
+import {DiscountFunctionSettingsData} from './launch-options';
+
+export interface DiscountFunctionSettingsApi<
+  ExtensionTarget extends AnyExtensionTarget,
+> extends StandardApi<ExtensionTarget> {
+  /**
+   * Applies a change to the discount function settings.
+   */
+  applyMetafieldChange: ApplyMetafieldChange;
+  data: DiscountFunctionSettingsData;
+}
diff --git a/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/launch-options.ts b/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/launch-options.ts
new file mode 100644
index 000000000..0a2806e2a
--- /dev/null
+++ b/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/launch-options.ts
@@ -0,0 +1,29 @@
+interface Metafield {
+  description?: string;
+  id: string;
+  namespace: string;
+  key: string;
+  value: string;
+  type: string;
+}
+
+export enum DiscountClass {
+  Product = 'PRODUCT',
+  Order = 'ORDER',
+  Shipping = 'SHIPPING',
+}
+
+interface Discount {
+  /**
+   * the discount's gid
+   */
+  id: string;
+}
+
+/**
+ * The object that exposes the validation with its settings.
+ */
+export interface DiscountFunctionSettingsData {
+  id: Discount;
+  metafields: Metafield[];
+}
diff --git a/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/metafields.ts b/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/metafields.ts
new file mode 100644
index 000000000..a93e9be79
--- /dev/null
+++ b/packages/ui-extensions/src/surfaces/admin/api/discount-function-settings/metafields.ts
@@ -0,0 +1,31 @@
+import {SupportedDefinitionType} from '../shared';
+
+interface MetafieldUpdateChange {
+  type: 'updateMetafield';
+  key: string;
+  namespace?: string;
+  value: string | number;
+  valueType?: SupportedDefinitionType;
+}
+
+interface MetafieldRemoveChange {
+  type: 'removeMetafield';
+  key: string;
+  namespace: string;
+}
+
+type MetafieldChange = MetafieldUpdateChange | MetafieldRemoveChange;
+interface MetafieldChangeResultError {
+  type: 'error';
+  message: string;
+}
+interface MetafieldChangeSuccess {
+  type: 'success';
+}
+type MetafieldChangeResult =
+  | MetafieldChangeSuccess
+  | MetafieldChangeResultError;
+
+export type ApplyMetafieldChange = (
+  change: MetafieldChange,
+) => Promise<MetafieldChangeResult>;
diff --git a/packages/ui-extensions/src/surfaces/admin/api/shared.ts b/packages/ui-extensions/src/surfaces/admin/api/shared.ts
index 62de98989..b4c1a6d1c 100644
--- a/packages/ui-extensions/src/surfaces/admin/api/shared.ts
+++ b/packages/ui-extensions/src/surfaces/admin/api/shared.ts
@@ -4,3 +4,47 @@ export interface Data {
    */
   selected: {id: string}[];
 }
+
+export type SupportedDefinitionType =
+  | 'boolean'
+  | 'collection_reference'
+  | 'color'
+  | 'date'
+  | 'date_time'
+  | 'dimension'
+  | 'file_reference'
+  | 'json'
+  | 'metaobject_reference'
+  | 'mixed_reference'
+  | 'money'
+  | 'multi_line_text_field'
+  | 'number_decimal'
+  | 'number_integer'
+  | 'page_reference'
+  | 'product_reference'
+  | 'rating'
+  | 'rich_text_field'
+  | 'single_line_text_field'
+  | 'product_taxonomy_value_reference'
+  | 'url'
+  | 'variant_reference'
+  | 'volume'
+  | 'weight'
+  | 'list.collection_reference'
+  | 'list.color'
+  | 'list.date'
+  | 'list.date_time'
+  | 'list.dimension'
+  | 'list.file_reference'
+  | 'list.metaobject_reference'
+  | 'list.mixed_reference'
+  | 'list.number_decimal'
+  | 'list.number_integer'
+  | 'list.page_reference'
+  | 'list.product_reference'
+  | 'list.rating'
+  | 'list.single_line_text_field'
+  | 'list.url'
+  | 'list.variant_reference'
+  | 'list.volume'
+  | 'list.weight';
diff --git a/packages/ui-extensions/src/surfaces/admin/extension-targets.ts b/packages/ui-extensions/src/surfaces/admin/extension-targets.ts
index fc4589851..594144185 100644
--- a/packages/ui-extensions/src/surfaces/admin/extension-targets.ts
+++ b/packages/ui-extensions/src/surfaces/admin/extension-targets.ts
@@ -11,6 +11,7 @@ import type {
   ProductVariantDetailsConfigurationApi,
   OrderRoutingRuleApi,
   ValidationSettingsApi,
+  DiscountFunctionSettingsApi,
 } from './api';
 import {AnyComponentBuilder} from '../../shared';
 import {PurchaseOptionsCardConfigurationApi} from './api/purchase-options-card-action/purchase-options-card-action';
@@ -100,7 +101,7 @@ export interface ExtensionTargets {
    * See the [list of available components](/docs/api/admin-extensions/components).
    */
   'admin.discount-details.function-settings.render': RenderExtension<
-    BlockExtensionApi<'admin.discount-details.function-settings.render'>,
+    DiscountFunctionSettingsApi<'admin.discount-details.function-settings.render'>,
     AllComponents
   >;