diff --git a/src/build/open-api/types.ts b/src/build/open-api/types.ts
index d9311e252f7015..20d07a6947d26a 100644
--- a/src/build/open-api/types.ts
+++ b/src/build/open-api/types.ts
@@ -17,6 +17,7 @@ export type Parameter = {
     type: string;
     items?: {[key: string]: unknown};
   };
+  'x-sentry-experimental'?: boolean;
 };
 
 type Markdown = {
diff --git a/src/build/resolveOpenAPI.spec.ts b/src/build/resolveOpenAPI.spec.ts
new file mode 100644
index 00000000000000..62aef56e2acc3c
--- /dev/null
+++ b/src/build/resolveOpenAPI.spec.ts
@@ -0,0 +1,46 @@
+import {describe, expect, test} from 'vitest';
+
+import {toDocumentedParameter} from './resolveOpenAPI';
+
+const EXPERIMENTAL_NOTICE =
+  '**Experimental:** This parameter is under active development and may change.\n\n';
+
+describe('toDocumentedParameter', () => {
+  test('marks a parameter experimental and keeps the notice in the description', () => {
+    const description = `${EXPERIMENTAL_NOTICE}Optional fields to expand. Pass \`context\` to include attribute metadata.`;
+    const parameter = toDocumentedParameter({
+      name: 'expand',
+      description,
+      required: false,
+      'x-sentry-experimental': true,
+    });
+
+    expect(parameter.experimental).toBe(true);
+    expect(parameter.description).toBe(description);
+  });
+
+  test('keeps the description when the extension is set without a notice', () => {
+    const parameter = toDocumentedParameter({
+      name: 'expand',
+      description: 'Optional fields to expand.',
+      required: false,
+      'x-sentry-experimental': true,
+    });
+
+    expect(parameter.experimental).toBe(true);
+    expect(parameter.description).toBe('Optional fields to expand.');
+  });
+
+  test('leaves stable parameters unchanged', () => {
+    const parameter = toDocumentedParameter({
+      name: 'project',
+      description: '**Experimental:** not really, this is just text.',
+      required: true,
+    });
+
+    expect(parameter.experimental).toBe(false);
+    expect(parameter.description).toBe(
+      '**Experimental:** not really, this is just text.'
+    );
+  });
+});
diff --git a/src/build/resolveOpenAPI.ts b/src/build/resolveOpenAPI.ts
index 12588201e435ba..86aafb07c8ff09 100644
--- a/src/build/resolveOpenAPI.ts
+++ b/src/build/resolveOpenAPI.ts
@@ -2,7 +2,7 @@
 
 import {promises as fs} from 'fs';
 
-import {DeRefedOpenAPI} from './open-api/types';
+import {DeRefedOpenAPI, Parameter} from './open-api/types';
 
 // SENTRY_API_SCHEMA_SHA is used in the sentry-docs GHA workflow in getsentry/sentry-api-schema.
 // DO NOT change variable name unless you change it in the sentry-docs GHA workflow in getsentry/sentry-api-schema.
@@ -31,13 +31,16 @@ async function resolveOpenAPI(): Promise<DeRefedOpenAPI> {
 
 export type APIParameter = {
   description: string;
+  experimental: boolean;
   name: string;
   required: boolean;
   schema: {
     type: string;
+    enum?: string[];
     format?: string;
     items?: {
       type: string;
+      enum?: string[];
     };
   };
 };
@@ -99,10 +102,27 @@ function slugify(s: string): string {
 const DEPRECATED_PREFIX_REGEX = /^\(DEPRECATED\)\s*/;
 
 // Sentry prepends this notice to the description of every experimental operation, so
-// that consumers with no badge of their own still warn the reader. We render a badge,
-// so strip it rather than saying the same thing twice.
+// that consumers with no badge of their own still warn the reader. We render a badge
+// and the same sentence beside it, so strip the prefix rather than saying it twice.
+// Parameter notices stay in the description: the parameter badge does not repeat them.
 const EXPERIMENTAL_NOTICE_REGEX = /^\*\*Experimental:\*\*[^\n]*\n+/;
 
+type ExperimentalExtension = {
+  description?: string;
+  'x-sentry-experimental'?: boolean;
+};
+
+// `extensions={"x-sentry-experimental": True}` on an OpenAPI parameter or body
+// property lands as a sibling vendor extension.
+export function toDocumentedParameter<T extends ExperimentalExtension>(
+  param: T
+): T & {experimental: boolean} {
+  return {
+    ...param,
+    experimental: param['x-sentry-experimental'] === true,
+  };
+}
+
 function isDeprecatedOperationId(operationId: string | undefined): boolean {
   return operationId ? DEPRECATED_PREFIX_REGEX.test(operationId) : false;
 }
@@ -164,12 +184,8 @@ async function apiCategoriesUncached(): Promise<APICategory[]> {
           descriptionMarkdown: isExperimental
             ? apiData.description?.replace(EXPERIMENTAL_NOTICE_REGEX, '')
             : apiData.description,
-          pathParameters: (apiData.parameters || []).filter(
-            p => p.in === 'path'
-          ) as APIParameter[],
-          queryParameters: (apiData.parameters || []).filter(
-            p => p.in === 'query'
-          ) as APIParameter[],
+          pathParameters: documentedParameters(apiData.parameters, 'path'),
+          queryParameters: documentedParameters(apiData.parameters, 'query'),
           requestBodyContent: {
             example:
               apiData.requestBody?.content &&
@@ -208,6 +224,25 @@ async function apiCategoriesUncached(): Promise<APICategory[]> {
   return categories;
 }
 
+function documentedParameters(
+  parameters: Parameter[] | undefined,
+  location: 'path' | 'query'
+): APIParameter[] {
+  return (parameters || [])
+    .filter(param => param.in === location)
+    .map(param => {
+      const documented = toDocumentedParameter(param);
+      return {
+        name: documented.name,
+        description: documented.description,
+        required: documented.required,
+        experimental: documented.experimental,
+        // OpenAPI item schemas are an open record; the page only reads type and enum.
+        schema: documented.schema as APIParameter['schema'],
+      };
+    });
+}
+
 function getBodyParameters(apiData: APIData): APIParameter[] {
   const content = apiData.requestBody?.content;
   const contentType = content && Object.values(content)[0];
@@ -218,16 +253,19 @@ function getBodyParameters(apiData: APIData): APIParameter[] {
 
   const required: string[] = contentType?.schema?.required || [];
 
-  return Object.entries(properties).map(([name, props]: [string, any]) => ({
-    name,
-    description: props.description,
-    required: required.includes(name),
-    schema: {
-      type: props.type,
-      format: '',
-      items: props.items,
-    },
-  }));
+  return Object.entries(properties).map(([name, props]: [string, any]) =>
+    toDocumentedParameter({
+      name,
+      description: props.description,
+      required: required.includes(name),
+      'x-sentry-experimental': props['x-sentry-experimental'],
+      schema: {
+        type: props.type,
+        format: '',
+        items: props.items,
+      },
+    })
+  );
 }
 
 function getBodyContentType(apiData: APIData): string | undefined {
diff --git a/src/components/apiPage/index.tsx b/src/components/apiPage/index.tsx
index 3599b95e160f39..c5db2cf2f614db 100644
--- a/src/components/apiPage/index.tsx
+++ b/src/components/apiPage/index.tsx
@@ -2,7 +2,7 @@ import './styles.scss';
 
 import {bundleMDX} from 'mdx-bundler';
 import {Fragment, ReactElement, useMemo} from 'react';
-import {type API} from 'sentry-docs/build/resolveOpenAPI';
+import {type API, type APIParameter} from 'sentry-docs/build/resolveOpenAPI';
 import {getMDXComponent} from 'sentry-docs/getMDXComponent';
 import {mdxComponents} from 'sentry-docs/mdxComponents';
 import remarkCodeTabs from 'sentry-docs/remark-code-tabs';
@@ -12,7 +12,7 @@ import {ApiExamples} from '../apiExamples/apiExamples';
 import {DocPage} from '../docPage';
 import {SmartLink} from '../smartLink';
 
-function Params({params}) {
+function Params({params}: {params: APIParameter[]}) {
   return (
     <dl className="api-params">
       {params.map(param => {
@@ -27,6 +27,14 @@ function Params({params}) {
                     {param.schema.items && `(${param.schema.items.type})`})
                   </em>
                 )}
+                {param.experimental && (
+                  <span
+                    className="ml-2 align-middle text-xs font-medium px-2 py-0.5 rounded bg-yellow-100 text-yellow-800 dark:bg-yellow-900 dark:text-yellow-200"
+                    title="This parameter is under active development and may change."
+                  >
+                    Experimental
+                  </span>
+                )}
               </div>
               {!!param.required && <div className="required">REQUIRED</div>}
             </dt>