From fba98794ba0adb98c9d4b6ab563b54b13b8f9cf5 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 9 Feb 2026 14:19:15 +0000
Subject: [PATCH 1/7] Initial plan


From a0a9b958f83764970e5eca03d94028ae500c8849 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 9 Feb 2026 14:23:13 +0000
Subject: [PATCH 2/7] Add ResolvedRequestOptions with narrowed headers type to
 custom-client

Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>
---
 packages/custom-client/src/types.ts | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/packages/custom-client/src/types.ts b/packages/custom-client/src/types.ts
index 8cb353eb81..cac8883e06 100644
--- a/packages/custom-client/src/types.ts
+++ b/packages/custom-client/src/types.ts
@@ -53,6 +53,18 @@ export interface RequestOptions<
   url: Url;
 }
 
+export interface ResolvedRequestOptions<
+  ThrowOnError extends boolean = boolean,
+  Url extends string = string,
+> extends RequestOptions<ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
+  serializedBody?: string;
+}
+
 export type RequestResult<
   TData = unknown,
   TError = unknown,
@@ -96,7 +108,7 @@ type BuildUrlFn = <
 ) => string;
 
 export type Client = CoreClient<RequestFn, Config, MethodFn, BuildUrlFn> & {
-  interceptors: Middleware<Request, Response, unknown, RequestOptions>;
+  interceptors: Middleware<Request, Response, unknown, ResolvedRequestOptions>;
 };
 
 /**

From 6087f9a7887b1f23066ed1f43b1c0dd4fc55f7f4 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 9 Feb 2026 14:24:57 +0000
Subject: [PATCH 3/7] Add headers: Headers to ResolvedRequestOptions in all
 client bundles

Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>
---
 packages/custom-client/src/client.ts                         | 4 ++--
 .../src/plugins/@hey-api/client-angular/bundle/types.ts      | 5 +++++
 .../src/plugins/@hey-api/client-fetch/bundle/types.ts        | 5 +++++
 .../src/plugins/@hey-api/client-ky/bundle/types.ts           | 5 +++++
 .../src/plugins/@hey-api/client-next/bundle/types.ts         | 5 +++++
 .../src/plugins/@hey-api/client-ofetch/bundle/types.ts       | 5 +++++
 6 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/packages/custom-client/src/client.ts b/packages/custom-client/src/client.ts
index d0f5b2e49c..ce41702387 100644
--- a/packages/custom-client/src/client.ts
+++ b/packages/custom-client/src/client.ts
@@ -1,4 +1,4 @@
-import type { Client, Config, RequestOptions } from './types';
+import type { Client, Config, RequestOptions, ResolvedRequestOptions } from './types';
 import {
   buildUrl,
   createConfig,
@@ -24,7 +24,7 @@ export const createClient = (config: Config = {}): Client => {
     return getConfig();
   };
 
-  const interceptors = createInterceptors<Request, Response, unknown, RequestOptions>();
+  const interceptors = createInterceptors<Request, Response, unknown, ResolvedRequestOptions>();
 
   // @ts-expect-error
   const request: Client['request'] = async (options) => {
diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-angular/bundle/types.ts b/packages/openapi-ts/src/plugins/@hey-api/client-angular/bundle/types.ts
index 54a9dfe628..e9905be39a 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-angular/bundle/types.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-angular/bundle/types.ts
@@ -97,6 +97,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-fetch/bundle/types.ts b/packages/openapi-ts/src/plugins/@hey-api/client-fetch/bundle/types.ts
index f2789cbc52..4fd803261c 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-fetch/bundle/types.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-fetch/bundle/types.ts
@@ -90,6 +90,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-ky/bundle/types.ts b/packages/openapi-ts/src/plugins/@hey-api/client-ky/bundle/types.ts
index 136269181f..f63d63bbe6 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-ky/bundle/types.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-ky/bundle/types.ts
@@ -122,6 +122,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/types.ts b/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/types.ts
index 2a8de33eca..ee3856ff62 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/types.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/types.ts
@@ -72,6 +72,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-ofetch/bundle/types.ts b/packages/openapi-ts/src/plugins/@hey-api/client-ofetch/bundle/types.ts
index 38af322af3..30beb390aa 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-ofetch/bundle/types.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-ofetch/bundle/types.ts
@@ -154,6 +154,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 

From a16e39ed5c47f7f3d708ec0126086e3dcf962ee2 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 9 Feb 2026 14:34:56 +0000
Subject: [PATCH 4/7] Fix SSE request interceptor headers type in client-next
 and cleanup unused imports

Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>
---
 packages/custom-client/src/client.ts                        | 2 +-
 .../src/plugins/@hey-api/client-next/bundle/client.ts       | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/packages/custom-client/src/client.ts b/packages/custom-client/src/client.ts
index ce41702387..4d83b118f5 100644
--- a/packages/custom-client/src/client.ts
+++ b/packages/custom-client/src/client.ts
@@ -1,4 +1,4 @@
-import type { Client, Config, RequestOptions, ResolvedRequestOptions } from './types';
+import type { Client, Config, ResolvedRequestOptions } from './types';
 import {
   buildUrl,
   createConfig,
diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts b/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts
index 4e76ab03de..783abab7e7 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts
@@ -65,7 +65,6 @@ export const createClient = (config: Config = {}): Client => {
 
   // @ts-expect-error
   const request: Client['request'] = async (options) => {
-    // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
 
     for (const fn of interceptors.request.fns) {
@@ -207,12 +206,15 @@ export const createClient = (config: Config = {}): Client => {
         let request = new Request(url, init);
         const requestInit = {
           ...init,
+          // Convert init.headers (HeadersInit) back to Headers for the interceptor
+          headers: new Headers(init.headers),
           method: init.method as Config['method'],
           url,
         };
         for (const fn of interceptors.request.fns) {
           if (fn) {
-            await fn(requestInit);
+            // Type assertion: requestInit has headers: Headers, matching ResolvedRequestOptions
+            await fn(requestInit as ResolvedRequestOptions);
             request = new Request(requestInit.url, requestInit);
           }
         }

From 85bd7f14be97e2bde3b69e653d9e079c8ac060c5 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 9 Feb 2026 14:37:08 +0000
Subject: [PATCH 5/7] Improve type safety of SSE requestInit by explicitly
 typing required properties

Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>
---
 .../src/plugins/@hey-api/client-next/bundle/client.ts       | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts b/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts
index 783abab7e7..efc99fe7a4 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts
@@ -204,7 +204,9 @@ export const createClient = (config: Config = {}): Client => {
       method,
       onRequest: async (url, init) => {
         let request = new Request(url, init);
-        const requestInit = {
+        // Create options for interceptor with properly typed headers
+        const requestInit: Pick<ResolvedRequestOptions, 'headers' | 'method' | 'url'> &
+          RequestInit = {
           ...init,
           // Convert init.headers (HeadersInit) back to Headers for the interceptor
           headers: new Headers(init.headers),
@@ -213,7 +215,7 @@ export const createClient = (config: Config = {}): Client => {
         };
         for (const fn of interceptors.request.fns) {
           if (fn) {
-            // Type assertion: requestInit has headers: Headers, matching ResolvedRequestOptions
+            // requestInit structurally matches ResolvedRequestOptions for the interceptor
             await fn(requestInit as ResolvedRequestOptions);
             request = new Request(requestInit.url, requestInit);
           }

From f22080e113a58568fad3c9807f80afbe27d8f1f5 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 9 Feb 2026 14:39:05 +0000
Subject: [PATCH 6/7] Simplify type annotation in SSE onRequest per code review
 feedback

Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>
---
 .../src/plugins/@hey-api/client-next/bundle/client.ts    | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts b/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts
index efc99fe7a4..117c20f04e 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-next/bundle/client.ts
@@ -204,18 +204,17 @@ export const createClient = (config: Config = {}): Client => {
       method,
       onRequest: async (url, init) => {
         let request = new Request(url, init);
-        // Create options for interceptor with properly typed headers
-        const requestInit: Pick<ResolvedRequestOptions, 'headers' | 'method' | 'url'> &
-          RequestInit = {
+        // Create options for interceptor - convert headers to Headers instance
+        // to match ResolvedRequestOptions type
+        const requestInit = {
           ...init,
-          // Convert init.headers (HeadersInit) back to Headers for the interceptor
           headers: new Headers(init.headers),
           method: init.method as Config['method'],
           url,
         };
         for (const fn of interceptors.request.fns) {
           if (fn) {
-            // requestInit structurally matches ResolvedRequestOptions for the interceptor
+            // Cast to ResolvedRequestOptions: structurally matches with headers: Headers
             await fn(requestInit as ResolvedRequestOptions);
             request = new Request(requestInit.url, requestInit);
           }

From f292aa7a23f788bc2821a7365d4879ba156c7143 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 10 Feb 2026 06:51:03 +0000
Subject: [PATCH 7/7] Regenerate examples to sync with ResolvedRequestOptions
 type changes

Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>
---
 .../src/client/client/types.gen.ts                         | 5 +++++
 examples/openapi-ts-angular/src/client/client/types.gen.ts | 5 +++++
 examples/openapi-ts-fastify/src/client/client/types.gen.ts | 5 +++++
 examples/openapi-ts-fetch/src/client/client/types.gen.ts   | 5 +++++
 examples/openapi-ts-ky/src/client/client/types.gen.ts      | 5 +++++
 examples/openapi-ts-next/src/client/client/client.gen.ts   | 7 +++++--
 examples/openapi-ts-next/src/client/client/types.gen.ts    | 5 +++++
 examples/openapi-ts-ofetch/src/client/client/types.gen.ts  | 5 +++++
 examples/openapi-ts-openai/src/client/client/types.gen.ts  | 5 +++++
 .../openapi-ts-pinia-colada/src/client/client/types.gen.ts | 5 +++++
 .../src/client/client/types.gen.ts                         | 5 +++++
 .../src/client/client/types.gen.ts                         | 5 +++++
 .../src/client/client/types.gen.ts                         | 5 +++++
 .../src/client/client/types.gen.ts                         | 5 +++++
 14 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/examples/openapi-ts-angular-common/src/client/client/types.gen.ts b/examples/openapi-ts-angular-common/src/client/client/types.gen.ts
index 18bc780efb..76668ecc1d 100644
--- a/examples/openapi-ts-angular-common/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-angular-common/src/client/client/types.gen.ts
@@ -96,6 +96,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-angular/src/client/client/types.gen.ts b/examples/openapi-ts-angular/src/client/client/types.gen.ts
index 18bc780efb..76668ecc1d 100644
--- a/examples/openapi-ts-angular/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-angular/src/client/client/types.gen.ts
@@ -96,6 +96,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-fastify/src/client/client/types.gen.ts b/examples/openapi-ts-fastify/src/client/client/types.gen.ts
index 61a8dffa32..79041f6378 100644
--- a/examples/openapi-ts-fastify/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-fastify/src/client/client/types.gen.ts
@@ -89,6 +89,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-fetch/src/client/client/types.gen.ts b/examples/openapi-ts-fetch/src/client/client/types.gen.ts
index 61a8dffa32..79041f6378 100644
--- a/examples/openapi-ts-fetch/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-fetch/src/client/client/types.gen.ts
@@ -89,6 +89,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-ky/src/client/client/types.gen.ts b/examples/openapi-ts-ky/src/client/client/types.gen.ts
index 5b83a0ab00..4d66bba196 100644
--- a/examples/openapi-ts-ky/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-ky/src/client/client/types.gen.ts
@@ -121,6 +121,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-next/src/client/client/client.gen.ts b/examples/openapi-ts-next/src/client/client/client.gen.ts
index 45519b96b9..67f64c401e 100644
--- a/examples/openapi-ts-next/src/client/client/client.gen.ts
+++ b/examples/openapi-ts-next/src/client/client/client.gen.ts
@@ -67,7 +67,6 @@ export const createClient = (config: Config = {}): Client => {
 
   // @ts-expect-error
   const request: Client['request'] = async (options) => {
-    // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
 
     for (const fn of interceptors.request.fns) {
@@ -207,14 +206,18 @@ export const createClient = (config: Config = {}): Client => {
       method,
       onRequest: async (url, init) => {
         let request = new Request(url, init);
+        // Create options for interceptor - convert headers to Headers instance
+        // to match ResolvedRequestOptions type
         const requestInit = {
           ...init,
+          headers: new Headers(init.headers),
           method: init.method as Config['method'],
           url,
         };
         for (const fn of interceptors.request.fns) {
           if (fn) {
-            await fn(requestInit);
+            // Cast to ResolvedRequestOptions: structurally matches with headers: Headers
+            await fn(requestInit as ResolvedRequestOptions);
             request = new Request(requestInit.url, requestInit);
           }
         }
diff --git a/examples/openapi-ts-next/src/client/client/types.gen.ts b/examples/openapi-ts-next/src/client/client/types.gen.ts
index 6dcf29dca3..5c510c6459 100644
--- a/examples/openapi-ts-next/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-next/src/client/client/types.gen.ts
@@ -71,6 +71,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-ofetch/src/client/client/types.gen.ts b/examples/openapi-ts-ofetch/src/client/client/types.gen.ts
index a193bd1d75..6020d0a9d1 100644
--- a/examples/openapi-ts-ofetch/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-ofetch/src/client/client/types.gen.ts
@@ -153,6 +153,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-openai/src/client/client/types.gen.ts b/examples/openapi-ts-openai/src/client/client/types.gen.ts
index cb6d0d54a0..44b69e041f 100644
--- a/examples/openapi-ts-openai/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-openai/src/client/client/types.gen.ts
@@ -92,6 +92,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-pinia-colada/src/client/client/types.gen.ts b/examples/openapi-ts-pinia-colada/src/client/client/types.gen.ts
index 61a8dffa32..79041f6378 100644
--- a/examples/openapi-ts-pinia-colada/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-pinia-colada/src/client/client/types.gen.ts
@@ -89,6 +89,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-tanstack-angular-query-experimental/src/client/client/types.gen.ts b/examples/openapi-ts-tanstack-angular-query-experimental/src/client/client/types.gen.ts
index 18bc780efb..76668ecc1d 100644
--- a/examples/openapi-ts-tanstack-angular-query-experimental/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-tanstack-angular-query-experimental/src/client/client/types.gen.ts
@@ -96,6 +96,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-tanstack-react-query/src/client/client/types.gen.ts b/examples/openapi-ts-tanstack-react-query/src/client/client/types.gen.ts
index 61a8dffa32..79041f6378 100644
--- a/examples/openapi-ts-tanstack-react-query/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-tanstack-react-query/src/client/client/types.gen.ts
@@ -89,6 +89,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-tanstack-svelte-query/src/client/client/types.gen.ts b/examples/openapi-ts-tanstack-svelte-query/src/client/client/types.gen.ts
index 61a8dffa32..79041f6378 100644
--- a/examples/openapi-ts-tanstack-svelte-query/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-tanstack-svelte-query/src/client/client/types.gen.ts
@@ -89,6 +89,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }
 
diff --git a/examples/openapi-ts-tanstack-vue-query/src/client/client/types.gen.ts b/examples/openapi-ts-tanstack-vue-query/src/client/client/types.gen.ts
index 61a8dffa32..79041f6378 100644
--- a/examples/openapi-ts-tanstack-vue-query/src/client/client/types.gen.ts
+++ b/examples/openapi-ts-tanstack-vue-query/src/client/client/types.gen.ts
@@ -89,6 +89,11 @@ export interface ResolvedRequestOptions<
   ThrowOnError extends boolean = boolean,
   Url extends string = string,
 > extends RequestOptions<unknown, TResponseStyle, ThrowOnError, Url> {
+  /**
+   * Headers object after merging config and request headers.
+   * Always a Headers instance in request interceptors.
+   */
+  headers: Headers;
   serializedBody?: string;
 }