From c488be5f1220b3072bed1ead61261dc97775c973 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 14 Nov 2025 02:40:20 +0000
Subject: [PATCH] Update all examples and snapshots with FormData fix

Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>
---
 .../src/client/client/client.gen.ts             | 17 +++++++++++++++--
 .../base-url-false/client/client.gen.ts         | 17 +++++++++++++++--
 .../base-url-number/client/client.gen.ts        | 17 +++++++++++++++--
 .../base-url-strict/client/client.gen.ts        | 17 +++++++++++++++--
 .../base-url-string/client/client.gen.ts        | 17 +++++++++++++++--
 .../clean-false/client/client.gen.ts            | 17 +++++++++++++++--
 .../client-ofetch/default/client/client.gen.ts  | 17 +++++++++++++++--
 .../client/client.gen.ts                        | 17 +++++++++++++++--
 .../sdk-client-optional/client/client.gen.ts    | 17 +++++++++++++++--
 .../sdk-client-required/client/client.gen.ts    | 17 +++++++++++++++--
 .../tsconfig-nodenext-sdk/client/client.gen.ts  | 17 +++++++++++++++--
 .../3.1.x/sse-ofetch/client/client.gen.ts       | 17 +++++++++++++++--
 12 files changed, 180 insertions(+), 24 deletions(-)

diff --git a/examples/openapi-ts-ofetch/src/client/client/client.gen.ts b/examples/openapi-ts-ofetch/src/client/client/client.gen.ts
index e0e3c2a41..66fae47f7 100644
--- a/examples/openapi-ts-ofetch/src/client/client/client.gen.ts
+++ b/examples/openapi-ts-ofetch/src/client/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-false/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-false/client/client.gen.ts
index e0e3c2a41..66fae47f7 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-false/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-false/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-number/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-number/client/client.gen.ts
index e0e3c2a41..66fae47f7 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-number/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-number/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-strict/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-strict/client/client.gen.ts
index e0e3c2a41..66fae47f7 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-strict/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-strict/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-string/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-string/client/client.gen.ts
index e0e3c2a41..66fae47f7 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-string/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/base-url-string/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/clean-false/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/clean-false/client/client.gen.ts
index e0e3c2a41..66fae47f7 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/clean-false/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/clean-false/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/default/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/default/client/client.gen.ts
index e0e3c2a41..66fae47f7 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/default/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/default/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/import-file-extension-ts/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/import-file-extension-ts/client/client.gen.ts
index 952a4d0c2..ebee86e7a 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/import-file-extension-ts/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/import-file-extension-ts/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/sdk-client-optional/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/sdk-client-optional/client/client.gen.ts
index e0e3c2a41..66fae47f7 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/sdk-client-optional/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/sdk-client-optional/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/sdk-client-required/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/sdk-client-required/client/client.gen.ts
index e0e3c2a41..66fae47f7 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/sdk-client-required/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/sdk-client-required/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/tsconfig-nodenext-sdk/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/tsconfig-nodenext-sdk/client/client.gen.ts
index 3e1cf2053..8798e2a0e 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/tsconfig-nodenext-sdk/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-ofetch/tsconfig-nodenext-sdk/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-ofetch/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-ofetch/client/client.gen.ts
index e0e3c2a41..66fae47f7 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-ofetch/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-ofetch/client/client.gen.ts
@@ -125,6 +125,7 @@ export const createClient = (config: Config = {}): Client => {
   const applyRequestInterceptors = async (
     request: Request,
     opts: ResolvedRequestOptions,
+    body: BodyInit | null | undefined,
   ) => {
     for (const fn of interceptors.request.fns) {
       if (fn) {
@@ -138,6 +139,18 @@ export const createClient = (config: Config = {}): Client => {
     // body comes only from getValidRequestBody(options)
     // reflect signal if present
     opts.signal = (request as any).signal as AbortSignal | undefined;
+
+    // When body is FormData, remove Content-Type header to avoid boundary mismatch.
+    // Note: We already delete Content-Type in resolveOptions for FormData, but the
+    // Request constructor (line 175) re-adds it with an auto-generated boundary.
+    // Since we pass the original FormData (not the Request's body) to ofetch, and
+    // ofetch will generate its own boundary, we must remove the Request's Content-Type
+    // to let ofetch set the correct one. Otherwise the boundary in the header won't
+    // match the boundary in the actual multipart body sent by ofetch.
+    if (typeof FormData !== 'undefined' && body instanceof FormData) {
+      opts.headers.delete('Content-Type');
+    }
+
     return request;
   };
 
@@ -176,7 +189,7 @@ export const createClient = (config: Config = {}): Client => {
     };
     let request = new Request(url, requestInit);
 
-    request = await applyRequestInterceptors(request, opts);
+    request = await applyRequestInterceptors(request, opts, networkBody);
     const finalUrl = request.url;
 
     // build ofetch options and perform the request (.raw keeps the Response)
@@ -235,7 +248,7 @@ export const createClient = (config: Config = {}): Client => {
         method,
         onRequest: async (url, init) => {
           let request = new Request(url, init);
-          request = await applyRequestInterceptors(request, opts);
+          request = await applyRequestInterceptors(request, opts, networkBody);
           return request;
         },
         serializedBody: networkBody as BodyInit | null | undefined,
-- 
2.51.2