diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/content-types/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/content-types/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/content-types/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/content-types/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/parameter-explode-false-axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/parameter-explode-false-axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/parameter-explode-false-axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/parameter-explode-false-axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-false/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-false/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-false/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-false/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-number/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-number/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-number/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-number/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-strict/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-strict/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-strict/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-strict/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-string/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-string/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-string/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-string/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/clean-false/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/clean-false/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/clean-false/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/clean-false/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/default/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/default/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/default/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/default/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/import-file-extension-ts/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/import-file-extension-ts/client/client.gen.ts
index f458a0d4b..8bd1d5631 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/import-file-extension-ts/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/import-file-extension-ts/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen.ts';
 import type { HttpMethod } from '../core/types.gen.ts';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-optional/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-optional/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-optional/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-optional/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-required/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-required/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-required/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-required/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/tsconfig-nodenext-sdk/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/tsconfig-nodenext-sdk/client/client.gen.ts
index 35f02190c..f0000c3c1 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/tsconfig-nodenext-sdk/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/tsconfig-nodenext-sdk/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen.js';
 import type { HttpMethod } from '../core/types.gen.js';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/content-types/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/content-types/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/content-types/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/content-types/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/parameter-explode-false-axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/parameter-explode-false-axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/parameter-explode-false-axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/parameter-explode-false-axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/react-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-axios/client/client.gen.ts
index aea2484c7..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-axios/client/client.gen.ts
@@ -1,7 +1,7 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../core/serverSentEvents.gen';
 import type { HttpMethod } from '../core/types.gen';
@@ -69,6 +69,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -86,7 +87,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -105,22 +105,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };
 
diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-axios/__tests__/client.test.ts b/packages/openapi-ts/src/plugins/@hey-api/client-axios/__tests__/client.test.ts
index 45ce4e81b..f8fe1fa9a 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-axios/__tests__/client.test.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-axios/__tests__/client.test.ts
@@ -352,206 +352,3 @@ describe('confirming axios behaviour for constructing URLs', () => {
     expect(config).toBe('https://api.example.com/users');
   });
 });
-
-describe('error handling', () => {
-  it('should handle 404 response when throwOnError is false', async () => {
-    const client = createClient({ baseURL: 'https://api.example.com' });
-
-    const errorData = { error: 'Resource not found' };
-    const axiosError = new axios.AxiosError(
-      'Request failed with status code 404',
-      'ERR_BAD_REQUEST',
-      {} as any,
-      {},
-      {
-        config: {} as any,
-        data: errorData,
-        headers: {},
-        status: 404,
-        statusText: 'Not Found',
-      },
-    );
-
-    const mockAxios = vi.fn().mockResolvedValue(axiosError);
-
-    const result = await client.get({
-      axios: mockAxios as Partial<AxiosInstance> as AxiosInstance,
-      headers: {},
-      throwOnError: false,
-      url: '/users/999',
-    });
-
-    expect(mockAxios).toHaveBeenCalledWith(
-      expect.objectContaining({
-        url: 'https://api.example.com/users/999',
-      }),
-    );
-    expect(result).toBeInstanceOf(axios.AxiosError);
-    expect(result).toMatchObject({
-      error: errorData,
-      response: {
-        data: errorData,
-        status: 404,
-        statusText: 'Not Found',
-      },
-    });
-  });
-
-  it('should throw 404 error when throwOnError is true', async () => {
-    const client = createClient({ baseURL: 'https://api.example.com' });
-
-    const errorData = { error: 'Resource not found' };
-    const axiosError = new axios.AxiosError(
-      'Request failed with status code 404',
-      'ERR_BAD_REQUEST',
-      {} as any,
-      {},
-      {
-        config: {} as any,
-        data: errorData,
-        headers: {},
-        status: 404,
-        statusText: 'Not Found',
-      },
-    );
-
-    const mockAxios = vi.fn().mockResolvedValue(axiosError);
-
-    await expect(
-      client.get({
-        axios: mockAxios as Partial<AxiosInstance> as AxiosInstance,
-        headers: {},
-        throwOnError: true,
-        url: '/users/999',
-      }),
-    ).rejects.toMatchObject({
-      response: {
-        data: errorData,
-        status: 404,
-        statusText: 'Not Found',
-      },
-    });
-  });
-
-  it('should handle ECONNREFUSED error when throwOnError is false', async () => {
-    const client = createClient({ baseURL: 'https://api.example.com' });
-
-    const connectionError = axios.AxiosError.from(
-      new AggregateError(
-        [
-          new Error('connect ECONNREFUSED ::1:3000'),
-          new Error('connect ECONNREFUSED 127.0.0.1:3000'),
-        ],
-        'Error',
-      ),
-      'ECONNREFUSED',
-      {} as any,
-      {},
-      undefined, // no response object for connection errors
-    );
-
-    const mockAxios = vi.fn().mockResolvedValue(connectionError);
-
-    const result = await client.get({
-      axios: mockAxios as Partial<AxiosInstance> as AxiosInstance,
-      headers: {},
-      throwOnError: false,
-      url: '/users',
-    });
-
-    expect(mockAxios).toHaveBeenCalledWith(
-      expect.objectContaining({
-        url: 'https://api.example.com/users',
-      }),
-    );
-    expect(result).toMatchObject({
-      code: 'ECONNREFUSED',
-      error: {}, // error.response?.data ?? {}
-      message: 'Error',
-    });
-  });
-
-  it('should throw ECONNREFUSED error when throwOnError is true', async () => {
-    const client = createClient({ baseURL: 'https://api.example.com' });
-
-    const connectionError = axios.AxiosError.from(
-      new AggregateError(
-        [
-          new Error('connect ECONNREFUSED ::1:3000'),
-          new Error('connect ECONNREFUSED 127.0.0.1:3000'),
-        ],
-        'Error',
-      ),
-      'ECONNREFUSED',
-      {} as any,
-      {},
-      undefined,
-    );
-
-    const mockAxios = vi.fn().mockResolvedValue(connectionError);
-
-    await expect(
-      client.get({
-        axios: mockAxios as Partial<AxiosInstance> as AxiosInstance,
-        headers: {},
-        throwOnError: true,
-        url: '/users',
-      }),
-    ).rejects.toMatchObject({
-      code: 'ECONNREFUSED',
-      message: 'Error',
-      name: 'AggregateError',
-    });
-  });
-
-  it('should handle non-object error from responseValidator when throwOnError is false', async () => {
-    const client = createClient({ baseURL: 'https://api.example.com' });
-
-    const mockAxios = vi.fn().mockResolvedValue({
-      data: { id: 1, name: 'test' },
-      headers: {},
-      status: 200,
-      statusText: 'OK',
-    });
-
-    const result = await client.get({
-      axios: mockAxios as Partial<AxiosInstance> as AxiosInstance,
-      headers: {},
-      responseType: 'json',
-      responseValidator: vi.fn().mockRejectedValue('validation failed'),
-      throwOnError: false,
-      url: '/users/1',
-    });
-
-    expect(mockAxios).toHaveBeenCalledWith(
-      expect.objectContaining({
-        url: 'https://api.example.com/users/1',
-      }),
-    );
-    expect(result).toEqual({
-      error: {},
-    });
-  });
-
-  it('should throw non-object error from responseValidator when throwOnError is true', async () => {
-    const client = createClient({ baseURL: 'https://api.example.com' });
-
-    const mockAxios = vi.fn().mockResolvedValue({
-      data: { id: 1, name: 'test' },
-      headers: {},
-      status: 200,
-      statusText: 'OK',
-    });
-
-    await expect(
-      client.get({
-        axios: mockAxios as Partial<AxiosInstance> as AxiosInstance,
-        headers: {},
-        responseType: 'json',
-        responseValidator: vi.fn().mockRejectedValue('non-object error'),
-        throwOnError: true,
-        url: '/users/1',
-      }),
-    ).rejects.toBe('non-object error');
-  });
-});
diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-axios/bundle/client.ts b/packages/openapi-ts/src/plugins/@hey-api/client-axios/bundle/client.ts
index 28d35aa5b..fcbbfea0b 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-axios/bundle/client.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-axios/bundle/client.ts
@@ -1,5 +1,5 @@
-import type { AxiosInstance, RawAxiosRequestHeaders } from 'axios';
-import axios, { AxiosError } from 'axios';
+import type { AxiosError, AxiosInstance, RawAxiosRequestHeaders } from 'axios';
+import axios from 'axios';
 
 import { createSseClient } from '../../client-core/bundle/serverSentEvents';
 import type { HttpMethod } from '../../client-core/bundle/types';
@@ -67,6 +67,7 @@ export const createClient = (config: Config = {}): Client => {
     return { opts, url };
   };
 
+  // @ts-expect-error
   const request: Client['request'] = async (options) => {
     // @ts-expect-error
     const { opts, url } = await beforeRequest(options);
@@ -84,7 +85,6 @@ export const createClient = (config: Config = {}): Client => {
         params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
-      if (response instanceof Error) throw response;
 
       let { data } = response;
 
@@ -103,22 +103,13 @@ export const createClient = (config: Config = {}): Client => {
         data: data ?? {},
       };
     } catch (error) {
+      const e = error as AxiosError;
       if (opts.throwOnError) {
-        throw error;
+        throw e;
       }
-
-      if (error instanceof AxiosError) {
-        // @ts-expect-error
-        error.error = error.response?.data ?? {};
-        return error;
-      }
-
-      if (typeof error === 'object' && error !== null) {
-        error.error = {};
-        return error;
-      }
-
-      return { error: {} };
+      // @ts-expect-error
+      e.error = e.response?.data ?? {};
+      return e;
     }
   };