@hey-api/client-axios resolves with { status: 200, error, data: {} } instead of rejecting on HTTP 400/401 (even with throwOnError: true)

[maksymhryzodub]

My server returns 400 Bad Request (and 401 Unauthorized for a follow-up call), but the SDK generated with @hey-api/client-axios does not throw. Instead, the promise resolves to an object like:

{
  "status": 200,
  "error": { "code": null, "message": "An unknown error occurred" },
  "data": {}
}

This happens both with throwOnError: true and without it. As a result, try/catch never triggers.

Expected behavior
With throwOnError: true, non-2xx HTTP responses should reject the promise so that:
await returns typed data on success, and errors are caught in try/catch (no { status: 200, error } wrapper).

Actual behavior
Network tab shows POST /auth/jwt/login → 400 Bad Request.
SDK call resolves to { status: 200, error: {...}, data: {} } instead of rejecting, so my catch block is not hit.

OpenAPI generator config:

// openapi-config
export default defineConfig({
  input: "...openapi.json",
  output: {
    format: "prettier",
    lint: "eslint",
    path: "./app/slices/setup/api/data/repositories/api",
  },
  plugins: [
    {
      name: "@hey-api/client-axios",
      runtimeConfigPath: "../../../api.config",
      throwOnError: true,
    },
    { name: "@hey-api/typescript", enums: "typescript" },
    { name: "@hey-api/schemas", type: "json" },
    { name: "@hey-api/sdk", asClass: true },
  ],
});

Runtime config passed via runtimeConfigPath:

// api.config.ts
import queryString from "query-string";
import type { CreateClientConfig } from "./data/repositories/api/client.gen";

export const createClientConfig: CreateClientConfig = (override?) => {
  const env = import.meta.env;
  return {
    ...override,
    baseURL: env.VITE_MAIN_API || "http://localhost:3333",
    paramsSerializer: (params: any) =>
      queryString.stringify(params, { arrayFormat: "bracket", skipNull: true }),
  };
};

// Minimal call (simplified):
try {
  const res = await authSdk.authJWT({ body: credentials });
  console.log("login result", res); // <-- resolves with { status: 200, error, data: {} }
} catch (err) {
  console.error("caught in catch", err); // <-- never reached
}

Is the { status: 200, error, data } wrapper the intended runtime shape even when throwOnError: true?
How can I make the client reject on 4xx/5xx so try/catch works as documented/expected?

[dosubot[bot]]

Hi @maksymhryzodub! I'm Dosu and I’m helping the openapi-ts team.

The documentation does not confirm that throwOnError: true causes @hey-api/client-axios to reject promises on non-2xx responses, nor does it document the { status: 200, error, data } wrapper as the intended runtime shape for errors. In fact, the migration guide notes that not every client supports throwOnError, so it may have no effect in some cases, including this one see migration guide.

The client is a thin wrapper over Axios and exposes the underlying Axios instance, so you can add a response interceptor to customize error handling. To make the client reject on 4xx/5xx responses (so try/catch works as expected), you can add an interceptor like this:

import { client } from 'client/client.gen';

client.instance.interceptors.response.use(
  response => response,
  error => Promise.reject(error)
);

This restores standard Axios error handling, so non-2xx responses will reject and be caught by try/catch see docs. If you need more control, you can also provide your own Axios instance via setConfig.

Let me know if you want an example tailored to your setup!

To reply, just mention @dosu.

---

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[maksymhryzodub]

Yes, indeed, the interceptor solution helped. I discovered that a similar interceptor was located in another part of the project and it was returning this shell. After some changes, everything worked as it should. Thanks!