Currently, I generate a JWT from the SAML response, store it in the JwtResponse DTO, and send it to the frontend as part of the response, along with a redirect URL in the header indicating where the user should be redirected after authentication. However, after authentication, the JwtResponse is visible in the response of the URL (http://localhost:8080/login/saml2/sso/okta).

What I want instead is to redirect the user to http://localhost:8080/home and save the JwtResponse in localStorage for further use.How can I do that? I cannot sent the jwt in url query parameter. Kindly ignore that method (and also ignore usage of session cookies) and suggest any other method.

This is what i have tried:

@PostMapping("/auth")
    public ResponseEntity<JwtResponse> handleSAMLLogin(Authentication      authentication) {
            Saml2AuthenticatedPrincipal principal = (Saml2AuthenticatedPrincipal) authentication.getPrincipal();

        Map<String, Object> claims = new HashMap<>();
        principal.getAttributes().forEach((key, value) -> {
            claims.put(key, value.get(0));
        });

        JwtResponse jwtResponse = new JwtResponse(
                samlAuthenticationSuccessHandler.generateSamlJWTToken(principal, claims)
        );

        return ResponseEntity
                .ok()
                .header("X-Redirect-URL", "/home")
                .body(jwtResponse);
    }
}

This is my frontend code which is not saving the response in the localStorage:

import axios from "axios";

export const initiateAuth = () => {
  window.location.href = "http://localhost:8080/saml2/authenticate/okta";
}; 

export const handleAuthCallback = async () => {
  try {
    const response = await axios.get(
      "http://localhost:8080/login/saml2/sso/okta",
      {
        headers: {
          Accept: "application/json",
        },
      }
     );

    const { accessToken, tokenType } = response.data;

    if (accessToken) {
      localStorage.setItem("token", `${tokenType} ${accessToken}`);

      localStorage.setItem("expiresIn", response.data.expiresIn);

      axios.defaults.headers.common[
        "Authorization"
      ] = `${tokenType} ${accessToken}`;

      return true;
    }

    return false;
   } catch (error) {
    console.error("Failed to handle authentication callback", error);
    return false;
   }
};

export const isAuthenticated = () => {
  const token = localStorage.getItem("token");
  return !!token;
};

export const getToken = () => {
   return localStorage.getItem("token");
};

export const logout = () => {
  localStorage.removeItem("token");
  localStorage.removeItem("expiresIn");
   delete axios.defaults.headers.common["Authorization"];
};

axios.interceptors.request.use(
   (config) => {
    const token = getToken();
    if (token) {
      config.headers.Authorization = token; 
        }
        return config;
      },
      (error) => {
        return Promise.reject(error);
      }
    );

I am expecting to to redirect the user to http://localhost:8080/home and save the JwtResponse in localStorage for further use. How can I do that?