Bearer Token Authentication | Effect Http Client

Bearer token authentication is the most common auth scheme for modern APIs. The client includes a token — usually obtained by logging in or through an OAuth flow — in the Authorization header of every request. The server checks this token to verify who you are. The header format is Authorization: Bearer <token>.

HttpClientRequest.bearerToken() sets this header for you.

In the example below, we first log in to get an access token, then use that token to fetch the authenticated user’s profile.

1
import {
2
  FetchHttpClient,
3
  HttpClient,
4
  HttpClientRequest,
5
} from "effect/unstable/http";
6
import { Effect } from "effect";
7

8
function fetchAuthenticatedUser() {
9
  return Effect.gen(function* () {
10
    const client = yield* HttpClient.HttpClient;
11

12
    // Step 1: Log in to get a token
13
    const loginRequest = HttpClientRequest.post(
14
      "https://dummyjson.com/auth/login",
15
    ).pipe(
16
      HttpClientRequest.bodyJsonUnsafe({
17
        username: "emilys",
18
        password: "emilyspass",
19
      }),
20
    );
21

22
    const loginResponse = yield* client.execute(loginRequest);
23
    const { accessToken } = yield* loginResponse.json;
24

25
    // Step 2: Use the token to fetch the current user's profile
26
    const meRequest = HttpClientRequest.get(
27
      "https://dummyjson.com/auth/me",
28
    ).pipe(HttpClientRequest.bearerToken(accessToken));
29

30
    const meResponse = yield* client.execute(meRequest);
31
    const user = yield* meResponse.json;
32

33
    return user;
34
  }).pipe(Effect.provide(FetchHttpClient.layer));
35
}
36

37
// Test it
38
Effect.runPromise(fetchAuthenticatedUser()).then((user) => {
39
  console.log("Authenticated user:", user.firstName, user.lastName);
40
  console.log("Email:", user.email);
41
});

Output:

1
Authenticated user: Emily Johnson
2
Email: emily.johnson@x.dummyjson.com

bearerToken(token) is equivalent to setHeader("authorization", "Bearer " + token). It handles the formatting for you and keeps your code readable.

Stay in the loop