How to extract a bearer token

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Problem

Your handler or auth middleware needs the bearer token from the Authorization header.

Solution

case livery_ext:bearer_token(Req) of
    undefined -> livery_resp:text(401, <<"missing token">>);
    Token     -> use_token(Token)
end.

livery_ext:bearer_token/1:

  • Reads the Authorization header (case-insensitive).
  • Accepts Bearer, bearer, and BEARER prefixes (RFC 6750 §2.1 makes the scheme case-insensitive).
  • Returns the token bytes after the prefix, or undefined when the header is absent or uses another scheme.

Use it inside a middleware

-module(my_auth).
-behaviour(livery_middleware).
-export([call/3]).

call(Req, Next, _State) ->
    case livery_ext:bearer_token(Req) of
        undefined ->
            livery_resp:text(401, <<"missing token">>);
        Token ->
            case verify(Token) of
                {ok, User} -> Next(livery_req:set_meta(user, User, Req));
                error      -> livery_resp:text(401, <<"bad token">>)
            end
    end.

%% Replace with real verification; livery_auth does JWT/JWKS for you.
verify(_Token) -> {ok, #{}}.

Place it in the stack after livery_request_id and livery_access_log so the audit log records the failed attempt.

Non-bearer schemes

livery_ext:bearer_token/1 only matches the bearer scheme. For Basic auth, read the header directly and decode:

case livery_req:header(<<"authorization">>, Req) of
    <<"Basic ", B64/binary>> -> base64:decode(B64);
    _ -> undefined
end.

OIDC, JWKS rotation, and JWT verification ship as livery_auth.

See also