An exchange for managing authentication and token refresh in urql
npm install @urql/exchange-authAn exchange for managing authentication in urql
@urql/exchange-auth is an exchange for the urql GraphQL client which helps handle auth headers and token refresh
First install @urql/exchange-auth alongside urql:
``sh`
yarn add @urql/exchange-author
npm install --save @urql/exchange-auth
You'll then need to add the authExchange, that this package exposes to your urql Client
`js
import { createClient, cacheExchange, fetchExchange } from 'urql';
import { makeOperation } from '@urql/core';
import { authExchange } from '@urql/exchange-auth';
const client = createClient({
url: 'http://localhost:1234/graphql',
exchanges: [
cacheExchange,
authExchange(async utils => {
// called on initial launch,
// fetch the auth state from storage (local storage, async storage etc)
let token = localStorage.getItem('token');
let refreshToken = localStorage.getItem('refreshToken');
return {
addAuthToOperation(operation) {
if (token) {
return utils.appendHeaders(operation, {
Authorization: Bearer ${token},
});
}
return operation;
},
willAuthError(_operation) {
// e.g. check for expiration, existence of auth etc
return !token;
},
didAuthError(error, _operation) {
// check if the error was an auth error
// this can be implemented in various ways, e.g. 401 or a special error code
return error.graphQLErrors.some(e => e.extensions?.code === 'FORBIDDEN');
},
async refreshAuth() {
// called when auth error has occurred
// we should refresh the token with a GraphQL mutation or a fetch call,
// depending on what the API supports
const result = await mutate(refreshMutation, {
token: authState?.refreshToken,
});
if (result.data?.refreshLogin) {
// save the new tokens in storage for next restart
token = result.data.refreshLogin.token;
refreshToken = result.data.refreshLogin.refreshToken;
localStorage.setItem('token', token);
localStorage.setItem('refreshToken', refreshToken);
} else {
// otherwise, if refresh fails, log clear storage and log out
localStorage.clear();
logout();
}
},
};
}),
fetchExchange,
],
});
`
Handling the logout logic in refreshAuth is the easiest way to get started,authExchange
but it means the errors will always get swallowed by the .mapExchange
If you want to handle errors globally, this can be done using the :
`js
import { mapExchange } from 'urql';
// this needs to be placed ABOVE the authExchange in the exchanges array, otherwise the auth error
// will show up hear before the auth exchange has had the chance to handle it
mapExchange({
onError(error) {
// we only get an auth error here when the auth exchange had attempted to refresh auth and
// getting an auth error again for the second time
const isAuthError = error.graphQLErrors.some(
e => e.extensions?.code === 'FORBIDDEN',
);
if (isAuthError) {
// clear storage, log the user out etc
}
}
}),
``