API Authorization

Using a GlobusAuthorizer is hard to grasp without a few examples to reference. The basic usage should be to create these at client instantiation time.

Access Token Authorization on AuthClient and TransferClient

Perhaps you’re in a part of your application that only sees Access Tokens. Access Tokens are used to directly authenticate calls against Globus APIs, and are limited-lifetime credentials. You have distinct Access Tokens for each Globus service which you want to access.

With the tokens in hand, it’s just a simple matter of wrapping the tokens in AccessTokenAuthorizer objects.

from globus_sdk import AuthClient, TransferClient, AccessTokenAuthorizer


# note that we don't provide the client ID in this case
# if you're using an Access Token you can't do the OAuth2 flows
auth_client = AuthClient(

transfer_client = TransferClient(

Refresh Token Authorization on AuthClient and TransferClient

Refresh Tokens are long-lived credentials used to get new Access Tokens whenever they expire. However, it would be very awkward to create a new client instance every time your credentials expire!

Instead, use a RefreshTokenAuthorizer to automatically re-up your credentials whenever they near expiration.

Re-upping credentials is an operation that requires having client credentials for Globus Auth, so creating the authorizer is more complex this time.

from globus_sdk import (AuthClient, TransferClient, ConfidentialAppAuthClient,

# for doing the refresh
CLIENT_ID = '...'

# the actual tokens

# making the authorizer requires that we have an AuthClient which can talk
# OAuth2 to Globus Auth
internal_auth_client = ConfidentialAppAuthClient(CLIENT_ID, CLIENT_SECRET)

# now let's bake a couple of authorizers
auth_authorizer = RefreshTokenAuthorizer(AUTH_REFRESH_TOKEN,
transfer_authorizer = RefreshTokenAuthorizer(TRANSFER_REFRESH_TOKEN,

# auth_client here is totally different from "internal_auth_client" above
# the former is being used to request new tokens periodically, while this
# one represents a user authenticated with those tokens
auth_client = AuthClient(authorizer=auth_authorizer)
# transfer_client doesn't have to contend with this duality -- it's always
# representing a user
transfer_client = TransferClient(authorizer=transfer_authorizer)

Basic Auth on an AuthClient

If you’re using an AuthClient to do OAuth2 flows, you likely want to authenticate it using your client credentials – the client ID and client secret.

The preferred method is to use the AuthClient subclass which automatically specifies its authorizer. Internally, this will use a BasicAuthorizer to do Basic Authentication.

By way of example:

from globus_sdk import ConfidentialAppAuthClient

CLIENT_ID = '...'

client = ConfidentialAppAuthClient(CLIENT_ID, CLIENT_SECRET)

and you’re off to the races!

Under the hood, this is implicitly running

AuthClient(authorizer=BasicAuthorizer(CLIENT_ID, CLIENT_SECRET))

but don’t do this yourself – ConfidentialAppAuthClient has different methods from the base AuthClient.