google.auth.transport.urllib3 module

Transport adapter for urllib3.

class Request(http)[source]

Bases: Request

urllib3 request adapter.

This class is used internally for making requests using various transports in a consistent way. If you use AuthorizedHttp you do not need to construct or use this class directly.

This class can be useful if you want to manually refresh a Credentials instance:

import google.auth.transport.urllib3
import urllib3

http = urllib3.PoolManager()
request = google.auth.transport.urllib3.Request(http)


http (urllib3.request.RequestMethods) – An instance of any urllib3 class that implements RequestMethods, usually urllib3.PoolManager.

__call__(url, method='GET', body=None, headers=None, timeout=None, **kwargs)[source]

Make an HTTP request using urllib3.

  • url (str) – The URI to be requested.

  • method (str) – The HTTP method to use for the request. Defaults to ‘GET’.

  • body (bytes) – The payload / body in HTTP request.

  • headers (Mappingstr, str) – Request headers.

  • timeout (Optionalint) – The number of seconds to wait for a response from the server. If not specified or if None, the urllib3 default timeout will be used.

  • kwargs – Additional arguments passed throught to the underlying urllib3 urlopen() method.


The HTTP response.

Return type:



google.auth.exceptions.TransportError – If any exception occurred.

class AuthorizedHttp(credentials, http=None, refresh_status_codes=(HTTPStatus.UNAUTHORIZED,), max_refresh_attempts=2, default_host=None)[source]

Bases: RequestMethods

A urllib3 HTTP class with credentials.

This class is used to perform requests to API endpoints that require authorization:

from google.auth.transport.urllib3 import AuthorizedHttp

authed_http = AuthorizedHttp(credentials)

response = authed_http.request(
    'GET', '')

This class implements urllib3.request.RequestMethods and can be used just like any other urllib3.PoolManager.

The underlying urlopen() implementation handles adding the credentials’ headers to the request and refreshing credentials as needed.

This class also supports mutual TLS via configure_mtls_channel() method. In order to use this method, the GOOGLE_API_USE_CLIENT_CERTIFICATE environment variable must be explicitly set to true, otherwise it does nothing. Assume the environment is set to true, the method behaves in the following manner: If client_cert_callback is provided, client certificate and private key are loaded using the callback; if client_cert_callback is None, application default SSL credentials will be used. Exceptions are raised if there are problems with the certificate, private key, or the loading process, so it should be called within a try/except block.

First we set the environment variable to true, then create an AuthorizedHttp instance and specify the endpoints:

regular_endpoint = '{my_project_id}/topics'
mtls_endpoint = '{my_project_id}/topics'

authed_http = AuthorizedHttp(credentials)

Now we can pass a callback to configure_mtls_channel():

def my_cert_callback():
    # some code to load client cert bytes and private key bytes, both in
    # PEM format.
    if loaded:
        return cert, key
    raise MyClientCertFailureException()

# Always call configure_mtls_channel within a try/except block.
    is_mtls = authed_http.configure_mtls_channel(my_cert_callback)
    # handle exceptions.

if is_mtls:
    response = authed_http.request('GET', mtls_endpoint)
    response = authed_http.request('GET', regular_endpoint)

You can alternatively use application default SSL credentials like this:

    is_mtls = authed_http.configure_mtls_channel()
    # handle exceptions.
  • credentials (google.auth.credentials.Credentials) – The credentials to add to the request.

  • http (urllib3.PoolManager) – The underlying HTTP object to use to make requests. If not specified, a urllib3.PoolManager instance will be constructed with sane defaults.

  • refresh_status_codes (Sequenceint) – Which HTTP status codes indicate that credentials should be refreshed and the request should be retried.

  • max_refresh_attempts (int) – The maximum number of times to attempt to refresh the credentials and retry the request.

  • default_host (Optionalstr) – A host like “”. This is used when a self-signed JWT is created from service account credentials.


Configures mutual TLS channel using the given client_cert_callback or application default SSL credentials. The behavior is controlled by GOOGLE_API_USE_CLIENT_CERTIFICATE environment variable. (1) If the environment variable value is true, the function returns True if the channel is mutual TLS and False otherwise. The http provided in the constructor will be overwritten. (2) If the environment variable is not set or false, the function does nothing and it always return False.


client_cert_callback (OptionalCallable, bytes, bytes) – The optional callback returns the client certificate and private key bytes both in PEM format. If the callback is None, application default SSL credentials will be used.


True if the channel is mutual TLS and False otherwise.


google.auth.exceptions.MutualTLSChannelError – If mutual TLS channel creation failed for any reason.

urlopen(method, url, body=None, headers=None, **kwargs)[source]

Implementation of urllib3’s urlopen.

request(method: str, url: str, body: _TYPE_BODY | None = None, fields: _TYPE_FIELDS | None = None, headers: Mapping[str, str] | None = None, json: Any | None = None, **urlopen_kw: Any) BaseHTTPResponse

Make a request using urlopen() with the appropriate encoding of fields based on the method used.

This is a convenience method that requires the least amount of manual effort. It can be used in most situations, while still having the option to drop down to more specific methods when necessary, such as request_encode_url(), request_encode_body(), or even the lowest level urlopen().

request_encode_body(method: str, url: str, fields: _TYPE_FIELDS | None = None, headers: Mapping[str, str] | None = None, encode_multipart: bool = True, multipart_boundary: str | None = None, **urlopen_kw: str) BaseHTTPResponse

Make a request using urlopen() with the fields encoded in the body. This is useful for request methods like POST, PUT, PATCH, etc.

When encode_multipart=True (default), then urllib3.encode_multipart_formdata() is used to encode the payload with the appropriate content type. Otherwise urllib.parse.urlencode() is used with the ‘application/x-www-form-urlencoded’ content type.

Multipart encoding must be used when posting files, and it’s reasonably safe to use it in other times too. However, it may break request signing, such as with OAuth.

Supports an optional fields parameter of key/value strings AND key/filetuple. A filetuple is a (filename, data, MIME type) tuple where the MIME type is optional. For example:

fields = {
    'foo': 'bar',
    'fakefile': ('foofile.txt', 'contents of foofile'),
    'realfile': ('barfile.txt', open('realfile').read()),
    'typedfile': ('bazfile.bin', open('bazfile').read(),
    'nonamefile': 'contents of nonamefile field',

When uploading a file, providing a filename (the first parameter of the tuple) is optional but recommended to best mimic behavior of browsers.

Note that if headers are supplied, the ‘Content-Type’ header will be overwritten because it depends on the dynamic random boundary string which is used to compose the body of the request. The random boundary string can be explicitly set with the multipart_boundary parameter.

request_encode_url(method: str, url: str, fields: _TYPE_ENCODE_URL_FIELDS | None = None, headers: Mapping[str, str] | None = None, **urlopen_kw: str) BaseHTTPResponse

Make a request using urlopen() with the fields encoded in the url. This is useful for request methods like GET, HEAD, DELETE, etc.

property headers

Proxy to self.http.