HTTP Request

HTTP method

The first parameter of the request method of an HTTP adapter allows to specify the HTTP method to be used.

The HTTP adapter provides syntactic sugar for regular HTTP methods: get, options, head, post, put, patch, delete.


The URL will be computed from:

  • The url attribute of the HTTPAdapterSpec of each client
  • The url argument passed to the request method (or get, post, etc.)

The rules used for combining URLs are quite flexible, and allow for the most frequent use cases:

  • Appending to the URL (a / separator will be used)
  • Keeping only the base URL by using an absolute path (starting with /)
  • Replacing the URL entirely by specifying an other URL


The body and body_encoding decide the data that will be sent in the body of the request.

Here are the possible values for body_encoding:


Some heuristics are used to determine which encoding to use.


Only basic types such as bytes and str are allowed, and will be passed transparently.


Data will be JSON-encoded.


Only works for dict types; keys and values will be urlencoded like a query string.


Only works for dict types; all values are encoded as if they were file data.


The headers will be computed from:

  • The headers attribute of the HTTPAdapterSpec of each client
  • The headers argument passed to the request method (or get, post, etc.)

The later values override the former ones, in a case-insensitive manner.


Depending on the body_encoding value, a content-type header may be automatically added.

Expected status codes

The expected_status_codes parameter allows to specify which status codes are expected to be returned in the HTTP response. An HTTPStatusCodeError if the value in the response is unexpected.

This argument can be:

  • An int (e.g. 204)
  • A str where the character x means “any digit” (e.g. "2xx")
  • An iterable of the previous items (e.g. ("2xx", 404))


By default, only the 200 status code is considered expected.

In contrast, other libraries such as requests consider only status codes 4xx and 5xx to be unexpected.

Stream mode

To ask the server to stream the response, set the stream_response parameter to True.

It is then recommended to use the data_stream attribute of the response object and to use it as a context manager.

Retry options

If an exception is raised when performing the request, 2 more attempts will be made with some wait time between them.

This can be customized by passing some arguments:

  • retry_nb_attempts to specify the total number of attempts (defaults to 3 attempts)
  • retry_wait_initial, retry_wait_max and retry_wait_jitter allow to specify the exponential backoff parameters for the retry (they default to 1s, 60s and 1s respectively)

Finally, a retry_callback can be passed to be notified when a retry is performed. This can be used for logging purposes for instance.

All these parameters can be specified (by order of precedence):

  • When calling a request method (or get, post, etc.)
  • On the HTTPAdapterSpec of each client