Migrating from libsoup 2

Removed APIs

This is a list of APIs that have been removed:

XML-RPC support.
Handling of file:// and data:// URIs You should use GFile for the former and soup_uri_decode_data_uri() for the latter.
Define aliases for property names You must use the string name of properties directly which works in libsoup 2 already.
SoupSession:add-feature and SoupSession:add-feature-by-type You must call soup_session_add_feature() and soup_session_add_feature_by_type() directly.
SoupRequest: You should use soup_session_send() or soup_session_send_async() methods.
SoupAddress has been replaced with GInetAddress and GNetworkAddress.
SoupSocket has been removed.
SoupProxyResolverDefault is replaced by g_proxy_resolver_get_default().
SoupBuffer has been replaced by GBytes and GByteArray.
SoupDate has been replaced by GDateTime.
SoupSession:ssl-strict has been removed in favor of using the SoupMessage::accept-certificate signal.
soup_session_cancel_message() has been removed instead you pass a GCancellable to APIs and call g_cancellable_cancel().

Moved authenticate signal

The SoupSession::authenticate signal has been replaced by SoupMessage::authenticate. It now allows returning TRUE to signify if you will handle authentication which allows for asynchronous handling.

Structs are private

You can no longer directly access various structs such as SoupMessage. These are now accessed by getters and setters. See below for direct conversions:

Struct field	Getter/Setter function
SoupMessage.method	soup_message_get_method()
SoupMessage.status_code	soup_message_get_status()
SoupMessage.reason_phrase	soup_message_get_reason_phrase()
SoupMessage.uri	soup_message_get_uri(), soup_message_set_uri()
SoupMessage.request_headers	soup_message_get_request_headers()
SoupMessage.response_headers	soup_message_get_response_headers()
SoupMessage.request_body	soup_message_set_request_body(), soup_message_set_request_body_from_bytes()
SoupMessage.response_body	See section on IO

Similar struct changes exist for SoupCookie but have very straightforward replacements.

URI type changed

The SoupURI type has been replaced with the GUri type which has some implications.

Creating a GUri is generally as simple as g_uri_parse (uri, SOUP_HTTP_URI_FLAGS, NULL). You may want to add

G_URI_FLAGS_PARSE_RELAXED to accept input that used to be considered valid.

Note that unlike SoupURI, GUri is an immutable type so you cannot change the contents of one after it has been constructed. We provide soup_uri_copy() to aid in modifying them.

The equivalent behavior to soup_uri_to_string (uri, FALSE) is g_uri_to_string_partial (uri, G_URI_HIDE_PASSWORD).

Since GUri does not provide any function to check for equality soup_uri_equal() still exists.

Sending a OPTIONS message with a path of * is no longer a valid URI and has been replaced with SoupMessage:is-options-ping.

Status codes no longer used for internal errors

Previously SoupStatus was used to hold libsoup errors (SOUP_STATUS_IS_TRANSPORT_ERROR()). Now all of these errors are propagated up through the normal GError method on the various APIs to send messages. Here is a mapping chart between the status codes and new errors:

Old Status Codes	New `GError`
`SOUP_STATUS_CANCELLED`	`G_IO_ERROR_CANCELLED`
`SOUP_STATUS_MALFORMED`	`SOUP_SESSION_ERROR_PARSING`, `SOUP_SESSION_ERROR_ENCODING`
`SOUP_STATUS_TOO_MANY_REDIRECTS`	`SOUP_SESSION_ERROR_TOO_MANY_REDIRECTS`

All IO is now GIOStream-based

Previously there were ways to allow libsoup to read data into buffers and for you to read from those buffers such as SoupMessage:response-body SoupMessage:response-body-data, and SoupServerMessage::got-chunk.

libsoup no longer stores a buffer of data for you to read from and instead it returns a GInputStream which you read from using normal GIO APIs.

If you want to simply request a buffer and nothing more you can use the soup_session_send_and_read() or soup_session_send_and_read_async() APIs.

This also applies to writing data where you can set a GInputStream using soup_message_set_request_body() or use the convenience API soup_message_set_request_body_from_bytes() to use a GBytes buffer.

Clarification on thread-safety

In libsoup 2 there was an attempt at making various APIs of the library thread-safe. However this was never well tested, maintained, or documented.

libsoup 3 was initially designed to behave in line with other GObject libraries. Once you create a SoupSession all usage of that session must happen on the same thread. However, in version 3.2 thread safety support was introduced again, with the same approach as libsoup2.