1.20.0 (2026-05-08)

• WSTransport send, send_ping, send_pong, send_close can now accept str type as message. The message will be encoded as utf-8 before sending
• Introduce new exceptions: WSInvalidMessageError, WSInvalidStatusError, WSInvalidHeaderError, WSInvalidUpgradeError
• ws_connect/ws_create_server logger_name parameter can now accept a logger-like object
• ws_connect/ws_create_server websocket_handshake_timeout param can now accept None to disable handshake timeouts
• Allow sending close frames only using send_close to simplify logic
• Raise ValueError instead of assert on some invalid user input
• Added rsv2 and rsv3 to WSTransport send methods
• User on_ws_connect and on_ws_frame implementation can now signalize protocol errors by raising WSProtocolError
• Add is_disconnected property to WSTransport.
• Fix send_* methods raising exceptions when attempting to send after connection abort and without prior CLOSE frame.
• Add missing WSUpgradeResponse.body attribute at the client side.
• Add missing WSTransport.request attribute for the server side.
• ws_connect can now accept listener_factory that takes WSUpgradeRequest, WSUpgradeResponse as arguments. Old argument-less client_factory also works.

1.19.0 (2026-04-24)

• Enable sse2, avx2, avx512, neon speedups for windows builds
• Disconnect if unknown frame opcode is received (RFC 6455 requirement)
• Disconnect if client doesn't mask frame or server mask (RFC 6455 requirement)
• Do not log "Protocol writing pause/resume requested" if user overrides WSListener pause_writing/resume_writing
• Allow rsv2 and rsv3 bits in frames
• Use Transport.write_nocheck from aiofastnet 0.5.0 for performance

1.18.0 (2026-04-03)

• Raise exception if WSTransport methods are called from a wrong thread.
• Add examples illustrating how to properly utilized multithreading with free-threaded Python.
• Install aiofastnet and use it by default.
• Fix docs compilation and add 'free threaded python' topic guide

1.17.0 (2026-03-13)

1.17.0 (2026-03-13)

• Improve masking performance on large frames.
• Add aiofastnet as an optional dependency to speedup networking.

1.16.0 (2026-02-27)

• Add socket_factory argument to ws_connect
• Formalize exception hierarchy, new exceptions added: WSProtocolError, WSHandshakeError
• Send CLOSE(MESSAGE_TO_BIG) instead of CLOSE(PROTOCOL_ERROR) on frame size violation
• Deprecate zero_copy_unsafe_ssl_write in ws_connect and ws_create_server

1.15.0 (2026-02-22)

• Expose WSTransport.is_close_frame_sent read-only property
• Add 'Graceful websocket shutdown' topic guide
• Add 'Setting socket options' topic guide
• Always use BufferedProtocol (previously was only used with uvloop)
• Implement exponential grow of the internal read buffer
• Add read_buffer_init_size argument to ws_connect and ws_create_server
• Add zero_copy_unsafe_ssl_write argument to ws_connect and ws_create_server

1.14.0 (2026-02-19)

• WSTransport.wait_disconnected raises WSError exception if disconnect was cause by protocol parsing error.
• Transfer user exception from on_ws_disconnected to wait_disconnected on the client side
• Expand 'Exceptions handling' topic guide to explain how exceptions are transferred from user callbacks to wait_disconnected

1.13.1 (2026-02-15)

• Add more examples and update docs

1.13.0 (2026-02-14)

• #23: add support for SOCKS4, SOCKS5, HTTP proxies (no support for HTTPS proxy yet)

1.12.0 (2026-02-11)

• #71: add support for HTTP redirects
• Following discussion #68 added raw_header, raw_body and response attributes to WSError exception.
• Added additional checks for URL and WSInvalidURL exception
• Some non-latency critical code has been "de-cythonized" for better debugging experience.
• WSUpgradeRequest, WSUpgradeResponse, WSUpgradeResponseWithListener moved to a pure python module
• Mark picows extension module freethreading compatible

If your picows imports break after upgrading to 1.12.0 make sure you are importing from the package level.
Correct:
from picows import WSListener, WSFrame, WSUpgradeResponse

Wrong:
from picows.picows import WSListener, WSFrame, WSUpgradeResponse

The only exception to this are Cython definitions. You still have to cimport them from picows.picows
from picows.picows cimport WSListener, WSFrame