Autobahn on Conda

Overview

Conda is a popular cross-platform package manager and environment manager widely used in scientific computing, data science, and machine learning workflows. While Autobahn|Python is available on the conda-forge channel, the conda-forge version may lag behind the latest releases on PyPI.

TL;DR: Use pip install autobahn within your Conda environment to get the latest version with native wheels from PyPI.

Why Conda-Forge Lags Behind PyPI

Conda packages require additional steps beyond publishing to PyPI:

  1. A maintainer must update the autobahn-feedstock repository with the new version

  2. The conda-forge CI/CD pipeline builds packages for all platforms

  3. Review and merge process adds additional time

  4. Build times can vary depending on conda-forge infrastructure load

As a result, the conda-forge version may be weeks or months behind PyPI.

Current Version Status

You can check the current versions at:

As of this writing:

  • PyPI has v25.10.1 (October 2025)

  • conda-forge has v24.4.2 (March 2024)

Understanding Native Wheels vs Source Distribution

When you install with pip, you may get one of two formats:

Source Distribution (Fallback)

  • File extension: .tar.gz

  • Contains: Source code only

  • Installation: May require compilation (slower)

  • Use case: Platforms without pre-built wheels

To verify which format was installed:

pip list --format=freeze | grep autobahn

Native Acceleration (NVX)

Autobahn includes optional native acceleration called NVX (Native eXtensions) for improved WebSocket and WAMP performance on CPython and PyPy. See Wheels Inventory for details.

When installing from PyPI wheels:

  • “with-nvx” wheels: Include compiled NVX extensions (automatic)

  • “without-nvx” wheels: Pure Python fallback (automatic on incompatible systems)

NVX Status in Conda

If you see errors like:

ModuleNotFoundError: No module named '_nvx_utf8validator'

This means Autobahn is trying to use NVX but the extension is missing. This can happen if:

  1. You installed from conda-forge (which may not include NVX)

  2. The wheel didn’t match your platform

  3. Your system doesn’t support NVX (very old CPU)

Solution: Disable NVX with an environment variable:

export AUTOBAHN_USE_NVX=0
# Or on Windows:
set AUTOBAHN_USE_NVX=0

Alternatively, reinstall from PyPI to get the correct wheel:

pip uninstall autobahn
pip install autobahn

Verifying Your Installation

After installation, verify everything works:

python -c "import autobahn; print(autobahn.__version__)"

Expected output:

25.10.1

Check if NVX is enabled:

import autobahn
print(autobahn.nvx.HAS_NVX)  # True if NVX is available

Test a simple WebSocket echo server:

from autobahn.asyncio.websocket import WebSocketServerProtocol, \
    WebSocketServerFactory
import asyncio

class EchoServerProtocol(WebSocketServerProtocol):
    def onMessage(self, payload, isBinary):
        self.sendMessage(payload, isBinary)

factory = WebSocketServerFactory("ws://127.0.0.1:9000")
factory.protocol = EchoServerProtocol

loop = asyncio.get_event_loop()
coro = loop.create_server(factory, '127.0.0.1', 9000)
server = loop.run_until_complete(coro)

try:
    print("Server running on ws://127.0.0.1:9000")
    loop.run_forever()
except KeyboardInterrupt:
    pass
finally:
    server.close()
    loop.close()

Managing Dependencies

Autobahn has several dependencies that may also be installed via pip or conda:

Core Dependencies

  • txaio: Abstraction layer for asyncio/Twisted compatibility

  • cryptography: TLS/SSL support, WAMP-cryptosign authentication

  • hyperlink: URL parsing and manipulation

Optional Dependencies

  • twisted: Required for Twisted-based applications

  • msgpack: MessagePack serialization (WAMP)

  • cbor2: CBOR serialization (WAMP)

  • flatbuffers: FlatBuffers serialization (WAMP)

  • ujson: Fast JSON serialization (optional)

  • pyqrcode: QR code generation (WAMP-cryptosign)

Install optional features:

# All optional dependencies
pip install autobahn[all]

# Specific feature sets
pip install autobahn[twisted]          # Twisted support
pip install autobahn[asyncio]          # asyncio support (minimal)
pip install autobahn[serialization]    # All serializers
pip install autobahn[encryption]       # Crypto/TLS support
pip install autobahn[compress]         # WebSocket compression

Troubleshooting

Issue: “No module named ‘autobahn’”

Cause: Autobahn is not installed, or the wrong Python interpreter is active.

Solution:

# Verify you're in the correct Conda environment
conda activate myproject

# Verify the Python interpreter
which python

# Reinstall
pip install autobahn

Issue: “Import Error: cannot import name X”

Cause: Version mismatch between Autobahn and dependencies.

Solution:

# Update all dependencies
pip install --upgrade autobahn txaio cryptography

Issue: Old version from conda-forge

Cause: conda-forge package is outdated.

Solution:

# Uninstall conda version
conda remove autobahn

# Install latest from PyPI
pip install autobahn

Compatibility Matrix

Autobahn works with:

  • Python: 3.9, 3.10, 3.11, 3.12, 3.13, PyPy 7.3+

  • Operating Systems: Linux, macOS, Windows, BSD

  • Event Loops: asyncio (stdlib), Twisted

  • Package Managers: pip, conda, poetry, pipenv

For the full list of tested platforms and wheels, see Wheels Inventory.

Getting Help

If you encounter issues with Conda installations:

  1. Check GitHub Issues

  2. Review the Installation guide

  3. Ask on Stack Overflow with the autobahn tag

  4. Join the Crossbar.io mailing list

References

Note

Best Practice: Always use pip install autobahn within Conda environments to get the latest version with native wheels from PyPI. This ensures maximum compatibility and performance.