Docker 29.0 and Traefik Compatibility: The API Version Mismatch

After upgrading to Docker 29.0.0, my entire local development environment stopped working. All containers were running, Traefik was running, but none of the websites were reachable.

Checking the logs revealed the real cause:

error="Error response from daemon: client version 1.24 is too old.
Minimum supported API version is 1.44, please upgrade your client."

This isn't a configuration issue, it's a breaking change introduced in Docker 29. The new version enforces a minimum Docker API version 1.44, and older clients are rejected immediately.

Traefik uses Docker SDK v1.24, which means it can no longer communicate with Docker 29. I also tested the latest Traefik image (including latest and 3.4.4 tags) and the same problem persisted.

As a result, Traefik can't:

• discover running containers  
• read labels and routing rules  
• update routes dynamically  
• or function as a reverse proxy at all

Understanding the Root Cause

Before Docker 29, the daemon supported backward compatibility with API clients as old as v1.24. In version 29, Docker raised the minimum requirement to v1.44, introduced around Docker 25. See it here: https://docs.docker.com/reference/api/engine/version-history

That means any application built against an older Docker SDK, including the current Traefik release, will fail to connect before any configuration or routing logic is executed.

The Solution: Downgrade Docker

Until Traefik releases a version that supports Docker API 1.44+, the only reliable fix is to downgrade Docker to version 28.5.2.

I'm using Ubuntu, so the following steps apply to Debian/Ubuntu-based systems. If you're on another platform (Fedora, Arch, macOS, Windows, etc.), the process is similar — you'll just need to use your system's package manager or Docker Desktop downgrade option.

Steps (Ubuntu/Debian):

1. Stop Docker

sudo systemctl stop docker docker.socket containerd

2. Downgrade packages

sudo apt-get install -y --allow-downgrades docker-ce=5:28.5.2-1~ubuntu.22.04~jammy docker-ce-cli=5:28.5.2-1~ubuntu.22.04~jammy containerd.io

You can check available versions for your release with

apt-cache madison docker-ce | grep 28.5

3. Start and verify

sudo systemctl start docker
docker --version   # should show Docker version 28.5.2

4. Check Traefik logs

docker logs <traefik-container-name> --tail 20

You should now see:

[INFO] Configuration received from provider docker
[INFO] Register new service myapp@docker

5. Prevent automatic upgrade

sudo apt-mark hold docker-ce docker-ce-cli containerd.io

When Traefik adds support for API v1.44, remove the hold and upgrade safely.

Why Staying on Docker 28 Is Fine (for Now)

• Docker 28.5.2 is still stable.
• Functionality is nearly identical for local development.
• Compatibility with existing tools like Traefik remains intact.

For production or CI environments, monitor the Traefik GitHub repository for updates mentioning "Docker 29" or "API 1.44 support":

Traefik Releases
Traefik Issues

Key Takeaways

• Docker 29 enforces API 1.44+, breaking compatibility with Traefik (including latest builds as of November 2025).  
• This is not a bug, it's a deliberate change in Docker's API policy.  
• The only confirmed fix: downgrade to Docker 28.5.2 and hold updates.  
• Wait for a Traefik release that updates its Docker client library.

Update: Traefik is working on a fix!

Pull request #12256 https://github.com/traefik/traefik/pull/12256 introduces auto-negotiation of the Docker API version, which means Traefik will automatically detect and use the correct API version supported by your Docker daemon. This is a more elegant solution than hardcoding the version, as it will work with both current and future Docker versions. Test builds with this fix are already available (felixbuenemann/traefik:v3.6.1 on Docker Hub), and an official release is expected soon. This approach is recommended and represents the best long-term solution.