[BUG] OAuth authentication not persisting in Docker container despite credentials file being saved

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

I have been attempting to use Claude Code with my Synology NAS. Install works fine, but every time I open an instance of Claude, I am asked to set up (Dark mode, etc) and then reauthenticate. I initially ran into a segmentation fault and as a workaround attempted to use a docker container. I'm not sure if what I am attempting to do is even actually possible. Details follow.

Environment

• Synology NAS DS1522+ (AMD Ryzen, x86_64)
• DSM 7.2.2-72806 Update 5
• Docker 24.0.2
• Node 20 (official Docker image)
• Claude Code installed via npm install -g @anthropic-ai/claude-code

Background

Native installation on Synology fails with a segmentation fault when running claude, likely due to incompatibility with Synology's environment. Docker is used as a workaround.

Issue

OAuth authentication does not persist between container runs, despite the credentials file being correctly saved and mounted.

Docker setup:
docker run -it --rm --hostname claude-nas \
-v /path/to/.claude-docker:/root/.claude \
-v /volume1:/volume1 \
-w $(pwd) claude-code

What happens:

1. Run container, authenticate via OAuth successfully
2. Exit with /exit
3. Verify ~/.claude-docker/.credentials.json exists and contains valid tokens
4. Run container again
5. Claude Code prompts for authentication again

What Should Happen?

What I expected (or in any case wanted) to happen:
Authentication should persist since the .credentials.json file is saved and mounted at /root/.claude.

Troubleshooting attempted:

• Confirmed credentials file is saved with valid tokens
• Used absolute paths for volume mount
• Added fixed --hostname to container
• Verified mount works from inside container

Error Messages/Logs

Steps to Reproduce

As above:

1. Create a Docker image with Claude Code:

sudo docker build -t claude-code - << 'EOF'
FROM node:20
RUN npm install -g @anthropic-ai/claude-code
ENTRYPOINT ["claude"]
EOF

1. Create a directory to persist config:

mkdir -p ~/.claude-docker

1. Run the container with the config directory mounted:

sudo docker run -it --rm --hostname claude-nas \
-v ~/.claude-docker:/root/.claude \
-v /volume1:/volume1 \
-w /volume1 \
claude-code

1. Complete OAuth authentication when prompted (select "Yes, log in" and follow the browser flow)
2. After successful login, exit Claude Code:

/exit

1. Verify credentials were saved:

sudo cat ~/.claude-docker/.credentials.json
This shows valid tokens including accessToken, refreshToken, and expiresAt.

1. Run the container again with the same command from step 3

Expected: Claude Code should recognize existing credentials and skip authentication.

Actual: Claude Code prompts for authentication again, as if no credentials exist.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.27 (Claude Code)

Platform

Anthropic API

Operating System

Other

Terminal/Shell

Other

Additional Information

I'm connecting to my NAS from macOS and running Claude via Synology default shell (ash/sh) via SSH

Additional Attempted Troubleshooting

• Confirmed credentials file contains valid tokens with future expiry
• Used absolute paths for volume mount instead of ~
• Added fixed --hostname to ensure consistent container identity
• Verified the mount is accessible inside the container