[Bug] Version 0.0.13 - Credential authorization error

[nguyenngothuong]

Version: 0.0.13

Error: "This credential is only authorized for use with Claude Code and cannot be used for other API requests."

Description:
When trying to use the package, the Anthropic API returns this credential authorization error indicating the credentials are restricted to Claude Code only.

Expected behavior: The credentials should work for general API requests.

Steps to reproduce:

1. Install version 0.0.13
2. Attempt to make API calls
3. Receive authorization error

[ten3roberts]

I think it is this commit: 9362376

@rekram1-node (sorry to ping you)

Opencode recently bumped the deps pulling this commit into mainline.

Opencode 1.1.36 still works for me (have the binary open and running)

Launching a new instance to 1.1.39 breaks it

[nguyenngothuong]

Root cause identified: commit 9362376 adds the system message "You are Claude Code, Anthropic's official CLI for Claude." which triggers the API to check for Claude Code credentials and reject others.

Tested working versions:

• Opencode 1.1.36 - works
• Opencode 1.1.39 - breaks (deps bump pulled in commit 9362376)

The commit changes in index.mjs:

[ErcinDedeoglu]

I confirm the claim.

[elmagow]

To make it work while it's fixed, just replace the index.mjs with this one:
https://github.com/anomalyco/opencode-anthropic-auth/tree/ab81634b23bf82bdd1ad2d2eb22781fdff7c9477

[diogomartino]

I'm on opencode 1.1.36 and it was working fine without this plugin until today. I installed the latest version and still it wasn't working. But I found the problem: opencode was actually force installing the 0.0.9 version instead of the 0.0.13 for some reason. Forcing @latest or @0.0.13 didn't work. I force changed the version in ~/.cache/opencode/package.json, ran bun install and removed write permissions from the package.json. It's working fine now. Might be useful to someone else.

[devxoul]

1.1.36 works for me as well.

[Olbrasoft]

Same issue here, started today.

What we tried:

• Downgraded OpenCode from 1.1.39 to 1.1.36 (as suggested in comments) - didn't help
• Installed opencode-anthropic-auth@0.0.9 (older version without the experimental.chat.system.transform hook) - didn't help
• Set autoupdate: false in config to prevent auto-upgrades
• Cleared ~/.cache/opencode/ and reinstalled

Result: Still getting the error: "This credential is only authorized for use with Claude Code and cannot be used for other API requests."

It seems like Anthropic may have changed something on their API side that now blocks even older plugin versions. The issue might not be fixable just by reverting to older versions.

Environment:

• OS: Linux (Debian)
• OpenCode: tested with both 1.1.36 and 1.1.39
• Plugin: tested with 0.0.9 and 0.0.12

[ErcinDedeoglu]

#33