DeepSeek V4 Pro (OpenRouter) reasoning_content error - v1.14.27

[077dwei]

Description

[DeepSeek] The reasoning_content in the thinking mode must be passed back to the API.

OpenCode version

v1.14.27 (latest)

Plugins

No response

OpenCode version

V1.14.27

Steps to reproduce

No response

Screenshot and/or share link

Operating System

Debian GNU/Linux 13 (trixie) (6.12.74+deb13+1-amd64)

Terminal

No response

[github-actions]

This issue might be a duplicate of several existing issues reporting the same reasoning_content error with DeepSeek thinking mode. Please check:

• The bug requiring deepseek requests to include the thinking content still exists in versions 1.14.26 and 27. #24558: Same bug still present in v1.14.26 and v1.14.27
• deepseek v4 provider error: The reasoning_content in the thinking mode must be passed back to the API #24497: DeepSeek V4 reasoning_content provider error (same error message)
• DeepSeek V4: reasoning_content lost on second interleaved pass (regression from #24146) #24442: DeepSeek V4 reasoning_content lost on second interleaved pass (regression)
• DeepSeek V4 400: The reasoning_content in the thinking mode must be passed back to the API. #24385: DeepSeek V4 400 error — same error message
• Bug: DeepSeek reasoning_content not passed back in multi-turn conversations #24261: DeepSeek reasoning_content not passed back in multi-turn conversations
• [DeepSeek] The reasoning_content in the thinking mode must be passed back to the API. #24188: [DeepSeek] The reasoning_content in the thinking mode must be passed back to the API
• DeepSeek V4 Flash: reasoning_content must be passed back to API when using thinking mode #24130: DeepSeek V4 Flash — same reasoning_content error
• The reasoning_content in the thinking mode must be passed back to the API. #24083: The reasoning_content in the thinking mode must be passed back to the API

If your issue is the same, please consider adding a reaction or comment to one of the above instead of opening a new report.

[rekram1-node]

@077dwei please please provide a session demonstrating it:

opencode export > session.json

RUN THIS IN YOUR TERMINAL DO NOT USE /export

And then send me the session dump.

[Meepoljdx]

same issue @rekram1-node this is my session json

session.json

[077dwei]

@rekram1-node

session.json

Trimmed session (only error-related part):

[rekram1-node]

@Meepoljdx you are using something called:
"providerID": "deepseek-plat",

I need to see your provider config it's prolly missing interleaved settings

[broaz27]

I can't reproduce the issue anymore, but only in new sessions, im on deepseekv4 pro, provided by deepseek on openrouter, my interleaved settings are on their default "reasoning_content"

[rekram1-node]

@077dwei I can't have a trimmed session, I need your actual session otherwise it provides basically 0 value. If you need it secret use --sanitize

The session you sent has 0 assistant messages so the error would be impossible

[077dwei]

@rekram1-node Sorry for sending the trimmed version earlier. Here is the full session exported with --sanitize:

session_sanitized.json

[ngkhanhlinh2k4]

me too, still error like that

[rekram1-node]

@ngkhanhlinh2k4 more info plz