[Bug]: `oh-my-opencode run --agent Librarian` crashes with "undefined is not an object (evaluating 'agent.model')"

[qingduzhai]

Bug Description

Running oh-my-opencode run --agent Librarian fails before any assistant/user message is persisted. The session is created, but the run immediately throws undefined is not an object (evaluating 'agent.model') and then only polls /session/status until timeout/exit.

This does not look like a generic provider outage because:

• oh-my-opencode run works in the same project/config
• oh-my-opencode run --agent Sisyphus also works in the same project/config
• Atlas can at least enter a session and persist messages, even though that path later hits a separate provider-side Not Found

So this looks like a direct --agent Librarian resolution / agent config parsing bug.

Steps to Reproduce

1. Environment: WSL2 Ubuntu on Windows, OpenCode 1.2.23, oh-my-opencode 3.11.2
2. Configure librarian to use a valid model:

{
  "agents": {
    "librarian": {
      "model": "minimax/MiniMax-M2.5",
      "category": "quick",
      "reasoningEffort": "low"
    }
  },
  "categories": {
    "quick": {
      "model": "minimax/MiniMax-M2.5",
      "reasoningEffort": "low"
    }
  }
}

3. Verify the model exists in OpenCode:

opencode models

It includes:

minimax/MiniMax-M2.5

4. Run:

oh-my-opencode run --agent Librarian --json --no-timestamp 'List deploy_remote.py and app/tests/test_deploy_remote.py only.'

Expected Behavior

The Librarian agent should start normally and return a response, just like Sisyphus does in the same environment.

Actual Behavior

• A session is created successfully
• The run then errors very early with:

undefined is not an object (evaluating 'agent.model')

• After that it keeps polling /session/status
• The resulting session is effectively empty in sqlite:

ses_329243ea9ffengeI53pZD29j27  messages=0  parts=0
ses_3291c4533ffeeBeenCJ2gljNvr  messages=0  parts=0

For comparison, another failing path (Atlas) at least persisted data:

ses_32924512fffeOt1OjPcC6TWH6M  messages=2  parts=1

Doctor Output

 oMoMoMoMo Doctor 

 ? 1 issue found:

1. GitHub CLI not authenticated
   gh CLI is installed but not logged in.
   Fix: Run: gh auth login
   Affects: GitHub automation

Error Logs

INFO  2026-03-10T08:27:32 +4ms service=server method=POST path=/session/ses_329243ea9ffengeI53pZD29j27/prompt_async request
INFO  2026-03-10T08:27:32 +29ms service=server status=completed duration=29 method=POST path=/session/ses_329243ea9ffengeI53pZD29j27/prompt_async request
ERROR 2026-03-10T08:27:32 +3ms service=default e=undefined is not an object (evaluating 'agent.model') rejection

Relevant log file:

• /home/woody/.local/share/opencode/log/2026-03-10T082728.log

Configuration

Global config (sanitized):

{
  "default_run_agent": "sisyphus",
  "agents": {
    "sisyphus": {
      "model": "foxcode/gpt-5.4",
      "category": "unspecified-high",
      "reasoningEffort": "high"
    },
    "librarian": {
      "model": "minimax/MiniMax-M2.5",
      "category": "quick",
      "reasoningEffort": "low",
      "prompt_append": "Cheap evidence gatherer. Use for document lookup, quick summaries, and low-ambiguity retrieval work."
    }
  },
  "categories": {
    "quick": {
      "model": "minimax/MiniMax-M2.5",
      "reasoningEffort": "low"
    }
  }
}

Project config (sanitized):

{
  "agents": {
    "librarian": {
      "prompt_append": "Focus on cheap repo evidence gathering: config locations, route definitions, service/schema references, deploy artifacts, and test entry points. Escalate if ambiguity remains."
    }
  }
}

Additional Context

• This feels related to agent-specific config resolution, not generic model availability.
• OpenCode sees the model correctly.
• Sisyphus works in the same setup.
• The failure happens before any real message content is stored.
• Possibly related issue families, but this exact failure mode looks distinct from them: [Bug]: Agent model configuration causes model to revert to default after sending message in web mode #2351, [Bug]: Plugin/user agents not injected into Sisyphus system prompt (customAgentSummaries type mismatch) #2386, [Question]: How do I specify the subagent to use a specific model? #2416.

Operating System

Linux (WSL2 Ubuntu on Windows 11)

OpenCode Version

1.2.23