openclaw - 💡(How to fix) Fix sessions_spawn model parameter still ignored — all subagents run on parent's default model (2026.4.25) [1 comments, 2 participants]

Bug: sessions_spawn model override is completely ignored

Summary

The model parameter in sessions_spawn is silently ignored. All subagents run on the parent session's default model (agents.defaults.model.primary), regardless of what model is specified.

This is a different bug from #17479 which was fixed in PR #21088. The PR fix (capturing allowAnyModel from buildAllowedModelSet) IS present in our codebase, but subagents still use the default model.

Environment

• OpenClaw: 2026.4.25 (aa36ee6)
• Default model: ollama/glm-5.1:cloud
• Ollama provider with cloud models

Reproduction

1. Set agents.defaults.model.primary to ollama/glm-5.1:cloud
2. Add ollama/deepseek-v4-pro:cloud and ollama/kimi-k2.6:cloud to agents.defaults.models
3. Also set agents.defaults.subagents.model.primary to ollama/deepseek-v4-pro:cloud
4. Spawn subagents with different models:

sessions_spawn(model="ollama/kimi-k2.6:cloud", task="What model are you?")
sessions_spawn(model="ollama/deepseek-v4-pro:cloud", task="What model are you?")
sessions_spawn(model="ollama/glm-5.1:cloud", task="What model are you?")

Expected behavior

Each subagent runs on the specified model.

Actual behavior

All three subagents run on GLM 5.1, the parent's default model.

Subagent session transcripts confirm "model_change": {"provider": "ollama", "modelId": "glm-5.1:cloud"} in all cases.

Verified configurations that do NOT work

Code analysis

The fix from PR #21088 IS present in agent-command-Bxk-YetL.js (line 520: let allowAnyModel = !hasAllowlist). However, sessions_spawn tool execution goes through subagent-spawn-cbH-XgdN.js which calls resolveSubagentSpawnModelSelection() → returns the correct model string → passes it to persistInitialChildSessionRuntimeModel() → writes to session store.

But the session transcript shows the model was never changed from glm-5.1:cloud. The model_change event in the subagent transcript always records the parent's default model.

This suggests the model resolution happens at a different layer (possibly the PI agent loop or Ollama provider routing) that overrides the stored model selection before the first inference.

Related issues

• #17479 — Original bug (fixed by PR #21088, but fix doesn't cover this path)
• #13159 — Model override ignored in isolated sessions
• #10963 — Subagents ignore agents.defaults.subagents.model.primary
• zooclaw.ai workaround article — Documents the bug and suggests session_status(model=...) as workaround (which also doesn't work for subagents)

Workaround

None found for subagents. The only working workaround is to change the parent session model via session_status(model=...) and run the task in the main session instead of a subagent.