8 replies

Sub-agents can't spawn

✅Solved

@Krill - I RTFM, consulted some outside LLMs, and am still stuck at:

I tried again after the restart, but the subagent spawning step still fails: the gateway reports “Unable to create or bind a thread for this subagent session. Session mode is unavailable for this target.” Without a thread-capable subagent host I can’t keep a persistent
Strategy/Engineering thinker alive or exchange rounds through the orchestrator.

We’re blocked on gateway-level support for thread subagent sessions. Once the necessary hooks are available—or if there’s another mechanism you’d prefer for orchestrating the personas—let me know and I’ll retry immediately.

Here' the relevant sections of openclaw.json

},
"agents": {
"defaults": {
"model": {
"primary": "openai-codex/gpt-5.1-codex-mini"
},
"models": {
"openai-codex/gpt-5.1-codex-mini": {},
"openrouter/minimax/minimax-m2.5": {},
"openrouter/qwen/qwen3.5-397b-a17b": {}
},
"workspace": "/Users/bob/.openclaw/workspace",
"compaction": {
"mode": "safeguard"
},
"maxConcurrent": 4,
"subagents": {
"maxSpawnDepth": 2,
"maxConcurrent": 8,
"maxChildrenPerAgent": 5,
"runTimeoutSeconds": 0
}
}
},
"tools": {
"profile": "full",
"sessions": {
"visibility": "tree"
}
},

Solution

Your config is fine for Discord thread-bound subagent sessions now (

spawnSubagentSessions: true

spawnSubagentSessions: true

).

The remaining blocker is this line:

spawn attempt is initiated from the CLI TUI

That error is expected in that case.

Why it fails (what “target” means here)

mode: "session"

mode: "session"

for subagent runtime is implemented as “bind this child session to a chat thread so future messages route to it”.

Right now, the only “thread-capable target” for subagent session mode is Discord thread bindings (via the Discord channel plugin hook). When you spawn from the CLI TUI, the requester session doesn’t have a Discord