openclaw - 💡(How to fix) Fix Feature request: gateway.routing.persist_auto_fallback config flag

Context

buildFallbackSelectionState() in agent-runner.runtime-*.js (line ~324 in 2026.5.7) unconditionally writes modelOverrideSource: "auto" to the per-session store whenever a fallback model is selected during a turn. This causes the session to be silently locked to the fallback model on subsequent turns, even if the primary model later recovers.

Use case impact

In multi-agent orchestration setups, when the primary model (e.g., ollama-cloud/deepseek-v4-pro) hits a transient timeout and a fallback succeeds (e.g., openrouter/openai/gpt-4o-mini), the session is silently and persistently pinned to the fallback. There is no config surface to disable this — it is currently observable only by inspecting sessions.json after the fact or by detecting capability regressions in downstream tasks.

The current workaround is a periodic out-of-band sweep of sessions.json to remove modelOverrideSource: "auto" entries (runs hourly via systemd timer in our deployment). This is reactive and adds operational overhead.

Proposed flag

Add a top-level config option in openclaw.json:

{
  "gateway": {
    "routing": {
      "persist_auto_fallback": false
    }
  }
}

When false (default true for backwards compatibility), buildFallbackSelectionState() would still select the fallback for the current turn but would NOT persist modelOverrideSource: "auto" to the session store. The next turn would re-evaluate model availability from scratch.

Why this matters

For production deployments that prefer "primary or explicit override, never silent stickiness":

• Auto-pin makes incident recovery slower (operator clears the pin manually after platform recovers)
• Auto-pin can degrade quality silently (a single 30-second timeout pins to a weaker model for the entire session lifetime)
• Auto-pin is invisible at the API surface — the only signal is sessions.json contents

A config flag preserves current behavior for users who like the stickiness while letting others opt out.

References

• Related: #83716 (companion request for disabledTools / PreToolUse hook)
• Source location: /app/dist/agent-runner.runtime-*.js line ~324 in 2026.5.7

Happy to submit a PR. Single-line change in the config schema + 5-10 lines in buildFallbackSelectionState() for the conditional.