Bug type

Crash (process/app exits or hangs)

Beta release blocker

Yes

Summary

Browser tool errors (tab not found, CDP disconnect, Chrome process crash) cause the entire OpenClaw gateway to
receive SIGTERM and restart, instead of the error being caught and returned to the agent session gracefully. This creates a crash loop when the agent retries browser actions.

Steps to reproduce

1. Agent session uses the browser tool to navigate to a page (e.g., x.com)
2. The Chrome tab is closed or the CDP connection drops
3. Agent retries with browser snapshot on the now-missing tab
4. Gateway receives SIGTERM and restarts
5. On restart, agent session resumes and retries the browser action → restart loop

Expected behavior

Browser tool should return an error to the agent session (e.g., "tab not found" or "CDP disconnected") without
affecting the gateway process. The agent can then decide to retry or abandon the action.

Actual behavior

Gateway receives SIGTERM and fully restarts. On restart, the agent session resumes from its transcript and
immediately retries the failed browser action, causing an infinite restart loop.

OpenClaw version

OpenClaw: 2026.4.1 (also reproduced on 2026.3.28 and 2026.3.31)

Operating system

OS: Linux 6.17.0-19-generic (x64), Ubuntu Zorin OS 18 Core

Install method

npm (global)

Model

grok-4-1-fast-reasoning (xAI)

Provider / routing chain

xai/grok-4-1-fast-reasoning / openai-codex/gpt-5.4 / openai-codex/gpt-5.3-codex / lmstudio/qwen_qwen3.5-35b-a3b / nvidia/moonshotai/kimi-k2.5 / openrouter/auto / xai/grok-4.20-0309-reasoning

Additional provider/model setup details

Gateway config (openclaw.json)

• agents.defaults.model.primary: xai/grok-4-1-fast-reasoning
• agents.defaults.model.fallbacks: [openai-codex/gpt-5.4, openai-codex/gpt-5.3-codex,
  lmstudio/qwen_qwen3.5-35b-a3b, nvidia/moonshotai/kimi-k2.5, openrouter/auto, xai/grok-4.20-0309-reasoning]
• tools.exec: {security: "full", ask: "off"}
• tools.media: image (google/gemini-3-flash-preview), video (google/gemini-3-flash-preview)
• agents.defaults.sandbox.browser was toggled by the agent via config.patch during the crash loop

Agent setup

• main agent: xai/grok-4-1-fast-reasoning (Telegram, WhatsApp, webchat)
• qwen agent: lmstudio/qwen_qwen3.5-35b-a3b (cron jobs only, local LM Studio)
• auth-profiles: openai-codex (OAuth), xai (api_key), openrouter (api_key), nvidia (api_key), google (api_key)

Crash scenario

• main agent session via Telegram/webchat triggers browser tool
• browser tool launches Chrome on :18800 (openclaw managed)
• agent navigates to x.com, performs actions
• Chrome tab closes or CDP connection drops
• browser tool returns "tab not found" errors
• agent attempts config.patch to re-enable sandbox.browser.enabled
• config.patch triggers gateway restart via restartDelayMs
• on restart, session resumes from .jsonl transcript, immediately retries browser → loop
• even failed config.patch validation triggers the restart path

Workaround

• tools.deny: ["browser"] prevents all browser tool calls
• manual session clearing (rm agents/main/sessions/*.jsonl) breaks the loop

Logs, screenshots, and evidence

[tools] browser failed: tab not found
  raw_params={"action":"snapshot","targetId":"096521823C69306118207257C1B659D3","compact":true}
  [gateway] signal SIGTERM received
  [gateway] received SIGTERM; shutting down

  The browser tool errors appear multiple times before the SIGTERM, suggesting the error accumulates until it
  triggers a crash or the agent's config.patch attempt to re-enable sandbox browser triggers a restart.

Impact and severity

Impact: High — gateway becomes unusable in a restart loop, all channels (Telegram, WhatsApp), cron jobs, and
dashboard go down until sessions are manually cleared

Severity: Critical

Additional information

• The issue is amplified when the agent has a persistent plan in its session transcript that involves browser automation — each restart resumes the plan and re-triggers the failure.
  • config.patch calls from the agent to modify agents.defaults.sandbox.browser.enabled also trigger gateway restarts even when the patch fails validation, compounding the loop.
  • Workaround: Adding browser to tools.deny in openclaw.json prevents the crash loop entirely but disables all browser functionality.