openclaw - 💡(How to fix) Fix Sandboxed agents can't reply to channel DMs — message tool excluded from default sandbox allowlist; plain-text reply routes to internal webchat

Summary

A sandboxed agent (sandbox: { mode: "all", scope: "agent" }) receives a Telegram DM and generates a reply, but the reply never reaches the user. The same agent in host mode (sandbox: off) replies fine.

Environment

• OpenClaw 2026.5.27, model openai-codex/gpt-5.5
• Linux (Ubuntu), Docker sandbox backend
• One gateway hosting multiple agents, one Telegram bot per agent

Symptom

Inbound DM is received, the agent runs, then the reply is logged as:

[agent:nested] session=agent:<id>:telegram:direct:<uid> channel=webchat <reply text>

…and never delivered to the originating bot. The user sees "thinking…" then nothing.

Root cause (two parts)

1. message tool is excluded from the default sandbox allowlist. DEFAULT_TOOL_ALLOW for sandboxes includes sessions_send but not message. The gateway logs it clearly:

   [agents/tool-policy] tool policy removed N tool(s) via sandbox tools.allow: ..., message, ...

   So a sandboxed agent's only messaging tool is sessions_send, which is dispatched with deliver:false, channel:INTERNAL_MESSAGE_CHANNEL, lane:nested → logged via the nested lane, never delivered to a real channel.
2. The sandboxed plain-text auto-reply routes to the internal webchat channel instead of the session's inbound channel, so even without an explicit tool call the reply is lost.

Workaround

Add message to the agent's sandbox allowlist:

"tools": { "sandbox": { "tools": { "alsoAllow": ["message"] } } }

The agent then uses the message tool → message.action channel=telegram → outbound send ok. Host-mode agents are unaffected (they reply via the native path).

Suggested fixes

• Include message in the default sandbox tool allowlist (or surface a clear hint when a channel-bound sandboxed agent has no deliverable messaging tool).
• Route the sandboxed plain-text auto-reply to the session's inbound channel (lastChannel/origin.provider) instead of webchat.