Add fork-session lane, /kill command, and auto-routing

[1872-svg]

Summary

• Fork agent lane: /fork <prompt> spawns a parallel Claude session that doesn't touch the main session or queue. Useful for checking progress or asking quick questions while the main agent is running a long task.
• /kill command: Terminates the currently running Claude subprocess immediately.
• Auto-routing: When the main agent is busy, incoming messages are automatically routed to the fork lane instead of queuing behind the current task.
• Fork agent uses Haiku model with a speed-focused system prompt — denies long tasks (compiling, downloads, fuzzing) and answers in 1-3 sentences.

How it works

runner.ts exports killActive(), isMainBusy(), and runFork(). The fork agent runs with --output-format json in a separate subprocess, bypassing the serial queue used by the main session.

In telegram.ts, handleMessage checks isMainBusy() before dispatching — busy → fork, idle → main session.

Test plan

• Send a long-running prompt, then /fork what are you doing? — should get a fast response without interrupting the main task
• Send a long-running prompt, then send another message mid-run — should be auto-routed to fork
• /kill while a task is running — should terminate and confirm
• /kill with nothing running — should report "No active agent running"

[TerrysPOV]

Vision: PARTIAL — fork agent is lightweight but auto-routing silently switches to Haiku without user awareness, violating the "no hidden implicit behaviors" principle.

Overlapping PRs: #76 (modifies activeProc tracking in runner.ts — significant merge conflict risk), #82 (session isolation changes in runner.ts — moderate merge conflict risk)

Code review

Found 3 issues:

1. activeProc overwritten by fork: /kill targets wrong process — runFork calls runClaudeOnce, which unconditionally sets activeProc = proc. If a fork spawns while the main agent is running, activeProc is overwritten to the fork's subprocess. A subsequent /kill kills the fork and leaves the main agent running as an untrackable orphan.

claudeclaw/src/runner.ts

Lines 109 to 117 in 0f1f920

	activeProc = proc;
	const [rawStdout, stderr] = await Promise.all([
	new Response(proc.stdout).text(),
	new Response(proc.stderr).text(),
	]);
	await proc.exited;
	if (activeProc === proc) activeProc = null;

2. Auto-routing silently switches model and context with no notification — When isMainBusy() is true, the message routes to a Haiku fork with a completely different system prompt, with no indication to the user. The response comes from a different model with different capabilities and no main-session context.

claudeclaw/src/commands/telegram.ts

Lines 630 to 636 in 0f1f920

	const prefixedPrompt = promptParts.join("\n");
	const busy = isMainBusy();
	const result = busy
	? await runFork(prefixedPrompt)
	: await runUserMessage("telegram", prefixedPrompt);
	if (result.exitCode !== 0) {

3. Fork auto-routing is always-on with no opt-in gate — Busy-check routing activates for all users on upgrade with no settings.json flag to disable or opt in. This contradicts the established pattern (see feat: Telegram topic/thread support + suppress HEARTBEAT_OK noise #15, Add agentic model routing for intelligent task-based model selection #17) where new routing behaviors must be opt-in.

claudeclaw/src/commands/telegram.ts

Lines 630 to 636 in 0f1f920

	const prefixedPrompt = promptParts.join("\n");
	const busy = isMainBusy();
	const result = busy
	? await runFork(prefixedPrompt)
	: await runUserMessage("telegram", prefixedPrompt);
	if (result.exitCode !== 0) {

---

Closing in favour of #76. The fork agent idea is interesting, but this implementation has two blockers: (1) auto-routing silently switches to Haiku with no user notification — violates the "no hidden implicit behaviors" principle; (2) the feature is always-on with no settings.json opt-in, against the pattern from #15/#17. If you want to resubmit: make routing opt-in via settings, notify the user when a message routes to the fork ("Main busy — routing to fork agent"), and keep FORK_MODEL configurable. Happy to review a v2.

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