fix(tmux): defer subagent attach until pane focus

src/shared/tmux/tmux-utils.ts

@@ -9,9 +9,11 @@ export type { PaneDimensions } from "./tmux-utils/pane-dimensions"
 export { spawnTmuxPane } from "./tmux-utils/pane-spawn"
 export { closeTmuxPane } from "./tmux-utils/pane-close"
 export { replaceTmuxPane } from "./tmux-utils/pane-replace"
+export { activateTmuxPane } from "./tmux-utils/pane-activate"
 export { spawnTmuxWindow } from "./tmux-utils/window-spawn"
 export { spawnTmuxSession, getIsolatedSessionName } from "./tmux-utils/session-spawn"
 export { killTmuxSessionIfExists } from "./tmux-utils/session-kill"
 export { sweepStaleOmoAgentSessions, sweepTmuxSessionsWith } from "./tmux-utils/stale-session-sweep"
+export { buildTmuxAttachCommand, buildTmuxPlaceholderCommand } from "./tmux-utils/pane-command"
 
 export { applyLayout, enforceMainPaneWidth } from "./tmux-utils/layout"

src/shared/tmux/tmux-utils/pane-activate.ts

@@ -0,0 +1,33 @@
+import { getTmuxPath } from "../../../tools/interactive-bash/tmux-path-resolver"
+import { log } from "../../logger"
+import { runTmuxCommand } from "../runner"
+import { isInsideTmux } from "./environment"
+import { buildTmuxAttachCommand } from "./pane-command"
+
+export async function activateTmuxPane(
+  paneId: string,
+  sessionId: string,
+  serverUrl: string,
+  directory: string,
+): Promise<boolean> {
+  if (!isInsideTmux()) {
+    log("[activateTmuxPane] SKIP: not inside tmux", { paneId, sessionId })
+    return false
+  }
+
+  const tmux = await getTmuxPath()
+  if (!tmux) {
+    log("[activateTmuxPane] SKIP: tmux not found", { paneId, sessionId })
+    return false
+  }
+
+  const opencodeCmd = buildTmuxAttachCommand(serverUrl, sessionId, directory)
+  const result = await runTmuxCommand(tmux, ["respawn-pane", "-k", "-t", paneId, opencodeCmd])
+  if (result.exitCode !== 0) {
+    log("[activateTmuxPane] FAILED", { paneId, sessionId, exitCode: result.exitCode, stderr: result.stderr.trim() })
+    return false
+  }
+
+  log("[activateTmuxPane] SUCCESS", { paneId, sessionId })
+  return true
+}

src/shared/tmux/tmux-utils/pane-command.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect, it } from "bun:test"
+import { buildTmuxAttachCommand, buildTmuxPlaceholderCommand } from "./pane-command"
+
+describe("buildTmuxAttachCommand", () => {
+  it("escapes serverUrl shell metacharacters", () => {
+    const cmd = buildTmuxAttachCommand("http://localhost:3000$(whoami);rm -rf /", "ses_abc123")
+    expect(cmd).toContain("\\$")
+    expect(cmd).toContain("\\;")
+    expect(cmd).not.toMatch(/[^\\];\s*rm/)
+  })
+
+  it("escapes session id shell metacharacters", () => {
+    const cmd = buildTmuxAttachCommand("http://localhost:3000", 'ses_abc"$(whoami)"')
+    expect(cmd).toContain('\\"')
+    expect(cmd).toContain("\\$")
+  })
+})
+
+describe("buildTmuxPlaceholderCommand", () => {
+  it("produces inert placeholder command instead of immediate attach", () => {
+    const cmd = buildTmuxPlaceholderCommand("My Task")
+    expect(cmd).toContain("Focus this pane to attach.")
+    expect(cmd).toContain("tail -f /dev/null")
+    expect(cmd).not.toContain("opencode attach")
+  })
+
+  it("keeps single quotes and percent signs inside safe printf arguments", () => {
+    const cmd = buildTmuxPlaceholderCommand("Fix Bob's 100% broken pane")
+    expect(cmd).toContain(`printf '%s\\n%s\\n'`)
+    expect(cmd).toContain(`"OMO subagent pane ready: Fix Bob's 100% broken pane"`)
+  })
+})

src/shared/tmux/tmux-utils/pane-command.ts

@@ -0,0 +1,15 @@
+import { shellEscapeForDoubleQuotedCommand } from "../../shell-env"
+
+const TMUX_COMMAND_SHELL = "/bin/sh"
+
+export function buildTmuxAttachCommand(serverUrl: string, sessionId: string, directory: string): string {
+  const escapedUrl = shellEscapeForDoubleQuotedCommand(serverUrl)
+  const escapedSessionId = shellEscapeForDoubleQuotedCommand(sessionId)
+  const escapedDirectory = shellEscapeForDoubleQuotedCommand(directory || process.cwd())
+  return `${TMUX_COMMAND_SHELL} -c "opencode attach ${escapedUrl} --session ${escapedSessionId} --dir ${escapedDirectory}"`
+}
+
+export function buildTmuxPlaceholderCommand(description: string): string {
+  const escapedDescription = shellEscapeForDoubleQuotedCommand(description)
+  return `${TMUX_COMMAND_SHELL} -c "printf '%s\\n%s\\n' \"OMO subagent pane ready: ${escapedDescription}\" \"Focus this pane to attach.\"; exec tail -f /dev/null"`
+}

src/shared/tmux/tmux-utils/pane-replace.ts

@@ -3,7 +3,7 @@ import { getTmuxPath } from "../../../tools/interactive-bash/tmux-path-resolver"
 import type { SpawnPaneResult } from "../types"
 import type { runTmuxCommand as RunTmuxCommand } from "../runner"
 import { isInsideTmux } from "./environment"
-import { shellSingleQuote } from "../../shell-env"
+import { buildTmuxPlaceholderCommand } from "./pane-command"
 
 type ReplaceTmuxPaneDeps = {
 	log: (message: string, data?: unknown) => void
@@ -32,8 +32,8 @@ export async function replaceTmuxPane(
 	sessionId: string,
 	description: string,
 	config: TmuxConfig,
-	serverUrl: string,
-	directory: string,
+	_serverUrl: string,
+	_directory: string,
 	depsInput?: Partial<ReplaceTmuxPaneDeps>,
 ): Promise<SpawnPaneResult> {
 	const deps = await resolveReplaceTmuxPaneDeps(depsInput)
@@ -56,10 +56,9 @@ export async function replaceTmuxPane(
 	log("[replaceTmuxPane] sending Ctrl+C for graceful shutdown", { paneId })
 	await runTmuxCommand(tmux, ["send-keys", "-t", paneId, "C-c"])
 
-	const effectiveDirectory = directory || process.cwd()
-	const opencodeCmd = `opencode attach ${shellSingleQuote(serverUrl)} --session ${shellSingleQuote(sessionId)} --dir ${shellSingleQuote(effectiveDirectory)}`
+	const placeholderCmd = buildTmuxPlaceholderCommand(description)
 
-	const result = await runTmuxCommand(tmux, ["respawn-pane", "-k", "-t", paneId, opencodeCmd])
+	const result = await runTmuxCommand(tmux, ["respawn-pane", "-k", "-t", paneId, placeholderCmd])
 
 	if (result.exitCode !== 0) {
 		log("[replaceTmuxPane] FAILED", { paneId, exitCode: result.exitCode, stderr: result.stderr.trim() })

src/shared/tmux/tmux-utils/pane-spawn.ts

@@ -5,7 +5,7 @@ import type { runTmuxCommand as RunTmuxCommand } from "../runner"
 import type { SplitDirection } from "./environment"
 import { isInsideTmux } from "./environment"
 import { isServerRunning } from "./server-health"
-import { shellSingleQuote } from "../../shell-env"
+import { buildTmuxPlaceholderCommand } from "./pane-command"
 
 type SpawnTmuxPaneDeps = {
 	log: (message: string, data?: unknown) => void
@@ -36,7 +36,7 @@ export async function spawnTmuxPane(
 	description: string,
 	config: TmuxConfig,
 	serverUrl: string,
-	directory: string,
+	_directory: string,
 	targetPaneId?: string,
 	splitDirection: SplitDirection = "-h",
 	depsInput?: Partial<SpawnTmuxPaneDeps>,
@@ -76,8 +76,7 @@ export async function spawnTmuxPane(
 
 	log("[spawnTmuxPane] all checks passed, spawning...")
 
-	const effectiveDirectory = directory || process.cwd()
-	const opencodeCmd = `opencode attach ${shellSingleQuote(serverUrl)} --session ${shellSingleQuote(sessionId)} --dir ${shellSingleQuote(effectiveDirectory)}`
+	const placeholderCmd = buildTmuxPlaceholderCommand(description)
 
 	const args = [
 		"split-window",
@@ -87,7 +86,7 @@ export async function spawnTmuxPane(
 		"-F",
 		"#{pane_id}",
 		...(targetPaneId ? ["-t", targetPaneId] : []),
-		opencodeCmd,
+		placeholderCmd,
 	]
 
 	const result = await runTmuxCommand(tmux, args)