Merge pull request #2931 from sjawhar/feat/tmux-session-isolation

feat(tmux): add session isolation mode for subagent panes

src/features/tmux-subagent/manager.ts

@@ -8,6 +8,8 @@ import {
   POLL_INTERVAL_BACKGROUND_MS,
   SESSION_READY_POLL_INTERVAL_MS,
   SESSION_READY_TIMEOUT_MS,
+  spawnTmuxWindow,
+  spawnTmuxSession,
 } from "../../shared/tmux"
 import { queryWindowState } from "./pane-state-querier"
 import { decideSpawnActions, decideCloseAction, type SessionMapping } from "./decision-engine"
@@ -68,6 +70,7 @@ export class TmuxSessionManager {
   private nullStateCount = 0
   private deps: TmuxUtilDeps
   private pollingManager: TmuxPollingManager
+  private isolatedWindowPaneId: string | undefined
   constructor(ctx: PluginInput, tmuxConfig: TmuxConfig, deps: TmuxUtilDeps = defaultTmuxDeps) {
     this.client = ctx.client
     this.tmuxConfig = tmuxConfig
@@ -103,6 +106,47 @@ export class TmuxSessionManager {
     return this.tmuxConfig.enabled && this.deps.isInsideTmux()
   }
 
+  private isIsolated(): boolean {
+    return this.tmuxConfig.isolation === "window" || this.tmuxConfig.isolation === "session"
+  }
+
+  private getEffectiveSourcePaneId(): string | undefined {
+    if (this.isIsolated() && this.isolatedWindowPaneId) {
+      return this.isolatedWindowPaneId
+    }
+    return this.sourcePaneId
+  }
+
+  private async spawnInIsolatedContainer(
+    sessionId: string,
+    title: string,
+  ): Promise<string | null> {
+    if (!this.isIsolated()) return null
+    if (this.isolatedWindowPaneId) {
+      const state = await queryWindowState(this.isolatedWindowPaneId).catch(() => null)
+      if (state) return null
+      this.isolatedWindowPaneId = undefined
+    }
+
+    const isolation = this.tmuxConfig.isolation
+    log("[tmux-session-manager] creating isolated tmux container", { isolation, sessionId, title })
+
+    const result = isolation === "session"
+      ? await spawnTmuxSession(sessionId, title, this.tmuxConfig, this.serverUrl, this.sourcePaneId)
+      : await spawnTmuxWindow(sessionId, title, this.tmuxConfig, this.serverUrl)
+
+    if (result.success && result.paneId) {
+      this.isolatedWindowPaneId = result.paneId
+      log("[tmux-session-manager] isolated container created", {
+        isolation,
+        paneId: result.paneId,
+      })
+      return result.paneId
+    }
+    log("[tmux-session-manager] failed to create isolated container", { isolation, sessionId })
+    return null
+  }
+
   private getCapacityConfig(): CapacityConfig {
     return {
       layout: this.tmuxConfig.layout,
@@ -141,10 +185,11 @@ export class TmuxSessionManager {
   }
 
   private async queryWindowStateSafely(): Promise<WindowState | null> {
-    if (!this.sourcePaneId) return null
+    const paneId = this.getEffectiveSourcePaneId()
+    if (!paneId) return null
 
     try {
-      return await queryWindowState(this.sourcePaneId)
+      return await queryWindowState(paneId)
     } catch (error) {
       log("[tmux-session-manager] failed to query window state for close", {
         error: String(error),
@@ -164,7 +209,7 @@ export class TmuxSessionManager {
           config: this.tmuxConfig,
           serverUrl: this.serverUrl,
           windowState: state,
-          sourcePaneId: this.sourcePaneId,
+          sourcePaneId: this.getEffectiveSourcePaneId(),
         }
       )
 
@@ -301,7 +346,8 @@ export class TmuxSessionManager {
   }
 
   private async tryAttachDeferredSession(): Promise<void> {
-    if (!this.sourcePaneId) return
+    const effectiveSourcePaneId = this.getEffectiveSourcePaneId()
+    if (!effectiveSourcePaneId) return
     const sessionId = this.deferredQueue[0]
     if (!sessionId) {
       this.stopDeferredAttachLoop()
@@ -329,7 +375,7 @@ export class TmuxSessionManager {
       return
     }
 
-    const state = await queryWindowState(this.sourcePaneId)
+    const state = await queryWindowState(effectiveSourcePaneId)
     if (!state) {
       this.nullStateCount += 1
       log("[tmux-session-manager] deferred attach window state is null", {
@@ -365,7 +411,7 @@ export class TmuxSessionManager {
       config: this.tmuxConfig,
       serverUrl: this.serverUrl,
       windowState: state,
-      sourcePaneId: this.sourcePaneId,
+      sourcePaneId: effectiveSourcePaneId,
     })
 
     if (!result.success || !result.spawnedPaneId) {
@@ -470,12 +516,37 @@ export class TmuxSessionManager {
       log("[tmux-session-manager] session already tracked or pending", { sessionId })
       return
     }
-    const sourcePaneId = this.sourcePaneId
 
     this.pendingSessions.add(sessionId)
 
     await this.enqueueSpawn(async () => {
       try {
+        const isolatedPaneId = await this.spawnInIsolatedContainer(sessionId, title)
+        if (isolatedPaneId) {
+          const sessionReady = await this.waitForSessionReady(sessionId)
+          this.sessions.set(
+            sessionId,
+            createTrackedSession({ sessionId, paneId: isolatedPaneId, description: title }),
+          )
+          this.pollingManager.startPolling()
+          log("[tmux-session-manager] first subagent spawned in isolated window", {
+            sessionId,
+            paneId: isolatedPaneId,
+            sessionReady,
+          })
+          return
+        }
+
+        if (this.isIsolated()) {
+          log("[tmux-session-manager] isolated container failed, skipping inline fallback to preserve isolation", { sessionId })
+          return
+        }
+        const sourcePaneId = this.getEffectiveSourcePaneId()
+        if (!sourcePaneId) {
+          log("[tmux-session-manager] no effective source pane id")
+          return
+        }
+
         const state = await queryWindowState(sourcePaneId)
         if (!state) {
           log("[tmux-session-manager] failed to query window state, deferring session")
@@ -609,7 +680,7 @@ export class TmuxSessionManager {
 
   async onSessionDeleted(event: { sessionID: string }): Promise<void> {
     if (!this.isEnabled()) return
-    if (!this.sourcePaneId) return
+    if (!this.getEffectiveSourcePaneId()) return
 
     this.removeDeferredSession(event.sessionID)
 
@@ -635,7 +706,7 @@ export class TmuxSessionManager {
         config: this.tmuxConfig,
         serverUrl: this.serverUrl,
         windowState: state,
-        sourcePaneId: this.sourcePaneId,
+        sourcePaneId: this.getEffectiveSourcePaneId(),
       })
 
       if (!result.success) {
@@ -712,6 +783,7 @@ export class TmuxSessionManager {
     }
 
     await this.retryPendingCloses()
+    this.isolatedWindowPaneId = undefined
 
     log("[tmux-session-manager] cleanup complete")
   }