fix: resolve 3 community-reported bugs (#2915, #2917, #2918)

- background_output: snapshot read cursor before consuming, restore on
  /undo message removal so re-reads return data (fixes #2915)
- MCP loader: preserve oauth field in transformMcpServer, add scope/
  projectPath filtering so local-scoped MCPs only load in matching
  directories (fixes #2917)
- runtime-fallback: add 'reached your usage limit' to retryable error
  patterns so quota exhaustion triggers model fallback (fixes #2918)

Verified: bun test (4606 pass / 0 fail), tsc --noEmit clean

src/features/claude-code-mcp-loader/loader.ts

@@ -10,6 +10,7 @@ import type {
 } from "./types"
 import { transformMcpServer } from "./transformer"
 import { log } from "../../shared/logger"
+import { shouldLoadMcpServer } from "./scope-filter"
 
 interface McpConfigPath {
   path: string
@@ -75,6 +76,7 @@ export async function loadMcpConfigs(
   const loadedServers: LoadedMcpServer[] = []
   const paths = getMcpConfigPaths()
   const disabledSet = new Set(disabledMcps)
+  const cwd = process.cwd()
 
   for (const { path, scope } of paths) {
     const config = await loadMcpConfigFile(path)
@@ -86,6 +88,15 @@ export async function loadMcpConfigs(
         continue
       }
 
+      if (!shouldLoadMcpServer(serverConfig, cwd)) {
+        log(`Skipping MCP server "${name}" because local scope does not match cwd`, {
+          path,
+          projectPath: serverConfig.projectPath,
+          cwd,
+        })
+        continue
+      }
+
       if (serverConfig.disabled) {
         log(`Disabling MCP server "${name}"`, { path })
         delete servers[name]

src/features/claude-code-mcp-loader/scope-filter.ts

@@ -0,0 +1,28 @@
+import { existsSync, realpathSync } from "fs"
+import { resolve } from "path"
+import type { ClaudeCodeMcpServer } from "./types"
+
+function normalizePath(path: string): string {
+  const resolvedPath = resolve(path)
+
+  if (!existsSync(resolvedPath)) {
+    return resolvedPath
+  }
+
+  return realpathSync(resolvedPath)
+}
+
+export function shouldLoadMcpServer(
+  server: Pick<ClaudeCodeMcpServer, "scope" | "projectPath">,
+  cwd = process.cwd()
+): boolean {
+  if (server.scope !== "local") {
+    return true
+  }
+
+  if (!server.projectPath) {
+    return false
+  }
+
+  return normalizePath(server.projectPath) === normalizePath(cwd)
+}

src/features/claude-code-mcp-loader/scope-filtering.test.ts

@@ -0,0 +1,82 @@
+import { afterEach, beforeEach, describe, expect, it, mock } from "bun:test"
+import { mkdirSync, rmSync, writeFileSync } from "fs"
+import { tmpdir } from "os"
+import { join } from "path"
+
+const TEST_DIR = join(tmpdir(), `mcp-scope-filtering-test-${Date.now()}`)
+const TEST_HOME = join(TEST_DIR, "home")
+
+describe("loadMcpConfigs", () => {
+  beforeEach(() => {
+    mkdirSync(TEST_DIR, { recursive: true })
+    mkdirSync(TEST_HOME, { recursive: true })
+    mock.module("os", () => ({
+      homedir: () => TEST_HOME,
+      tmpdir,
+    }))
+    mock.module("../../shared", () => ({
+      getClaudeConfigDir: () => join(TEST_HOME, ".claude"),
+    }))
+    mock.module("../../shared/logger", () => ({
+      log: () => {},
+    }))
+  })
+
+  afterEach(() => {
+    mock.restore()
+    rmSync(TEST_DIR, { recursive: true, force: true })
+  })
+
+  describe("#given user-scoped MCP entries with local scope metadata", () => {
+    it("#when loading configs #then only servers matching the current project path are loaded", async () => {
+      writeFileSync(
+        join(TEST_HOME, ".claude.json"),
+        JSON.stringify({
+          mcpServers: {
+            globalServer: {
+              command: "npx",
+              args: ["global-server"],
+            },
+            matchingLocal: {
+              command: "npx",
+              args: ["matching-local"],
+              scope: "local",
+              projectPath: TEST_DIR,
+            },
+            nonMatchingLocal: {
+              command: "npx",
+              args: ["non-matching-local"],
+              scope: "local",
+              projectPath: join(TEST_DIR, "other-project"),
+            },
+            missingProjectPath: {
+              command: "npx",
+              args: ["missing-project-path"],
+              scope: "local",
+            },
+          },
+        })
+      )
+
+      const originalCwd = process.cwd()
+      process.chdir(TEST_DIR)
+
+      try {
+        const { loadMcpConfigs } = await import("./loader")
+        const result = await loadMcpConfigs()
+
+        expect(result.servers).toHaveProperty("globalServer")
+        expect(result.servers).toHaveProperty("matchingLocal")
+        expect(result.servers).not.toHaveProperty("nonMatchingLocal")
+        expect(result.servers).not.toHaveProperty("missingProjectPath")
+
+        expect(result.loadedServers.map((server) => server.name)).toEqual([
+          "globalServer",
+          "matchingLocal",
+        ])
+      } finally {
+        process.chdir(originalCwd)
+      }
+    })
+  })
+})

src/features/claude-code-mcp-loader/transformer.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from "bun:test"
+import { transformMcpServer } from "./transformer"
+
+describe("transformMcpServer", () => {
+  describe("#given a remote MCP server with oauth config", () => {
+    it("#when transforming the server #then preserves oauth on the remote config", () => {
+      const transformed = transformMcpServer("remote-oauth", {
+        type: "http",
+        url: "https://mcp.example.com",
+        headers: { Authorization: "Bearer test" },
+        oauth: {
+          clientId: "client-id",
+          scopes: ["read", "write"],
+        },
+      })
+
+      expect(transformed).toEqual({
+        type: "remote",
+        url: "https://mcp.example.com",
+        headers: { Authorization: "Bearer test" },
+        oauth: {
+          clientId: "client-id",
+          scopes: ["read", "write"],
+        },
+        enabled: true,
+      })
+    })
+  })
+})

src/features/claude-code-mcp-loader/transformer.ts

@@ -30,6 +30,10 @@ export function transformMcpServer(
       config.headers = expanded.headers
     }
 
+    if (expanded.oauth && Object.keys(expanded.oauth).length > 0) {
+      config.oauth = expanded.oauth
+    }
+
     return config
   }
 

src/features/claude-code-mcp-loader/types.ts

@@ -1,5 +1,10 @@
 export type McpScope = "user" | "project" | "local"
 
+export interface McpOAuthConfig {
+  clientId?: string
+  scopes?: string[]
+}
+
 export interface ClaudeCodeMcpServer {
   type?: "http" | "sse" | "stdio"
   url?: string
@@ -7,10 +12,9 @@ export interface ClaudeCodeMcpServer {
   args?: string[]
   env?: Record<string, string>
   headers?: Record<string, string>
-  oauth?: {
-    clientId?: string
-    scopes?: string[]
-  }
+  oauth?: McpOAuthConfig
+  scope?: McpScope
+  projectPath?: string
   disabled?: boolean
 }
 
@@ -29,6 +33,7 @@ export interface McpRemoteConfig {
   type: "remote"
   url: string
   headers?: Record<string, string>
+  oauth?: McpOAuthConfig
   enabled?: boolean
 }
 

src/features/claude-code-plugin-loader/mcp-server-loader.test.ts

@@ -0,0 +1,76 @@
+import { afterEach, beforeEach, describe, expect, it, mock } from "bun:test"
+import { mkdirSync, rmSync, writeFileSync } from "fs"
+import { tmpdir } from "os"
+import { join } from "path"
+import type { LoadedPlugin } from "./types"
+
+const TEST_DIR = join(tmpdir(), `plugin-mcp-loader-test-${Date.now()}`)
+const PROJECT_DIR = join(TEST_DIR, "project")
+const PLUGIN_DIR = join(TEST_DIR, "plugin")
+const MCP_CONFIG_PATH = join(PLUGIN_DIR, "mcp.json")
+
+describe("loadPluginMcpServers", () => {
+  beforeEach(() => {
+    mkdirSync(PROJECT_DIR, { recursive: true })
+    mkdirSync(PLUGIN_DIR, { recursive: true })
+    mock.module("../../shared/logger", () => ({
+      log: () => {},
+    }))
+  })
+
+  afterEach(() => {
+    mock.restore()
+    rmSync(TEST_DIR, { recursive: true, force: true })
+  })
+
+  describe("#given plugin MCP entries with local scope metadata", () => {
+    it("#when loading plugin MCP servers #then only entries matching the current cwd are included", async () => {
+      writeFileSync(
+        MCP_CONFIG_PATH,
+        JSON.stringify({
+          mcpServers: {
+            globalServer: {
+              command: "npx",
+              args: ["global-plugin-server"],
+            },
+            matchingLocal: {
+              command: "npx",
+              args: ["matching-plugin-local"],
+              scope: "local",
+              projectPath: PROJECT_DIR,
+            },
+            nonMatchingLocal: {
+              command: "npx",
+              args: ["non-matching-plugin-local"],
+              scope: "local",
+              projectPath: join(PROJECT_DIR, "other-project"),
+            },
+          },
+        })
+      )
+
+      const plugin: LoadedPlugin = {
+        name: "demo-plugin",
+        version: "1.0.0",
+        scope: "project",
+        installPath: PLUGIN_DIR,
+        pluginKey: "demo-plugin@test",
+        mcpPath: MCP_CONFIG_PATH,
+      }
+
+      const originalCwd = process.cwd()
+      process.chdir(PROJECT_DIR)
+
+      try {
+        const { loadPluginMcpServers } = await import("./mcp-server-loader")
+        const servers = await loadPluginMcpServers([plugin])
+
+        expect(servers).toHaveProperty("demo-plugin:globalServer")
+        expect(servers).toHaveProperty("demo-plugin:matchingLocal")
+        expect(servers).not.toHaveProperty("demo-plugin:nonMatchingLocal")
+      } finally {
+        process.chdir(originalCwd)
+      }
+    })
+  })
+})

src/features/claude-code-plugin-loader/mcp-server-loader.ts

@@ -1,6 +1,7 @@
 import { existsSync } from "fs"
 import type { McpServerConfig } from "../claude-code-mcp-loader/types"
 import { expandEnvVarsInObject } from "../claude-code-mcp-loader/env-expander"
+import { shouldLoadMcpServer } from "../claude-code-mcp-loader/scope-filter"
 import { transformMcpServer } from "../claude-code-mcp-loader/transformer"
 import type { ClaudeCodeMcpConfig } from "../claude-code-mcp-loader/types"
 import { log } from "../../shared/logger"
@@ -11,6 +12,7 @@ export async function loadPluginMcpServers(
   plugins: LoadedPlugin[],
 ): Promise<Record<string, McpServerConfig>> {
   const servers: Record<string, McpServerConfig> = {}
+  const cwd = process.cwd()
 
   for (const plugin of plugins) {
     if (!plugin.mcpPath || !existsSync(plugin.mcpPath)) continue
@@ -25,6 +27,15 @@ export async function loadPluginMcpServers(
       if (!config.mcpServers) continue
 
       for (const [name, serverConfig] of Object.entries(config.mcpServers)) {
+        if (!shouldLoadMcpServer(serverConfig, cwd)) {
+          log(`Skipping local plugin MCP server "${name}" outside current cwd`, {
+            path: plugin.mcpPath,
+            projectPath: serverConfig.projectPath,
+            cwd,
+          })
+          continue
+        }
+
         if (serverConfig.disabled) {
           log(`Skipping disabled MCP server "${name}" from plugin ${plugin.name}`)
           continue

src/hooks/runtime-fallback/constants.ts

@@ -27,6 +27,7 @@ export const RETRYABLE_ERROR_PATTERNS = [
   /too.?many.?requests/i,
   /quota.?exceeded/i,
   /quota\s+will\s+reset\s+after/i,
+  /(?:you(?:'ve|\s+have)\s+)?reached\s+your\s+usage\s+limit/i,
   /all\s+credentials\s+for\s+model/i,
   /cool(?:ing)?\s+down/i,
   /exhausted\s+your\s+capacity/i,

src/hooks/runtime-fallback/error-classifier.test.ts

@@ -253,6 +253,17 @@ describe("quota error detection (fixes #2747)", () => {
     expect(retryable).toBe(true)
   })
 
+  test("treats hard usage-limit wording as retryable", () => {
+    //#given
+    const error = { message: "You've reached your usage limit for this month. Please upgrade to continue." }
+
+    //#when
+    const retryable = isRetryableError(error, [429, 503])
+
+    //#then
+    expect(retryable).toBe(true)
+  })
+
   test("classifies QuotaExceededError by errorName even without quota keywords in message", () => {
     //#given
     const error = { name: "QuotaExceededError", message: "Request failed." }

src/hooks/runtime-fallback/index.test.ts

@@ -64,6 +64,11 @@ describe("runtime-fallback", () => {
 
   function createMockPluginConfigWithCategoryFallback(fallbackModels: string[]): OhMyOpenCodeConfig {
     return {
+      git_master: {
+        commit_footer: true,
+        include_co_authored_by: true,
+        git_env_prefix: "GIT_MASTER=1",
+      },
       categories: {
         test: {
           fallback_models: fallbackModels,
@@ -79,6 +84,11 @@ describe("runtime-fallback", () => {
     variant?: string,
   ): OhMyOpenCodeConfig {
     return {
+      git_master: {
+        commit_footer: true,
+        include_co_authored_by: true,
+        git_env_prefix: "GIT_MASTER=1",
+      },
       categories: {
         [categoryName]: {
           model,
@@ -272,6 +282,39 @@ describe("runtime-fallback", () => {
       expect(errorLog).toBeDefined()
     })
 
+    test("should trigger fallback when session.error says you've reached your usage limit", async () => {
+      const hook = createRuntimeFallbackHook(createMockPluginInput(), {
+        config: createMockConfig({ notify_on_fallback: false }),
+        pluginConfig: createMockPluginConfigWithCategoryFallback(["zai-coding-plan/glm-5.1"]),
+      })
+      const sessionID = "test-session-usage-limit"
+      SessionCategoryRegistry.register(sessionID, "test")
+
+      await hook.event({
+        event: {
+          type: "session.created",
+          properties: { info: { id: sessionID, model: "kimi-for-coding/k2p5" } },
+        },
+      })
+
+      await hook.event({
+        event: {
+          type: "session.error",
+          properties: {
+            sessionID,
+            error: { message: "You've reached your usage limit for this month. Please upgrade to continue." },
+          },
+        },
+      })
+
+      const fallbackLog = logCalls.find((c) => c.msg.includes("Preparing fallback"))
+      expect(fallbackLog).toBeDefined()
+      expect(fallbackLog?.data).toMatchObject({ from: "kimi-for-coding/k2p5", to: "zai-coding-plan/glm-5.1" })
+
+      const skipLog = logCalls.find((c) => c.msg.includes("Error not retryable"))
+      expect(skipLog).toBeUndefined()
+    })
+
     test("should continue fallback chain when fallback model is not found", async () => {
       const hook = createRuntimeFallbackHook(createMockPluginInput(), {
         config: createMockConfig({ notify_on_fallback: false }),
@@ -767,7 +810,13 @@ describe("runtime-fallback", () => {
     test("should log when no fallback models configured", async () => {
       const hook = createRuntimeFallbackHook(createMockPluginInput(), {
         config: createMockConfig(),
-        pluginConfig: {},
+        pluginConfig: {
+          git_master: {
+            commit_footer: true,
+            include_co_authored_by: true,
+            git_env_prefix: "GIT_MASTER=1",
+          },
+        },
       })
       const sessionID = "test-session-no-fallbacks"
 
@@ -2299,6 +2348,11 @@ describe("runtime-fallback", () => {
   describe("fallback models configuration", () => {
     function createMockPluginConfigWithAgentFallback(agentName: string, fallbackModels: string[]): OhMyOpenCodeConfig {
       return {
+        git_master: {
+          commit_footer: true,
+          include_co_authored_by: true,
+          git_env_prefix: "GIT_MASTER=1",
+        },
         agents: {
           [agentName]: {
             fallback_models: fallbackModels,
@@ -2496,6 +2550,11 @@ describe("runtime-fallback", () => {
         {
           config: createMockConfig({ notify_on_fallback: false }),
           pluginConfig: {
+            git_master: {
+              commit_footer: true,
+              include_co_authored_by: true,
+              git_env_prefix: "GIT_MASTER=1",
+            },
             categories: {
               test: {
                 fallback_models: ["provider-a/model-a", "provider-b/model-b"],
@@ -2548,6 +2607,11 @@ describe("runtime-fallback", () => {
       const hook = createRuntimeFallbackHook(createMockPluginInput(), {
         config: createMockConfig({ notify_on_fallback: false }),
         pluginConfig: {
+          git_master: {
+            commit_footer: true,
+            include_co_authored_by: true,
+            git_env_prefix: "GIT_MASTER=1",
+          },
           categories: {
             test: {
               fallback_models: ["provider-a/model-a", "provider-b/model-b"],
@@ -2605,6 +2669,11 @@ describe("runtime-fallback", () => {
         {
           config: createMockConfig({ notify_on_fallback: false }),
           pluginConfig: {
+            git_master: {
+              commit_footer: true,
+              include_co_authored_by: true,
+              git_env_prefix: "GIT_MASTER=1",
+            },
             categories: {
               test: {
                 fallback_models: ["provider-a/model-a", "provider-b/model-b"],
@@ -2647,6 +2716,11 @@ describe("runtime-fallback", () => {
       const hook = createRuntimeFallbackHook(createMockPluginInput(), {
         config: createMockConfig({ notify_on_fallback: false }),
         pluginConfig: {
+          git_master: {
+            commit_footer: true,
+            include_co_authored_by: true,
+            git_env_prefix: "GIT_MASTER=1",
+          },
           categories: {
             test: {
               fallback_models: ["provider-a/model-a", "provider-b/model-b"],

src/plugin/event.ts

@@ -17,6 +17,11 @@ import {
   setPendingModelFallback,
 } from "../hooks/model-fallback/hook";
 import { getRawFallbackModels } from "../hooks/runtime-fallback/fallback-models";
+import {
+  clearBackgroundOutputConsumptionsForParentSession,
+  clearBackgroundOutputConsumptionsForTaskSession,
+  restoreBackgroundOutputConsumption,
+} from "../shared/background-output-consumption";
 import { resetMessageCursor } from "../shared";
 import { getAgentConfigKey } from "../shared/agent-display-names";
 import { readConnectedProvidersCache } from "../shared/connected-providers-cache";
@@ -366,6 +371,8 @@ export function createEventHandler(args: {
         clearPendingModelFallback(sessionInfo.id);
         clearSessionFallbackChain(sessionInfo.id);
         resetMessageCursor(sessionInfo.id);
+        clearBackgroundOutputConsumptionsForParentSession(sessionInfo.id);
+        clearBackgroundOutputConsumptionsForTaskSession(sessionInfo.id);
         firstMessageVariantGate.clear(sessionInfo.id);
         clearSessionModel(sessionInfo.id);
         clearSessionPromptParams(sessionInfo.id);
@@ -382,6 +389,12 @@ export function createEventHandler(args: {
       }
     }
 
+    if (event.type === "message.removed") {
+      const messageID = props?.messageID as string | undefined;
+      const sessionID = props?.sessionID as string | undefined;
+      restoreBackgroundOutputConsumption(sessionID, messageID);
+    }
+
     if (event.type === "message.updated") {
       const info = props?.info as Record<string, unknown> | undefined;
       const sessionID = info?.sessionID as string | undefined;

src/shared/background-output-consumption.ts

@@ -0,0 +1,69 @@
+import { getMessageCursor, restoreMessageCursor, type CursorState } from "./session-cursor"
+
+type MessageConsumptionKey = `${string}:${string}`
+
+const cursorSnapshotsByMessage = new Map<MessageConsumptionKey, Map<string, CursorState | undefined>>()
+
+function getMessageKey(sessionID: string, messageID: string): MessageConsumptionKey {
+  return `${sessionID}:${messageID}`
+}
+
+export function recordBackgroundOutputConsumption(
+  parentSessionID: string | undefined,
+  parentMessageID: string | undefined,
+  taskSessionID: string | undefined
+): void {
+  if (!parentSessionID || !parentMessageID || !taskSessionID) return
+
+  const messageKey = getMessageKey(parentSessionID, parentMessageID)
+  const existing = cursorSnapshotsByMessage.get(messageKey) ?? new Map<string, CursorState | undefined>()
+
+  if (!cursorSnapshotsByMessage.has(messageKey)) {
+    cursorSnapshotsByMessage.set(messageKey, existing)
+  }
+
+  if (existing.has(taskSessionID)) return
+  existing.set(taskSessionID, getMessageCursor(taskSessionID))
+}
+
+export function restoreBackgroundOutputConsumption(
+  parentSessionID: string | undefined,
+  parentMessageID: string | undefined
+): void {
+  if (!parentSessionID || !parentMessageID) return
+
+  const messageKey = getMessageKey(parentSessionID, parentMessageID)
+  const snapshots = cursorSnapshotsByMessage.get(messageKey)
+  if (!snapshots) return
+
+  cursorSnapshotsByMessage.delete(messageKey)
+  for (const [taskSessionID, cursor] of snapshots) {
+    restoreMessageCursor(taskSessionID, cursor)
+  }
+}
+
+export function clearBackgroundOutputConsumptionsForParentSession(sessionID: string | undefined): void {
+  if (!sessionID) return
+
+  const prefix = `${sessionID}:`
+  for (const messageKey of cursorSnapshotsByMessage.keys()) {
+    if (messageKey.startsWith(prefix)) {
+      cursorSnapshotsByMessage.delete(messageKey)
+    }
+  }
+}
+
+export function clearBackgroundOutputConsumptionsForTaskSession(taskSessionID: string | undefined): void {
+  if (!taskSessionID) return
+
+  for (const [messageKey, snapshots] of cursorSnapshotsByMessage) {
+    snapshots.delete(taskSessionID)
+    if (snapshots.size === 0) {
+      cursorSnapshotsByMessage.delete(messageKey)
+    }
+  }
+}
+
+export function clearBackgroundOutputConsumptionState(): void {
+  cursorSnapshotsByMessage.clear()
+}

src/shared/session-cursor.ts

@@ -13,13 +13,21 @@ export type CursorMessage = {
   info?: MessageInfo
 }
 
-interface CursorState {
+export interface CursorState {
   lastKey?: string
   lastCount: number
 }
 
 const sessionCursors = new Map<string, CursorState>()
 
+function cloneCursorState(state: CursorState | undefined): CursorState | undefined {
+  if (!state) return undefined
+  return {
+    lastKey: state.lastKey,
+    lastCount: state.lastCount,
+  }
+}
+
 function buildMessageKey(message: CursorMessage, index: number): string {
   const id = message.info?.id
   if (id) return `id:${id}`
@@ -83,3 +91,18 @@ export function resetMessageCursor(sessionID?: string): void {
   }
   sessionCursors.clear()
 }
+
+export function getMessageCursor(sessionID: string | undefined): CursorState | undefined {
+  if (!sessionID) return undefined
+  return cloneCursorState(sessionCursors.get(sessionID))
+}
+
+export function restoreMessageCursor(sessionID: string | undefined, cursor: CursorState | undefined): void {
+  if (!sessionID) return
+  if (!cursor) {
+    sessionCursors.delete(sessionID)
+    return
+  }
+
+  sessionCursors.set(sessionID, cloneCursorState(cursor)!)
+}

src/tools/background-task/create-background-output.ts

@@ -10,11 +10,13 @@ import { formatTaskResult } from "./task-result-format"
 import { formatTaskStatus } from "./task-status-format"
 
 import { getAgentDisplayName } from "../../shared/agent-display-names"
+import { recordBackgroundOutputConsumption } from "../../shared/background-output-consumption"
 
 const SISYPHUS_JUNIOR_AGENT = getAgentDisplayName("sisyphus-junior")
 
 type ToolContextWithMetadata = {
   sessionID: string
+  messageID?: string
   metadata?: (input: { title?: string; metadata?: Record<string, unknown> }) => void
   callID?: string
   callId?: string
@@ -139,6 +141,7 @@ export function createBackgroundOutput(manager: BackgroundOutputManager, client:
         }
 
         if (resolvedTask.status === "completed") {
+          recordBackgroundOutputConsumption(ctx.sessionID, ctx.messageID, resolvedTask.sessionID)
           return await formatTaskResult(resolvedTask, client)
         }
 

src/tools/background-task/create-background-output.undo.test.ts

@@ -0,0 +1,129 @@
+/// <reference types="bun-types" />
+
+import { afterEach, describe, expect, test } from "bun:test"
+import type { ToolContext } from "@opencode-ai/plugin/tool"
+import type { BackgroundTask } from "../../features/background-agent"
+import { createEventHandler } from "../../plugin/event"
+import { clearBackgroundOutputConsumptionState } from "../../shared/background-output-consumption"
+import { resetMessageCursor } from "../../shared/session-cursor"
+import type { BackgroundOutputClient, BackgroundOutputManager } from "./clients"
+import { createBackgroundOutput } from "./create-background-output"
+
+const projectDir = "/Users/yeongyu/local-workspaces/oh-my-opencode"
+
+const parentSessionID = "parent-session"
+const taskSessionID = "task-session"
+
+type ToolContextWithCallID = ToolContext & {
+  callID: string
+}
+
+const baseContext = {
+  sessionID: parentSessionID,
+  agent: "test-agent",
+  directory: projectDir,
+  worktree: projectDir,
+  abort: new AbortController().signal,
+  metadata: () => {},
+  ask: async () => {},
+  callID: "call-1",
+} as const satisfies Partial<ToolContextWithCallID>
+
+function createTask(overrides: Partial<BackgroundTask> = {}): BackgroundTask {
+  return {
+    id: "task-1",
+    sessionID: taskSessionID,
+    parentSessionID,
+    parentMessageID: "msg-parent",
+    description: "background task",
+    prompt: "do work",
+    agent: "test-agent",
+    status: "completed",
+    ...overrides,
+  }
+}
+
+function createMockClient(): BackgroundOutputClient {
+  return {
+    session: {
+      messages: async () => ({
+        data: [
+          {
+            id: "m1",
+            info: { role: "assistant", time: "2026-01-01T00:00:00Z" },
+            parts: [{ type: "text", text: "final result" }],
+          },
+        ],
+      }),
+    },
+  }
+}
+
+function createMockEventHandler() {
+  return createEventHandler({
+    ctx: {} as never,
+    pluginConfig: {} as never,
+    firstMessageVariantGate: {
+      markSessionCreated: () => {},
+      clear: () => {},
+    },
+    managers: {
+      skillMcpManager: {
+        disconnectSession: async () => {},
+      },
+      tmuxSessionManager: {
+        onSessionCreated: async () => {},
+        onSessionDeleted: async () => {},
+      },
+    } as never,
+    hooks: {} as never,
+  })
+}
+
+afterEach(() => {
+  resetMessageCursor(taskSessionID)
+  clearBackgroundOutputConsumptionState()
+})
+
+describe("createBackgroundOutput undo regression", () => {
+  test("#given consumed background output #when undo removes the parent message #then output can be consumed again", async () => {
+    // #given
+    const task = createTask()
+    const manager: BackgroundOutputManager = {
+      getTask: id => (id === task.id ? task : undefined),
+    }
+    const tool = createBackgroundOutput(manager, createMockClient())
+    const eventHandler = createMockEventHandler()
+
+    // #when
+    const firstOutput = await tool.execute(
+      { task_id: task.id },
+      { ...baseContext, messageID: "msg-result-1" } as ToolContextWithCallID
+    )
+
+    const secondOutput = await tool.execute(
+      { task_id: task.id },
+      { ...baseContext, callID: "call-2", messageID: "msg-result-2" } as ToolContextWithCallID
+    )
+
+    await eventHandler({
+      event: {
+        type: "message.removed",
+        properties: {
+          sessionID: parentSessionID,
+          messageID: "msg-result-1",
+        },
+      },
+    })
+
+    const thirdOutput = await tool.execute(
+      { task_id: task.id },
+      { ...baseContext, callID: "call-3", messageID: "msg-result-3" } as ToolContextWithCallID
+    )
+
+    // #then
+    expect(firstOutput).toContain("final result")
+    expect(secondOutput).toContain("No new output since last check")
+    expect(thirdOutput).toContain("final result")
+  })
+})