diff --git a/com.github.copilot/hooks/hooks.json b/com.github.copilot/hooks/hooks.json
index 7b5c3b0..7550a40 100644
--- a/com.github.copilot/hooks/hooks.json
+++ b/com.github.copilot/hooks/hooks.json
@@ -4,14 +4,16 @@
     "SessionStart": [
       {
         "type": "command",
-        "command": "node \"${PLUGIN_ROOT}/hooks/session-start.mjs\" --host copilot",
+        "command": "if [ -f \"${PLUGIN_ROOT}/hooks/session-start.mjs\" ]; then node \"${PLUGIN_ROOT}/hooks/session-start.mjs\" --host copilot; fi",
+        "powershell": "if ($env:PLUGIN_ROOT -and (Test-Path -LiteralPath ($env:PLUGIN_ROOT + '/hooks/session-start.mjs'))) { node ($env:PLUGIN_ROOT + '/hooks/session-start.mjs') --host copilot }",
         "timeout": 5
       }
     ],
     "SubagentStart": [
       {
         "type": "command",
-        "command": "node \"${PLUGIN_ROOT}/hooks/subagent-start.mjs\" --host copilot",
+        "command": "if [ -f \"${PLUGIN_ROOT}/hooks/subagent-start.mjs\" ]; then node \"${PLUGIN_ROOT}/hooks/subagent-start.mjs\" --host copilot; fi",
+        "powershell": "if ($env:PLUGIN_ROOT -and (Test-Path -LiteralPath ($env:PLUGIN_ROOT + '/hooks/subagent-start.mjs'))) { node ($env:PLUGIN_ROOT + '/hooks/subagent-start.mjs') --host copilot }",
         "timeout": 5
       }
     ]
diff --git a/hooks/hook-hosts.mjs b/hooks/hook-hosts.mjs
index 1c3c4a9..f915840 100644
--- a/hooks/hook-hosts.mjs
+++ b/hooks/hook-hosts.mjs
@@ -38,15 +38,26 @@ export const HOSTS = {
   },
   // Copilot CLI. PascalCase names put it in its VS Code-compatible mode
   // (snake_case SessionStart input; SubagentStart still sends camelCase
-  // agentName in 1.0.88); it drops prompt-hook output, so there's no prompt hook.
-  // VS Code reads this file too but doesn't expand ${PLUGIN_ROOT} for Agent
-  // Plugins hooks or pass their output to the model (pluginParsers.ts,
-  // copilotPluginConverters.ts on microsoft/vscode main, 2026-09).
+  // agentName in 1.0.88); it drops prompt-hook output, so it has no prompt
+  // reminder hook. The other events it lists run only telemetry.
+  // VS Code reads this file too but doesn't set or expand ${PLUGIN_ROOT} for
+  // Agent Plugins hooks or pass their output to the model (pluginParsers.ts,
+  // copilotPluginConverters.ts on microsoft/vscode main, 2026-09), so each
+  // command checks that its script exists and otherwise exits 0 without output.
   copilot: {
     manifest: "com.github.copilot/hooks/hooks.json",
     format: "flat",
     rootVariable: "PLUGIN_ROOT",
-    events: { SessionStart: "SessionStart", SubagentStart: "SubagentStart" },
+    runOnlyIfScriptExists: true,
+    telemetry: "copilot-cli",
+    events: {
+      SessionStart: "SessionStart",
+      SubagentStart: "SubagentStart",
+      UserPromptSubmit: "UserPromptSubmit",
+      PostToolUse: "PostToolUse",
+      PostToolUseFailure: "PostToolUseFailure",
+      SubagentStop: "SubagentStop",
+    },
     contextOutput: (eventName, text) => ({
       additionalContext: text,
       hookSpecificOutput: { hookEventName: eventName, additionalContext: text },
diff --git a/hooks/telemetry-adapters/copilot-cli.mjs b/hooks/telemetry-adapters/copilot-cli.mjs
new file mode 100644
index 0000000..7323ebe
--- /dev/null
+++ b/hooks/telemetry-adapters/copilot-cli.mjs
@@ -0,0 +1,103 @@
+// @ts-check
+
+import {
+  serviceForToolkit,
+  serviceForToolName,
+} from "../telemetry-classify.mjs";
+import { GATEWAY_TOOLS } from "../telemetry-contract.mjs";
+import {
+  arcadeToolProperties,
+  otherServerProperties,
+} from "../telemetry-events.mjs";
+
+/** @typedef {import("../telemetry-adapter.mjs").TelemetryAdapter} TelemetryAdapter */
+/** @typedef {import("../telemetry-adapter.mjs").HookInput} HookInput */
+
+export const COPILOT_ARCADE_SERVER = "arcade";
+
+const pickString = (/** @type {unknown} */ value) =>
+  typeof value === "string" && value !== "" ? value : undefined;
+
+/**
+ * @param {Record<string, any>} raw
+ * @returns {HookInput}
+ */
+const normalize = (raw) => {
+  /** @type {HookInput} */
+  const input = {};
+  const hook_event_name = pickString(raw.hook_event_name);
+  if (hook_event_name) input.hook_event_name = hook_event_name;
+  const session_id = pickString(raw.session_id);
+  if (session_id) input.session_id = session_id;
+  const prompt_id = pickString(raw.prompt_id);
+  if (prompt_id) input.prompt_id = prompt_id;
+  const source = pickString(raw.source);
+  if (source) input.source = source;
+  if (raw.prompt !== undefined) input.prompt = raw.prompt;
+  const tool_name = pickString(raw.tool_name);
+  if (tool_name) input.tool_name = tool_name;
+  if (raw.tool_input !== undefined && raw.tool_input !== null && typeof raw.tool_input === "object") {
+    input.tool_input = raw.tool_input;
+  }
+  if (
+    raw.tool_result !== null &&
+    typeof raw.tool_result === "object" &&
+    typeof raw.tool_result.text_result_for_llm === "string"
+  ) {
+    input.tool_response = raw.tool_result.text_result_for_llm;
+  }
+  if (raw.error !== undefined) input.error = raw.error;
+  if (raw.is_interrupt !== undefined) input.is_interrupt = raw.is_interrupt;
+  const agent_type = pickString(raw.agent_type);
+  if (agent_type) input.agent_type = agent_type;
+  const agent_id = pickString(raw.agent_id);
+  if (agent_id) input.agent_id = agent_id;
+  if (raw.last_assistant_message !== undefined) input.last_assistant_message = raw.last_assistant_message;
+  return input;
+};
+
+/**
+ * @param {unknown} toolName
+ * @param {Record<string, any> | undefined} toolInput
+ */
+const toolProperties = (toolName, toolInput) => {
+  if (typeof toolName !== "string") return null;
+  // Arcade tool names never contain "-", so the last one ends the server name.
+  const splitAt = toolName.lastIndexOf("-");
+  // Built-in tools (Bash, Agent) have no server prefix.
+  if (splitAt <= 0 || splitAt === toolName.length - 1) return null;
+  const server = toolName.slice(0, splitAt);
+  const tool = toolName.slice(splitAt + 1);
+  if (server === COPILOT_ARCADE_SERVER) {
+    return arcadeToolProperties("arcade", tool, toolInput);
+  }
+  if (/** @type {readonly string[]} */ (GATEWAY_TOOLS).includes(tool)) {
+    return arcadeToolProperties("other_arcade", tool, toolInput);
+  }
+  const serverParts = server.split(/[^A-Za-z0-9]+/);
+  const service =
+    serviceForToolName(tool) ?? serverParts.map(serviceForToolkit).find(Boolean);
+  return otherServerProperties(service);
+};
+
+/** @type {TelemetryAdapter} */
+const copilotCliAdapter = {
+  host: "copilot-cli",
+  dataVariable: "COPILOT_PLUGIN_DATA",
+  // Copilot documents "true" and doesn't say which other values it
+  // accepts, so any value that isn't clearly off counts.
+  optOutSwitches: [{ name: "COPILOT_OFFLINE", anyValue: false }],
+  requiresTurn: false,
+  promptReminder: false,
+  subagentSession: true,
+  hookRows: [
+    { event: "UserPromptSubmit" },
+    { event: "PostToolUse", matcher: ".+-.+" },
+    { event: "PostToolUseFailure", matcher: ".+-.+" },
+    { event: "SubagentStop" },
+  ],
+  normalize,
+  toolProperties,
+};
+
+export default copilotCliAdapter;
diff --git a/test/fixtures/telemetry/copilot-cli/app-prompt.json b/test/fixtures/telemetry/copilot-cli/app-prompt.json
new file mode 100644
index 0000000..b9483ab
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/app-prompt.json
@@ -0,0 +1,17 @@
+{
+  "input": {
+    "hook_event_name": "UserPromptSubmit",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "prompt": "What is on my calendar tomorrow?"
+  },
+  "expected": {
+    "event": "Plugin prompt submitted",
+    "extra": {
+      "could_use_arcade": true,
+      "service_hints": ["calendar"],
+      "reminder_sent": false
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/confirmation-prompt.json b/test/fixtures/telemetry/copilot-cli/confirmation-prompt.json
new file mode 100644
index 0000000..37ca03d
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/confirmation-prompt.json
@@ -0,0 +1,26 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "UserPromptSubmit",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "prompt": "ok"
+  },
+  "expected": {
+    "event": "Plugin prompt submitted",
+    "extra": {
+      "could_use_arcade": false,
+      "service_hints": [],
+      "reminder_sent": false
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/hooks.enabled.json b/test/fixtures/telemetry/copilot-cli/hooks.enabled.json
new file mode 100644
index 0000000..d7aa7d3
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/hooks.enabled.json
@@ -0,0 +1,55 @@
+{
+  "version": 1,
+  "hooks": {
+    "SessionStart": [
+      {
+        "type": "command",
+        "command": "if [ -f \"${PLUGIN_ROOT}/hooks/session-start.mjs\" ]; then node \"${PLUGIN_ROOT}/hooks/session-start.mjs\" --host copilot; fi",
+        "powershell": "if ($env:PLUGIN_ROOT -and (Test-Path -LiteralPath ($env:PLUGIN_ROOT + '/hooks/session-start.mjs'))) { node ($env:PLUGIN_ROOT + '/hooks/session-start.mjs') --host copilot }",
+        "timeout": 5
+      }
+    ],
+    "SubagentStart": [
+      {
+        "type": "command",
+        "command": "if [ -f \"${PLUGIN_ROOT}/hooks/subagent-start.mjs\" ]; then node \"${PLUGIN_ROOT}/hooks/subagent-start.mjs\" --host copilot; fi",
+        "powershell": "if ($env:PLUGIN_ROOT -and (Test-Path -LiteralPath ($env:PLUGIN_ROOT + '/hooks/subagent-start.mjs'))) { node ($env:PLUGIN_ROOT + '/hooks/subagent-start.mjs') --host copilot }",
+        "timeout": 5
+      }
+    ],
+    "UserPromptSubmit": [
+      {
+        "type": "command",
+        "command": "if [ -f \"${PLUGIN_ROOT}/hooks/telemetry.mjs\" ]; then node \"${PLUGIN_ROOT}/hooks/telemetry.mjs\" --host copilot; fi",
+        "powershell": "if ($env:PLUGIN_ROOT -and (Test-Path -LiteralPath ($env:PLUGIN_ROOT + '/hooks/telemetry.mjs'))) { node ($env:PLUGIN_ROOT + '/hooks/telemetry.mjs') --host copilot }",
+        "timeout": 5
+      }
+    ],
+    "PostToolUse": [
+      {
+        "type": "command",
+        "command": "if [ -f \"${PLUGIN_ROOT}/hooks/telemetry.mjs\" ]; then node \"${PLUGIN_ROOT}/hooks/telemetry.mjs\" --host copilot; fi",
+        "powershell": "if ($env:PLUGIN_ROOT -and (Test-Path -LiteralPath ($env:PLUGIN_ROOT + '/hooks/telemetry.mjs'))) { node ($env:PLUGIN_ROOT + '/hooks/telemetry.mjs') --host copilot }",
+        "timeout": 5,
+        "matcher": ".+-.+"
+      }
+    ],
+    "PostToolUseFailure": [
+      {
+        "type": "command",
+        "command": "if [ -f \"${PLUGIN_ROOT}/hooks/telemetry.mjs\" ]; then node \"${PLUGIN_ROOT}/hooks/telemetry.mjs\" --host copilot; fi",
+        "powershell": "if ($env:PLUGIN_ROOT -and (Test-Path -LiteralPath ($env:PLUGIN_ROOT + '/hooks/telemetry.mjs'))) { node ($env:PLUGIN_ROOT + '/hooks/telemetry.mjs') --host copilot }",
+        "timeout": 5,
+        "matcher": ".+-.+"
+      }
+    ],
+    "SubagentStop": [
+      {
+        "type": "command",
+        "command": "if [ -f \"${PLUGIN_ROOT}/hooks/telemetry.mjs\" ]; then node \"${PLUGIN_ROOT}/hooks/telemetry.mjs\" --host copilot; fi",
+        "powershell": "if ($env:PLUGIN_ROOT -and (Test-Path -LiteralPath ($env:PLUGIN_ROOT + '/hooks/telemetry.mjs'))) { node ($env:PLUGIN_ROOT + '/hooks/telemetry.mjs') --host copilot }",
+        "timeout": 5
+      }
+    ]
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-agent.json b/test/fixtures/telemetry/copilot-cli/post-tool-agent.json
new file mode 100644
index 0000000..611a9a4
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-agent.json
@@ -0,0 +1,24 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUse",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "Agent",
+    "tool_input": { "agent_type": "arcade:arcade-operator" },
+    "tool_result": {
+      "result_type": "success",
+      "text_result_for_llm": "done"
+    }
+  },
+  "expected": null
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-arcade-list-apps.json b/test/fixtures/telemetry/copilot-cli/post-tool-arcade-list-apps.json
new file mode 100644
index 0000000..66c8d1e
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-arcade-list-apps.json
@@ -0,0 +1,30 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUse",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "arcade-Arcade_ListApps",
+    "tool_input": {},
+    "tool_result": {
+      "result_type": "success",
+      "text_result_for_llm": "[\"Gmail\",\"Slack\",\"Calendar\"]"
+    }
+  },
+  "expected": {
+    "event": "Plugin tool called",
+    "extra": {
+      "server": "arcade",
+      "tool": "Arcade_ListApps"
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-bash.json b/test/fixtures/telemetry/copilot-cli/post-tool-bash.json
new file mode 100644
index 0000000..df98da9
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-bash.json
@@ -0,0 +1,24 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUse",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "Bash",
+    "tool_input": { "command": "echo done" },
+    "tool_result": {
+      "result_type": "success",
+      "text_result_for_llm": "done"
+    }
+  },
+  "expected": null
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-failure-auth-required.json b/test/fixtures/telemetry/copilot-cli/post-tool-failure-auth-required.json
new file mode 100644
index 0000000..dc3a937
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-failure-auth-required.json
@@ -0,0 +1,29 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUseFailure",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "arcade-Slack_SendMessage",
+    "tool_input": {},
+    "error": "MCP server 'arcade': Slack requires authorization"
+  },
+  "expected": {
+    "event": "Plugin tool failed",
+    "extra": {
+      "server": "arcade",
+      "tool": "app_tool",
+      "service": "chat",
+      "failure_kind": "auth_required"
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-failure-tool-error.json b/test/fixtures/telemetry/copilot-cli/post-tool-failure-tool-error.json
new file mode 100644
index 0000000..f784035
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-failure-tool-error.json
@@ -0,0 +1,28 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUseFailure",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "arcade-error_tool",
+    "tool_input": {},
+    "error": "MCP server 'arcade': Something went wrong in the upstream service"
+  },
+  "expected": {
+    "event": "Plugin tool failed",
+    "extra": {
+      "server": "arcade",
+      "tool": "other",
+      "failure_kind": "tool_error"
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-manage-auth-needed.json b/test/fixtures/telemetry/copilot-cli/post-tool-manage-auth-needed.json
new file mode 100644
index 0000000..9a1d94f
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-manage-auth-needed.json
@@ -0,0 +1,31 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUse",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "arcade-System_ManageAuthorization",
+    "tool_input": {},
+    "tool_result": {
+      "result_type": "success",
+      "text_result_for_llm": "{\"providers\":[{\"status\":\"authorization_required\"}]}"
+    }
+  },
+  "expected": {
+    "event": "Plugin tool called",
+    "extra": {
+      "server": "arcade",
+      "tool": "System_ManageAuthorization",
+      "auth_needed": true
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-manage-auth-not-needed.json b/test/fixtures/telemetry/copilot-cli/post-tool-manage-auth-not-needed.json
new file mode 100644
index 0000000..b2f5f91
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-manage-auth-not-needed.json
@@ -0,0 +1,31 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUse",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "arcade-System_ManageAuthorization",
+    "tool_input": {},
+    "tool_result": {
+      "result_type": "success",
+      "text_result_for_llm": "{\"providers\":[{\"status\":\"authorized\"}]}"
+    }
+  },
+  "expected": {
+    "event": "Plugin tool called",
+    "extra": {
+      "server": "arcade",
+      "tool": "System_ManageAuthorization",
+      "auth_needed": false
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-other-arcade.json b/test/fixtures/telemetry/copilot-cli/post-tool-other-arcade.json
new file mode 100644
index 0000000..3055da4
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-other-arcade.json
@@ -0,0 +1,30 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUse",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "arcade-staging-Arcade_UseTool",
+    "tool_input": {},
+    "tool_result": {
+      "result_type": "success",
+      "text_result_for_llm": "ok"
+    }
+  },
+  "expected": {
+    "event": "Plugin tool called",
+    "extra": {
+      "server": "other_arcade",
+      "tool": "Arcade_UseTool"
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-other-mcp.json b/test/fixtures/telemetry/copilot-cli/post-tool-other-mcp.json
new file mode 100644
index 0000000..a0e42c9
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-other-mcp.json
@@ -0,0 +1,30 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUse",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "granola-Granola_ListMeetings",
+    "tool_input": {},
+    "tool_result": {
+      "result_type": "success",
+      "text_result_for_llm": "[]"
+    }
+  },
+  "expected": {
+    "event": "Plugin tool called",
+    "extra": {
+      "server": "other",
+      "service": "meetings"
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-select-tools.json b/test/fixtures/telemetry/copilot-cli/post-tool-select-tools.json
new file mode 100644
index 0000000..25180f4
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-select-tools.json
@@ -0,0 +1,30 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUse",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "arcade-Arcade_SelectTools",
+    "tool_input": {},
+    "tool_result": {
+      "result_type": "success",
+      "text_result_for_llm": "[]"
+    }
+  },
+  "expected": {
+    "event": "Plugin tool called",
+    "extra": {
+      "server": "arcade",
+      "tool": "Arcade_SelectTools"
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/post-tool-use-tool.json b/test/fixtures/telemetry/copilot-cli/post-tool-use-tool.json
new file mode 100644
index 0000000..f017e2f
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/post-tool-use-tool.json
@@ -0,0 +1,31 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PostToolUse",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "arcade-Arcade_UseTool",
+    "tool_input": { "tool_name": "GoogleCalendar.ListEvents" },
+    "tool_result": {
+      "result_type": "success",
+      "text_result_for_llm": "[]"
+    }
+  },
+  "expected": {
+    "event": "Plugin tool called",
+    "extra": {
+      "server": "arcade",
+      "tool": "Arcade_UseTool",
+      "service": "calendar"
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/pre-tool-use.json b/test/fixtures/telemetry/copilot-cli/pre-tool-use.json
new file mode 100644
index 0000000..68baf39
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/pre-tool-use.json
@@ -0,0 +1,20 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "PreToolUse",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "tool_name": "arcade-list_apps",
+    "tool_input": {}
+  },
+  "expected": null
+}
diff --git a/test/fixtures/telemetry/copilot-cli/session-start.json b/test/fixtures/telemetry/copilot-cli/session-start.json
new file mode 100644
index 0000000..374834e
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/session-start.json
@@ -0,0 +1,10 @@
+{
+  "input": {
+    "hook_event_name": "SessionStart",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "source": "startup"
+  },
+  "expected": null
+}
diff --git a/test/fixtures/telemetry/copilot-cli/subagent-prompt.json b/test/fixtures/telemetry/copilot-cli/subagent-prompt.json
new file mode 100644
index 0000000..1c6da05
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/subagent-prompt.json
@@ -0,0 +1,17 @@
+{
+  "input": {
+    "hook_event_name": "UserPromptSubmit",
+    "session_id": "57946be7-1a73-40ca-a042-abb0f68d9445",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "prompt": "Complete todo listing-arcade-apps"
+  },
+  "expected": {
+    "event": "Plugin prompt submitted",
+    "extra": {
+      "could_use_arcade": false,
+      "service_hints": [],
+      "reminder_sent": false
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/subagent-start-camelcase.json b/test/fixtures/telemetry/copilot-cli/subagent-start-camelcase.json
new file mode 100644
index 0000000..1e5e75d
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/subagent-start-camelcase.json
@@ -0,0 +1,10 @@
+{
+  "input": {
+    "sessionId": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": 1790285282793,
+    "cwd": "/Users/someone/private-repo",
+    "agentName": "arcade:arcade-operator",
+    "agentDisplayName": "arcade-operator"
+  },
+  "expected": null
+}
diff --git a/test/fixtures/telemetry/copilot-cli/subagent-stop-non-operator.json b/test/fixtures/telemetry/copilot-cli/subagent-stop-non-operator.json
new file mode 100644
index 0000000..a66be76
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/subagent-stop-non-operator.json
@@ -0,0 +1,12 @@
+{
+  "input": {
+    "hook_event_name": "SubagentStop",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "agent_type": "general-purpose",
+    "agent_name": "general-purpose",
+    "last_assistant_message": "status: completed"
+  },
+  "expected": null
+}
diff --git a/test/fixtures/telemetry/copilot-cli/subagent-stop-operator.json b/test/fixtures/telemetry/copilot-cli/subagent-stop-operator.json
new file mode 100644
index 0000000..3e3d8f8
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/subagent-stop-operator.json
@@ -0,0 +1,23 @@
+{
+  "input": {
+    "hook_event_name": "SubagentStop",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "transcript_path": "/Users/someone/.copilot/session-state/dd3beb80-4471-4513-99a4-a57d3d7c08df/events.jsonl",
+    "agent_id": "57946be7-1a73-40ca-a042-abb0f68d9445",
+    "agent_type": "arcade:arcade-operator",
+    "agent_name": "arcade:arcade-operator",
+    "agent_display_name": "arcade-operator",
+    "stop_reason": "end_turn",
+    "last_assistant_message": "Done.\n\nstatus: completed"
+  },
+  "expected": {
+    "event": "Plugin subagent stopped",
+    "extra": {
+      "agent": "arcade-operator",
+      "status": "completed",
+      "subagent_session": "$hash:57946be7-1a73-40ca-a042-abb0f68d9445"
+    }
+  }
+}
diff --git a/test/fixtures/telemetry/copilot-cli/unrelated-prompt.json b/test/fixtures/telemetry/copilot-cli/unrelated-prompt.json
new file mode 100644
index 0000000..d5777e8
--- /dev/null
+++ b/test/fixtures/telemetry/copilot-cli/unrelated-prompt.json
@@ -0,0 +1,19 @@
+{
+  "prelude": [
+    {
+      "hook_event_name": "UserPromptSubmit",
+      "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+      "timestamp": "2026-09-24T21:27:02.743Z",
+      "cwd": "/Users/someone/private-repo",
+      "prompt": "What is on my calendar tomorrow?"
+    }
+  ],
+  "input": {
+    "hook_event_name": "UserPromptSubmit",
+    "session_id": "dd3beb80-4471-4513-99a4-a57d3d7c08df",
+    "timestamp": "2026-09-24T21:27:02.743Z",
+    "cwd": "/Users/someone/private-repo",
+    "prompt": "Fix the parser in src/main.ts"
+  },
+  "expected": null
+}
diff --git a/test/hooks.test.mjs b/test/hooks.test.mjs
index aac0f40..7f38eae 100644
--- a/test/hooks.test.mjs
+++ b/test/hooks.test.mjs
@@ -1,5 +1,8 @@
 import assert from "node:assert/strict";
 import { spawnSync } from "node:child_process";
+import { mkdtempSync } from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
 import { test } from "node:test";
 import { HOSTS } from "../hooks/hook-hosts.mjs";
 import { shouldRemind } from "../hooks/prompt-filters.mjs";
@@ -32,28 +35,117 @@ test("every client in the hook table has an expected output format", () => {
   assert.deepEqual(Object.keys(EXPECTED_OUTPUT).sort(), Object.keys(HOSTS).sort());
 });
 
+const HOOK_INPUT = JSON.stringify({ prompt: "What's on my calendar?", agent_type: "Explore" });
+
+const assertPrintsContext = (hostName, event, result, label) => {
+  assert.equal(result.status, 0, `${label}: ${result.stderr}`);
+  const out = JSON.parse(result.stdout);
+  const text = out.hookSpecificOutput?.additionalContext ?? out.additional_context;
+  assert.ok(text, `${label}: no context in ${result.stdout}`);
+  assert.deepEqual(out, EXPECTED_OUTPUT[hostName](event, text), label);
+};
+
 test("every command in every generated hooks.json runs and prints what its client reads", () => {
   for (const [hostName, { manifest, rootVariable }] of Object.entries(HOSTS)) {
     for (const [event, entries] of Object.entries(JSON.parse(readRepoFile(manifest)).hooks)) {
       for (const { command } of entries.flatMap((entry) => entry.hooks ?? [entry])) {
         // Telemetry prints nothing; the telemetry tests run its commands.
         if (command.includes("/hooks/telemetry.mjs")) continue;
-        const label = `${hostName} ${event}`;
         const result = spawnSync(command.replaceAll(`\${${rootVariable}}`, ROOT), {
           shell: true,
-          input: JSON.stringify({ prompt: "What's on my calendar?", agent_type: "Explore" }),
+          input: HOOK_INPUT,
           encoding: "utf8",
         });
-        assert.equal(result.status, 0, `${label}: ${result.stderr}`);
-        const out = JSON.parse(result.stdout);
-        const text = out.hookSpecificOutput?.additionalContext ?? out.additional_context;
-        assert.ok(text, `${label}: no context in ${result.stdout}`);
-        assert.deepEqual(out, EXPECTED_OUTPUT[hostName](event, text), label);
+        assertPrintsContext(hostName, event, result, `${hostName} ${event}`);
       }
     }
   }
 });
 
+// VS Code reads com.github.copilot/hooks/hooks.json but runs each command as
+// written, through `spawn(command, { shell: true })` from the workspace root,
+// without setting or replacing PLUGIN_ROOT (microsoft/vscode main, 2026-09:
+// pluginParsers.ts, hookExecutor.ts). Copilot CLI replaces ${PLUGIN_ROOT} in
+// the command and also sets it in the environment.
+const copilotEntries = () =>
+  Object.entries(JSON.parse(readRepoFile(HOSTS.copilot.manifest)).hooks).flatMap(([event, entries]) =>
+    entries.map((entry) => ({ event, ...entry })),
+  );
+
+const PLUGIN_VARIABLES = ["PLUGIN_ROOT", "COPILOT_PLUGIN_DATA", "CLAUDE_PLUGIN_DATA"];
+
+/** process.env without the variables a client sets for plugin hooks, plus `extra`. */
+const hookEnv = (extra = {}) => ({
+  ...Object.fromEntries(Object.entries(process.env).filter(([name]) => !PLUGIN_VARIABLES.includes(name))),
+  ...extra,
+});
+
+const VSCODE_INPUT = JSON.stringify({
+  hook_event_name: "SessionStart",
+  session_id: "vscode-session",
+  cwd: "/workspace",
+  prompt: "What's on my calendar?",
+  agent_type: "Explore",
+});
+
+// The `command` field is the macOS and Linux form; cmd.exe can't run it.
+const skipOnWindows = { skip: process.platform === "win32" && "the command field is for macOS and Linux" };
+
+test("in VS Code every Copilot hook command exits 0 without output", skipOnWindows, () => {
+  const cwd = mkdtempSync(path.join(tmpdir(), "arcade-vscode-"));
+  for (const extra of [{}, { PLUGIN_ROOT: "/nonexistent" }]) {
+    for (const { event, command } of copilotEntries()) {
+      const label = `${event} ${command} ${JSON.stringify(extra)}`;
+      const result = spawnSync(command, { shell: true, cwd, env: hookEnv(extra), input: VSCODE_INPUT, encoding: "utf8" });
+      assert.equal(result.status, 0, `${label}: ${result.stderr}`);
+      assert.equal(result.stdout, "", label);
+      assert.equal(result.stderr, "", label);
+    }
+  }
+});
+
+/** Checks the output of a Copilot hook run with PLUGIN_ROOT set to the repo. */
+const assertCopilotHookRan = (event, command, result, label) => {
+  if (command.includes("/hooks/telemetry.mjs")) {
+    assert.equal(result.status, 0, `${label}: ${result.stderr}`);
+    assert.equal(result.stdout, "", label);
+    return;
+  }
+  assertPrintsContext("copilot", event, result, label);
+};
+
+test("in Copilot CLI every Copilot hook command runs with PLUGIN_ROOT set only in the environment", skipOnWindows, () => {
+  const cwd = mkdtempSync(path.join(tmpdir(), "arcade-copilot-"));
+  for (const { event, command } of copilotEntries()) {
+    const result = spawnSync(command, { shell: true, cwd, env: hookEnv({ PLUGIN_ROOT: ROOT }), input: HOOK_INPUT, encoding: "utf8" });
+    assertCopilotHookRan(event, command, result, `${event} ${command}`);
+  }
+});
+
+// GitHub's ubuntu-latest image includes pwsh.
+const POWERSHELL = (process.platform === "win32" ? ["pwsh", "powershell.exe"] : ["pwsh"]).find(
+  (exe) => !spawnSync(exe, ["-NoProfile", "-NonInteractive", "-Command", "exit 0"]).error,
+);
+
+test("every Copilot hook's powershell command skips without PLUGIN_ROOT and runs with it", { skip: !POWERSHELL && "pwsh not found" }, () => {
+  const cwd = mkdtempSync(path.join(tmpdir(), "arcade-powershell-"));
+  const runPowerShell = (script, env) =>
+    spawnSync(String(POWERSHELL), ["-NoProfile", "-NonInteractive", "-Command", script], {
+      cwd,
+      env,
+      input: HOOK_INPUT,
+      encoding: "utf8",
+    });
+  for (const { event, command, powershell } of copilotEntries()) {
+    assert.ok(powershell, `${event} ${command}: no powershell command`);
+    const skipped = runPowerShell(powershell, hookEnv());
+    assert.equal(skipped.status, 0, `${powershell}: ${skipped.stderr}`);
+    assert.equal(skipped.stdout, "", powershell);
+    assert.equal(skipped.stderr, "", powershell);
+    assertCopilotHookRan(event, powershell, runPowerShell(powershell, hookEnv({ PLUGIN_ROOT: ROOT })), powershell);
+  }
+});
+
 test("shouldRemind skips acknowledgements and background task results", () => {
   for (const prompt of ["What's on my calendar?", "fix it", "go ahead and send it"]) {
     assert.equal(shouldRemind(prompt), true, prompt);
diff --git a/test/telemetry-copilot.test.mjs b/test/telemetry-copilot.test.mjs
new file mode 100644
index 0000000..4287498
--- /dev/null
+++ b/test/telemetry-copilot.test.mjs
@@ -0,0 +1,531 @@
+// @ts-check
+
+import assert from "node:assert/strict";
+import { spawn, spawnSync } from "node:child_process";
+import { mkdtempSync, readdirSync, readFileSync, rmSync } from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { test } from "node:test";
+import { HOOKS, HOSTS, telemetryHookRows } from "../hooks/hook-hosts.mjs";
+import { SCOPE_DIRECTORY, SCOPE_TTL_MS } from "../hooks/hook-scope.mjs";
+import { ARCADE_USED_FILE, EVENT_ENV, OPT_OUT_ENV } from "../hooks/telemetry-config.mjs";
+import { buildEvent, isArcadeCall } from "../hooks/telemetry-events.mjs";
+import { isOptedOut, runTelemetry } from "../hooks/telemetry-run.mjs";
+import copilotAdapter, { COPILOT_ARCADE_SERVER } from "../hooks/telemetry-adapters/copilot-cli.mjs";
+import { buildHookManifest } from "../scripts/generate-manifests.mjs";
+import { readRepoFile, ROOT } from "./helpers.mjs";
+import {
+  assertMatchesContract,
+  assertNoLeak,
+  captureTelemetry,
+  expectedEvent,
+  hash16,
+  runTelemetryScript,
+  sleep,
+  startServer,
+  tempDataDir,
+  waitForRequests,
+} from "./telemetry-helpers.mjs";
+
+const FIXTURE_DIR = path.join(ROOT, "test/fixtures/telemetry/copilot-cli");
+const SESSION_ID = "dd3beb80-4471-4513-99a4-a57d3d7c08df";
+const SUBAGENT_ID = "57946be7-1a73-40ca-a042-abb0f68d9445";
+const OPERATOR = "arcade:arcade-operator";
+const MCP_TOOL_MATCHER = ".+-.+";
+
+const copilotInput = (fields) => ({
+  session_id: SESSION_ID,
+  timestamp: "2026-09-24T21:27:02.743Z",
+  cwd: "/Users/someone/private-repo",
+  ...fields,
+});
+
+const fixtureFiles = () =>
+  readdirSync(FIXTURE_DIR)
+    .filter((name) => name.endsWith(".json") && name !== "hooks.enabled.json")
+    .sort();
+
+const readFixture = (name) => JSON.parse(readFileSync(path.join(FIXTURE_DIR, name), "utf8"));
+
+const resolveExpected = (fixture, input) => {
+  if (fixture.expected === null) return null;
+  const extra = { ...fixture.expected.extra };
+  if (extra.subagent_session?.startsWith("$hash:")) {
+    extra.subagent_session = hash16(extra.subagent_session.slice("$hash:".length));
+  }
+  if (extra.subagent_session === SUBAGENT_ID) {
+    extra.subagent_session = hash16(SUBAGENT_ID);
+  }
+  const sessionId = input.session_id ?? SESSION_ID;
+  const event = expectedEvent(fixture.expected.event, extra, copilotAdapter, sessionId, undefined);
+  const os = /** @type {readonly string[]} */ (["darwin", "linux", "win32"]).includes(process.platform)
+    ? process.platform
+    : "other";
+  event.properties.os = os;
+  return event;
+};
+
+const runFixture = async (fixture, dataDir) => {
+  for (const step of fixture.prelude ?? []) {
+    await captureTelemetry({ adapter: copilotAdapter, input: step, dataDir });
+  }
+  return captureTelemetry({ adapter: copilotAdapter, input: fixture.input, dataDir });
+};
+
+// An inherited opt-out would make the hook skip even with the hard-OFF gate open.
+const PLUGIN_VARIABLES = [
+  "PLUGIN_ROOT",
+  "COPILOT_PLUGIN_DATA",
+  "CLAUDE_PLUGIN_DATA",
+  OPT_OUT_ENV,
+  "DO_NOT_TRACK",
+  ...copilotAdapter.optOutSwitches.map(({ name }) => name),
+];
+const hookEnv = (extra = {}) => ({
+  ...Object.fromEntries(Object.entries(process.env).filter(([name]) => !PLUGIN_VARIABLES.includes(name))),
+  ...extra,
+});
+
+const POWERSHELL = (process.platform === "win32" ? ["pwsh", "powershell.exe"] : ["pwsh"]).find(
+  (exe) => !spawnSync(exe, ["-NoProfile", "-NonInteractive", "-Command", "exit 0"]).error,
+);
+
+const skipOnWindows = { skip: process.platform === "win32" && "the command field is for macOS and Linux" };
+
+// Classified as app work, so these hooks would send an event if the hard-OFF gate were open.
+const SENDABLE_PROMPT = copilotInput({ hook_event_name: "UserPromptSubmit", prompt: "What is on my calendar tomorrow?" });
+
+const SEND_SCRIPT = path.join(ROOT, "hooks", "telemetry-send.mjs");
+// Async spawn keeps this process's event loop free so the in-process server can answer.
+const exitCode = (command, args, options) =>
+  new Promise((resolve) => spawn(command, args, { ...options, stdio: "ignore" }).on("exit", resolve));
+const sendWithNode = (env) => exitCode(process.execPath, [SEND_SCRIPT], { env });
+
+// Asserts nothing reached the server, then proves the hook environment resolves to it,
+// so the empty request list could not come from sending somewhere else.
+const assertCaptureObservesSend = async (server, env, send = sendWithNode) => {
+  assert.deepEqual(server.requests, []);
+  const event = buildEvent(SENDABLE_PROMPT, {
+    adapter: copilotAdapter,
+    os: "linux",
+    arcadeUsedBefore: false,
+    appWork: true,
+  });
+  assert.ok(event);
+  assert.equal(await send({ ...env, [EVENT_ENV]: JSON.stringify(event) }), 0);
+  await waitForRequests(server.requests, 1);
+  assert.equal(server.requests.length, 1);
+  assert.equal(JSON.parse(server.requests[0].body).event, "Plugin prompt submitted");
+};
+
+const enabledManifest = JSON.parse(readFileSync(path.join(FIXTURE_DIR, "hooks.enabled.json"), "utf8"));
+const enabledTelemetryEntries = () =>
+  Object.entries(enabledManifest.hooks).flatMap(([event, entries]) =>
+    entries
+      .filter((entry) => entry.command?.includes("telemetry.mjs"))
+      .map((entry) => ({ event, ...entry })),
+  );
+
+for (const file of fixtureFiles()) {
+  test(`fixture ${file} maps through captureTelemetry`, async () => {
+    const fixture = readFixture(file);
+    const dataDir = tempDataDir();
+    const { sent } = await runFixture(fixture, dataDir);
+    const want = resolveExpected(fixture, fixture.input);
+    if (want === null) {
+      assert.equal(sent.length, 0, file);
+      return;
+    }
+    assert.equal(sent.length, 1, file);
+    assert.deepEqual(sent[0], want, file);
+    assertMatchesContract(sent[0], file);
+    assertNoLeak(JSON.stringify(sent[0]), /private-repo|dd3beb80|57946be7|SECRET/i);
+  });
+}
+
+test("Copilot-shaped hook input never carries turn and PreToolUse sends no attempt event", async () => {
+  const dataDir = tempDataDir();
+  await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({ hook_event_name: "UserPromptSubmit", prompt: "What is on my calendar tomorrow?" }),
+    dataDir,
+  });
+  const { sent } = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({
+      hook_event_name: "PostToolUse",
+      tool_name: "arcade-Gmail_ListEmails",
+      tool_input: {},
+      tool_result: { result_type: "success", text_result_for_llm: "[]" },
+    }),
+    dataDir,
+  });
+  assert.equal(sent[0].properties.turn, undefined);
+  const attempt = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({ hook_event_name: "PreToolUse", tool_name: "arcade-list_apps", tool_input: {} }),
+    dataDir,
+  });
+  assert.equal(attempt.sent.length, 0);
+  assert.ok(!attempt.sent.some((event) => event.event === "Plugin tool attempted"));
+});
+
+test("session scope follows Copilot prompts and tools in one data dir", async () => {
+  const dataDir = tempDataDir();
+  const baseNow = 1_700_000_000_000;
+  await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({ hook_event_name: "UserPromptSubmit", prompt: "What is on my calendar tomorrow?" }),
+    dataDir,
+    now: baseNow,
+  });
+  const tool = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({
+      hook_event_name: "PostToolUse",
+      tool_name: "arcade-Gmail_ListEmails",
+      tool_input: {},
+      tool_result: { result_type: "success", text_result_for_llm: "[]" },
+    }),
+    dataDir,
+    now: baseNow + 1000,
+  });
+  assert.equal(tool.sent.length, 1);
+  assert.equal(tool.sent[0].properties.turn, undefined);
+
+  const unrelated = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({ hook_event_name: "UserPromptSubmit", prompt: "Fix the parser in src/main.ts" }),
+    dataDir,
+    now: baseNow + 2000,
+  });
+  assert.equal(unrelated.sent.length, 0);
+  const silentTool = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({
+      hook_event_name: "PostToolUse",
+      tool_name: "granola-Granola_ListMeetings",
+      tool_input: {},
+      tool_result: { result_type: "success", text_result_for_llm: "[]" },
+    }),
+    dataDir,
+    now: baseNow + 3000,
+  });
+  assert.equal(silentTool.sent.length, 0);
+
+  await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({ hook_event_name: "UserPromptSubmit", prompt: "What is on my calendar tomorrow?" }),
+    dataDir,
+    now: baseNow + 4000,
+  });
+  const confirm = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({ hook_event_name: "UserPromptSubmit", prompt: "ok" }),
+    dataDir,
+    now: baseNow + 5000,
+  });
+  assert.equal(confirm.sent.length, 1);
+  const scopeFile = path.join(dataDir, SCOPE_DIRECTORY, readdirSync(path.join(dataDir, SCOPE_DIRECTORY))[0]);
+  const expiresAt = JSON.parse(readFileSync(scopeFile, "utf8")).expiresAt;
+  assert.ok(expiresAt <= baseNow + SCOPE_TTL_MS + 5000);
+
+  await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({ hook_event_name: "SessionStart", source: "startup" }),
+    dataDir,
+    now: baseNow + 6000,
+  });
+  const afterStart = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({
+      hook_event_name: "PostToolUse",
+      tool_name: "granola-Granola_ListMeetings",
+      tool_input: {},
+      tool_result: { result_type: "success", text_result_for_llm: "[]" },
+    }),
+    dataDir,
+    now: baseNow + 7000,
+  });
+  assert.equal(afterStart.sent.length, 0);
+
+  await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({ hook_event_name: "UserPromptSubmit", prompt: "What is on my calendar tomorrow?" }),
+    dataDir,
+    now: baseNow + 8000,
+  });
+  const expired = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({
+      hook_event_name: "PostToolUse",
+      tool_name: "granola-Granola_ListMeetings",
+      tool_input: {},
+      tool_result: { result_type: "success", text_result_for_llm: "[]" },
+    }),
+    dataDir,
+    now: baseNow + SCOPE_TTL_MS + 9000,
+  });
+  assert.equal(expired.sent.length, 0);
+});
+
+test("operator stop subagent_session matches the subagent session hash", async () => {
+  const subagentPrompt = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({
+      hook_event_name: "UserPromptSubmit",
+      session_id: SUBAGENT_ID,
+      prompt: "Complete todo listing-arcade-apps",
+    }),
+  });
+  const { sent } = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({
+      hook_event_name: "SubagentStop",
+      agent_id: SUBAGENT_ID,
+      agent_type: OPERATOR,
+      last_assistant_message: "status: completed",
+    }),
+  });
+  assert.equal(sent[0].properties.subagent_session, subagentPrompt.sent[0].properties.session);
+});
+
+test("arcade-used flag is stored in COPILOT_PLUGIN_DATA", async () => {
+  const dataDir = tempDataDir();
+  await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({
+      hook_event_name: "UserPromptSubmit",
+      prompt: "What is on my calendar tomorrow?",
+    }),
+    dataDir,
+  });
+  await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({
+      hook_event_name: "PostToolUse",
+      tool_name: "arcade-Gmail_ListEmails",
+      tool_input: {},
+      tool_result: { result_type: "success", text_result_for_llm: "private inbox" },
+    }),
+    dataDir,
+  });
+  assert.equal(readFileSync(path.join(dataDir, ARCADE_USED_FILE), "utf8"), "true");
+  const second = await captureTelemetry({
+    adapter: copilotAdapter,
+    input: copilotInput({
+      hook_event_name: "PostToolUse",
+      tool_name: "arcade-Gmail_ListEmails",
+      tool_input: {},
+      tool_result: { result_type: "success", text_result_for_llm: "private inbox" },
+    }),
+    dataDir,
+  });
+  assert.equal(second.sent[0].properties.arcade_used_before, true);
+  assert.equal(isArcadeCall(second.sent[0]), true);
+});
+
+test("opt-out and missing data dir send nothing", async () => {
+  const input = copilotInput({
+    hook_event_name: "PostToolUse",
+    tool_name: "arcade-Gmail_ListEmails",
+    tool_input: {},
+    tool_result: { result_type: "success", text_result_for_llm: "[]" },
+  });
+  const cases = [
+    ["ARCADE_PLUGIN_TELEMETRY=0", { ARCADE_PLUGIN_TELEMETRY: "0" }],
+    ["DO_NOT_TRACK=1", { DO_NOT_TRACK: "1" }],
+    ["COPILOT_OFFLINE=true", { COPILOT_OFFLINE: "true" }],
+    ["COPILOT_OFFLINE=1", { COPILOT_OFFLINE: "1" }],
+    ["no COPILOT_PLUGIN_DATA", { COPILOT_PLUGIN_DATA: "" }],
+    ["relative COPILOT_PLUGIN_DATA", { COPILOT_PLUGIN_DATA: "relative/data" }],
+  ];
+  for (const [label, env] of cases) {
+    const dataDir = tempDataDir();
+    const { sent } = await captureTelemetry({ adapter: copilotAdapter, input, dataDir, env });
+    assert.equal(sent.length, 0, label);
+    assert.deepEqual(readdirSync(dataDir), [], label);
+  }
+  for (const extra of [{ COPILOT_OFFLINE: "false" }, { COPILOT_OFFLINE: "0" }, { DISABLE_TELEMETRY: "1" }]) {
+    const dataDir = tempDataDir();
+    await captureTelemetry({
+      adapter: copilotAdapter,
+      input: copilotInput({ hook_event_name: "UserPromptSubmit", prompt: "What is on my calendar tomorrow?" }),
+      dataDir,
+      env: extra,
+    });
+    const { sent } = await captureTelemetry({ adapter: copilotAdapter, input, dataDir, env: extra });
+    assert.ok(sent.length > 0, JSON.stringify(extra));
+  }
+  assert.equal(isOptedOut(copilotAdapter.optOutSwitches, { COPILOT_OFFLINE: "true" }), true);
+  assert.equal(isOptedOut(copilotAdapter.optOutSwitches, { COPILOT_OFFLINE: "false" }), false);
+});
+
+test("malformed stdin sends nothing through runTelemetry", async () => {
+  const dataDir = tempDataDir();
+  const sent = [];
+  await runTelemetry({
+    input: { session_id: SESSION_ID, hook_event_name: "UserPromptSubmit" },
+    adapter: copilotAdapter,
+    env: { ...process.env, COPILOT_PLUGIN_DATA: dataDir },
+    enabled: true,
+    send: (event) => sent.push(event),
+  });
+  assert.equal(sent.length, 0);
+});
+
+test("enabled Copilot manifest wiring matches hooks.enabled.json", async () => {
+  const rows = [
+    ...HOOKS.filter((hook) => hook.script !== "telemetry.mjs"),
+    ...(await telemetryHookRows()).filter((row) => row.hosts.includes("copilot")),
+  ];
+  const built = buildHookManifest("copilot", rows);
+  assert.deepEqual(built, enabledManifest);
+});
+
+test("checked-in Copilot manifest has no telemetry rows", () => {
+  assert.equal(readRepoFile(HOSTS.copilot.manifest).includes("telemetry.mjs"), false);
+});
+
+test("enabled telemetry commands exit quietly while telemetry is off", skipOnWindows, async () => {
+  const server = await startServer();
+  const cwd = mkdtempSync(path.join(os.tmpdir(), "arcade-copilot-telemetry-off-"));
+  const dataDir = mkdtempSync(path.join(os.tmpdir(), "arcade-copilot-data-"));
+  const captureEnv = { COPILOT_PLUGIN_DATA: dataDir, ARCADE_PLUGIN_TELEMETRY: "1", ARCADE_PLUGIN_TELEMETRY_HOST: server.url };
+  try {
+    for (const { command } of enabledTelemetryEntries()) {
+      for (const extra of [{}, { PLUGIN_ROOT: ROOT }]) {
+        const result = spawnSync(command, {
+          shell: true,
+          cwd,
+          env: hookEnv({ ...extra, ...captureEnv }),
+          input: JSON.stringify(SENDABLE_PROMPT),
+          encoding: "utf8",
+        });
+        assert.equal(result.status, 0, command);
+        assert.equal(result.stdout, "", command);
+        assert.equal(result.stderr, "", command);
+      }
+    }
+    await sleep(200);
+    await assertCaptureObservesSend(server, hookEnv(captureEnv));
+    assert.deepEqual(readdirSync(dataDir), []);
+  } finally {
+    rmSync(cwd, { recursive: true, force: true });
+    rmSync(dataDir, { recursive: true, force: true });
+    await server.close();
+  }
+});
+
+test(
+  "enabled telemetry powershell commands exit quietly while telemetry is off",
+  { skip: !POWERSHELL && "pwsh not found" },
+  async () => {
+    const server = await startServer();
+    const cwd = mkdtempSync(path.join(os.tmpdir(), "arcade-copilot-ps-"));
+    const dataDir = mkdtempSync(path.join(os.tmpdir(), "arcade-copilot-ps-data-"));
+    try {
+      const runPs = (script, env, input) =>
+        spawnSync(String(POWERSHELL), ["-NoProfile", "-NonInteractive", "-Command", script], {
+          cwd,
+          env: hookEnv({ ARCADE_PLUGIN_TELEMETRY_HOST: server.url, ...env }),
+          input,
+          encoding: "utf8",
+        });
+      for (const { powershell } of enabledTelemetryEntries()) {
+        assert.ok(powershell);
+        const input = JSON.stringify(SENDABLE_PROMPT);
+        const skipped = runPs(powershell, {}, input);
+        assert.equal(skipped.status, 0);
+        assert.equal(skipped.stdout, "");
+        const ran = runPs(powershell, { PLUGIN_ROOT: ROOT, COPILOT_PLUGIN_DATA: dataDir }, input);
+        assert.equal(ran.status, 0);
+        assert.equal(ran.stdout, "");
+      }
+      await sleep(200);
+      await assertCaptureObservesSend(server, hookEnv({ ARCADE_PLUGIN_TELEMETRY_HOST: server.url }), (env) =>
+        exitCode(
+          String(POWERSHELL),
+          ["-NoProfile", "-NonInteractive", "-Command", `& '${process.execPath}' '${SEND_SCRIPT}'; exit $LASTEXITCODE`],
+          { cwd, env },
+        ),
+      );
+      assert.deepEqual(readdirSync(dataDir), []);
+    } finally {
+      rmSync(cwd, { recursive: true, force: true });
+      rmSync(dataDir, { recursive: true, force: true });
+      await server.close();
+    }
+  },
+);
+
+test("the Copilot MCP tool matcher picks server tools, not built-ins", () => {
+  const matcher = new RegExp(`^(?:${MCP_TOOL_MATCHER})$`);
+  for (const name of ["arcade-Arcade_UseTool", "github-mcp-server-get_issue"]) assert.match(name, matcher);
+  for (const name of ["Bash", "Agent", "view"]) assert.doesNotMatch(name, matcher);
+});
+
+test("normalize reads tool_result text_result_for_llm and ignores top-level tool_response", () => {
+  const normalized = copilotAdapter.normalize({
+    session_id: SESSION_ID,
+    agent_type: OPERATOR,
+    tool_name: "arcade-System_ManageAuthorization",
+    tool_response: '{"providers":[{"status":"authorization_required"}]}',
+    tool_result: { result_type: "success", text_result_for_llm: '{"providers":[]}' },
+    transcript_path: "/SECRET/path",
+    cwd: "/SECRET/cwd",
+  });
+  assert.equal(normalized.tool_response, '{"providers":[]}');
+  assert.equal(normalized.prompt_id, undefined);
+  assert.equal(normalized.session_id, SESSION_ID);
+  const withPromptId = copilotAdapter.normalize({ session_id: SESSION_ID, prompt_id: "turn-1" });
+  assert.equal(withPromptId.prompt_id, "turn-1");
+  const built = buildEvent(
+    { ...normalized, hook_event_name: "PostToolUse" },
+    { adapter: copilotAdapter, os: "darwin", arcadeUsedBefore: false, appWork: true },
+  );
+  assert.equal(built?.properties.auth_needed, false);
+  assertNoLeak(JSON.stringify(built), /SECRET/i);
+});
+
+test("normalize does not map SubagentStart camelCase fields into hook input", () => {
+  const normalized = copilotAdapter.normalize({
+    sessionId: SESSION_ID,
+    agentName: OPERATOR,
+    agentDisplayName: "arcade-operator",
+  });
+  assert.equal(normalized.session_id, undefined);
+  assert.equal(normalized.agent_type, undefined);
+});
+
+test("Copilot CLI sends no built-in tool events", () => {
+  const options = { adapter: copilotAdapter, os: "darwin", arcadeUsedBefore: false, appWork: true };
+  assert.equal(
+    buildEvent(copilotInput({ hook_event_name: "PostToolUse", tool_name: "WebFetch" }), options),
+    null,
+  );
+  assert.equal(
+    buildEvent(
+      copilotInput({ hook_event_name: "PostToolUse", tool_name: "Bash", tool_input: { command: "gh pr list" } }),
+      { ...options, cli: "gh" },
+    ),
+    null,
+  );
+});
+
+test("telemetry.mjs with --host copilot exits quietly while disabled", () => {
+  const dataDir = tempDataDir();
+  const result = runTelemetryScript(
+    JSON.stringify(copilotInput({ hook_event_name: "PostToolUse", tool_name: "arcade-Gmail_ListEmails" })),
+    { COPILOT_PLUGIN_DATA: dataDir },
+    "copilot",
+  );
+  assert.equal(result.status, 0);
+  assert.equal(result.stdout, "");
+  assert.deepEqual(readdirSync(dataDir), []);
+});
+
+test("arcade server prefix matches mcp.json", () => {
+  const [server] = Object.keys(JSON.parse(readRepoFile("mcp.json")).mcpServers);
+  assert.equal(COPILOT_ARCADE_SERVER, server);
+});