teallarson · Oct 7, 2026 · Oct 7, 2026 · Oct 7, 2026 · Oct 7, 2026 · Oct 7, 2026
diff --git a/com.github.copilot/hooks/hooks.json b/com.github.copilot/hooks/hooks.json
diff --git 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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -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"
+    }
+  }
+}