feat: add Google Calendar native tool integration

docs/content/docs/(features)/google-calendar.mdx

@@ -0,0 +1,154 @@
+---
+title: Google Calendar
+description: Native Google Calendar integration for listing, creating, and managing events.
+---
+
+# Google Calendar
+
+Native Google Calendar integration that gives workers and branches access to calendar tools — list events, create meetings, find free time, and more. No MCP server needed; credentials are configured directly in Spacebot.
+
+## Overview
+
+When configured, Spacebot registers calendar tools on the appropriate process types:
+
+| Tool | Branches | Workers |
+|------|----------|---------|
+| `google_calendar_list_events` | read-only | read-only |
+| `google_calendar_list_calendars` | read-only | read-only |
+| `google_calendar_find_free_time` | read-only | read-only |
+| `google_calendar_create_event` | — | write |
+| `google_calendar_update_event` | — | write |
+| `google_calendar_delete_event` | — | write |
+| `google_calendar_respond_event` | — | write |
+
+Branches get read-only tools. Workers get both read and write tools. This follows the delegation model — when you ask the channel to check your schedule, it spawns a branch to do the lookup, and only workers can modify calendar data.
+
+## Prerequisites
+
+1. A Google Cloud project with the **Google Calendar API** enabled
+2. An OAuth 2.0 Client ID (type: **Web application** or **Desktop**)
+3. A refresh token obtained via the OAuth consent flow
+
+## Step 1: Create OAuth Credentials
+
+1. Go to the [Google Cloud Console](https://console.cloud.google.com/)
+2. Create a new project or select an existing one
+3. Navigate to **APIs & Services → Library**
+4. Search for **Google Calendar API** and enable it
+5. Go to **APIs & Services → Credentials**
+6. Click **Create Credentials → OAuth client ID**
+7. Choose **Web application** as the application type
+8. Under **Authorized redirect URIs**, add: `https://developers.google.com/oauthplayground`
+9. Click **Create** and note the **Client ID** and **Client Secret**
+
+<Callout type="info">
+If your project's OAuth consent screen is in "Testing" mode, add your Google account as a test user under **APIs & Services → OAuth consent screen → Test users**.
+</Callout>
+
+## Step 2: Get a Refresh Token
+
+### Option A: OAuth Playground
+
+1. Open [Google OAuth Playground](https://developers.google.com/oauthplayground)
+2. Click the gear icon (⚙️) in the top right
+3. Check **Use your own OAuth credentials**
+4. Enter your Client ID and Client Secret
+5. In the left panel, find **Google Calendar API v3** and select `https://www.googleapis.com/auth/calendar`
+6. Click **Authorize APIs** and complete the consent flow
+7. Click **Exchange authorization code for tokens**
+8. Copy the **Refresh token**
+
+### Option B: Manual curl
+
+```bash
+# 1. Open this URL in your browser (replace CLIENT_ID):
+https://accounts.google.com/o/oauth2/v2/auth?\
+client_id=YOUR_CLIENT_ID&\
+redirect_uri=urn:ietf:wg:oauth:2.0:oob&\
+response_type=code&\
+scope=https://www.googleapis.com/auth/calendar&\
+access_type=offline&\
+prompt=consent
+
+# 2. After consent, you'll get an authorization code. Exchange it:
+curl -s -X POST https://oauth2.googleapis.com/token \
+  -d client_id=YOUR_CLIENT_ID \
+  -d client_secret=YOUR_CLIENT_SECRET \
+  -d code=AUTH_CODE \
+  -d grant_type=authorization_code \
+  -d redirect_uri=urn:ietf:wg:oauth:2.0:oob | jq .refresh_token
+```
+
+## Step 3: Configure Spacebot
+
+<Tabs items={["Dashboard UI", "TOML Config"]}>
+<Tab value="Dashboard UI">
+
+1. Open the Spacebot dashboard
+2. Go to **Settings → API Keys**
+3. Find the **Google Calendar** card and click **Configure**
+4. Enter your Client ID, Client Secret, and Refresh Token
+5. Optionally set a Default Calendar ID (defaults to `primary`)
+6. Click **Save**
+
+</Tab>
+<Tab value="TOML Config">
+
+Add to your `config.toml`:
+
+```toml
+[defaults.google_calendar]
+client_id = "YOUR_CLIENT_ID.apps.googleusercontent.com"
+client_secret = "GOCSPX-YOUR_SECRET"
+refresh_token = "1//YOUR_REFRESH_TOKEN"
+default_calendar_id = "primary"
+```
+
+You can also use `env:` references to load from environment variables:
+
+```toml
+[defaults.google_calendar]
+client_id = "env:GOOGLE_CALENDAR_CLIENT_ID"
+client_secret = "env:GOOGLE_CALENDAR_CLIENT_SECRET"
+refresh_token = "env:GOOGLE_CALENDAR_REFRESH_TOKEN"
+default_calendar_id = "primary"
+```
+
+</Tab>
+</Tabs>
+
+## Per-Agent Override
+
+You can override Google Calendar credentials for a specific agent:
+
+```toml
+[[agents]]
+id = "personal-assistant"
+
+[agents.google_calendar]
+client_id = "DIFFERENT_CLIENT_ID.apps.googleusercontent.com"
+client_secret = "GOCSPX-DIFFERENT_SECRET"
+refresh_token = "1//DIFFERENT_REFRESH_TOKEN"
+default_calendar_id = "work@example.com"
+```
+
+This lets different agents access different Google accounts or calendars.
+
+## Troubleshooting
+
+**"invalid_grant" errors**
+- Your refresh token may have expired. Google revokes tokens if the OAuth consent screen is in "Testing" mode and the token is older than 7 days. Publish your app or re-generate the token.
+- Make sure `access_type=offline` and `prompt=consent` were used when obtaining the token.
+
+**Tools not appearing**
+- Verify all three required fields are set: `client_id`, `client_secret`, `refresh_token`.
+- Check the dashboard — the Google Calendar card should show "Configured".
+- Config changes hot-reload automatically; no restart needed.
+
+**"Access Not Configured" or 403 errors**
+- Ensure the Google Calendar API is enabled in your Google Cloud project.
+- Verify the OAuth consent screen includes your account as a test user (if in Testing mode).
+
+**Wrong calendar**
+- Set `default_calendar_id` to the specific calendar email address (e.g., `work@example.com`) instead of `primary`.
+- Use the `google_calendar_list_calendars` tool to see available calendars.

docs/content/docs/(features)/meta.json

@@ -1,4 +1,4 @@
 {
   "title": "Features",
-  "pages": ["workers", "tasks", "opencode", "tools", "mcp", "browser", "cron", "skills", "ingestion"]
+  "pages": ["workers", "tasks", "opencode", "tools", "mcp", "browser", "cron", "skills", "ingestion", "google-calendar"]
 }

interface/src/api/client.ts

@@ -1338,6 +1338,11 @@ export interface OpenCodeSettingsUpdate {
 
 export interface GlobalSettingsResponse {
 	brave_search_key: string | null;
+	google_calendar_configured: boolean;
+	google_calendar_client_id: string | null;
+	google_calendar_client_secret: string | null;
+	google_calendar_refresh_token: string | null;
+	google_calendar_default_calendar_id: string | null;
 	api_enabled: boolean;
 	api_port: number;
 	api_bind: string;
@@ -1347,6 +1352,12 @@ export interface GlobalSettingsResponse {
 
 export interface GlobalSettingsUpdate {
 	brave_search_key?: string | null;
+	google_calendar?: {
+		client_id?: string;
+		client_secret?: string;
+		refresh_token?: string;
+		default_calendar_id?: string;
+	};
 	api_enabled?: boolean;
 	api_port?: number;
 	api_bind?: string;

interface/src/routes/Settings.tsx

@@ -7,7 +7,7 @@ import { PlatformCatalog, InstanceCard, AddInstanceCard } from "@/components/Cha
 import { ModelSelect } from "@/components/ModelSelect";
 import { ProviderIcon } from "@/lib/providerIcons";
 import { FontAwesomeIcon } from "@fortawesome/react-fontawesome";
-import { faSearch } from "@fortawesome/free-solid-svg-icons";
+import { faSearch, faCalendarDays } from "@fortawesome/free-solid-svg-icons";
 
 import { parse as parseToml } from "smol-toml";
 import { useTheme, THEMES, type ThemeId } from "@/hooks/useTheme";
@@ -1619,6 +1619,11 @@ function ApiKeysSection({ settings, isLoading }: GlobalSettingsSectionProps) {
 	const queryClient = useQueryClient();
 	const [editingBraveKey, setEditingBraveKey] = useState(false);
 	const [braveKeyInput, setBraveKeyInput] = useState("");
+	const [editingGCalCredentials, setEditingGCalCredentials] = useState(false);
+	const [gCalClientId, setGCalClientId] = useState("");
+	const [gCalClientSecret, setGCalClientSecret] = useState("");
+	const [gCalRefreshToken, setGCalRefreshToken] = useState("");
+	const [gCalDefaultCalendarId, setGCalDefaultCalendarId] = useState("");
 	const [message, setMessage] = useState<{ text: string; type: "success" | "error" } | null>(null);
 
 	const updateMutation = useMutation({
@@ -1627,6 +1632,11 @@ function ApiKeysSection({ settings, isLoading }: GlobalSettingsSectionProps) {
 			if (result.success) {
 				setEditingBraveKey(false);
 				setBraveKeyInput("");
+				setEditingGCalCredentials(false);
+				setGCalClientId("");
+				setGCalClientSecret("");
+				setGCalRefreshToken("");
+				setGCalDefaultCalendarId("");
 				setMessage({ text: result.message, type: "success" });
 				queryClient.invalidateQueries({ queryKey: ["global-settings"] });
 			} else {
@@ -1646,6 +1656,28 @@ function ApiKeysSection({ settings, isLoading }: GlobalSettingsSectionProps) {
 		updateMutation.mutate({ brave_search_key: null });
 	};
 
+	const handleSaveGCalCredentials = () => {
+		const calId = gCalDefaultCalendarId.trim();
+		updateMutation.mutate({
+			google_calendar: {
+				client_id: gCalClientId.trim(),
+				client_secret: gCalClientSecret.trim(),
+				refresh_token: gCalRefreshToken.trim(),
+				...(calId ? { default_calendar_id: calId } : {}),
+			},
+		});
+	};
+
+	const handleRemoveGCalCredentials = () => {
+		updateMutation.mutate({
+			google_calendar: {
+				client_id: "",
+				client_secret: "",
+				refresh_token: "",
+			},
+		});
+	};
+
 	return (
 		<div className="mx-auto max-w-2xl px-6 py-6">
 			<div className="mb-6">
@@ -1701,6 +1733,50 @@ function ApiKeysSection({ settings, isLoading }: GlobalSettingsSectionProps) {
 							</div>
 						</div>
 					</div>
+
+					{/* Google Calendar */}
+					<div className="rounded-lg border border-app-line bg-app-box p-4">
+						<div className="flex items-center gap-3">
+							<FontAwesomeIcon icon={faCalendarDays} className="text-ink-faint" />
+							<div className="flex-1">
+								<div className="flex items-center gap-2">
+									<span className="text-sm font-medium text-ink">Google Calendar</span>
+									{settings?.google_calendar_configured && (
+										<span className="text-tiny text-green-400">● Configured</span>
+									)}
+								</div>
+								<p className="mt-0.5 text-sm text-ink-dull">
+									Enables calendar tools for listing, creating, and managing events
+								</p>
+							</div>
+							<div className="flex gap-2">
+								<Button
+									onClick={() => {
+										setEditingGCalCredentials(true);
+										setGCalClientId(settings?.google_calendar_client_id || "");
+										setGCalClientSecret(settings?.google_calendar_client_secret || "");
+										setGCalRefreshToken(settings?.google_calendar_refresh_token || "");
+										setGCalDefaultCalendarId(settings?.google_calendar_default_calendar_id || "");
+										setMessage(null);
+									}}
+									variant="outline"
+									size="sm"
+								>
+									{settings?.google_calendar_configured ? "Update" : "Configure"}
+								</Button>
+								{settings?.google_calendar_configured && (
+									<Button
+										onClick={handleRemoveGCalCredentials}
+										variant="outline"
+										size="sm"
+										loading={updateMutation.isPending}
+									>
+										Remove
+									</Button>
+								)}
+							</div>
+						</div>
+					</div>
 				</div>
 			)}
 
@@ -1748,6 +1824,60 @@ function ApiKeysSection({ settings, isLoading }: GlobalSettingsSectionProps) {
 					</DialogFooter>
 				</DialogContent>
 			</Dialog>
+
+			{/* Google Calendar Dialog */}
+			<Dialog open={editingGCalCredentials} onOpenChange={(open) => { if (!open) setEditingGCalCredentials(false); }}>
+				<DialogContent className="max-w-md">
+					<DialogHeader>
+						<DialogTitle>{settings?.google_calendar_configured ? "Update" : "Configure"} Google Calendar</DialogTitle>
+						<DialogDescription>
+							Enter your Google OAuth credentials. See the{" "}
+							<a href="/docs/google-calendar" target="_blank" rel="noopener noreferrer" className="text-accent underline">setup guide</a>{" "}
+							for instructions.
+						</DialogDescription>
+					</DialogHeader>
+					<div className="flex flex-col gap-3">
+						<Input
+							type="password"
+							value={gCalClientId}
+							onChange={(e) => setGCalClientId(e.target.value)}
+							placeholder="xxxx.apps.googleusercontent.com"
+							autoFocus
+						/>
+						<Input
+							type="password"
+							value={gCalClientSecret}
+							onChange={(e) => setGCalClientSecret(e.target.value)}
+							placeholder="GOCSPX-..."
+						/>
+						<Input
+							type="password"
+							value={gCalRefreshToken}
+							onChange={(e) => setGCalRefreshToken(e.target.value)}
+							placeholder="1//0..."
+						/>
+						<Input
+							type="text"
+							value={gCalDefaultCalendarId}
+							onChange={(e) => setGCalDefaultCalendarId(e.target.value)}
+							placeholder="primary (optional)"
+						/>
+					</div>
+					<DialogFooter>
+						<Button onClick={() => setEditingGCalCredentials(false)} variant="ghost" size="sm">
+							Cancel
+						</Button>
+						<Button
+							onClick={handleSaveGCalCredentials}
+							disabled={!gCalClientId.trim() || !gCalClientSecret.trim() || !gCalRefreshToken.trim()}
+							loading={updateMutation.isPending}
+							size="sm"
+						>
+							Save
+						</Button>
+					</DialogFooter>
+				</DialogContent>
+			</Dialog>
 		</div>
 	);
 }

prompts/en/tools/google_calendar_create_event_description.md.j2

@@ -0,0 +1 @@
+Create a new event on Google Calendar. Specify a title, start/end time, and optionally a description, location, attendees, or recurrence rule. Use this to schedule meetings, set reminders, or block time.

prompts/en/tools/google_calendar_delete_event_description.md.j2

@@ -0,0 +1 @@
+Delete an event from Google Calendar. Requires the event ID. Use this to cancel meetings or remove events that are no longer needed.

prompts/en/tools/google_calendar_find_free_time_description.md.j2

@@ -0,0 +1 @@
+Check free/busy status across one or more Google Calendars for a given time range. Returns busy periods. Use this to find available meeting slots or check if someone is free at a specific time.

prompts/en/tools/google_calendar_list_calendars_description.md.j2

@@ -0,0 +1 @@
+List all calendars available to the authenticated Google account. Returns calendar names, IDs, and access roles. Use this to discover which calendars exist before querying events.

prompts/en/tools/google_calendar_list_events_description.md.j2

@@ -0,0 +1 @@
+List events from Google Calendar. Returns event titles, times, locations, and attendees. Use this to check someone's schedule, find upcoming meetings, or search for specific events by keyword.

prompts/en/tools/google_calendar_respond_event_description.md.j2

@@ -0,0 +1 @@
+Respond to a Google Calendar event invitation. Set your RSVP status to accepted, declined, or tentative. Requires the event ID.

prompts/en/tools/google_calendar_update_event_description.md.j2

@@ -0,0 +1 @@
+Update an existing Google Calendar event. Modify the title, time, description, location, attendees, or `color_id`. Only the fields you provide will be changed. Requires the event ID from a previous list or create call.

src/api/agents.rs

@@ -619,6 +619,7 @@ pub async fn create_agent_internal(
         channel: None,
         mcp: None,
         brave_search_key: None,
+        google_calendar: None,
         cron_timezone: None,
         user_timezone: None,
         sandbox: None,