Add Google Calendar Tool (OneCLI-native)

This skill wires @cocal/google-calendar-mcp into selected agent groups. The MCP server reads stub credentials containing the onecli-managed placeholder; the OneCLI gateway intercepts outbound calls to calendar.googleapis.com / oauth2.googleapis.com and swaps the bearer for the real OAuth token from its vault.

Why this package (and not gongrzhe's): @gongrzhe/server-calendar-autoauth-mcp only supports the primary calendar and exposes 5 tools (no list_calendars). @cocal/google-calendar-mcp explicitly supports multi-calendar and multi-account, and is actively maintained.

Tools exposed (surfaced as mcp__calendar__<name>, exact set depends on version — run tools/list against the MCP server to enumerate): list-calendars, list-events, search-events, create-event, update-event, delete-event, get-event, list-colors, get-freebusy, get-current-time, plus multi-account management tools.

Why this pattern: v2's invariant is that containers never receive raw API keys (CHANGELOG 2.0.0). Same stub pattern /add-gmail-tool uses. This skill is deliberately a sibling, not a combined "Google Workspace" skill — installs independently and removes cleanly.

Phase 1: Pre-flight

Verify OneCLI has Google Calendar connected

onecli apps get --provider google-calendar

Expected: "connection": { "status": "connected" } with scopes including calendar.readonly and calendar.events.

If not connected, tell the user:

Open the OneCLI web UI at http://127.0.0.1:10254, go to Apps → Google Calendar, and click Connect. Sign in with the Google account the agent should act as. calendar.readonly + calendar.events are the minimum useful scopes.

Verify stub credentials exist

The stub lives at ~/.calendar-mcp/ by convention (shared with /add-gmail-tool's sibling). cocal doesn't default to this path (it uses ~/.config/google-calendar-mcp/tokens.json) — we override via env vars below so it reads our stubs instead.

ls -la ~/.calendar-mcp/gcp-oauth.keys.json ~/.calendar-mcp/credentials.json 2>&1

If both exist with onecli-managed:

grep -l onecli-managed ~/.calendar-mcp/gcp-oauth.keys.json ~/.calendar-mcp/credentials.json

...skip to Phase 2. If either file has real credentials (no onecli-managed), STOP — back up and delete before proceeding.

If absent, write them:

mkdir -p ~/.calendar-mcp
cat > ~/.calendar-mcp/gcp-oauth.keys.json <<'EOF'
{
  "installed": {
    "client_id": "onecli-managed.apps.googleusercontent.com",
    "client_secret": "onecli-managed",
    "redirect_uris": ["http://localhost:3000/oauth2callback"]
  }
}
EOF
cat > ~/.calendar-mcp/credentials.json <<'EOF'
{
  "access_token": "onecli-managed",
  "refresh_token": "onecli-managed",
  "token_type": "Bearer",
  "expiry_date": 99999999999999,
  "scope": "https://www.googleapis.com/auth/calendar.readonly https://www.googleapis.com/auth/calendar.events"
}
EOF
chmod 600 ~/.calendar-mcp/*.json

Verify mount allowlist covers the path

cat ~/.config/nanoclaw/mount-allowlist.json

~/.calendar-mcp must sit under an allowedRoots entry.

Check agent secret-mode

For each target agent group, confirm OneCLI will inject the Google Calendar token:

onecli agents list

secretMode: all is sufficient. If selective, explicitly assign the Calendar secret.

Phase 2: Apply Code Changes

Check if already applied

grep -q 'CALENDAR_MCP_VERSION' container/Dockerfile && \
grep -q "mcp__calendar__\*" container/agent-runner/src/providers/claude.ts && \
echo "ALREADY APPLIED — skip to Phase 3"

Add MCP server to Dockerfile

Edit container/Dockerfile. Find the pinned-version ARG block and add:

ARG CALENDAR_MCP_VERSION=2.6.1

If /add-gmail-tool has already been applied, the pnpm global-install block already exists with its zod-to-json-schema@3.22.5 pin. Just append the calendar package — the calendar-mcp uses zod@4.x and does NOT need that pin, but it's harmless to share the block:

RUN --mount=type=cache,target=/root/.cache/pnpm \
    pnpm install -g \
        "@gongrzhe/server-gmail-autoauth-mcp@${GMAIL_MCP_VERSION}" \
        "@cocal/google-calendar-mcp@${CALENDAR_MCP_VERSION}" \
        "zod-to-json-schema@3.22.5"

If /add-gmail-tool hasn't been applied, install Calendar standalone:

RUN --mount=type=cache,target=/root/.cache/pnpm \
    pnpm install -g "@cocal/google-calendar-mcp@${CALENDAR_MCP_VERSION}"

Add tools to allowlist

Edit container/agent-runner/src/providers/claude.ts. Add 'mcp__calendar__*' to TOOL_ALLOWLIST after 'mcp__nanoclaw__*' (or after 'mcp__gmail__*' if present).

Rebuild the container image

./container/build.sh

Phase 3: Wire Per-Agent-Group

For each agent group, merge into groups/<folder>/container.json:

{
  "mcpServers": {
    "calendar": {
      "command": "google-calendar-mcp",
      "args": [],
      "env": {
        "GOOGLE_OAUTH_CREDENTIALS": "/workspace/extra/.calendar-mcp/gcp-oauth.keys.json",
        "GOOGLE_CALENDAR_MCP_TOKEN_PATH": "/workspace/extra/.calendar-mcp/credentials.json"
      }
    }
  },
  "additionalMounts": [
    {
      "hostPath": "/home/<user>/.calendar-mcp",
      "containerPath": ".calendar-mcp",
      "readonly": false
    }
  ]
}

Substitute <user> with echo $HOME. containerPath is relative (mount-security rejects absolute paths — additional mounts land at /workspace/extra/<relative>).

Same-group-as-gmail tip: if this group already has the gmail MCP + .gmail-mcp mount, merge, don't replace — both entries coexist in mcpServers and additionalMounts.

Phase 4: Build and Restart

pnpm run build
systemctl --user restart nanoclaw   # Linux
# launchctl kickstart -k gui/$(id -u)/com.nanoclaw   # macOS

Kill any existing agent containers so they respawn with the new mcpServers config:

docker ps -q --filter 'name=nanoclaw-v2-' | xargs -r docker kill

Phase 5: Verify

Test from a wired agent

Send: "list my calendars" or "what's on my work calendar next Monday?".

First call takes 2–3s while the MCP server starts and OneCLI does the token exchange.

Check logs if the tool isn't working

tail -100 logs/nanoclaw.log | grep -iE 'calendar|mcp'

Common signals:

• command not found: google-calendar-mcp → image not rebuilt.
• ENOENT ...credentials.json → mount missing. Check the mount allowlist.
• 401 Unauthorized from *.googleapis.com → OneCLI isn't injecting; verify agent's secret mode and that Google Calendar is connected.
• Agent says "I don't have calendar tools" → mcp__calendar__* missing from TOOL_ALLOWLIST, or image cache stale (./container/build.sh again).

Removal

1. Delete "calendar" from mcpServers and the .calendar-mcp mount from additionalMounts in each group's container.json.
2. Remove 'mcp__calendar__*' from TOOL_ALLOWLIST.
3. Remove CALENDAR_MCP_VERSION ARG and the calendar package from the Dockerfile install block.
4. pnpm run build && ./container/build.sh && systemctl --user restart nanoclaw.
5. Optional: rm -rf ~/.calendar-mcp/ and onecli apps disconnect --provider google-calendar.

Credits & references

• MCP server: @cocal/google-calendar-mcp — MIT-licensed, actively maintained, multi-account and multi-calendar.
• Why not gongrzhe: earlier versions of this skill used @gongrzhe/server-calendar-autoauth-mcp@1.0.2 which only supports the primary calendar with 5 event-level tools. The cocal server supersedes it.
• Skill pattern: direct sibling of /add-gmail-tool; same OneCLI stub mechanism.