/google-chat-messages

name: google-chat-messages
description: "Send Google Chat messages via incoming webhooks — text, rich cards (cardsV2), threaded replies. TypeScript types, card builder utility, widget reference inline. Use whenever the user wants to post to Google Chat from a script, build a chatbot reply, send a notification card, build a Google Chat webhook integration, or troubleshoot card / threading issues."
compatibility: claude-code-only

Google Chat Messages

Send messages to Google Chat spaces via incoming webhooks. Produces text messages, rich cards (cardsV2), and threaded replies.

What You Produce

• Text messages with Google Chat formatting
• Rich card messages (cardsV2) with headers, sections, widgets
• Threaded conversations
• Reusable webhook sender utility

Workflow

Step 1: Get Webhook URL

In Google Chat: 1. Open a Space > click space name > **Manage webhooks** 2. Create webhook (name it, optionally add avatar URL) 3. Copy the webhook URL

Store the URL as an environment variable or in your secrets manager — never hardcode.

Step 2: Choose Message Type

| Need | Type | Complexity | |------|------|------------| | Simple notification | Text message | Low | | Structured info (status, digest) | Card message (cardsV2) | Medium | | Ongoing updates | Threaded replies | Medium | | Action buttons (open URL) | Card with buttonList | Medium |

Step 3: Send the Message

Use `assets/webhook-sender.ts` for the sender utility. Use `assets/card-builder.ts` for structured card construction.

Text Formatting

Google Chat does NOT use standard Markdown.

| Format | Syntax | Example | |--------|--------|---------| | Bold | `*text*` | `*important*` | | Italic | `_text_` | `_emphasis_` | | Strikethrough | `~text~` | `~removed~` | | Monospace | `` `text` `` | `` `code` `` | | Code block | ` ```text``` ` | Multi-line code | | Link | `<url\|text>` | `<https://example.com\|Click here>` | | Mention user | `<users/USER_ID>` | `<users/123456>` | | Mention all | `<users/all>` | `<users/all>` |

**Not supported**: `**double asterisks**`, headings (`###`), blockquotes, tables, images inline.

Text Message Example

await sendText(webhookUrl, '*Build Complete*\n\nBranch: `main`\nStatus: Passed\n<https://ci.example.com/123|View Build>');

cardsV2 Structure

Cards use the cardsV2 format (recommended over legacy cards).

const message = {
  cardsV2: [{
    cardId: 'unique-id',
    card: {
      header: {
        title: 'Card Title',
        subtitle: 'Optional subtitle',
        imageUrl: 'https://example.com/icon.png',
        imageType: 'CIRCLE'  // or 'SQUARE'
      },
      sections: [{
        header: 'Section Title',  // optional
        widgets: [
          // widgets go here
        ]
      }]
    }
  }]
};

Widget Reference

All widget types available in cardsV2 sections.

textParagraph

Formatted text block. Supports Google Chat formatting (`*bold*`, `_italic_`, `<url|text>`).

{
  textParagraph: {
    text: '*Status*: All systems operational\n_Last checked_: 5 minutes ago'
  }
}

decoratedText

Labelled value with optional icons. Most versatile widget for key-value data.

**Basic:**

{
  decoratedText: {
    topLabel: 'Environment',
    text: 'Production',
    bottomLabel: 'Last deployed 2h ago'
  }
}

**With start icon:**

{
  decoratedText: {
    topLabel: 'Status',
    text: 'Healthy',
    startIcon: { knownIcon: 'STAR' }
  }
}

**With custom icon URL:**

{
  decoratedText: {
    topLabel: 'GitHub',
    text: 'PR #142 merged',
    startIcon: {
      iconUrl: 'https://github.githubassets.com/favicons/favicon.svg',
      altText: 'GitHub'
    }
  }
}

**With button:**

{
  decoratedText: {
    topLabel: 'Alert',
    text: 'CPU at 95%',
    button: {
      text: 'View',
      onClick: { openLink: { url: 'https://monitoring.example.com' } }
    }
  }
}

**Clickable (whole widget):**

{
  decoratedText: {
    text: 'View full report',
    wrapText: true,
    onClick: { openLink: { url: 'https://reports.example.com' } }
  }
}

**With wrap text:**

{
  decoratedText: {
    topLabel: 'Description',
    text: 'This is a longer description that should wrap to multiple lines instead of being truncated',
    wrapText: true
  }
}

buttonList

One or more action buttons. Buttons open URLs or trigger actions.

**Single button:**

{
  buttonList: {
    buttons: [{
      text: 'Open Dashboard',
      onClick: { openLink: { url: 'https://dashboard.example.com' } }
    }]
  }
}

**Multiple buttons:**

{
  buttonList: {
    buttons: [
      {
        text: 'Approve',
        onClick: { openLink: { url: 'https://app.example.com/approve/123' } },
        color: { red: 0, green: 0.5, blue: 0, alpha: 1 }
      },
      {
        text: 'Reject',
        onClick: { openLink: { url: 'https://app.example.com/reject/123' } }
      }
    ]
  }
}

**Button with icon:**

{
  buttonList: {
    buttons: [{
      text: 'View on GitHub',
      icon: { knownIcon: 'BOOKMARK' },
      onClick: { openLink: { url: 'https://github.com/org/repo/pull/42' } }
    }]
  }
}

image

Standalone image widget.

{
  image: {
    imageUrl: 'https://example.com/chart.png',
    altText: 'Monthly usage chart'
  }
}

divider

Horizontal line separator between widgets.

{ divider: {} }

Collapsible Sections

Sections can be collapsed with only the first N widgets visible:

{
  header: 'Details',
  collapsible: true,
  uncollapsibleWidgetsCount: 2,  // Show first 2, collapse rest
  widgets: [
    { decoratedText: { topLabel: 'Status', text: 'Active' } },
    { decoratedText: { topLabel: 'Region', text: 'AU' } },
    // These start collapsed
    { decoratedText: { topLabel: 'Instance', text: 'prod-01' } },
    { decoratedText: { topLabel: 'Memory', te