Group iMessage API — Send Group Texts Programmatically

Create and manage group iMessage conversations via API. Add up to 25 recipients to a single thread and let everyone see each other's replies.

How Group Messaging Works

Sendblue's group messaging API lets you create native iMessage group conversations programmatically. Unlike bulk SMS blasts where each recipient gets an individual message, group iMessage creates a shared thread — every participant sees every reply, just like a regular group chat.

You specify an array of phone numbers (up to 25), and Sendblue creates the group conversation. Subsequent messages to the same group use the returned group_id to continue the thread.

Create a Group Conversation

curl -X POST https://api.sendblue.co/api/send-group-message \
  -H "sb-api-key-id: YOUR_API_KEY" \
  -H "sb-api-secret-key: YOUR_SECRET_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "numbers": ["+19998887777", "+19998886666", "+19998885555"],
    "content": "Hey team! Let us coordinate on the launch.",
    "status_callback": "https://yourapp.com/webhook/status"
  }'

The response includes a group_id that you use for all subsequent messages to this group. Replies from any participant are delivered to your webhook with the same group identifier.

Key Capabilities

Up to 25 Recipients

Add up to 25 phone numbers to a single group iMessage conversation. All participants see the full thread.

Persistent Threads

Each group gets a unique group_id. Send follow-up messages to the same thread without recreating the group.

Webhook Replies

Receive incoming messages from any group participant via webhooks. Identify the sender and the group in every callback.

Media Support

Send images, videos, and files to groups. All media types supported in individual messages work in group conversations too.

Use Cases

Sales Team Deals

Create a group chat with the prospect and your team. Everyone stays in the loop on the same iMessage thread — no forwarding required.

Event Coordination

Spin up group chats for event attendees, volunteers, or speakers. Share updates, logistics, and last-minute changes in real time.

Client Onboarding

Add the client and your implementation team to a group. Share documents, answer questions, and track progress in one thread.

Why Group iMessage Beats Group SMS

Group SMS (MMS group messaging) has severe limitations: media gets compressed, there's no delivery confirmation, and many carriers handle group MMS inconsistently. Group iMessage, on the other hand, delivers a native, rich experience that users already know and trust.

Thread persistence: iMessage groups maintain their history. Every participant can scroll back through the conversation — context is never lost.

Rich interactions: Send images and videos at full quality, share contact cards, and see typing indicators from participants. It feels personal because it is.

Combine group messaging with Sendblue's number lookup to verify all recipients have iMessage before creating the group. Use the API directly or integrate with your CRM via the Sendblue CLI or MCP server.

Start sending group iMessages today

Free sandbox, no credit card required. Create your first group in minutes.

Get API Access

Frequently Asked Questions

How many recipients can I add to a group iMessage?

Sendblue supports group iMessage conversations with up to 25 recipients. All participants see each other's replies in the same thread, just like a native group chat.

Can I send media in group messages?

Yes. Group messages support all the same media types as individual messages — images, videos, PDFs, audio files, and vCards. Use the media_url parameter to attach media to any group message.

Do I get notifications when someone replies to the group?

Yes. Sendblue fires webhooks for every incoming message in the group conversation. You receive the sender's number, message content, and group ID so you can track the full conversation.

What happens if some recipients don't have iMessage?

Group iMessage requires all participants to have iMessage enabled. Sendblue's number lookup API lets you check iMessage availability before creating a group, so you can handle non-iMessage contacts separately.