Send a message to an existing chat
chats.messages.send(strchat_id, MessageSendParams**kwargs) -> MessageSendResponse
POST/v3/chats/{chatId}/messages
Send a message to an existing chat. Use this endpoint when you already have a chat ID and want to send additional messages to it.
Message Effects
You can add iMessage effects to make your messages more expressive. Effects are optional and can be either screen effects (full-screen animations) or bubble effects (message bubble animations).
Screen Effects: confetti, fireworks, lasers, sparkles, celebration,
hearts, love, balloons, happy_birthday, echo, spotlight
Bubble Effects: slam, loud, gentle, invisible
Only one effect type can be applied per message.
Inline Text Decorations (iMessage only)
Use the text_decorations array on a text part to apply styling and animations to character ranges.
Each decoration specifies a range: [start, end) and exactly one of style or animation.
Styles: bold, italic, strikethrough, underline
Animations: big, small, shake, nod, explode, ripple, bloom, jitter
{
"type": "text",
"value": "Hello world",
"text_decorations": [
{ "range": [0, 5], "style": "bold" },
{ "range": [6, 11], "animation": "shake" }
]
}Note: Style ranges (bold, italic, etc.) may overlap, but animation ranges must not overlap with other animations or styles. Decorations render per recipient, not per message: in a group with both iMessage and SMS/RCS participants, iMessage recipients see the decorations and SMS/RCS recipients receive the same message as plain text.
Send a message to an existing chat
import os
from linq import LinqAPIV3
client = LinqAPIV3(
api_key=os.environ.get("LINQ_API_V3_API_KEY"), # This is the default and can be omitted
)
response = client.chats.messages.send(
chat_id="550e8400-e29b-41d4-a716-446655440000",
message={
"parts": [{
"type": "text",
"value": "Hello, world!",
}]
},
)
print(response.chat_id){
"chat_id": "550e8400-e29b-41d4-a716-446655440000",
"message": {
"id": "69a37c7d-af4f-4b5e-af42-e28e98ce873a",
"created_at": "2025-10-23T13:07:55.019-05:00",
"delivery_status": "pending",
"is_read": false,
"parts": [
{
"reactions": [
{
"handle": {
"id": "69a37c7d-af4f-4b5e-af42-e28e98ce873a",
"handle": "+15551234567",
"joined_at": "2025-05-21T15:30:00.000-05:00",
"service": "iMessage",
"is_me": false,
"left_at": "2019-12-27T18:11:19.117Z",
"status": "active"
},
"is_me": false,
"type": "love",
"custom_emoji": null,
"sticker": {
"file_name": "sticker.png",
"height": 420,
"mime_type": "image/png",
"url": "https://cdn.linqapp.com/attachments/a1b2c3d4/sticker.png?signature=...",
"width": 420
}
}
],
"type": "text",
"value": "Hello!",
"mention": "+14155551234",
"mention_range": [
4,
9
],
"text_decorations": [
{
"range": [
0,
5
],
"animation": "shake",
"style": "bold"
}
]
}
],
"sent_at": null,
"delivered_at": null,
"effect": {
"name": "confetti",
"type": "screen"
},
"from_handle": {
"id": "550e8400-e29b-41d4-a716-446655440000",
"handle": "+15551234567",
"joined_at": "2025-05-21T15:30:00.000-05:00",
"service": "iMessage",
"is_me": false,
"left_at": "2019-12-27T18:11:19.117Z",
"status": "active"
},
"preferred_service": "iMessage",
"reply_to": {
"message_id": "550e8400-e29b-41d4-a716-446655440000",
"part_index": 0
},
"service": "iMessage"
}
}{
"error": {
"status": 400,
"code": 1002,
"message": "Phone number must be in E.164 format",
"doc_url": "https://docs.linqapp.com/error/codes/1xxx/1002/"
},
"success": false
}{
"error": {
"status": 401,
"code": 2004,
"message": "Unauthorized - missing or invalid authentication token",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2004/"
},
"success": false
}{
"error": {
"status": 403,
"code": 2005,
"message": "Access denied - insufficient permissions for this resource",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2005/"
},
"success": false
}{
"error": {
"status": 404,
"code": 2001,
"message": "Resource not found",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2001/"
},
"success": false
}{
"error": {
"status": 409,
"code": 2023,
"message": "mentions are only supported in group chats",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2023/"
},
"success": false
}{
"error": {
"status": 409,
"code": 2015,
"message": "mention target +14155551234 is no longer a participant of this chat",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2015/"
},
"success": false
}{
"error": {
"status": 409,
"code": 2013,
"message": "cannot interact with a chat you have left",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2013/"
},
"success": false
}{
"error": {
"status": 500,
"code": 3006,
"message": "Internal server error",
"doc_url": "https://docs.linqapp.com/error/codes/3xxx/3006/"
},
"success": false
}Returns Examples
{
"chat_id": "550e8400-e29b-41d4-a716-446655440000",
"message": {
"id": "69a37c7d-af4f-4b5e-af42-e28e98ce873a",
"created_at": "2025-10-23T13:07:55.019-05:00",
"delivery_status": "pending",
"is_read": false,
"parts": [
{
"reactions": [
{
"handle": {
"id": "69a37c7d-af4f-4b5e-af42-e28e98ce873a",
"handle": "+15551234567",
"joined_at": "2025-05-21T15:30:00.000-05:00",
"service": "iMessage",
"is_me": false,
"left_at": "2019-12-27T18:11:19.117Z",
"status": "active"
},
"is_me": false,
"type": "love",
"custom_emoji": null,
"sticker": {
"file_name": "sticker.png",
"height": 420,
"mime_type": "image/png",
"url": "https://cdn.linqapp.com/attachments/a1b2c3d4/sticker.png?signature=...",
"width": 420
}
}
],
"type": "text",
"value": "Hello!",
"mention": "+14155551234",
"mention_range": [
4,
9
],
"text_decorations": [
{
"range": [
0,
5
],
"animation": "shake",
"style": "bold"
}
]
}
],
"sent_at": null,
"delivered_at": null,
"effect": {
"name": "confetti",
"type": "screen"
},
"from_handle": {
"id": "550e8400-e29b-41d4-a716-446655440000",
"handle": "+15551234567",
"joined_at": "2025-05-21T15:30:00.000-05:00",
"service": "iMessage",
"is_me": false,
"left_at": "2019-12-27T18:11:19.117Z",
"status": "active"
},
"preferred_service": "iMessage",
"reply_to": {
"message_id": "550e8400-e29b-41d4-a716-446655440000",
"part_index": 0
},
"service": "iMessage"
}
}{
"error": {
"status": 400,
"code": 1002,
"message": "Phone number must be in E.164 format",
"doc_url": "https://docs.linqapp.com/error/codes/1xxx/1002/"
},
"success": false
}{
"error": {
"status": 401,
"code": 2004,
"message": "Unauthorized - missing or invalid authentication token",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2004/"
},
"success": false
}{
"error": {
"status": 403,
"code": 2005,
"message": "Access denied - insufficient permissions for this resource",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2005/"
},
"success": false
}{
"error": {
"status": 404,
"code": 2001,
"message": "Resource not found",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2001/"
},
"success": false
}{
"error": {
"status": 409,
"code": 2023,
"message": "mentions are only supported in group chats",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2023/"
},
"success": false
}{
"error": {
"status": 409,
"code": 2015,
"message": "mention target +14155551234 is no longer a participant of this chat",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2015/"
},
"success": false
}{
"error": {
"status": 409,
"code": 2013,
"message": "cannot interact with a chat you have left",
"doc_url": "https://docs.linqapp.com/error/codes/2xxx/2013/"
},
"success": false
}{
"error": {
"status": 500,
"code": 3006,
"message": "Internal server error",
"doc_url": "https://docs.linqapp.com/error/codes/3xxx/3006/"
},
"success": false
}