## Create a new chat

`chats.create(ChatCreateParams**kwargs)  -> ChatCreateResponse`

**post** `/v3/chats`

Create a new chat with specified participants and send an initial message.
The initial message is required when creating a chat.

## 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`

```json
{
  "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. Text decorations only render for iMessage recipients.
For SMS/RCS, text decorations are not applied.

## First-Message Link Restriction

To protect sender deliverability, the **first outbound message** of a new chat cannot be a link.
The request is rejected with `400` (error code `1005`) when:

- The message contains a `link` part (explicit rich-preview link), or
- Any `text` part contains a URL.

This rule applies only to `POST /v3/chats`. Follow-up messages on an existing chat
(`POST /v3/chats/{chatId}/messages`) are not subject to this restriction.

### Parameters

- `from_: str`

  Sender phone number in E.164 format. Must be a phone number that the
  authenticated partner has permission to send from.

- `message: MessageContentParam`

  Message content container. Groups all message-related fields together,
  separating the "what" (message content) from the "where" (routing fields like from/to).

  - `parts: List[Part]`

    Array of message parts. Each part can be text, media, or link.
    Parts are displayed in order. Text and media can be mixed freely,
    but a `link` part must be the only part in the message.

    **Rich Link Previews:**

    - Use a `link` part to send a URL with a rich preview card
    - A `link` part must be the **only** part in the message
    - To send a URL as plain text (no preview), use a `text` part instead

    **Supported Media:**

    - Images: .jpg, .jpeg, .png, .gif, .heic, .heif, .tif, .tiff, .bmp
    - Videos: .mp4, .mov, .m4v, .mpeg, .mpg, .3gp
    - Audio: .m4a, .mp3, .aac, .caf, .wav, .aiff, .amr
    - Documents: .pdf, .txt, .rtf, .csv, .doc, .docx, .xls, .xlsx, .ppt, .pptx, .pages, .numbers, .key, .epub, .zip, .html, .htm
    - Contact & Calendar: .vcf, .ics

    **Audio:**

    - Audio files (.m4a, .mp3, .aac, .caf, .wav, .aiff, .amr) are fully supported as media parts
    - To send audio as an **iMessage voice memo bubble** (inline playback UI), use the dedicated
      `/v3/chats/{chatId}/voicememo` endpoint instead

    **Validation Rules:**

    - A `link` part must be the **only** part in the message. It cannot be combined
      with text or media parts.
    - Consecutive text parts are not allowed. Text parts must be separated by
      media parts. For example, [text, text] is invalid, but [text, media, text] is valid.
    - Maximum of **100 parts** total.
    - Media parts using a public `url` (downloaded by the server on send) are
      capped at **40**. Parts using `attachment_id` or presigned URLs
      are exempt from this sub-limit. For bulk media sends exceeding 40 files,
      pre-upload via `POST /v3/attachments` and reference by `attachment_id` or `download_url`.

    - `class TextPart: …`

      - `type: Literal["text"]`

        Indicates this is a text message part

        - `"text"`

      - `value: str`

        The text content of the message. This value is sent as-is with no parsing or transformation — Markdown syntax will be delivered as plain text. Use `text_decorations` to apply inline formatting and animations (iMessage only).

      - `text_decorations: Optional[List[TextDecoration]]`

        Optional array of text decorations applied to character ranges in the `value` field (iMessage only).

        Each decoration specifies a character range `[start, end)` and exactly one of `style` or `animation`.

        **Styles:** `bold`, `italic`, `strikethrough`, `underline`
        **Animations:** `big`, `small`, `shake`, `nod`, `explode`, `ripple`, `bloom`, `jitter`

        Style ranges may overlap (e.g. bold + italic on the same text), but animation ranges must not overlap with other animations or styles.

        *Characters are measured as UTF-16 code units. Most characters count as 1; some emoji count as 2.*

        **Note:** Text decorations only render for iMessage recipients. For SMS/RCS, text decorations are not applied.

        - `range: List[int]`

          Character range `[start, end)` in the `value` string where the decoration applies.
          `start` is inclusive, `end` is exclusive.
          *Characters are measured as UTF-16 code units. Most characters count as 1; some emoji count as 2.*

        - `animation: Optional[Literal["big", "small", "shake", 5 more]]`

          Animated text effect to apply. Mutually exclusive with `style`.

          - `"big"`

          - `"small"`

          - `"shake"`

          - `"nod"`

          - `"explode"`

          - `"ripple"`

          - `"bloom"`

          - `"jitter"`

        - `style: Optional[Literal["bold", "italic", "strikethrough", "underline"]]`

          Text style to apply. Mutually exclusive with `animation`.

          - `"bold"`

          - `"italic"`

          - `"strikethrough"`

          - `"underline"`

    - `class MediaPart: …`

      - `type: Literal["media"]`

        Indicates this is a media attachment part

        - `"media"`

      - `attachment_id: Optional[str]`

        Reference to a file pre-uploaded via `POST /v3/attachments` (optional).
        The file is already stored, so sends using this ID skip the download step —
        useful when sending the same file to many recipients.

        Either `url` or `attachment_id` must be provided, but not both.

      - `url: Optional[str]`

        Any publicly accessible HTTPS URL to the media file. The server downloads and
        sends the file automatically — no pre-upload step required.

        **Size limit:** 10MB maximum for URL-based downloads. For larger files (up to 100MB),
        use the pre-upload flow: `POST /v3/attachments` to get a presigned URL, upload directly,
        then reference by `attachment_id`.

        **Requirements:**

        - URL must use HTTPS
        - File content must be a supported format (the server validates the actual file content)

        **Supported formats:**

        - Images: .jpg, .jpeg, .png, .gif, .heic, .heif, .tif, .tiff, .bmp
        - Videos: .mp4, .mov, .m4v, .mpeg, .mpg, .3gp
        - Audio: .m4a, .mp3, .aac, .caf, .wav, .aiff, .amr
        - Documents: .pdf, .txt, .rtf, .csv, .doc, .docx, .xls, .xlsx, .ppt, .pptx, .pages, .numbers, .key, .epub, .zip, .html, .htm
        - Contact & Calendar: .vcf, .ics

        **Tip:** Audio sent here appears as a regular file attachment. To send audio as an
        iMessage voice memo bubble (with inline playback), use `/v3/chats/{chatId}/voicememo`.
        For repeated sends of the same file, use `attachment_id` to avoid redundant downloads.

        Either `url` or `attachment_id` must be provided, but not both.

    - `class LinkPart: …`

      - `type: Literal["link"]`

        Indicates this is a rich link preview part

        - `"link"`

      - `value: str`

        URL to send with a rich link preview. The recipient will see an inline card
        with the page's title, description, and preview image (when available).

        A `link` part must be the **only** part in the message. To send a URL as plain
        text (no preview card), use a `text` part instead.

  - `effect: Optional[MessageEffect]`

    iMessage effect to apply to this message (screen or bubble effect)

    - `name: Optional[str]`

      Name of the effect. Common values:

      - Screen effects: confetti, fireworks, lasers, sparkles, celebration, hearts, love, balloons, happy_birthday, echo, spotlight
      - Bubble effects: slam, loud, gentle, invisible

    - `type: Optional[Literal["screen", "bubble"]]`

      Type of effect

      - `"screen"`

      - `"bubble"`

  - `idempotency_key: Optional[str]`

    Optional idempotency key for this message.
    Use this to prevent duplicate sends of the same message.

  - `preferred_service: Optional[ServiceType]`

    Messaging service type

    - `"iMessage"`

    - `"SMS"`

    - `"RCS"`

  - `reply_to: Optional[ReplyTo]`

    Reply to another message to create a threaded conversation

    - `message_id: str`

      The ID of the message to reply to

    - `part_index: Optional[int]`

      The specific message part to reply to (0-based index).
      Defaults to 0 (first part) if not provided.
      Use this when replying to a specific part of a multipart message.

- `to: Sequence[str]`

  Array of recipient handles (phone numbers in E.164 format or email addresses).
  For individual chats, provide one recipient. For group chats, provide multiple.

### Returns

- `class ChatCreateResponse: …`

  Response for creating a new chat with an initial message

  - `chat: Chat`

    - `id: str`

      Unique identifier for the created chat (UUID)

    - `display_name: Optional[str]`

      Display name for the chat. Defaults to a comma-separated list of recipient handles. Can be updated for group chats.

    - `handles: List[ChatHandle]`

      List of participants in the chat. Always contains at least two handles (your phone number and the other participant).

      - `id: str`

        Unique identifier for this handle

      - `handle: str`

        Phone number (E.164) or email address of the participant

      - `joined_at: datetime`

        When this participant joined the chat

      - `service: ServiceType`

        Messaging service type

        - `"iMessage"`

        - `"SMS"`

        - `"RCS"`

      - `is_me: Optional[bool]`

        Whether this handle belongs to the sender (your phone number)

      - `left_at: Optional[datetime]`

        When they left (if applicable)

      - `status: Optional[Literal["active", "left", "removed"]]`

        Participant status

        - `"active"`

        - `"left"`

        - `"removed"`

    - `health_status: ChatHealthStatus`

      **[BETA]** Current health for a chat. Always present — chats start at `HEALTHY` and may shift based on engagement and delivery signals on the conversation. Many `AT_RISK` or `CRITICAL` chats on a single line increase the risk of line flagging.

      Switch on `status` to gate sends or surface line health in your UI — the enum is the long-term contract. Each status carries a `doc_url` that deep-links to the relevant section of the Chat Health guide.

      See the [Chat Health guide](/guides/chats/chat-health) for what each status means and how to react.

      - `doc_url: str`

        Deep-link to the relevant section of the Chat Health guide for this status.

      - `status: Literal["HEALTHY", "AT_RISK", "CRITICAL", "OPTED_OUT"]`

        Current health bucket for the chat. See the [Chat Health guide](/guides/chats/chat-health) for what each value means and how to react. `doc_url` deep-links to the relevant section.

        - `"HEALTHY"`

        - `"AT_RISK"`

        - `"CRITICAL"`

        - `"OPTED_OUT"`

      - `updated_at: datetime`

        When this status last changed.

    - `is_group: bool`

      Whether this is a group chat

    - `message: SentMessage`

      A message that was sent (used in CreateChat and SendMessage responses)

      - `id: str`

        Message identifier (UUID)

      - `created_at: datetime`

        When the message was created

      - `delivery_status: Literal["pending", "queued", "sent", 2 more]`

        Current delivery status of a message

        - `"pending"`

        - `"queued"`

        - `"sent"`

        - `"delivered"`

        - `"failed"`

      - `is_read: bool`

        Whether the message has been read

      - `parts: List[Part]`

        Message parts in order (text, media, and link)

        - `class TextPartResponse: …`

          A text message part

          - `reactions: Optional[List[Reaction]]`

            Reactions on this message part

            - `handle: ChatHandle`

              - `id: str`

                Unique identifier for this handle

              - `handle: str`

                Phone number (E.164) or email address of the participant

              - `joined_at: datetime`

                When this participant joined the chat

              - `service: ServiceType`

                Messaging service type

              - `is_me: Optional[bool]`

                Whether this handle belongs to the sender (your phone number)

              - `left_at: Optional[datetime]`

                When they left (if applicable)

              - `status: Optional[Literal["active", "left", "removed"]]`

                Participant status

            - `is_me: bool`

              Whether this reaction is from the current user

            - `type: ReactionType`

              Type of reaction. Standard iMessage tapbacks are love, like, dislike, laugh, emphasize, question.
              Custom emoji reactions have type "custom" with the actual emoji in the custom_emoji field.
              Sticker reactions have type "sticker" with sticker attachment details in the sticker field.

              - `"love"`

              - `"like"`

              - `"dislike"`

              - `"laugh"`

              - `"emphasize"`

              - `"question"`

              - `"custom"`

              - `"sticker"`

            - `custom_emoji: Optional[str]`

              Custom emoji if type is "custom", null otherwise

            - `sticker: Optional[Sticker]`

              Sticker attachment details when reaction_type is "sticker". Null for non-sticker reactions.

              - `file_name: Optional[str]`

                Filename of the sticker

              - `height: Optional[int]`

                Sticker image height in pixels

              - `mime_type: Optional[str]`

                MIME type of the sticker image

              - `url: Optional[str]`

                Presigned URL for downloading the sticker image (expires in 1 hour).

              - `width: Optional[int]`

                Sticker image width in pixels

          - `type: Literal["text"]`

            Indicates this is a text message part

            - `"text"`

          - `value: str`

            The text content

          - `text_decorations: Optional[List[TextDecoration]]`

            Text decorations applied to character ranges in the value

            - `range: List[int]`

              Character range `[start, end)` in the `value` string where the decoration applies.
              `start` is inclusive, `end` is exclusive.
              *Characters are measured as UTF-16 code units. Most characters count as 1; some emoji count as 2.*

            - `animation: Optional[Literal["big", "small", "shake", 5 more]]`

              Animated text effect to apply. Mutually exclusive with `style`.

              - `"big"`

              - `"small"`

              - `"shake"`

              - `"nod"`

              - `"explode"`

              - `"ripple"`

              - `"bloom"`

              - `"jitter"`

            - `style: Optional[Literal["bold", "italic", "strikethrough", "underline"]]`

              Text style to apply. Mutually exclusive with `animation`.

              - `"bold"`

              - `"italic"`

              - `"strikethrough"`

              - `"underline"`

        - `class MediaPartResponse: …`

          A media attachment part

          - `id: str`

            Unique attachment identifier

          - `filename: str`

            Original filename

          - `mime_type: str`

            MIME type of the file

          - `reactions: Optional[List[Reaction]]`

            Reactions on this message part

            - `handle: ChatHandle`

            - `is_me: bool`

              Whether this reaction is from the current user

            - `type: ReactionType`

              Type of reaction. Standard iMessage tapbacks are love, like, dislike, laugh, emphasize, question.
              Custom emoji reactions have type "custom" with the actual emoji in the custom_emoji field.
              Sticker reactions have type "sticker" with sticker attachment details in the sticker field.

            - `custom_emoji: Optional[str]`

              Custom emoji if type is "custom", null otherwise

            - `sticker: Optional[Sticker]`

              Sticker attachment details when reaction_type is "sticker". Null for non-sticker reactions.

          - `size_bytes: int`

            File size in bytes

          - `type: Literal["media"]`

            Indicates this is a media attachment part

            - `"media"`

          - `url: str`

            Presigned URL for downloading the attachment (expires in 1 hour).

        - `class LinkPartResponse: …`

          A rich link preview part

          - `reactions: Optional[List[Reaction]]`

            Reactions on this message part

            - `handle: ChatHandle`

            - `is_me: bool`

              Whether this reaction is from the current user

            - `type: ReactionType`

              Type of reaction. Standard iMessage tapbacks are love, like, dislike, laugh, emphasize, question.
              Custom emoji reactions have type "custom" with the actual emoji in the custom_emoji field.
              Sticker reactions have type "sticker" with sticker attachment details in the sticker field.

            - `custom_emoji: Optional[str]`

              Custom emoji if type is "custom", null otherwise

            - `sticker: Optional[Sticker]`

              Sticker attachment details when reaction_type is "sticker". Null for non-sticker reactions.

          - `type: Literal["link"]`

            Indicates this is a rich link preview part

            - `"link"`

          - `value: str`

            The URL

      - `sent_at: Optional[datetime]`

        When the message was actually sent (null if still queued)

      - `delivered_at: Optional[datetime]`

        When the message was delivered

      - `effect: Optional[MessageEffect]`

        iMessage effect applied to a message (screen or bubble effect)

        - `name: Optional[str]`

          Name of the effect. Common values:

          - Screen effects: confetti, fireworks, lasers, sparkles, celebration, hearts, love, balloons, happy_birthday, echo, spotlight
          - Bubble effects: slam, loud, gentle, invisible

        - `type: Optional[Literal["screen", "bubble"]]`

          Type of effect

          - `"screen"`

          - `"bubble"`

      - `from_handle: Optional[ChatHandle]`

        The sender of this message as a full handle object

      - `preferred_service: Optional[ServiceType]`

        Messaging service type

      - `reply_to: Optional[ReplyTo]`

        Indicates this message is a threaded reply to another message

        - `message_id: str`

          The ID of the message to reply to

        - `part_index: Optional[int]`

          The specific message part to reply to (0-based index).
          Defaults to 0 (first part) if not provided.
          Use this when replying to a specific part of a multipart message.

      - `service: Optional[ServiceType]`

        Messaging service type

    - `service: ServiceType`

      Messaging service type

### Example

```python
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
)
chat = client.chats.create(
    from_="+12052535597",
    message={
        "parts": [{
            "type": "text",
            "value": "Hello! How can I help you today?",
        }]
    },
    to=["+12052532136"],
)
print(chat.chat)
```

#### Response

```json
{
  "chat": {
    "id": "94c6bf33-31d9-40e3-a0e9-f94250ecedb9",
    "display_name": "+14155551234, +14155559876",
    "handles": [
      {
        "id": "550e8400-e29b-41d4-a716-446655440010",
        "handle": "+14155551234",
        "joined_at": "2025-05-21T15:30:00.000Z",
        "service": "iMessage",
        "is_me": true,
        "left_at": "2019-12-27T18:11:19.117Z",
        "status": "active"
      },
      {
        "id": "550e8400-e29b-41d4-a716-446655440011",
        "handle": "+14155559876",
        "joined_at": "2025-05-21T15:30:00.000Z",
        "service": "iMessage",
        "is_me": false,
        "left_at": "2019-12-27T18:11:19.117Z",
        "status": "active"
      }
    ],
    "health_status": {
      "doc_url": "https://docs.linqapp.com/guides/chats/chat-health#at-risk",
      "status": "AT_RISK",
      "updated_at": "2026-05-01T18:28:25Z"
    },
    "is_group": false,
    "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!",
          "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"
    },
    "service": "iMessage"
  }
}
```
