## 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. 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.

## 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.

## Reusing an Existing Chat

Chats are keyed on the `from` line plus the exact set of `to` handles. Repeating this
request with the same `from` and `to` returns the **existing** chat and sends the message
into it instead of starting a second conversation.

A group chat that has a `display_name` is excluded from that matching. To run several
parallel groups over the same participants, name each one with `PUT /v3/chats/{chatId}`
before creating the next: the following `POST /v3/chats` with the same `to` then returns a
new, separate `chat_id`. Two other cases also produce a new chat instead of reusing one —
the participant set changed (a participant was added or removed), or the `from` line left
the group.

Whenever the response is a new chat, the first-message rules above apply to that request:
no link in the first message, and no `reply_to` or message effect. To send into a chat you
already know, use `POST /v3/chats/{chatId}/messages` with its `chat_id`.

### 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).

  A message carries EITHER `parts` — text and attachments, which compose
  into one bubble — or a single `experience` invocation, which renders an
  experience inside Linq's iMessage app. Never both: an app card is the whole message
  (Apple's `MSMessage` cannot coexist with text), so copy and a card are
  two sends, not one.

  - `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"`

  - `experience: Optional[Experience]`

    Invokes an action on an experience — a third party that renders inside
    Linq's iMessage app. Linq resolves the recipient's connection, mints any
    session the action needs, composes the card and sends it; none of that
    is visible to you.

    Call `GET /v3/experiences/{experience}` for the actions you may invoke
    and the fields each accepts.

    - `action: str`

      Which of its actions, e.g. `attach_card`.

    - `name: str`

      The experience to invoke, e.g. `agentcard` or `agentpay`.

    - `params: Optional[Dict[str, object]]`

      Values for the fields this action exposes. Keys are exactly the
      field names listed for the action — no mapping, no nesting.

      Display copy only, except a `url`-type field — that value sets the
      destination, and must be an absolute `https` URL.

      Some fields are read rather than sent: `agentpay`'s
      `request_payment` takes only a `checkout_url` and resolves the
      amount and reason from that payment request itself, so the card
      cannot state a figure the checkout will not charge.

  - `idempotency_key: Optional[str]`

    Optional idempotency key for this message.
    Use this to prevent duplicate sends of the same message. Reusing a key
    whose message was deleted — or was an ephemeral message that has since
    expired — returns 404; the message is never resent.

  - `parts: Optional[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

    **App Clip Payment Cards:**

    - Use an `app_clip` part to send a Linq checkout link as an Apple Pay
      App Clip card (the payment preview with the Open button)
    - An `app_clip` part must be the **only** part in the message
    - iMessage-only: unlike `link`, it never downgrades to SMS/RCS — the
      send fails instead of delivering a bare URL

    **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.
    - An `app_clip` part must be the **only** part in the message. Its `value`
      must be a Linq checkout link (e.g. from `POST /v3/payment_requests`);
      any other URL is rejected.
    - 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).

      - `mention: Optional[str]`

        Mention a chat participant. Group chats only — sending a mention to a direct
        chat is rejected with `409` / `2023`. The chat's service is not a constraint:
        a mention is accepted in any group, including one with SMS/RCS participants.

        Set to their handle — E.164 phone number or Apple ID email. `value` is the
        display text; use the bare name (`"Juan"`, not `"@Juan"`). By default the entire
        `value` renders as the mention; use `mention_range` to highlight only part of it.

        Rendering is per recipient, not per message. iMessage recipients see the mention
        highlighted and are notified even if they have muted the chat. SMS and RCS
        recipients receive the same message as plain text — no highlight, and no mute
        override. One send, two experiences.

      - `mention_range: Optional[List[int]]`

        Optional character range `[start, end)` in `value` that renders as the `mention`
        highlight (e.g. just the name in `"Hey Kevin, can you look at this?"`). Requires
        `mention`. Without it, the entire `value` is highlighted. `start` is inclusive,
        `end` is exclusive.
        *Characters are measured as UTF-16 code units. Most characters count as 1; some emoji count as 2.*

        Applies to iMessage recipients only, matching `mention` — SMS and RCS recipients
        receive the text with no highlight.

      - `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:** decorations render per recipient, not per message. In a group containing
        both iMessage and SMS/RCS participants, iMessage recipients see the decorations and
        SMS/RCS recipients receive the same message as plain text.

        - `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.

      - `sticker: Optional[bool]`

        Send this image as a **sticker** rather than a photo. The recipient can peel it off
        and place it on any message in the conversation, and it renders without a bubble.

        An opaque photo is cut out automatically — the subject is lifted from its background,
        the same way "Add Sticker" does on iOS. An image that already has transparency is
        sent as-is. If no subject can be found, the image sends as an ordinary photo.

        **iMessage only.** On SMS/RCS the flag is ignored and the image sends as a photo.

        Stickers can be combined with a `text` part in the same message; the text arrives as
        its own bubble. To place a sticker *onto* an existing message instead, use
        `POST /v3/messages/{messageId}/reactions` with `type: "sticker"`.

      - `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.

    - `class PartIMessageAppPart: …`

      An iMessage app card, backed by a Messages app extension. iMessage only —
      an `imessage_app` part must be the **only** part in the message and is never delivered over
      SMS/RCS. See the IMessageAppServiceUnsupported (2018) and RecipientUnsupportedMessageType
      (4005) error codes.

      - `app: PartIMessageAppPartApp`

        Identifies the iMessage app (Messages app extension) that backs the card.

        - `bundle_id: str`

          Bundle identifier of the Messages app extension. Must not contain `:`.

        - `name: str`

          Display name of the app, shown by Messages' fallback UI.

        - `team_id: str`

          The app's 10-character uppercase alphanumeric team identifier.

        - `app_store_id: Optional[int]`

          The owning app's App Store id (optional). When set, recipients without the iMessage app
          installed see a "Get the app" affordance.

      - `layout: PartIMessageAppPartLayout`

        Visible layout of the card. At least one of
        `caption`, `subcaption`, `trailing_caption`, `trailing_subcaption`, or `image_url` must be
        set, otherwise the card renders as an empty bubble.

        `image_url` displays a preview image at the top of the card. The image renders on the
        recipient's card whether or not they have your app installed. The small icon beside the
        caption is the app's own icon and is not settable here.

        `* Note - requires a trusted chat w/ inbound activity`

        `image_title` and `image_subtitle` render as text overlaid on the image (title bold, subtitle
        beneath it). They only appear when `image_url` is set — without an image there is nothing to
        overlay — so setting either without `image_url` is rejected.

        - `caption: Optional[str]`

          Primary label, top-left and bold.

        - `image_subtitle: Optional[str]`

          Text shown below `image_title`, overlaid on the card image. Requires `image_url`.

        - `image_title: Optional[str]`

          Bold text overlaid on the card image. Requires `image_url` (rejected without it).

        - `image_url: Optional[str]`

          URL of an image (JPEG, PNG, HEIF, or WebP) to display as the card's preview image; an unreachable or non-image URL returns a validation error. Renders for all recipients regardless of whether they have the app. Note - requires a trusted chat w/ inbound activity. In responses, this is the re-hosted `cdn.linqapp.com` copy of the image you supplied, not your original URL.

        - `subcaption: Optional[str]`

          Secondary label, below `caption` on the left.

        - `trailing_caption: Optional[str]`

          Label shown top-right.

        - `trailing_subcaption: Optional[str]`

          Label shown below `trailing_caption`, on the right.

      - `type: Literal["imessage_app"]`

        Indicates this is an iMessage app card part.

        - `"imessage_app"`

      - `fallback_text: Optional[str]`

        Text shown on surfaces that cannot render the card (notifications, lock screen). Defaults
        to the caption when omitted.

      - `interactive: Optional[bool]`

        Whether the card renders as your app's interactive balloon for recipients who have your
        iMessage app installed. `true` (default) lets your installed extension draw its live,
        interactive view for those recipients; everyone else sees the static card built from
        `layout`. `false` always shows the static `layout` card, even to recipients who have the
        app installed. Recipients without your app always see the static card regardless of this
        flag.

      - `url: Optional[str]`

        URL the recipient's app opens when they tap the card. Either an absolute `https://` URL
        (capped at 2048 characters) or a `data:` URL carrying inline app state, e.g. a game's
        encoded state (capped at 16384 characters).

    - `class PartAppClipPart: …`

      Sends a **registered App Clip** — not only Linq's Apple Pay checkout, but any
      partner's own App Clip. `caption` is optional.

      An `app_clip` part must be the **only** part in the message.

      **iMessage only**, and it never downgrades. A `service_preference` of
      `sms` or `rcs` is rejected (`AppClipServiceUnsupported`, 2028). A
      recipient who can't receive it fails the send rather than being sent a
      plain link in its place.

      - `type: Literal["app_clip"]`

        Indicates this is an App Clip card

        - `"app_clip"`

      - `value: str`

        An https link whose page is a registered App Clip — Linq's checkout link
        (e.g. the `checkout_url` from `POST /v3/payment_requests`) or a partner's
        own App Clip URL. A URL that doesn't resolve to a sendable App Clip page is
        rejected.

      - `caption: Optional[str]`

        Optional caption for the card's **Open** button row. Omit it and the
        card uses the App Clip's own default (`Tap open`). Set it to override
        that with your own short call to action.

  - `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.

- `override_optout: Optional[bool]`

  Send even though the recipient asked you to stop (`403`, error code
  `2024`). Applies to this request only: the opt-out stays in place, so
  the next send without this flag is rejected again. Every override is
  recorded against your API key.

### 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 surface chat and 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. To gate a send, act on the response rather than the status: a `403` is the authoritative answer.

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

        `OPTED_OUT` — the recipient sent `STOP`, `UNSUBSCRIBE`, `OPTOUT`, `CANCEL`, `END`, or `QUIT`.
        The keyword must be the whole trimmed message, never part of a longer one: `STOP` counts, `please stop`
        does not. Most keywords must match exactly, including case. `OPT OUT` is the exception — it matches in any
        casing, with or without the space or a hyphen, so `opt out`, `Opt-Out` and `optout` all count. It clears as
        soon as they reply again: any later message from them that is not itself an opt-out keyword opts them back
        in immediately — a reply in any conversation with you counts, the same way the block does.

        `OPTED_OUT` marks only the conversation the keyword arrived in. The block below is wider than the mark, so
        a conversation still reading `HEALTHY` can be blocked as well — gate on the `403`, not on the status.
        Group threads are never marked and are never blocked.

        Linq enforces this: while a recipient is opted out, every send to them is rejected with `403` (error code
        `2024`) before the message is queued, across every chat and every line on your account. Nothing is
        delivered, including a final courtesy message — to send one, set `override_optout: true` on that single
        request.

        - `"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", 4 more]`

        Current delivery status of a message

        - `"pending"`

        - `"queued"`

        - `"sent"`

        - `"delivered"`

        - `"received"`

        - `"read"`

        - `"failed"`

      - `is_read: bool`

        DEPRECATED: Use `delivery_status == "read"` instead. 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"`

            - `id: Optional[str]`

              Identifier for this reaction. Pass it to
              `PATCH /v3/messages/{messageId}/reactions/{reactionId}` to move a sticker.

              Stickers placed before this API shipped can be read but not moved: the
              device-side reference needed to reposition them was never recorded, so
              `PATCH` returns 404 for those.

            - `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

          - `mention: Optional[str]`

            DEPRECATED: Use `mentions` instead. Handle (E.164 phone number or Apple ID email)
            of the **first** mention on this part. A part may carry several mentions; this
            field shows only the first in `value` order, so it cannot be used to determine
            whether a given participant was mentioned. `null` when the part carries no mention.

          - `mention_range: Optional[List[int]]`

            DEPRECATED: Use `mentions[].range` instead. Character range `[start, end)` in
            `value` highlighted as the **first** mention only. `null` when the range was
            omitted (the whole `value` is highlighted) or the part carries no mention.
            *Characters are measured as UTF-16 code units. Most characters count as 1; some emoji count as 2.*

          - `mentions: Optional[List[Mention]]`

            Every mention on this part, in the order they appear in `value`. `null` when the
            part carries no mention. A part can carry several mentions of different people —
            check `is_me` to tell whether this line was one of them.

            Only iMessage carries mentions. On a received message this is populated when the
            sender was on iMessage; SMS and RCS have no way to mark a mention, so a message
            from an SMS or RCS participant arrives as plain text with `mentions` null, even in
            a group where other participants are on iMessage.

            - `handle: str`

              Address of the mentioned participant, exactly as the device recorded it — an E.164
              phone number or an email address.

            - `is_me: bool`

              Whether the mentioned participant is this line.

            - `range: List[int]`

              Character range `[start, end)` in `value` highlighted as this mention.
              *Characters are measured as UTF-16 code units. Most characters count as 1; some emoji count as 2.*

          - `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.

            - `id: Optional[str]`

              Identifier for this reaction. Pass it to
              `PATCH /v3/messages/{messageId}/reactions/{reactionId}` to move a sticker.

              Stickers placed before this API shipped can be read but not moved: the
              device-side reference needed to reposition them was never recorded, so
              `PATCH` returns 404 for those.

            - `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.

            - `id: Optional[str]`

              Identifier for this reaction. Pass it to
              `PATCH /v3/messages/{messageId}/reactions/{reactionId}` to move a sticker.

              Stickers placed before this API shipped can be read but not moved: the
              device-side reference needed to reposition them was never recorded, so
              `PATCH` returns 404 for those.

            - `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

        - `class PartIMessageAppPartResponse: …`

          An iMessage app card part.

          - `app: PartIMessageAppPartResponseApp`

            Identifies the iMessage app (Messages app extension) that backs the card.

            - `bundle_id: str`

              Bundle identifier of the Messages app extension. Must not contain `:`.

            - `name: str`

              Display name of the app, shown by Messages' fallback UI.

            - `team_id: str`

              The app's 10-character uppercase alphanumeric team identifier.

            - `app_store_id: Optional[int]`

              The owning app's App Store id (optional). When set, recipients without the iMessage app
              installed see a "Get the app" affordance.

          - `layout: PartIMessageAppPartResponseLayout`

            Visible layout of the card. At least one of
            `caption`, `subcaption`, `trailing_caption`, `trailing_subcaption`, or `image_url` must be
            set, otherwise the card renders as an empty bubble.

            `image_url` displays a preview image at the top of the card. The image renders on the
            recipient's card whether or not they have your app installed. The small icon beside the
            caption is the app's own icon and is not settable here.

            `* Note - requires a trusted chat w/ inbound activity`

            `image_title` and `image_subtitle` render as text overlaid on the image (title bold, subtitle
            beneath it). They only appear when `image_url` is set — without an image there is nothing to
            overlay — so setting either without `image_url` is rejected.

            - `caption: Optional[str]`

              Primary label, top-left and bold.

            - `image_subtitle: Optional[str]`

              Text shown below `image_title`, overlaid on the card image. Requires `image_url`.

            - `image_title: Optional[str]`

              Bold text overlaid on the card image. Requires `image_url` (rejected without it).

            - `image_url: Optional[str]`

              URL of an image (JPEG, PNG, HEIF, or WebP) to display as the card's preview image; an unreachable or non-image URL returns a validation error. Renders for all recipients regardless of whether they have the app. Note - requires a trusted chat w/ inbound activity. In responses, this is the re-hosted `cdn.linqapp.com` copy of the image you supplied, not your original URL.

            - `subcaption: Optional[str]`

              Secondary label, below `caption` on the left.

            - `trailing_caption: Optional[str]`

              Label shown top-right.

            - `trailing_subcaption: Optional[str]`

              Label shown below `trailing_caption`, on the right.

          - `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.

            - `id: Optional[str]`

              Identifier for this reaction. Pass it to
              `PATCH /v3/messages/{messageId}/reactions/{reactionId}` to move a sticker.

              Stickers placed before this API shipped can be read but not moved: the
              device-side reference needed to reposition them was never recorded, so
              `PATCH` returns 404 for those.

            - `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["imessage_app"]`

            Indicates this is an iMessage app card part.

            - `"imessage_app"`

          - `url: str`

            The URL delivered to the iMessage app on tap.

          - `fallback_text: Optional[str]`

            Fallback text for surfaces that cannot render the card.

        - `class PartAppClipPartResponse: …`

          An App Clip card 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.

            - `id: Optional[str]`

              Identifier for this reaction. Pass it to
              `PATCH /v3/messages/{messageId}/reactions/{reactionId}` to move a sticker.

              Stickers placed before this API shipped can be read but not moved: the
              device-side reference needed to reposition them was never recorded, so
              `PATCH` returns 404 for those.

            - `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["app_clip"]`

            Indicates this is an App Clip card part

            - `"app_clip"`

          - `value: str`

            The App Clip link the card opens

          - `description: Optional[str]`

            The card's summary line, composed by Linq from the App Clip page

          - `image_url: Optional[str]`

            The card's preview image

          - `title: Optional[str]`

            The card's headline, composed by Linq from the App Clip page

      - `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/channel/imessage/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",
              "id": "9f8b1c2d-3e4f-5061-7283-94a5b6c7d8e9",
              "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
          ],
          "mentions": [
            {
              "handle": "+14155550123",
              "is_me": true,
              "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"
    },
    "service": "iMessage"
  }
}
```
