---
title: "Add a new message to the conversation"
method: POST
path: "/v1/Conversations/{ConversationSid}/Messages"
tags: ["ConversationsV1Message"]
---

# Add a new message to the conversation

`POST /v1/Conversations/{ConversationSid}/Messages`

Add a new message to the conversation

## Path parameters

- `ConversationSid` string, required

## Headers

- `X-Twilio-Webhook-Enabled` 'true' | 'false'

## Response `201`

Created

- ConversationsV1ConversationConversationMessage
  - `account_sid` string, nullable — The unique ID of the [Account](https://www.twilio.com/docs/iam/api/account) responsible for this message.
  - `conversation_sid` string, nullable — The unique ID of the [Conversation](https://www.twilio.com/docs/conversations/api/conversation-resource) for this message.
  - `sid` string, nullable — A 34 character string that uniquely identifies this resource.
  - `index` integer — The index of the message within the [Conversation](https://www.twilio.com/docs/conversations/api/conversation-resource). Indices may skip numbers, but will always be in order of when the message was received.
  - `author` string, nullable — The channel specific identifier of the message's author. Defaults to `system`.
  - `body` string, nullable — The content of the message, can be up to 1,600 characters long.
  - `media` unknown[], nullable — An array of objects that describe the Message's media, if the message contains media. Each object contains these fields: `content_type` with the MIME type of the media, `filename` with the name of the media, `sid` with the SID of the Media resource, and `size` with the media object's file size in bytes. If the Message has no media, this value is `null`.
    - unknown
  - `attributes` string, nullable — A string metadata field you can use to store any data you wish. The string value must contain structurally valid JSON if specified. **Note** that if the attributes are not set "{}" will be returned.
  - `participant_sid` string, nullable — The unique ID of messages's author participant. Null in case of `system` sent message.
  - `date_created` string, date-time, nullable — The date that this resource was created.
  - `date_updated` string, date-time, nullable — The date that this resource was last updated. `null` if the message has not been edited.
  - `url` string, uri, nullable — An absolute API resource API URL for this message.
  - `delivery` unknown
  - `links` object, nullable — Contains an absolute API resource URL to access the delivery & read receipts of this message.
  - `content_sid` string, nullable — The unique ID of the multi-channel [Rich Content](https://www.twilio.com/docs/content) template.

## Changes

- **2025-07-03** (v1) `92d1169c37c2` — 2 breaking
  - the `delivery` response's property type changed from `object` to no type for status `201`
  - the `media/items/` response's property type changed from `object` to no type for status `201`
- **2025-03-11** (v1) `b4d0e634cd69` — 2 breaking
  - the `delivery` response's property type changed from no type to `object` for status `201`
  - the `media/items/` response's property type changed from no type to `object` for status `201`
- **2024-08-26** (v1) `5265b2a49bcb` — 1 info
  - the `index` response's property default value `0` was added for the status `201`
- **2023-09-21** (v1) `bf66b70e986b` — 1 info
  - added the new optional request property `Subject`
- **2023-08-10** (v1) `4e3f150aaa78` — 1 info
  - api tag `ConversationsV1Message` added

[Change history](https://skmtc.dev/twilio/apis/conversations-v1/changes/v1/Conversations/:ConversationSid/Messages/post.md)

---

[API](https://skmtc.dev/twilio/apis/conversations-v1.md) · [All operations](https://skmtc.dev/twilio/apis/conversations-v1/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/twilio/conversations-v1/revisions/6a37056c7727/schema)