> ## Documentation Index
> Fetch the complete documentation index at: https://help.withallo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Create conversation note

> Adds an internal team note to a conversation. Notes are never visible to the contact.

<Note>
  **Required scope:** `NOTES_WRITE`
</Note>

## Behavior

Adds an internal team note to the conversation with `contact_number`. Notes are never visible to the contact.

Identify the line the conversation belongs to with either `allo_number` (E.164, list your lines with `GET /v2/api/numbers`) or `sender_id` (for sender-ID inbox conversations). Omitting both returns `400` with code `MISSING_ALLO_NUMBER_OR_SENDER_ID`.

## Mentions

Mention teammates inline in `content` with `@[Display Name](usr-xxxx)` — they receive the same push, email, and in-app notifications as mentions made from the Allo apps. See the [mentions guide](/en/v2/api-reference/notes/overview#mentions).

## Errors

| Status | Code                               | When                                               |
| ------ | ---------------------------------- | -------------------------------------------------- |
| `400`  | `EMPTY_NOTE_CONTENT`               | `content` is missing or blank                      |
| `400`  | `NOTE_CONTENT_TOO_LONG`            | `content` exceeds 4,000 characters                 |
| `400`  | `MISSING_ALLO_NUMBER_OR_SENDER_ID` | Neither `allo_number` nor `sender_id` was provided |
| `403`  | `ALLO_NUMBER_FORBIDDEN`            | You do not have access to this Allo line           |
| `404`  | `SENDER_ID_NOT_FOUND`              | No sender ID with this identifier on your account  |


## OpenAPI

````yaml POST /v2/api/conversations/{contact_number}/notes
openapi: 3.0.3
info:
  title: Allo API
  description: >-
    Allo API provides programmatic access to your Allo account, allowing you to
    manage webhooks, retrieve calls and contacts, and send SMS messages.


    All requests to `/v1/api/**` endpoints automatically go through quota
    checking and scope validation.
  version: 1.0.0
  contact:
    name: Allo Support
servers:
  - url: https://api.withallo.com
    description: Production server
security: []
tags:
  - name: Summary Templates
    description: >-
      Manage call summary templates that control how AI-generated call summaries
      are structured for your team.
  - name: Webhooks
    description: >-
      Manage webhook endpoints to receive real-time notifications about events
      in your Allo account. Each endpoint subscribes to one or more event topics
      and is verified with a signing secret.
  - name: Calls
    description: >-
      Retrieve and search call records with filtering and pagination. Filter
      calls by your Allo phone number.
  - name: Contacts
    description: >-
      Search and retrieve contact information with sorting and pagination.
      Includes engagement level tracking.
  - name: SMS
    description: Send SMS messages to phone numbers using your Allo numbers.
  - name: Phone Numbers
    description: Retrieve information about your Allo phone numbers.
  - name: Analytics
    description: Pre-computed call metrics, team performance, and outbound dial funnel
  - name: CRM
    description: Manage people, companies, and deals in your CRM.
  - name: Notes
    description: >-
      Internal team notes on conversations and CRM people, with @mention
      support. Notes are never visible to the contact.
  - name: Threads
    description: >-
      Team discussion threads attached to a conversation item (call, SMS, or
      conversation note). One thread per item.
paths:
  /v2/api/conversations/{contact_number}/notes:
    post:
      tags:
        - Notes
      summary: Create conversation note
      description: >-
        Adds an internal team note to a conversation. Notes are never visible to
        the contact.
      operationId: createConversationNote
      parameters:
        - name: contact_number
          in: path
          required: true
          description: The contact's phone number (E.164)
          schema:
            type: string
            example: '+14155551234'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                content:
                  type: string
                  description: >-
                    Note text (max 4000 characters). Mention teammates inline
                    with `@[Name](usr-...)`, or `@[all](all)` to notify the
                    whole team.
                  example: Escalate to @[Jane Doe](usr-abc123) tomorrow
                allo_number:
                  type: string
                  description: >-
                    The Allo line the conversation belongs to (E.164). Required
                    unless `sender_id` is provided.
                  example: '+14155550100'
                sender_id:
                  type: string
                  nullable: true
                  description: >-
                    Sender-ID inbox identifier, as an alternative to
                    `allo_number` for sender-ID conversations.
              required:
                - content
            example:
              content: Escalate to @[Jane Doe](usr-abc123) tomorrow
              allo_number: '+14155550100'
      responses:
        '201':
          description: Note created
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    $ref: '#/components/schemas/ConversationNote'
              example:
                data:
                  id: not-2NyMabc123
                  content: Escalate to @[Jane Doe](usr-abc123) tomorrow
                  contact_number: '+14155551234'
                  allo_number: '+14155550100'
                  user:
                    id: usr-def456
                    name: John Smith
                  mentions:
                    - user_id: usr-abc123
                      name: Jane Doe
                      deleted: false
                  created_at: '2026-07-13T10:00:00'
                  updated_at: '2026-07-13T10:00:00'
        '400':
          $ref: '#/components/responses/ApiValidationError'
        '401':
          $ref: '#/components/responses/ApiUnauthorized'
        '403':
          $ref: '#/components/responses/ApiForbidden'
        '404':
          $ref: '#/components/responses/ApiNotFound'
        '429':
          $ref: '#/components/responses/ApiRateLimited'
      security:
        - ApiKeyAuth: []
components:
  schemas:
    ConversationNote:
      type: object
      properties:
        id:
          type: string
          description: Note ID (`not-*`)
          example: not-2NyMabc123
        content:
          type: string
          description: Note text, with mentions inline as `@[Name](usr-...)`.
        contact_number:
          type: string
          description: The contact's phone number (E.164).
          example: '+14155551234'
        allo_number:
          type: string
          nullable: true
          description: The Allo line the conversation belongs to (E.164).
          example: '+14155550100'
        user:
          $ref: '#/components/schemas/NoteUser'
        mentions:
          type: array
          items:
            $ref: '#/components/schemas/NoteMention'
        created_at:
          type: string
          format: date-time
        updated_at:
          type: string
          format: date-time
    NoteUser:
      type: object
      description: Author of a note or comment.
      properties:
        id:
          type: string
          example: usr-def456
        name:
          type: string
          nullable: true
          example: John Smith
    NoteMention:
      type: object
      description: A user mentioned in the content via `@[Name](usr-...)`.
      properties:
        user_id:
          type: string
          example: usr-abc123
        name:
          type: string
          nullable: true
          example: Jane Doe
        deleted:
          type: boolean
          description: '`true` if the mentioned user has since been removed from the team.'
    ApiError:
      type: object
      properties:
        error:
          type: object
          properties:
            type:
              type: string
            code:
              type: string
            message:
              type: string
            retryable:
              type: boolean
            request_id:
              type: string
            retry_after_seconds:
              type: integer
              nullable: true
  responses:
    ApiValidationError:
      description: Invalid request parameters
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiError'
    ApiUnauthorized:
      description: Invalid or missing API key
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiError'
    ApiForbidden:
      description: API key lacks the required scope or access to the resource
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiError'
    ApiNotFound:
      description: Resource not found
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiError'
    ApiRateLimited:
      description: Rate limit exceeded
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ApiError'
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: Authorization

````