> ## Documentation Index > Fetch the complete documentation index at: https://docs.dialtu.com/llms.txt > Use this file to discover all available pages before exploring further. # Create a client > Create a contact in your account. At least one of `phone_number` or `email` is required. A contact that already exists with the same phone number is rejected with `DUPLICATE_CLIENT`. Tags are created on the fly when they do not exist yet. ## OpenAPI ````yaml POST /api/v2/public/clients openapi: 3.1.0 info: title: Dialtu Public API version: '2.0' description: >- Programmatic access to your Dialtu account: schedule AI voice calls, create contacts, push leads into Salesflow pipelines, book calendar appointments and read WhatsApp conversation history. Every request is authenticated with an API key created in the dashboard under **Settings → API Keys**, sent as `Authorization: Bearer pk_...`. servers: - url: https://api.dialtu.com description: Production - url: https://api.stg.dialtu.com description: Staging security: - ApiKeyBearer: [] tags: - name: Calls description: Schedule outbound AI voice calls. - name: Clients description: Create contacts in your account. - name: Salesflow description: Push leads into a pipeline through an API input node. - name: Salesflow pipelines description: Read a pipeline's stages and add, move or remove clients. - name: Calendar description: Check bookable capacity, book appointments and manage waiting lists. - name: WhatsApp description: Read-only conversation history and transcripts. paths: /api/v2/public/clients: post: tags: - Clients summary: Create a client description: >- Create a contact in your account. At least one of `phone_number` or `email` is required. A contact that already exists with the same phone number is rejected with `DUPLICATE_CLIENT`. Tags are created on the fly when they do not exist yet. operationId: createClient parameters: [] requestBody: content: application/json: schema: $ref: '#/components/schemas/PublicCreateClientSchema' required: true responses: '201': description: Created content: application/json: schema: $ref: '#/components/schemas/PublicClientResponse' '400': description: Bad Request content: application/json: schema: $ref: '#/components/schemas/PublicClientErrorResponse' '401': description: Missing, malformed or revoked API key. content: application/json: schema: $ref: '#/components/schemas/DetailErrorResponse' examples: missing_header: summary: No Authorization header value: detail: Unauthorized invalid_key: summary: Unknown or revoked key value: detail: Invalid or expired API key. Please check your credentials. '422': description: The request did not match the documented schema. content: application/json: schema: $ref: '#/components/schemas/RequestValidationError' example: detail: - type: missing loc: - body - payload - phone_number msg: Field required '500': description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/PublicClientErrorResponse' security: - ApiKeyBearer: [] components: schemas: PublicCreateClientSchema: description: Public API request schema for creating a client. examples: - company: Acme data: source: website email: ana@example.com first_name: Ana last_name: García phone_number: '+525512345678' tags: - color: '#7B61FF' name: lead timezone: America/Mexico_City properties: first_name: anyOf: - type: string - type: 'null' description: Given name. title: First Name last_name: anyOf: - type: string - type: 'null' description: Family name. title: Last Name area_code: anyOf: - type: string - type: 'null' default: '' description: >- Country calling code (for example `52`) stored alongside the phone number. Optional when `phone_number` is already in E.164 format. title: Area Code phone_number: anyOf: - type: string - type: 'null' description: >- Phone number, preferably E.164 (`+525512345678`). Required unless `email` is provided. title: Phone Number email: anyOf: - type: string - type: 'null' description: Email address. Required unless `phone_number` is provided. title: Email company: anyOf: - type: string - type: 'null' description: Company or organization name. title: Company timezone: default: UTC description: IANA timezone of the contact (for example `America/Bogota`). title: Timezone type: string data: anyOf: - additionalProperties: true type: object - type: 'null' description: >- Free-form custom fields stored on the contact and available to agents as prompt variables. title: Data tags: anyOf: - items: $ref: '#/components/schemas/PublicTagSchema' type: array - type: 'null' description: Tags to attach. Tags that do not exist yet are created. title: Tags title: PublicCreateClientSchema type: object PublicClientResponse: description: Public API response schema for created client. properties: status: const: success description: Response status title: Status type: string client_id: description: Unique identifier for the created client title: Client Id type: integer message: description: Human-readable success message title: Message type: string required: - status - client_id - message title: PublicClientResponse type: object PublicClientErrorResponse: description: Public API error response for client operations. properties: status: const: error description: Error status title: Status type: string error_code: description: Machine-readable error code title: Error Code type: string message: description: Human-readable error message title: Message type: string details: anyOf: - additionalProperties: true type: object - type: 'null' description: Additional error details title: Details required: - status - error_code - message title: PublicClientErrorResponse type: object DetailErrorResponse: description: 'Plain error body: `{"detail": "..."}`. No `error_code` is included.' properties: detail: description: Human-readable reason for the failure. title: Detail type: string required: - detail title: DetailErrorResponse type: object RequestValidationError: title: RequestValidationError type: object description: >- Returned when the request body, query string or path could not be parsed against the documented schema. Fix the listed fields and retry. properties: detail: type: array title: Detail description: One entry per invalid field. items: $ref: '#/components/schemas/RequestValidationErrorItem' required: - detail PublicTagSchema: description: Tag info for public API. properties: name: description: Tag name; matched case-sensitively against existing tags. title: Name type: string color: description: Hex color used when the tag has to be created, e.g. `#7B61FF`. title: Color type: string description: anyOf: - type: string - type: 'null' description: Optional description shown in the dashboard. title: Description required: - name - color title: PublicTagSchema type: object RequestValidationErrorItem: title: RequestValidationErrorItem type: object properties: loc: type: array title: Loc description: >- Where the problem is: the first element is `body`, `query` or `path`, followed by the field path. items: anyOf: - type: string - type: integer msg: type: string title: Msg description: What is wrong with the value. type: type: string title: Type description: >- Machine-readable validation error type, e.g. `missing` or `int_parsing`. required: - loc - msg - type securitySchemes: ApiKeyBearer: type: http scheme: bearer bearerFormat: pk_... description: >- API key created in the dashboard under **Settings → API Keys**. Send it as `Authorization: Bearer pk_...`. ````