> ## Documentation Index > Fetch the complete documentation index at: https://docs.hightouch.com/llms.txt > Use this file to discover all available pages before exploring further. # Trigger an API campaign send > Start an API-triggered campaign: send to the given recipients. ## OpenAPI ````yaml https://api.hightouch.io/api/swagger.json post /campaigns/{campaignId}/trigger openapi: 3.0.0 info: title: Hightouch API version: 1.0.0 description: Hightouch Public Rest API to access syncs, models, sources and destinations contact: name: Hightouch url: https://hightouch.com servers: - url: https://api.hightouch.com/api/v1 security: [] paths: /campaigns/{campaignId}/trigger: post: summary: Trigger an API campaign send description: 'Start an API-triggered campaign: send to the given recipients.' operationId: TriggerCampaign parameters: - in: path name: campaignId required: true schema: type: string requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/StartCampaignRequest' responses: '200': description: Ok content: application/json: schema: anyOf: - $ref: '#/components/schemas/StartCampaignResponse' - $ref: '#/components/schemas/TriggerErrorResponse' '400': description: Bad Request content: application/json: schema: $ref: '#/components/schemas/TriggerErrorResponse' '401': description: Unauthorized '404': description: Campaign not found content: application/json: schema: $ref: '#/components/schemas/TriggerErrorResponse' '422': description: Validation Failed content: application/json: schema: $ref: '#/components/schemas/ValidateErrorJSON' '429': description: Rate limited content: application/json: schema: $ref: '#/components/schemas/TriggerErrorResponse' '500': description: Something went wrong content: application/json: schema: $ref: '#/components/schemas/InternalServerError' security: - bearerAuth: [] components: schemas: StartCampaignRequest: description: Request body for triggering an API campaign send. properties: properties: properties: {} additionalProperties: {} type: object description: >- Shared personalization properties applied to all recipients. Keys must match the variable names shown in the message editor. Per-recipient `properties` take precedence when a key appears in both. draft: type: boolean description: |- When `true`, sends the campaign even if it has not been activated. Intended for test sends against draft campaigns only. default: 'false' recipients: items: $ref: '#/components/schemas/CampaignRecipient' type: array description: >- List of recipients to send to. Each entry must include either a `handle` (delivery address) or an `id` (Personalization API based profile ID). minItems: 1 maxItems: 100 required: - recipients type: object additionalProperties: false StartCampaignResponse: description: >- Response body for a campaign trigger request. Results are returned in the same order as the input `recipients` array. properties: results: items: $ref: '#/components/schemas/CampaignSendResult' type: array description: |- Per-recipient outcomes. Accepted recipients are queued for delivery; rejected recipients were not sent. required: - results type: object additionalProperties: false TriggerErrorResponse: description: |- Body returned on a request-level failure (400/404/409/429) so the caller knows why the request was rejected. properties: error: type: string description: Human-readable description of why the request failed. required: - error type: object additionalProperties: false ValidateErrorJSON: properties: message: type: string enum: - Validation failed nullable: false details: properties: {} additionalProperties: {} type: object required: - message - details type: object additionalProperties: false InternalServerError: type: string enum: - Internal Server Error nullable: false CampaignRecipient: anyOf: - $ref: '#/components/schemas/HandleCampaignRecipient' - $ref: '#/components/schemas/ProfileCampaignRecipient' description: >- A single send target. Provide either `handle` (inline delivery address) or `id` (Personalization API profile ID), but not both. CampaignSendResult: description: >- Per-recipient result returned synchronously after the trigger request. Accepted recipients are queued for delivery; check the send status endpoint for delivery confirmation. properties: handle: type: string description: >- Delivery address of the recipient, present for inline (`handle`) recipients. id: type: string description: >- Primary key of the recipient as configured on the Personalization API sync, present for profile (`id`) recipients. status: type: string enum: - accepted - rejected description: >- Whether this recipient was accepted for delivery or rejected at validation time. sendId: type: string description: >- Unique identifier for this send, present when `status` is `"accepted"`. Use with `POST /campaigns/{id}/sends/batch-get` to poll for delivery status; it accepts up to 100 `sendId` values per request. reason: type: string enum: - invalid_handle - missing_variables - invalid_id - missing_handle_or_id - invalid_locale - whatsapp_marketing_us_number description: >- Reason for rejection, present when `status` is `"rejected"`. - `invalid_handle` — the delivery address is not a valid email or phone number - `missing_variables` — one or more required template variables are absent (`handle` recipients only; `id` recipients are checked at send time) - `invalid_id` — the profile ID is empty or missing - `missing_handle_or_id` — the recipient has neither `handle` nor `id` - `invalid_locale` — the `locale` is empty or longer than 7 characters - `whatsapp_marketing_us_number` — the message uses a marketing WhatsApp template, which Meta does not deliver to US phone numbers missingVariables: items: type: string type: array description: >- Names of the required template variables absent from the recipient's data, present when `reason` is `"missing_variables"`. required: - status type: object additionalProperties: false HandleCampaignRecipient: description: >- A recipient identified by their delivery address (email or phone number). Personalization data is provided inline in the request. properties: handle: type: string description: >- Delivery address for this recipient. Must be a valid email address for email campaigns, or an E.164-formatted phone number for SMS and WhatsApp campaigns. properties: properties: {} additionalProperties: {} type: object description: >- Per-recipient personalization properties. Keys must match the variable names shown in the message editor. These are merged with the top-level `properties` and take precedence when a key appears in both. locale: type: string description: >- The recipient's locale as a BCP 47 language tag, such as `es-ES`, matched against the locales the message is localized into (case-insensitive). When omitted, the recipient gets the message's source language. A locale the message is not localized into follows the workspace's localization fallback setting. At most 7 characters. type: object additionalProperties: false ProfileCampaignRecipient: description: >- A recipient identified by their Personalization API Cached profile ID. Template variables are checked at send time, after the cached profile is merged with `properties`. A required variable (one without a Liquid default) missing from both drops the send, which the send status endpoint reports as `dropped`. A variable present with a null or empty value renders blank. properties: id: type: string description: >- Primary key of the recipient as configured on the Personalization API sync. The delivery address is resolved from the cache at send time. properties: properties: {} additionalProperties: {} type: object description: >- Per-recipient personalization overrides. Merged with the top-level `properties` and the cached profile; these values take precedence when a key appears in multiple sources. locale: type: string description: >- The recipient's locale as a BCP 47 language tag, such as `es-ES`, matched against the locales the message is localized into (case-insensitive). When omitted, the recipient gets the message's source language. A locale the message is not localized into follows the workspace's localization fallback setting. At most 7 characters. type: object additionalProperties: false securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: Bearer ````