> ## Documentation Index > Fetch the complete documentation index at: https://knowledge.flowella.io/llms.txt > Use this file to discover all available pages before exploring further. # Queue template send job > Accepts a bulk template send and processes it in the background. The request is validated at the door, queued durably, and returns `202 Accepted` immediately with a job id. Send an `Idempotency-Key` header to make retries safe: repeats of the same key within seven days return the original job id instead of sending the batch again. Without the header, Flowella derives a key from the request body, so an identical batch submitted twice in quick succession is not double-sent. Recipients are processed individually, so one invalid number does not block the rest of the batch. ## OpenAPI ````yaml /api-reference/openapi.json post /v1/templates/send openapi: 3.0.0 info: title: Flowella REST API version: 2.1.0 description: >- Public v1 HTTP API for Flowella. Authenticate with `Authorization: Bearer ` (`flo_` prefix). Canonical base: `https://api.flowella.io/v1`. Legacy `https://app.flowella.io/api/v1/...` requests are permanently redirected (308) to the canonical host, preserving method and body. servers: - url: https://api.flowella.io description: Canonical API host - url: https://app.flowella.io description: Legacy app host — /api/v1 permanently redirects (308) to the API host /v1 security: [] tags: - name: System description: Health and auth checks - name: Messages description: Send WhatsApp messages - name: Conversations description: Inbox conversations - name: Contacts description: CRM contacts - name: Templates description: WhatsApp templates and bulk send - name: Analytics description: Usage and delivery metrics paths: /v1/templates/send: post: tags: - Templates summary: Queue template send job description: >- Accepts a bulk template send and processes it in the background. The request is validated at the door, queued durably, and returns `202 Accepted` immediately with a job id. Send an `Idempotency-Key` header to make retries safe: repeats of the same key within seven days return the original job id instead of sending the batch again. Without the header, Flowella derives a key from the request body, so an identical batch submitted twice in quick succession is not double-sent. Recipients are processed individually, so one invalid number does not block the rest of the batch. operationId: v1SendTemplatesBulk parameters: - name: Idempotency-Key in: header required: false description: >- Unique key (up to 200 characters) identifying this batch. Repeats of the same key within seven days return the original job id without re-sending. If omitted, Flowella derives a key from the request body. schema: type: string maxLength: 200 requestBody: required: true content: application/json: schema: type: object properties: templateId: type: string minLength: 1 maxLength: 128 templateWabaId: type: string minLength: 1 whatsappChannelId: type: string format: cuid headerMedia: type: object properties: url: type: string minLength: 1 maxLength: 4000 format: uri fileName: type: string minLength: 1 maxLength: 240 required: - url recipients: type: array items: type: object properties: phone: type: string minLength: 3 maxLength: 32 contactId: type: string nullable: true format: cuid bodyParameters: type: array items: type: string minLength: 1 maxItems: 20 buttonParameters: type: array items: oneOf: - type: object properties: index: type: integer nullable: true minimum: 0 maximum: 9 subType: type: string enum: - url text: type: string minLength: 1 maxLength: 2000 required: - index - subType - text - type: object properties: index: type: integer nullable: true minimum: 0 maximum: 9 subType: type: string enum: - flow flowToken: type: string minLength: 1 maxLength: 256 flowActionData: type: object additionalProperties: nullable: true required: - index - subType - flowToken - type: object properties: index: type: integer nullable: true minimum: 0 maximum: 9 subType: type: string enum: - copy_code couponCode: type: string minLength: 1 maxLength: 20 pattern: ^[a-zA-Z0-9]+$ required: - index - subType - couponCode maxItems: 20 required: - phone minItems: 1 maxItems: 50000 carouselCards: type: array minItems: 2 maxItems: 10 items: type: object properties: mediaUrl: type: string maxLength: 4000 format: uri description: >- Public HTTPS URL of this card's image or video. Omit to use the card's approved sample media. mediaId: type: string minLength: 1 maxLength: 256 description: >- Meta media ID for this card's image or video. Use instead of `mediaUrl`. bodyParameters: type: array items: type: string minLength: 1 maxItems: 20 description: Values for the card body variables, in order. buttonParameters: type: array maxItems: 2 items: type: object properties: index: type: integer minimum: 0 maximum: 1 description: Zero-based button position on the card. text: type: string minLength: 1 maxLength: 2000 description: Value for a URL button variable. payload: type: string minLength: 1 maxLength: 256 description: Payload for a quick reply button. required: - index description: >- Media card carousel parameters. Send one entry per template card, in card order. The same card media, card body values, and button values are used for every recipient. If a card has no `mediaUrl` or `mediaId`, Flowella sends that card's approved sample media. scheduledAt: type: string nullable: true throttlePerHour: type: integer minimum: 1 maximum: 100000 required: - templateId - whatsappChannelId - recipients example: templateId: clxxxxxxxxxxxxxxxxxxxxxxxx whatsappChannelId: clxxxxxxxxxxxxxxxxxxxxxxxx recipients: - phone: '+15551234567' bodyParameters: - Ada carouselCards: - mediaUrl: https://cdn.example/card-1.jpg buttonParameters: - index: 1 text: summer - mediaUrl: https://cdn.example/card-2.jpg responses: '202': description: Request accepted for durable processing content: application/json: schema: type: object properties: id: type: string status: type: string enum: - accepted required: - id - status example: id: v1ts-0123456789abcdef status: accepted '400': description: Bad body content: application/json: schema: type: object properties: error: type: object properties: code: type: string message: type: string required: - code - message required: - error example: error: code: UNAUTHORIZED message: Invalid API key '401': description: Unauthorized content: application/json: schema: type: object properties: error: type: object properties: code: type: string message: type: string required: - code - message required: - error example: error: code: UNAUTHORIZED message: Invalid API key '402': description: Payment required content: application/json: schema: type: object properties: error: type: object properties: code: type: string message: type: string required: - code - message required: - error example: error: code: UNAUTHORIZED message: Invalid API key '429': description: Rate limited content: application/json: schema: type: object properties: error: type: object properties: code: type: string message: type: string required: - code - message required: - error example: error: code: UNAUTHORIZED message: Invalid API key security: - bearerAuth: [] components: securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: API key description: >- Organization API key (`flo_…`). Paste the full key; Scalar sends `Authorization: Bearer `. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.