> ## Documentation Index > Fetch the complete documentation index at: https://www.vobiz.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Preview a broadcast > Renders the template for the first pending recipients so you can check personalisation, encoding and segment counts before you launch. Nothing is sent and nothing is charged. ## OpenAPI ````yaml openapi-sms.yaml GET /broadcasts/{id}/preview openapi: 3.0.3 info: title: Vobiz Messaging API description: > Send and receive SMS, MMS and RCS messages, buy messaging numbers, register for US 10DLC and toll-free, run broadcasts, manage conversations, opt-outs and webhooks. **Base URL:** `https://api.vobiz.ai/api/v1/sms` **Authentication:** every request needs the `X-Auth-ID` and `X-Auth-Token` headers. The account is taken from your credentials; you never put an account ID in a path or body. Field names in this API are camelCase. version: '1.0' contact: email: support@vobiz.ai url: https://vobiz.ai servers: - url: https://api.vobiz.ai/api/v1/sms description: Production security: - AuthID: [] AuthToken: [] tags: - name: Messages description: Send messages and inspect their delivery state. - name: Numbers description: >- Messaging-capable numbers on your account, inventory search, purchase and release. - name: Coverage description: Where you can send, per country. - name: Conversations description: Two-way threads between one of your numbers and a contact. - name: Opt-outs description: Numbers that must not receive messages on a channel. - name: Webhooks description: Subscriptions that deliver message and broadcast events to your server. - name: Broadcasts description: Bulk sends from an uploaded recipient list. - name: RCS Senders description: RCS sender (agent) identities and their message templates. - name: 10DLC Brands description: US 10DLC brand registration. - name: 10DLC Campaigns description: US 10DLC campaigns, toll-free verification and supporting documents. paths: /broadcasts/{id}/preview: get: tags: - Broadcasts summary: Preview a broadcast description: >- Renders the template for the first pending recipients so you can check personalisation, encoding and segment counts before you launch. Nothing is sent and nothing is charged. `missingVariables` lists placeholders that have no matching upload column; they render as empty text, so fix the template or re-upload before launching. `estimatedSegments` totals the segments across every pending recipient, not only the samples shown. operationId: preview-broadcast parameters: - name: id in: path required: true description: >- The broadcast's `id` (UUID), as returned by `POST /broadcasts` or `GET /broadcasts`. An id that is not a UUID, or that belongs to another account, returns `404` with `broadcast not found`. schema: type: string format: uuid example: 3f8d2a6e-5b1c-4e7f-a9d0-2c4b6e8f1a35 - name: limit in: query description: >- Number of pending recipients to render in `samples`, from 1 to 50. Defaults to 5 when you omit it or pass `0`. A value above 50 returns `400` with `limit must be between 1 and 50`, and a non-integer returns `400` with `limit must be an integer`. schema: type: integer minimum: 1 maximum: 50 default: 5 responses: '200': description: Rendered samples and totals. content: application/json: schema: $ref: '#/components/schemas/BroadcastPreview' example: samples: - to: '+14155550123' text: Hi Priya, your refund of $42.00 is on its way. segments: 1 encoding: GSM-7 - to: '+14155550124' text: Hi Sam, your refund of $18.50 is on its way. segments: 1 encoding: GSM-7 missingVariables: [] estimatedSegments: 2 '400': description: '`limit` is out of range.' content: application/json: schema: $ref: '#/components/schemas/Error' example: error: limit must be between 1 and 50 '401': $ref: '#/components/responses/Unauthorized' '404': description: The broadcast does not exist on your account. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: broadcast not found x-codeSamples: - lang: typescript label: Node SDK source: > import { VobizClient } from "@vobiz/sdk"; const client = new VobizClient({ apiKey: "MA_XXXXXXXX", authToken: "YOUR_AUTH_TOKEN" }); await client.sms.broadcasts.previewBroadcast({ id: "3f8d2a6e-5b1c-4e7f-a9d0-2c4b6e8f1a35" }) - lang: python label: Python SDK source: | from vobiz import Vobiz client = Vobiz(api_key="MA_XXXXXXXX", auth_token="YOUR_AUTH_TOKEN") client.sms.broadcasts.preview_broadcast( id="3f8d2a6e-5b1c-4e7f-a9d0-2c4b6e8f1a35", ) - lang: go label: Go SDK source: | import ( "context" vobiz "github.com/vobiz-ai/Vobiz-Go-SDK" "github.com/vobiz-ai/Vobiz-Go-SDK/client" "github.com/vobiz-ai/Vobiz-Go-SDK/option" "github.com/vobiz-ai/Vobiz-Go-SDK/sms" ) c := client.NewClient( option.WithAPIKey("MA_XXXXXXXX"), option.WithAuthToken("YOUR_AUTH_TOKEN"), ) request := &sms.PreviewBroadcastRequest{ ID: "3f8d2a6e-5b1c-4e7f-a9d0-2c4b6e8f1a35", } c.Sms.Broadcasts.PreviewBroadcast( context.TODO(), request, ) - lang: java label: Java SDK source: | import com.vobiz.api.VobizApiClient; VobizApiClient client = VobizApiClient .builder() .apiKey("MA_XXXXXXXX") .authToken("YOUR_AUTH_TOKEN") .build(); client.sms().broadcasts().previewBroadcast( "3f8d2a6e-5b1c-4e7f-a9d0-2c4b6e8f1a35", PreviewBroadcastRequest .builder() .build() ); - lang: ruby label: Ruby SDK source: > require 'vobiz' client = Vobiz::Client.new(api_key: 'MA_XXXXXXXX', auth_token: 'YOUR_AUTH_TOKEN') client.sms.broadcasts.preview_broadcast(id: "3f8d2a6e-5b1c-4e7f-a9d0-2c4b6e8f1a35") - lang: csharp label: C# SDK source: | using Vobiz; using Vobiz.Sms; var client = new VobizApiClient("YOUR_AUTH_TOKEN", "MA_XXXXXXXX"); await client.Sms.Broadcasts.PreviewBroadcastAsync( new PreviewBroadcastRequest { Id = "3f8d2a6e-5b1c-4e7f-a9d0-2c4b6e8f1a35" } ); - lang: php label: PHP SDK source: > sms->broadcasts->previewBroadcast( '3f8d2a6e-5b1c-4e7f-a9d0-2c4b6e8f1a35', new PreviewBroadcastRequest([]), ); components: schemas: BroadcastPreview: type: object properties: samples: type: array description: >- The template rendered for up to `limit` pending recipients, in upload order. Empty when no recipient is pending. items: $ref: '#/components/schemas/BroadcastPreviewSample' missingVariables: type: array description: >- Placeholders in the template that have no matching upload column. They render as empty text; an empty array means every placeholder is filled. items: type: string example: [] estimatedSegments: type: integer description: >- Total SMS segments across all pending recipients. Multiply by your per-segment rate to estimate the cost of the launch. example: 3 description: >- The template rendered for the first pending recipients, with the information you need to check a broadcast before launching it. Error: type: object description: >- The body of every error response: a flat object with one `error` string that explains what went wrong. Use the HTTP status code to decide how to handle the error, and log `error` for diagnosis. required: - error properties: error: type: string example: 'recipient has opted out: +14155550123' description: >- Human-readable explanation of the error, for example `phoneNumber is required` or `recipient has opted out: +14155550123`. Branch on the HTTP status code rather than on this text. BroadcastPreviewSample: type: object properties: to: type: string example: '+14155550123' description: The recipient's number in E.164 format. text: type: string description: >- The exact message text this recipient will receive, with their variables filled. example: Hi Priya, your refund of $42.00 is on its way. segments: type: integer description: Number of SMS segments this text is sent and billed as. example: 1 encoding: type: string enum: - GSM-7 - UCS-2 description: >- `GSM-7` when every character is in the GSM alphabet (160 characters in a single segment). `UCS-2` when the text contains other characters, such as emoji or most non-Latin scripts (70 characters in a single segment). example: GSM-7 description: >- The template rendered for one recipient, with the encoding and segment count it will be sent with. responses: Unauthorized: description: Missing or invalid `X-Auth-ID` / `X-Auth-Token`. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: missing or invalid credentials securitySchemes: AuthID: type: apiKey in: header name: X-Auth-ID description: Your Vobiz account Auth ID (`MA_XXXXXXXX`). AuthToken: type: apiKey in: header name: X-Auth-Token description: Your Vobiz account Auth Token. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.