> ## Documentation Index > Fetch the complete documentation index at: https://docs.brew.new/llms.txt > Use this file to discover all available pages before exploring further. # Preview across clients & devices > Render the design’s latest version across REAL email clients & devices — Gmail, Outlook, Apple Mail, iOS (with dark-mode variants), plus Yahoo — and return a screenshot per client rehosted on the Brew CDN. See exactly how the email looks in a specific inbox before sending. Pass `clients` (ids from the supported catalogue) to target specific inboxes/devices, or send `{}` for a popular default spread. Rendering is async: this is a single bounded call, so any clients still rendering when the window elapses come back in `pending` (`status: "partial"`) — call again to retry them. FIXED cost: 10 credits, charged (`X-Credit-Cost: 10`) ONLY when at least one client renders. If ZERO clients finish in time (or the provider is unavailable), the call returns a retryable `503` and is NOT billed. ## OpenAPI ````yaml /api-reference/openapi-public-v1.yaml post /v1/emails/{emailId}/client-previews openapi: 3.1.0 info: title: Brew Public API v1 version: 1.0.0 description: >- Generated from the Brew app Zod contracts (`lib//contracts.ts`). This file is the source of truth for the public API documentation. ## Resource paths Identity lives in the URL path (`/v1/analytics/sends/{sendId}`) — never in a query param or request body. Collections are plural top-level segments (`/v1/emails`); query params exist only for collection pagination + simple filters. Relationships are sub-resources (`/v1/emails/{emailId}/sends`), and non-CRUD operations are explicit action sub-paths (`/v1/automations/{automationId}/test`). ## Response envelopes - Lists: `{ data: Row[], pagination: { limit, cursor: string | null, hasMore } }` — loop `while (cursor !== null)`. - Get-one and writes: the bare resource (creates return `201`; async sends `202`). - Deletes: `{ , deleted: boolean }` — idempotent (already-gone ids resolve with `deleted: false`). - Errors: `{ error: { code, type, message, param?, suggestion, docs } }` — branch on the stable `code`. - ONE exception: `POST /v1/automations/triggers/{triggerEventId}/fire` responds with the legacy fire envelope `{ success, status, code, message, receivedAt, details }` (shared with internal webhook infrastructure). ## Brand scoping API keys are always scoped to a specific brand. The brand is resolved from the key on every request. **No public endpoint accepts a `brandId` field** in its request body or query string — sending one returns `400 INVALID_REQUEST`. Resources that exist in a different brand surface as `404` (never `403`), so the API does not leak cross-brand existence. `GET /v1/templates` is organization-wide and not constrained to the key brand. Brands themselves are managed in the Brew dashboard. ## Idempotency Send an `Idempotency-Key` header (≤ 100 chars) on any POST your code might retry. Same key + same body within 24h returns the original response; same key + different body returns `409 IDEMPOTENCY_CONFLICT`. contact: name: Brew Support url: https://docs.brew.new email: support@brew.new servers: - url: https://brew.new/api description: Production - url: http://localhost:3000/api description: Local development security: - bearerAuth: [] - apiKeyAuth: [] tags: - name: Emails description: >- Email designs and sending. Generate a design with the Brew email agent, edit, version, restore — then send it: `POST /v1/sends` delivers a design to a target (a saved audience, an inline list, or a single address) via a verified domain, and `POST /v1/sends/test` fires a one-off test. Sending is not campaign-specific. Send reads (list, status, per-send event feeds) live under Analytics (`/v1/analytics/sends`). - name: Analytics description: >- Read-only cross-resource analytics: lifetime per-campaign KPIs, windowed automation performance, the unified event feed, send reads (`/v1/analytics/sends`), and the fired-trigger audit log (`/v1/analytics/trigger-instances`). - name: Automations description: >- Automation graphs — deterministic create from explicit `nodes` + `connections`, update, version, publish / unpublish, test. Includes trigger event definitions + the fire endpoint (`/v1/automations/triggers`) and run history (`/v1/automations/runs`). - name: Contacts description: Create, search, patch, and delete contacts. Email is the primary key. - name: Contact Fields description: List, create, and delete custom contact field definitions. - name: Audiences description: Saved contact filter sets — a recipient target for sends. - name: Domains description: 'Sending domains: add, read DNS records, verify, configure sender defaults.' - name: Templates description: Public template gallery (read-only) usable as generation references. - name: Brand description: The single brand bound to the API key. - name: Chats description: >- Read a brand-scoped digest of a Brew chat — referenced emails/automations/triggers + a trimmed transcript — so an external agent can resume the conversation. - name: Meta description: >- Public discovery surface (no auth): the machine-readable API catalog (`/v1/help`). paths: /v1/emails/{emailId}/client-previews: post: tags: - Emails summary: Preview across clients & devices description: >- Render the design’s latest version across REAL email clients & devices — Gmail, Outlook, Apple Mail, iOS (with dark-mode variants), plus Yahoo — and return a screenshot per client rehosted on the Brew CDN. See exactly how the email looks in a specific inbox before sending. Pass `clients` (ids from the supported catalogue) to target specific inboxes/devices, or send `{}` for a popular default spread. Rendering is async: this is a single bounded call, so any clients still rendering when the window elapses come back in `pending` (`status: "partial"`) — call again to retry them. FIXED cost: 10 credits, charged (`X-Credit-Cost: 10`) ONLY when at least one client renders. If ZERO clients finish in time (or the provider is unavailable), the call returns a retryable `503` and is NOT billed. operationId: previewEmailAcrossClients parameters: - name: Idempotency-Key in: header required: false description: >- Optional idempotency key for safe retries. Reusing the same key with the same request body returns the original response for 24 hours. schema: type: string minLength: 1 maxLength: 100 example: api-request-2026-04-08-001 - schema: type: string minLength: 1 maxLength: 64 description: >- Design id returned by `POST /v1/emails` and listed by `GET /v1/emails`. example: eml_2SmZOWV3ZQ7W5x6g3m4p required: true description: >- Design id returned by `POST /v1/emails` and listed by `GET /v1/emails`. name: emailId in: path requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/EmailClientPreviewRequest' examples: default: summary: Popular default spread value: {} specific: summary: Target specific inboxes/devices value: clients: - gmailcom-lm_chrcurrent_win10 - outlook2021_win11_lm_dt - iphone16_18 responses: '200': description: >- Per-client screenshots. `ready` clients carry a rehosted `imageUrl`; clients still rendering are listed in `pending` with `status: "processing"`. headers: x-request-id: schema: type: string description: >- Unique request identifier. Share this with support when debugging a request. example: req_8cac13fd94e6420cacdd75a1aa403a28 required: true description: >- Unique request identifier. Share this with support when debugging a request. X-RateLimit-Limit: schema: type: integer description: Requests allowed in the current rolling rate limit window. example: 100 required: true description: Requests allowed in the current rolling rate limit window. X-RateLimit-Remaining: schema: type: integer description: Requests remaining in the current rolling rate limit window. example: 99 required: true description: Requests remaining in the current rolling rate limit window. X-RateLimit-Reset: schema: type: integer description: >- Unix timestamp in seconds for when the rolling window fully resets. example: 1712592360 required: true description: >- Unix timestamp in seconds for when the rolling window fully resets. content: application/json: schema: $ref: '#/components/schemas/EmailClientPreviewResponse' example: emailId: eml_welcome inspectionId: DdbNga1MdL3N7sO19v5MAmpOKIqFrLg9cgpCIgS4othXJ status: partial previews: - id: gmailcom-lm_chrcurrent_win10 label: Gmail (Web) category: gmail os: Web dark: false status: ready imageUrl: >- https://cdn.brew.new/email-preview/eml_welcome/gmailcom-lm_chrcurrent_win10-abc.png - id: outlook2021_win11_lm_dt label: Outlook 2021 (Windows) category: outlook os: Windows dark: false status: processing imageUrl: null pending: - outlook2021_win11_lm_dt '401': description: The API key was missing, invalid, or revoked. headers: x-request-id: schema: type: string description: >- Unique request identifier. Share this with support when debugging a request. example: req_8cac13fd94e6420cacdd75a1aa403a28 required: true description: >- Unique request identifier. Share this with support when debugging a request. content: application/json: schema: $ref: '#/components/schemas/ApiErrorEnvelope' example: error: code: INVALID_API_KEY type: authentication_error message: The provided API key is invalid. suggestion: Check the API key format and retry with a valid active key. docs: https://docs.brew.new/api-reference/api/authentication '402': description: >- The org's remaining credit balance is below what this operation requires. Credit cost is published PER-OPERATION (see `GET /v1/help`): content/media operations charge a flat cost, while AI generation (email generate/edit/import, image generation) is usage-metered — charged by actual model usage rather than a flat price. `details.cost` carries the amount the runtime required for THIS call. Check your balance up front via `GET /v1/usage`. No `Retry-After` — credits reset at the billing-period boundary. headers: x-request-id: schema: type: string description: >- Unique request identifier. Share this with support when debugging a request. example: req_8cac13fd94e6420cacdd75a1aa403a28 required: true description: >- Unique request identifier. Share this with support when debugging a request. content: application/json: schema: $ref: '#/components/schemas/ApiErrorEnvelope' example: error: code: INSUFFICIENT_CREDITS type: payment_required message: >- This operation required more credits than the 0 remaining on the 'free' plan. See the per-operation cost in GET /v1/help. suggestion: >- Upgrade your plan or wait for the next billing period to reset. Check your balance up front with GET /v1/usage. docs: https://docs.brew.new/api-reference/api/credits details: cost: 2 remaining: 0 planKey: free '403': description: The caller does not have the required `emails` permission. headers: x-request-id: schema: type: string description: >- Unique request identifier. Share this with support when debugging a request. example: req_8cac13fd94e6420cacdd75a1aa403a28 required: true description: >- Unique request identifier. Share this with support when debugging a request. content: application/json: schema: $ref: '#/components/schemas/ApiErrorEnvelope' example: error: code: INSUFFICIENT_PERMISSIONS type: authorization_error message: The caller does not have the required permission. suggestion: Use an API key or session with the required permission. docs: https://docs.brew.new/api-reference/api/authentication param: emails '404': description: No email exists with that id (cross-brand ids surface as 404). headers: x-request-id: schema: type: string description: >- Unique request identifier. Share this with support when debugging a request. example: req_8cac13fd94e6420cacdd75a1aa403a28 required: true description: >- Unique request identifier. Share this with support when debugging a request. content: application/json: schema: $ref: '#/components/schemas/ApiErrorEnvelope' example: error: code: EMAIL_NOT_FOUND type: not_found message: No email exists with id 'eml_welcome'. suggestion: Verify the emailId via GET /v1/emails. docs: https://docs.brew.new/api-reference/api/errors '409': description: The same `Idempotency-Key` was reused with a different request body. headers: x-request-id: schema: type: string description: >- Unique request identifier. Share this with support when debugging a request. example: req_8cac13fd94e6420cacdd75a1aa403a28 required: true description: >- Unique request identifier. Share this with support when debugging a request. content: application/json: schema: $ref: '#/components/schemas/ApiErrorEnvelope' example: error: code: IDEMPOTENCY_CONFLICT type: conflict message: >- The same idempotency key was reused with a different request payload. suggestion: Reuse the original payload or send a new idempotency key. docs: https://docs.brew.new/api-reference/api/idempotency '422': description: >- The email has no rendered HTML yet, or no supported clients were requested. headers: x-request-id: schema: type: string description: >- Unique request identifier. Share this with support when debugging a request. example: req_8cac13fd94e6420cacdd75a1aa403a28 required: true description: >- Unique request identifier. Share this with support when debugging a request. content: application/json: schema: $ref: '#/components/schemas/ApiErrorEnvelope' example: error: code: CONTENT_OPERATION_FAILED type: invalid_request message: >- The client-preview operation could not be completed: the email has no rendered HTML yet (it may still be generating). suggestion: >- Poll GET /v1/emails?emailId= until status is complete, then retry. docs: https://docs.brew.new/api-reference/api/errors '429': description: The request hit the rolling rate limit window. headers: x-request-id: schema: type: string description: >- Unique request identifier. Share this with support when debugging a request. example: req_8cac13fd94e6420cacdd75a1aa403a28 required: true description: >- Unique request identifier. Share this with support when debugging a request. X-RateLimit-Limit: schema: type: integer description: Requests allowed in the current rolling rate limit window. example: 100 required: true description: Requests allowed in the current rolling rate limit window. X-RateLimit-Remaining: schema: type: integer description: Requests remaining in the current rolling rate limit window. example: 99 required: true description: Requests remaining in the current rolling rate limit window. X-RateLimit-Reset: schema: type: integer description: >- Unix timestamp in seconds for when the rolling window fully resets. example: 1712592360 required: true description: >- Unix timestamp in seconds for when the rolling window fully resets. Retry-After: schema: type: integer description: Seconds to wait before retrying the request. example: 42 required: true description: Seconds to wait before retrying the request. content: application/json: schema: $ref: '#/components/schemas/ApiErrorEnvelope' example: error: code: RATE_LIMITED type: rate_limit message: Too many requests. suggestion: Wait for the retry window before sending another request. docs: https://docs.brew.new/api-reference/api/rate-limits retryAfter: 42 '500': description: Unexpected internal error. headers: x-request-id: schema: type: string description: >- Unique request identifier. Share this with support when debugging a request. example: req_8cac13fd94e6420cacdd75a1aa403a28 required: true description: >- Unique request identifier. Share this with support when debugging a request. content: application/json: schema: $ref: '#/components/schemas/ApiErrorEnvelope' example: error: code: INTERNAL_ERROR type: internal_error message: An unexpected error occurred. suggestion: Retry the request. If it keeps failing, contact support. docs: https://docs.brew.new/api-reference/api/errors '503': description: >- RETRYABLE. Either no client finished rendering within the time limit (or the preview provider is temporarily unavailable) — in which case you are NOT billed — or the credit balance could not be verified (fail-closed rather than doing unmeterable paid work). headers: x-request-id: schema: type: string description: >- Unique request identifier. Share this with support when debugging a request. example: req_8cac13fd94e6420cacdd75a1aa403a28 required: true description: >- Unique request identifier. Share this with support when debugging a request. content: application/json: schema: $ref: '#/components/schemas/ApiErrorEnvelope' example: error: code: SERVICE_UNAVAILABLE type: service_unavailable message: >- The email preview is still rendering — no client finished within the time limit. suggestion: >- Retry in a few seconds. You are not charged when no preview is produced. docs: https://docs.brew.new/api-reference/api/errors components: schemas: EmailClientPreviewRequest: type: object properties: clients: type: array items: type: string minLength: 1 maxLength: 80 minItems: 1 maxItems: 12 description: >- Client ids to render. Omit for a default popular spread of Gmail, Outlook, Apple Mail & iOS. Supported: gmailcom-lm_chrcurrent_win10 = Gmail (Web); gmailcom-dm_chrcurrent_win10 = Gmail (Web, Dark); android16_gmailapp_pixel10_lm = Gmail (Android); android16_gmailapp_pixel10_dm = Gmail (Android, Dark); iphone16gmail_18 = Gmail (iOS); outlook2021_win11_lm_dt = Outlook 2021 (Windows); outlook2021_win11_dm_dt = Outlook 2021 (Windows, Dark); o365_w10_lm_dt = Outlook 365 (Windows); outlookcom-lm_chrcurrent_win10 = Outlook.com (Web); applemail16 = Apple Mail (macOS); applemail16_dm = Apple Mail (macOS, Dark); iphone16_18 = Apple Mail (iOS); iphone16_18_dm = Apple Mail (iOS, Dark); yahoocom-lm_chrcurrent_win10 = Yahoo Mail (Web). additionalProperties: false EmailClientPreviewResponse: type: object properties: emailId: type: string inspectionId: type: string status: type: string enum: - ready - partial previews: type: array items: type: object properties: id: type: string label: type: string category: type: string enum: - gmail - outlook - apple - yahoo - other os: type: string dark: type: boolean status: type: string enum: - ready - processing - failed imageUrl: type: - string - 'null' format: uri required: - id - label - category - os - dark - status - imageUrl additionalProperties: false pending: type: array items: type: string required: - emailId - inspectionId - status - previews - pending additionalProperties: false ApiErrorEnvelope: type: object properties: error: type: object properties: code: type: string minLength: 1 type: type: string enum: - authentication_error - authorization_error - invalid_request - not_found - not_implemented - conflict - rate_limit - payment_required - service_unavailable - internal_error message: type: string minLength: 1 param: type: string minLength: 1 suggestion: type: string minLength: 1 docs: type: string format: uri retryAfter: type: integer minimum: 0 details: type: object additionalProperties: {} required: - code - type - message - suggestion - docs required: - error securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: API key description: 'Send your Brew API key as `Authorization: Bearer brew_xxx`.' x-default: Bearer brew_your_api_key apiKeyAuth: type: apiKey in: header name: X-API-Key description: 'Send your Brew API key as `X-API-Key: brew_xxx`.' x-default: brew_your_api_key ````