> ## Documentation Index > Fetch the complete documentation index at: https://docs.orbit.devotel.io/llms.txt > Use this file to discover all available pages before exploring further. # Estimate a campaign's send cost > Estimate what a campaign will cost before sending, using the same pricing resolver the send path bills against so the preview matches the actual wallet deduction within rounding. Pass the channel, estimated recipient count, and optionally a destination country and message sub-type; the response returns the per-unit price, the projected total, and which pricing source (tenant override, rate card, or fallback) produced it. Read-only — it never charges the wallet. ## OpenAPI ````yaml /openapi.yaml post /api/v1/campaigns/preview-cost openapi: 3.1.0 info: title: Devotel CPaaS API description: Orbit by Devotel — Communications Platform as a Service API version: 1.0.0 contact: name: Devotel url: https://devotel.io email: support@devotel.io license: name: Proprietary servers: - url: https://api.orbit.devotel.io description: Production security: - Bearer: [] - ApiKey: [] tags: - name: Messages description: >- Send and manage messages across all channels (SMS, WhatsApp, RCS, Email, Viber, etc.) - name: Fax description: >- List and track fax (MMS/T.38) transmissions on Telnyx-backed fax numbers (sending flows through the Messaging API) - name: Agents description: AI agent creation, configuration, and execution - name: Voice description: Voice calls, IVR, conferencing, and SIP trunking - name: OnCall description: On-call rotations and escalation policy planning for incident alerting - name: Webhooks description: Webhook endpoint management and delivery logs - name: Numbers description: Phone number search, provisioning, and configuration - name: Brand Identity description: >- Unified cross-channel brand trust posture (10DLC, toll-free, WhatsApp, RCS, branded calling, number KYC) - name: Contacts description: Contact management, segmentation, and lifecycle tracking - name: Campaigns description: Marketing campaign orchestration and analytics - name: Flows description: Automation flow builder and execution engine - name: Templates description: Message template management and approval workflows - name: Settings description: Organization, channel, and user preference settings - name: Verify description: OTP generation and verification across channels - name: Push description: Push notification delivery via FCM and APNs - name: Integrations description: Third-party service connections and OAuth management - name: CDP description: >- Customer Data Platform — activation surface (CRM object sync, streaming destinations, ad-audience activation) - name: Files description: >- Server-to-server media upload, listing, retrieval, and deletion (signed-URL backed) - name: Commerce description: >- Omnichannel conversational-commerce — persistent cart + checkout state machine, channel-agnostic hosted pay-by-link, native WhatsApp checkout, and AP2-style agent payment mandates. - name: Sync description: >- Real-time shared-state primitive (Twilio Sync parity) — Documents, Maps, Lists, and ephemeral Streams, with change events relayed over the /api/v1/ws/sync WebSocket gateway - name: Risk description: >- Unified cross-channel Trust & Fraud risk scoring — fuses SMS-pumping, URL-reputation, Verify Fraud Guard, and Voice Biometrics signals into one composite verdict queryable before a send or a call. - name: Orby description: >- In-dashboard Orby operator assistant: streamed assistant turns, conversation threads, product knowledge-base search, and the tool-action approval gate. Available to signed-in operators only (dashboard session auth — API-key requests are rejected). paths: /api/v1/campaigns/preview-cost: post: tags: - Campaigns summary: Estimate a campaign's send cost description: >- Estimate what a campaign will cost before sending, using the same pricing resolver the send path bills against so the preview matches the actual wallet deduction within rounding. Pass the channel, estimated recipient count, and optionally a destination country and message sub-type; the response returns the per-unit price, the projected total, and which pricing source (tenant override, rate card, or fallback) produced it. Read-only — it never charges the wallet. requestBody: required: true content: application/json: schema: type: object required: - channel - estimated_recipients properties: channel: type: string enum: - sms - mms - whatsapp - email - rcs - viber - voice - push - instagram - messenger - line - telegram - fax - kakao - zalo - wechat description: Channel the campaign will send on. estimated_recipients: type: integer minimum: 0 maximum: 10000000 description: Number of recipients to price the send for. country_code: type: string description: >- Destination country (ISO alpha-2, or `*` for the default rate). Affects per-country wholesale pricing. sub_type: type: string maxLength: 64 description: >- Message sub-type lane (e.g. WhatsApp `marketing` vs `utility`). example: channel: sms estimated_recipients: 5000 country_code: US responses: '200': description: Estimated per-unit and total cost for the send content: application/json: schema: type: object description: Estimated per-unit and total cost for the send properties: data: type: object properties: channel: type: string estimated_recipients: type: integer unit_price_cents: type: number description: Customer-charge price per message, in cents. total_cents: type: number description: Projected total charge, in cents. source: type: string description: >- Which pricing source resolved the rate (e.g. `override`, `rate_card`, `fallback`). fell_back: type: boolean description: >- True when no specific rate matched and the fallback rate was used. pricing_rate_id: type: - 'null' - string override_id: type: - 'null' - string meta: type: object properties: request_id: type: string description: >- Unique request identifier (also returned in X-Request-Id header) timestamp: type: string format: date-time description: ISO 8601 UTC timestamp of the response example: data: channel: sms estimated_recipients: 5000 unit_price_cents: 0.75 total_cents: 3750 source: rate_card fell_back: false pricing_rate_id: rate_us_sms_mt override_id: null meta: request_id: req_7c1e9a2b3f timestamp: '2026-08-02T14:23:11.000Z' components: securitySchemes: Bearer: type: http scheme: bearer bearerFormat: JWT description: Dashboard JWT token from Clerk ApiKey: type: apiKey name: X-API-Key in: header description: Server-to-server API key (dv_live_sk_*) ````