Which API Should I Use?

Meet the two ways to send messages on Kudosity. Both run on the same platform and share your account, API keys, senders, reporting, and billing — so you can pick what fits your build today and evolve later.

Quick Recommendation

TransmitMessage (V2)

Recommended for new builds

Modern API with MMS, WhatsApp, RCS support and API-managed webhooks.

TransmitSMS (V1)

For classic integrations

Fully supported with multi-recipient sends and custom tracked links.

API Comparison

Choose TransmitMessage (V2) when you need:

MMS via API (send & receive) - V2 is the only API with MMS support, including an inbound_mms webhook
Simple, programmatic sends with modern webhooks - Webhooks are created/managed by API; JSON responses; streamlined API-key auth
WhatsApp (send & receive) - Rich WhatsApp messaging, notifications
RCS (send & receive) - RCS notifications, rich messaging
Track multiple links in one SMS - Auto-detect & track multiple links in a message
Your own message reference alongside our message ID - Add a message_ref for reconciliation/workflows

💡 Recommendation: Start on V2. Keep V1 if you rely on multi-recipient requests or custom tracked links. You can use both under the same account and senders.

Feature Comparison

Account & Authentication

Unified account & UI: Same login, senders, reporting, and billing across both APIs
Auth: V2 uses API-key auth; V1 uses Basic Auth (key + secret)

Webhooks & Delivery

Webhooks: V2 webhooks are managed via API (create/list/update/delete). V1 webhooks are configured in the UI
Delivery reports: V2 via webhook; V1 via webhook or email
Retries: Both retry failed webhook deliveries; V2 has a more granular schedule

Message Features

Message Types: V2 supports SMS, MMS, WhatsApp, RCS; V1 supports SMS only
Link Tracking: V2 auto-detects multiple links; V1 supports custom domains
Multi-recipient: V1 supports batch sends; V2 requires individual requests
Response Format: V2 is JSON-only; V1 supports both JSON and XML

Migration Guidance

New Customers

Build on TransmitMessage (V2) to access:

MMS capabilities
Multi-link tracking
Message references
API-managed webhooks
Modern messaging channels (WhatsApp, RCS)

Existing V1 Customers

No rush to migrate. Continue on TransmitSMS (V1) and consider migrating when you need:

MMS support
API-managed webhooks
Multiple tracked links per message
WhatsApp or RCS messaging