{"id":2958,"date":"2026-09-11T09:25:52","date_gmt":"2026-09-11T03:55:52","guid":{"rendered":"https:\/\/www.smsgatewaycenter.com\/blog\/?p=2958"},"modified":"2026-09-11T09:25:54","modified_gmt":"2026-09-11T03:55:54","slug":"rcs-messaging-api-reference-migration-from-sms","status":"publish","type":"post","link":"https:\/\/www.smsgatewaycenter.com\/blog\/rcs-messaging-api-reference-migration-from-sms\/","title":{"rendered":"RCS Messaging API: Complete Reference and Migration Path from SMS"},"content":{"rendered":"\n

A field reference for the SMSGatewayCenter RCS API written for engineers who already run SMS. Two API generations, three response envelopes, the bot and template model, the delivery report with read and click timestamps, the inbox, and how to run RCS alongside SMS with fallback rather than replacing it.<\/p>\n\n\n\n

\"Diagram<\/a>
RCS and SMS are two pipelines that run side by side, joined by a fallback path. They are not one pipeline with a richer payload.<\/figcaption><\/figure>\n\n\n\n

TABLE OF CONTENTS<\/h1>\n\n\n\n
    \n
  1. The Short Answer<\/a><\/li>\n\n\n\n
  2. TL;DR<\/a><\/li>\n\n\n\n
  3. What RCS Actually Changes, at the Protocol and Billing Level<\/a><\/li>\n\n\n\n
  4. Two API Generations Inside One Product<\/a><\/li>\n\n\n\n
  5. Bots: The Identity Layer SMS Does Not Have<\/a><\/li>\n\n\n\n
  6. Templates: Create, List, Delete, and the Approval Clock<\/a><\/li>\n\n\n\n
  7. The Three Send Methods and Why the Response Union Collapsed<\/a><\/li>\n\n\n\n
  8. The Correlation Chain and Its Two Renames<\/a><\/li>\n\n\n\n
  9. The Delivery Report: Read and Click Are New Terminal States<\/a><\/li>\n\n\n\n
  10. The Inbox: Two-Way RCS Is a Polling Problem<\/a><\/li>\n\n\n\n
  11. The Summary Endpoint and Reconciliation<\/a><\/li>\n\n\n\n
  12. Endpoint Reference Table<\/a><\/li>\n\n\n\n
  13. Success Codes Across the RCS Families<\/a><\/li>\n\n\n\n
  14. RCS Against SMS: A Field-Level Comparison<\/a><\/li>\n\n\n\n
  15. Fallback Is the Migration Path, Not Replacement<\/a><\/li>\n\n\n\n
  16. Your First RCS Send in Six Steps<\/a><\/li>\n\n\n\n
  17. Working Code: cURL, Python, PHP, Node.js<\/a><\/li>\n\n\n\n
  18. Ten Mistakes That Cost a Week<\/a><\/li>\n\n\n\n
  19. A Decision Matrix for Channel Choice<\/a><\/li>\n\n\n\n
  20. Production Readiness Checklist<\/a><\/li>\n\n\n\n
  21. Unspecified Behaviour and How to Code Around It<\/a><\/li>\n\n\n\n
  22. FAQs<\/a><\/li>\n<\/ol>\n\n\n\n

    <\/p>\n\n\n\n

    The Short Answer<\/h2>\n\n\n\n

    The RCS API on SMSGatewayCenter is a different API from the SMS API, not a channel flag on the same one. Sends go to https:\/\/unify.smsgateway.center\/RCSApi\/send<\/code> rather than SMSApi\/send<\/code>, they require a botId<\/code> instead of a senderid<\/code>, the message body is a JSON payload naming an approved templateCode<\/code> rather than free text, and the format parameter is spelled format<\/code> here where the SMS API spells it output<\/code>. Reporting lives on a second, newer base path entirely, https:\/\/unify.smsgateway.center\/rest\/rcs\/v1\/<\/code>, which uses page<\/code> and limit<\/code> paging, accepts an apikey<\/code> header, and returns a flat envelope with no response<\/code> wrapper. Three distinct response envelope shapes exist across the RCS endpoints, so a single parser will not cover them. The practical migration is not a cutover: you keep your SMS path, add an RCS path, and route between them, because RCS only reaches handsets where the recipient has RCS available and enabled, and the delivery report tells you exactly when it did not with globalErrorCode<\/code> 5007 and cause<\/code> “RCS Not Enabled”.<\/p>\n\n\n\n

    TL;DR<\/h2>\n\n\n\n