The RCS Developer Starter Kit
Building for RCS Business Messaging? You've probably noticed the problem: the documentation is scattered, the GSMA specs are 200+ pages, and carrier requirements vary by region.
We've been building RCS X for months. Along the way, we compiled everything we learned about the GSMA Universal Profile, carrier requirements, and AI agent integration into a single developer kit.
What's Inside
15+ Production-Ready JSON Templates
Every RCS message type, ready to copy-paste and customize:
- Simple text messages with suggested actions
- Rich cards (vertical/horizontal, with media)
- Carousels (2-card to 7-card product catalogs)
- Calendar action integration
- Location sharing
- Video rich cards
- Multi-message sequences
- AI agent formats (MCP-compatible)
Each template includes the complete JSON payload, field-by-field annotations, carrier-specific notes, and common mistakes to avoid.
GSMA Universal Profile Validation Checklist
A line-by-line checklist to validate your payloads before carrier submission. Covers message structure, text content limits, rich card validation, carousel constraints, media specs, ID field requirements, and carrier-specific rules for US, EU, and APAC.
SMS-to-RCS Migration Playbook
A 6-phase migration guide covering assessment, design, build, test, launch, and optimization. Includes real migration patterns, fallback strategies, and success metrics.
MCP Server Integration Patterns
6 patterns for connecting AI agents to RCS channels: basic bridge, multi-turn conversation, event-driven callbacks, rich media responses, rate limiting with error recovery, and bot-to-human handoff.
Carrier Approval Guide
Region-specific requirements for US, EU, and APAC carriers, including pre-submission checklists, brand registration requirements, common rejection reasons, and timeline expectations.
Testing Matrix
A comprehensive testing framework with rendering matrices, interaction test cases, carrier validation checklists, A/B testing framework, performance targets, and accessibility tests.
Why We Built This
- Specs are dense — Most developers need 5% of the GSMA spec, not 200+ pages.
- Carrier requirements are fragmented — What works on T-Mobile might fail on Vodafone.
- Testing is painful — Without an emulator, you burn carrier API quotas just to see how messages render.
- Agent integration is undocumented — MCP + RCS is the future, but there are no public patterns.
Get the Kit
The RCS Developer Starter Kit is available for $39 — less than the cost of one carrier resubmission.
Read the free templates on DEV →
Built by the team behind RCS X — the professional RCS emulator for developers. Test your messages free, no carrier agreements needed.