Pinnacle

Overview

Pinnacle, from Pinnacle Software Development, Inc. and backed by Y Combinator, is a developer API built around RCS Business Messaging, with SMS, MMS and voice calls on the same platform. It registers 10DLC, toll-free and RCS campaigns by API and says it chases carrier approvals for you. Its site says iMessage is enabled per account on request and sent through the MMS endpoint, but the API docs do not describe it.

Key features

• RCS with rich cards, carousels, quick replies, typing indicators and SMS/MMS fallback
• RCS test agents that message whitelisted phones before approval
• SMS, MMS, group MMS, blasts and scheduled sends
• Voice calls with live audio WebSockets, recording and conferences
• SDKs for Python, TypeScript and Ruby, and an MCP server with 95 tools
• Conversations API, embeddable inbox and a simulate endpoint for testing
• HIPAA environment with a BAA; number lookup and carrier network APIs

Pricing

Per-message rates include carrier fees: SMS $0.015 per segment, MMS $0.027, RCS text $0.025 and RCS media $0.035 per segment. Voice costs $0.01 a minute outbound and $0.0085 inbound. A monthly base fee is quoted on request, and Pinnacle offers to match lower competitor rates.

How it compares to Linq

Linq is built on iMessage, with group chats, tapbacks, polls and other iMessage features documented in its API; Pinnacle offers iMessage only by per-account onboarding and documents none of those features. Linq charges a flat fee from $260 a month with no per-message fees, while Pinnacle bills per segment and minute. Pinnacle places and answers calls, while Linq's docs say its API does not. Both publish TypeScript and Python SDKs and an MCP server.

Best for

US developers who want RCS with SMS fallback, voice and HIPAA support from one API, including teams building AI text agents.

Sources

• pinnacle.sh
• pinnacle.sh/llms.txt
• pinnacle.sh/pricing
• pinnacle.sh/plans
• pinnacle.sh/faq
• pinnacle.sh/security
• pinnacle.sh/ai
• pinnacle.sh/blog/rcs-business-messaging-vs-imessage-why-rbm-wins-for-business
• pinnacle.sh/blog/bulk-messaging-send-sms-mms-rcs-to-thousands-at-once
• docs.pinnacle.sh/v-2/llms.txt
• docs.pinnacle.sh/v-2/documentation/introduction
• docs.pinnacle.sh/v-2/documentation/hipaa
• docs.pinnacle.sh/v-2/guides/messages
• docs.pinnacle.sh/v-2/guides/messages/sending
• docs.pinnacle.sh/v-2/guides/messages/receiving
• docs.pinnacle.sh/v-2/guides/voice-calls
• docs.pinnacle.sh/v-2/guides/branded-test-agents
• docs.pinnacle.sh/v-2/mcp
• docs.pinnacle.sh/v-2/api-reference/messages/react
• docs.pinnacle.sh/v-2/api-reference/messages/simulate-user
• docs.pinnacle.sh/v-2/changelog/llms.txt