RCS (Rich Communication Services) lets you send rich, interactive messages on supported mobile networks: branding, rich cards, carousels, suggested replies, dial and open-url actions, and read receipts where carriers support them.

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Agents and channels

RCS on this platform is built around two related concepts that appear in different contexts:
ConceptFieldWhere it appears
Agentagent_idSend requests (POST /v1/messages), RCS management API, conversation.* webhook events
Channelchannel_idMessage log responses (GET /v1/messages), billing records
An agent is your brand’s verified identity with Google and the carriers — it holds the display name, logo, description, and approval status. When you send an RCS message, you pass agent_id. The platform maps each agent to a channel internally. Message history and log endpoints expose channel_id for consistency across all channel types (Email, RCS, SMS) — even though you sent via agent_id. Both are visible in the dashboard; they identify the same configured sender from different angles.
You send with agent_id. You query history with channel_id. See Identifiers for the full ID reference.

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Agent lifecycle

Production agents go through submission and Google / carrier review. The lifecycle is: DRAFT → PENDING_REVIEW → APPROVED (or REJECTED). After approval, the agent is launched on carriers before you can reach subscribers. The Test Agent is a shared, already-approved agent that lets developers send real RCS to one verified handset before investing in full agent setup. See RCS sandbox quickstart.

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Content and traffic types

TypeWhen to use
MESSAGEOutbound-initiated sends — text, rich cards, carousels
CONVERSATIONFollow-up within an active 24-hour session opened by a user reply
NEWSLETTEROpted-in subscriber broadcasts — requires newsletter_enabled: true on the agent

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Billing (high level)

RCS uses Basic vs Single for outbound sends, Conversation for session-based two-way messaging, and MAU for newsletter-style subscriber broadcasts. Every successful API response includes billing metadata inline. Details: Billing (RCS) and Billing units.