RCS-Box

Overview

RCS-Box is a multi-tenant API for Google RCS Business Messaging, best suited to development teams building messaging into products for multiple brands. It combines rich RCS formats with tenant-level controls, but the free tier is capped at 100 sessions per calendar month and the paid plans carry monthly fees.

Key features

Messages can use text with suggestions, rich cards, carousels and XL messages; video and image links are unfurled automatically. That gives teams several ways to make business messages more expressive than plain text. XL messages are included from Skizze onward and count as one conversation, a useful allowance for teams that need the larger format without it counting as multiple conversations.

Webhooks cover incoming messages and opt-in and opt-out events. Forwarded requests include a lowercase hexadecimal HMAC-SHA256 signature derived from the tenant API key, giving integrations a mechanism to verify webhook authenticity. API requests authenticate with a tenant-specific 64-character hexadecimal key, sent as a Bearer token or in an X-API-Key header.

Each tenant has a dedicated API key and brand-level isolation, plus a configurable country allowlist that defaults to Germany (+49). RCS-Box also handles STOP and START blacklist status per agent automatically. These controls suit services serving distinct brands or audiences, while the Germany-first default means teams targeting other markets should configure the allowlist.

The API includes EU hosting and a German contract partner. It supports standard mode or newsletter mode on every plan; newsletter billing is based on active recipients per month. The API also offers two-way messaging, a verified sender, rich media messaging and delivery analytics.

Pricing

The Free plan costs nothing and allows 100 sessions per calendar month. It is a practical starting point for a small evaluation or low-volume workload, but the monthly session cap makes it unsuitable as a default for larger messaging programs.

Skizze costs €49 a month, billed monthly, and includes XL Messages with standard or newsletter mode. It is the entry paid tier for teams ready to exceed the free allowance or needing XL messages. Atelier costs €249 a month, billed monthly, and Manufaktur costs €999 a month, billed monthly; both include the same stated XL-message and mode options. The plan facts do not distinguish their additional allowances, so buyers should match the higher fees to their workload requirements before committing. Newsletter mode bills by active recipients per month rather than using standard-mode billing.

Platforms

RCS-Box is available as an API and on the web. Its API focus fits teams integrating RCS into software; it is not presented as a standalone consumer messaging app.

Who it's for

RCS-Box is aimed at development teams, CTOs and tech leads in startups, scale-ups and enterprise technology units. Its tenant separation, event webhooks and country controls make it a stronger fit for organizations integrating branded, two-way RCS messaging than for small teams seeking a ready-made messaging interface.

Pros and cons

• Pro: Multiple rich formats, automatic media unfurling and XL messages support more varied business messaging than text alone.
• Pro: Per-tenant keys, brand isolation, country allowlists and signed webhooks provide useful controls for multi-brand integrations.
• Pro: EU hosting and a German contract partner may suit organizations that prioritize those operating arrangements.
• Con: The free plan's 100-session monthly limit constrains sustained or higher-volume use.
• Con: Paid monthly prices rise from 49.00 EUR to 999.00 EUR, while the stated plan differences do not clarify what greater scale the upper tiers provide.

Alternatives

For a broader comparison, see RCS Messaging Platforms.

SimplyRCS is another freemium API and web option; its Pay-as-you-go plan has no platform fee, with messaging at published rates, while Starter costs $20 a month and includes about 400 AI conversations per month. It may suit buyers seeking usage-based messaging costs and an AI-conversation allowance.

Gupshup offers API and web access with a 0.001 USD per-message standard fee and bills WhatsApp fees at actuals. Consider it when per-message billing is a better fit than RCS-Box's monthly plan structure.

Orbit by Devotel offers API, self-hosted and web platforms, with prepaid pay-as-you-go credits, no monthly fee or minimums, and two team members included. It is worth considering when self-hosting or usage-based charges are priorities.

Bandwidth Messaging API is a paid API and web service with a free trial and per-message SMS outbound plans. It may be a better fit for teams seeking SMS messaging rather than RCS-focused plans.

Sinch RCS for Business is a paid RCS option with custom pricing; regional carrier fees and setup costs may apply. Choose it when a detailed sales quote is preferable to a fixed monthly plan.

smsmode RCS API is a paid API and web alternative with a free trial; Basic costs €9 a month for 500 messages per month or more, excluding taxes. It may suit teams whose needs align with that stated message volume.

360dialog offers paid API and web plans, including Regular at $59 a month with 24/7 human support, a direct Meta escalation path and integrations for Zapier, Make and n8n. Consider it when those support and integration features matter.

Community RCS Business Messaging is another option.

Verdict

RCS-Box is a strong fit for technical teams that need Google RCS Business Messaging across separated brands, with rich message formats and event webhooks. Its clearest advantage is the combination of tenant-level controls and RCS-specific formats; its main drawback is the tight free cap and substantial step-up in paid monthly cost. Choose it when those integration controls justify the spend, and look elsewhere if you need a clearly defined high-volume allowance or a lower-cost usage-based model.