Sent is a messaging API for developers who need to deliver messages by SMS, WhatsApp, and RCS from a single integration. You send one message to a recipient, and Sent determines the delivery channel for that individual. If you run a SaaS product sending login codes and notifications, this approach avoids writing separate dispatch code for each telecom network. Sent does not provide email delivery, so password resets and invoices still require an email API like Resend or SendGrid.
You can find Sent on its Huzzler product page or at sent.dm.
Who Sent is for
Sent is built for developers and product teams adding messaging directly into software. Typical examples include SaaS platforms dispatching appointment reminders, ecommerce stores texting delivery updates, and AI assistants conversing with customers on WhatsApp. It is especially useful when your application serves many client businesses that each require their own sender identity, like a booking tool where every salon sends reminders under its own brand name.
Sent does not handle email campaigns or newsletters, so marketing teams that primarily send email have no use for it. Voice calls on Sent are programmable building blocks where your code dictates what happens on every call. Support teams that need ready-to-use agent seats and call queues will want a contact center product like Twilio Flex. If your product roadmap relies immediately on RCS rich cards or carousels, Sent has not released those features yet.
What Sent does
When you omit the channel field from an API request, Sent selects the delivery path for each recipient automatically. Sent evaluates the destination country, the message text, per-channel routing rates, and the recipient phone's supported protocols. The same API call can become a WhatsApp message for one customer and an SMS for the next, leaving your backend free of channel-routing logic. Whenever a specific channel is mandatory for legal or compliance reasons, you can pin it.
If the selected channel fails to deliver, Sent retries through viable alternative routes and finishes at SMS. That automated fallback only triggers when you let Sent choose the channel. A pinned channel that cannot deliver simply fails, which removes that fallback safety net.
You write message templates once using dynamic variables, and Sent formats them to match each channel. An order status update delivers as plain text on SMS, but renders as a structured card with a tracking button on WhatsApp. Sent submits WhatsApp templates directly to Meta, monitors their approval progress, and resubmits them if rejected. While a WhatsApp template awaits Meta's review, you can dispatch that same template over SMS immediately.
Sender Profiles provide tenancy separation for multi-tenant SaaS products. Each profile corresponds to one of your business customers and maintains isolated contacts, templates, phone numbers, and API tokens, preventing any profile from viewing another customer's data. Billing structures are flexible: costs can bill to your parent organization, charge the profile directly, or bill the profile first while your organization pays for remaining balances. If your application communicates through a central API key, you can target a specific customer account by including the x-profile-id header.
You can monitor message events through webhooks that report delivery confirmations and incoming customer replies. Sent unifies unsubscribe handling: an incoming STOP keyword on any channel blocks that contact on SMS, WhatsApp, and RCS automatically. Sent also enforces regional quiet hours per country, holding outbound messages until the recipient's permitted contact window opens.
For software developers, Sent publishes official client SDKs for TypeScript, Python, Go, Java, C#, PHP, and Ruby. The MCP server at mcp.sent.dm supplies 19 tools that let AI coding agents in Cursor and Claude Code trigger test dispatches, query phone numbers, organize contacts and templates, and inspect deliverability. Sent also includes a sandbox mode, allowing automated test suites to run API calls without dispatching real messages over telecom networks.
Onboarding requires very little setup: verifying an email address and mobile phone number grants immediate API access, six pre-configured OTP templates, and an allowance of 500 sends per day for each template. Business verification (KYC) only becomes necessary when you request custom templates or a dedicated sender number, so you can test the API thoroughly before submitting corporate paperwork.
Sent also supports voice calls through a browser audio SDK, call recording capabilities, and programmable IVR phone menus. Calling features are not enabled by default: Sent's support team must activate voice on your account.
What works well
- One API call routes to SMS, WhatsApp, or RCS per recipient.
- Undelivered messages fall back to SMS automatically when Sent picks the channel.
- Sender Profiles keep each customer's contacts, templates, and credentials strictly separate.
- A verified email and phone number give you instant sandbox access.
- The MCP server runs test sends and lookups directly inside your editor.
What to watch out for
- You still handle your own consent gathering and US sender registration.
- Sent lacks email, requiring a separate API for password resets.
Pricing
Sent charges a monthly platform fee of $0.015 for each person you message during the billing cycle, plus carrier pass-through charges for each dispatched message. Messaging 10,000 distinct individuals in a month produces a $150 platform fee, with carrier delivery expenses for SMS, WhatsApp, or RCS billed additionally.
Delivery charges depend on the destination country, the selected channel, total SMS segment counts, leased phone numbers, and how frequently messages step down to fallback routes. Sent's website provides a pricing calculator where you can enter recipient totals, monthly message numbers, and destination regions to project costs. Sent notes that real-world carrier rates fluctuate based on telecom rules and fallback frequency. Custom enterprise arrangements require contacting sales directly.
This per-contact fee structure is advantageous when each user receives multiple messages every month, such as daily fitness reminders or ongoing order milestones. It is disadvantageous if you broadcast occasional single messages to a massive subscriber list. When comparing Sent against traditional per-message providers, calculate a typical month of your historical traffic on both pricing models before deciding.
Alternatives to Sent
Twilio is the primary alternative for established telecom infrastructure. Alongside SMS, WhatsApp, and RCS, Twilio provides email delivery, full voice calling, hosted identity verification, and contact center suites, with immediate support for interactive RCS rich cards. Our Sent vs Twilio comparison examines routing mechanics, RCS readiness, and real-world pricing differences.
Bird, formerly MessageBird, delivers email, SMS, WhatsApp, and Apple Messages for Business, paired with contact audiences and visual marketing automations. RCS is currently limited to a private beta on Bird. Our Sent vs Bird comparison explores Bird's marketing toolset, RCS availability, and cost models.