Infrastructure for business messaging.
SendiMessage provides managed iMessage and SMS messaging infrastructure for developers, SaaS products, and AI applications: dedicated lines we operate, one REST API, incoming replies, and signed webhooks.
Why SendiMessage exists.
Messaging inside a product looks simple from the outside: send a message, receive a reply, update a conversation. In practice a team ends up owning line provisioning and health, iMessage/SMS routing, inbound processing, webhook delivery, opt-out compliance, and an API layer that has to stay reliable in production.
Developers shouldn't need to build and operate that infrastructure just to add customer conversations to their product. SendiMessage packages it behind a developer-friendly API: we provision and run the lines, your application sends one authenticated request, and replies come back as signed events.
Four parts of one system.
Every capability below is live in the product and documented in the API reference — nothing aspirational.
Managed messaging lines
Dedicated messaging identities provisioned to a customer's organization and operated by SendiMessage — including configuration, routing, sending limits, and monitoring.
Developer APIs
A server-side REST API for sending messages, checking status, browsing history, and managing contacts, conversations, lines, and webhooks — with official SDKs for JavaScript, Python, PHP, and Go.
Incoming messaging
Customer replies arrive on the line, are threaded into conversations, matched to contacts, and made queryable over the API — messaging is two-way by default.
Webhooks & conversations
Signed webhook events deliver inbound messages and send outcomes to customer backends, with conversation history as the queryable source of truth.
Built for product teams.
SaaS companies, AI-agent and Voice-AI builders, CRM platforms, automation teams, and development agencies — anyone adding customer messaging to software they run.
How we make decisions.
Engineering and product decisions, not poster copy.
Built as infrastructure, not another inbox.
The dashboard helps teams operate the service, but the core product is designed to be integrated into your application: server-side API credentials, webhook events into your backend, and conversation state you can query. If the API disappeared, the product would too — that's the test we build against.
Built for legitimate customer communication.
SendiMessage is designed for product and business workflows — appointment updates, lead and customer follow-up, customer service, product notifications, and conversational application flows. It is not built for unsolicited bulk messaging, and using it still requires the consent and compliance obligations that apply to your messaging (such as the TCPA in the US).
Security
How SendiMessage approaches API authentication, tenant isolation, webhook signature verification, and data protection — stated honestly, including what we are not certified for.
Security →Reliability
The status page shows live component health pulled directly from the platform, refreshed automatically — not a decorative green dot. If a component's state can't be verified, the page says "Unknown" instead of guessing.
Status →Built by an engineering-led team.
SendiMessage is built and operated by a small team focused on messaging infrastructure: line operations, the public API and SDKs, inbound processing, and the onboarding that gets customers to production. The same team that builds the platform reviews pilots, provisions lines, and supports integrations — assisted onboarding isn't a sales script, it's how the product works.
We hire for that work: open roles →
From evaluation to production.
The commercial path mirrors the product: prove it on a real line, then scale. Lines are provisioned and reviewed by our team — never an unattended checkout.
Explore the product and docs, see the API → message → reply → webhook loop in a technical demo, start with a one-line Developer Pilot, integrate with assisted onboarding, then move to production pricing and add lines as workflows grow. Full details on the pricing page.
The basics, verified.
- Brand
- SendiMessage — www.sendimessage.com
- Category
- Developer messaging infrastructure (managed iMessage + SMS lines)
- Primary interface
- REST API + signed webhooks; dashboard for operating the service
- Commercial model
- Managed lines, billed monthly per line; assisted onboarding
- Sales and demos
- hello@sendimessage.com
- Technical support
- support@sendimessage.com
- Legal
- Terms · Privacy · Acceptable Use
Public, verifiable, technical.
- API documentation
- Full reference — generated from the live contract, with a downloadable Postman collection
- JavaScript / TypeScript
- github.com/sendimessage/sendimessage-js
- PHP
composer require sendimessage/sdk
Everything verifiable, in one place.
Where to go, depending on what you need.
Evaluating the product?
Pricing, demos, the Developer Pilot, or multi-line setups — talk to the team that provisions lines.
Already integrating?
Technical help, line questions, and account matters for active customers and pilots.
Or email hello@sendimessage.com
Security review?
Vulnerability reports and security questionnaires — see the trust center, or use the monitored security route.
Machine-readable: /.well-known/security.txt
Building for clients?
Agencies and development partners implement SendiMessage for their clients — same API, same assisted provisioning.
Building customer messaging into your product?
Explore the API, start with one managed line, or see the complete workflow in a technical demo.