CPaaS with built-in fallback

Every message finds a way through

Siddhira routes SMS, WhatsApp, RCS, voice, and email through one API. If a channel fails or goes unread, we reroute automatically — so the message still lands.

No credit card required · Free sandbox with 1,000 test messages
send.js
await siddhira.messages.send({
  to: "+14155550142",
  body: "Your order has shipped.",
  channels: ["whatsapp", "sms", "voice"],
  fallback: { on: "unread", after: "15s" }
});

// WhatsApp: no response after 15s
// → rerouted to SMS automatically
// SMS: delivered in 340ms
99.97%blended delivery rate
<400msaverage failover time
190+countries covered
5-wayfallback chain
Trusted by 400+ businesses across fintech, e-commerce, logistics, and healthtech  ·  delivering since 2019  ·  offices in Hong Kong and London
One integration

Stop building a fallback plan for every channel yourself

Most teams wire SMS, then bolt on WhatsApp, then patch in voice as an afterthought — each with its own retry logic. Siddhira handles the handoff between channels natively, so your integration stays a single API call.

  • Set your own channel order, or let Siddhira pick the cheapest reliable path per country
  • Reroute on failure, timeout, or unread status — you define the trigger
  • One delivery log across every channel, not five separate dashboards
send.js
await siddhira.messages.send({
  to: "+14155550142",
  body: "Your order has shipped.",
  channels: ["whatsapp", "sms", "voice"],
  fallback: { on: "unread", after: "15s" }
});
// Siddhira tries WhatsApp, falls back to SMS,
// then places a voice call — one request, one result.
Platform

Every channel, one delivery guarantee

Pick the products you need today. They all share the same routing engine, so adding a channel later doesn't mean a new integration.

Messaging API

Send SMS, WhatsApp, and RCS from one endpoint, with templates, media, and two-way replies handled the same way across all three.

Voice API

Programmable calls and text-to-speech for the moments a written message won't do — OTPs, alerts, and confirmations that need to be heard.

Verification & OTP

One-time codes that escalate on their own: SMS first, voice call if it isn't entered in time, so drop-off from a missed text doesn't cost you a signup.

Fallback orchestration

The routing layer underneath every product. Define the channel order, the failure conditions, and the timeout — Siddhira executes it in real time.

Global numbers

Local, toll-free, and short code numbers in 190+ countries, provisioned through the same API you use to send.

Delivery analytics

See exactly which channel a message finally landed on, how long each hop took, and where your fallback rules are triggering most.

How fallback routing works

Three steps, no manual retries

Detect

Siddhira watches for a failed send, a timeout, or a message that goes unread past the window you set.

Reroute

The next channel in your chain picks up the same message automatically — no new API call from you.

Deliver

Once it lands, Siddhira stops the chain and logs which channel actually got through, with the full timeline.

5-minute integration

Server-side SDKs for Node, Python, PHP, Java, and Go, plus a REST API for everything else.

Built for engineers

Ship your first message before the coffee's cold

Sandbox credentials on sign-up, clear error codes instead of vague failures, and webhooks for every status change — sent, delivered, read, rerouted, or failed.

  • Idempotent requests, so retries on your side never double-send
  • Sandbox mode that simulates channel failures for testing fallback rules
  • Status webhooks for sent, delivered, read, and rerouted events
Why teams pick Siddhira

Delivery, not just sending

Fallback is native, not bolted on

Channel switching runs inside the same request, with one status object at the end — not five parallel integrations you stitch together.

You set the rules

Channel order, timeout windows, and trigger conditions are configurable per message type, not fixed by us.

Full delivery trail

Every hop is logged — which channel tried, when, and why it moved to the next — so support tickets stop starting with "did the message even send?"

Let's route your first message.

Talk to our team about your channel mix, volumes, and the countries you send to — we'll help you set up a fallback chain that fits.