Headless Chat · Voice · Video API

Add 1-on-1 chat, voice & video to your app in minutes

Pay for people who chat — not your whole user base. Mapped to your existing user IDs and auth, no parallel user database. Built for marketplaces, delivery apps, and SaaS, with SDKs for JavaScript, React, Flutter, and more.

Start free — no credit card View pricing Read the docs

Start on the Free plan or message us on Telegram — we'll help you wire up chat, calls, and production.

server.ts

// Your server — API key stays here
const { token } = await fetch(`${API_URL}/v1/auth/token`, {
  method: "POST",
  headers: { "x-api-key": process.env.SENDSAR_API_KEY },
  body: JSON.stringify({
    userId: user.id,
    displayName: user.name,
  }),
}).then((r) => r.json());

// Client connects with short-lived JWT
await client.connect(token);

Your app

Existing users & auth

Your server

Issues session JWT

Sendsar

Rooms & delivery

Your UI

Headless — you design it

Built for platform teams

Flat pricing: Pay for chatters, not signups
Headless: Your UI, our engine
2-party: Native room model
Calls: Voice & video optional

Core products

The headless stack for every conversation

Modular building blocks — start with two-party messaging, add calls when you need them. Your auth, your UI, our delivery engine.

Core

Headless messaging API

Rooms, messages, delivery, and presence — mapped to your user IDs and business objects. No parallel user directory.

1:1 rooms · group optional
Typing & read receipts
Reactions & media
REST + WebSocket

Platform

Real-time infrastructure

Multi-tenant gateway with session JWTs, webhooks, and optional voice/video when your workflow needs more than text.

Session JWT from your server
Webhooks for automations
Multi-tenant isolation
Optional LiveKit calls

How it works

Three steps. No platform swap.

Most chat SDKs expect a greenfield build. Sendsar is built for the opposite — platforms that already ship.

Keep your user system

Sendsar maps to your existing user IDs. No parallel user directory, no auth migration, no SSO rebuild.

Issue sessions from your server

Your backend holds the API key and mints short-lived JWTs. Clients never see secrets — same pattern you already trust.

Ship your own UI

We deliver rooms, messages, and real-time events. You render the chat experience inside your product's design system.

Platform features

Powerful by default

Infrastructure for delivery and state — not a design system you have to adopt wholesale.

Rooms & messages: Create scoped conversations mapped to your business objects.
Real-time delivery: WebSocket transport with REST fallbacks for server workflows.
Presence & typing: Online status and typing signals without extra infrastructure.
Session JWTs: Short-lived client tokens minted by your backend — keys never exposed.
Multi-tenant: Isolate customers, brands, or environments on one backend.
Webhooks: React to message events in your own services and automations.
Reactions & receipts: Modern chat primitives without bolting on a full UI framework.
Voice & video: Optional calls via LiveKit when your workflow needs more than text.

Use cases

Two-party workflows, native to your product

Driver ↔ passenger

On-demand marketplaces

Trip-scoped rooms tied to order IDs. Chat opens when a match happens — no separate messaging app.

Account ↔ vendor

B2B SaaS platforms

Let customers talk to suppliers or support inside your dashboard, using the accounts you already manage.

Client ↔ provider

Service marketplaces

Booking-based conversations with your auth layer intact. Add chat without adopting someone else's UI kit.

Pricing

Simple, transparent, predictable

Free, Plus, Pro, and Enterprise — flat monthly tiers for apps of any size. Limits are based on active chatters (people who actually message), not total registered users. Text chat, voice call, video call, and call recording are metered separately.

Save 20% with annual billing on base plans

Billed once per year — save 20% vs paying monthly on the base plan

Free

$0/month

Hackathons & MVPs

Get started

Up to 200 active chatters / mo
2,500 text chat messages/month
3 days text chat history
1 GB
30 Voice call participant-minutes/month
15 Video call participant-minutes/month
No call recording
Voice and video calls pause after included minutes

Plus

Save 20% · $46/year

$19/month

$15.17/month

$182 billed once per year ($228 if paid monthly)

Local shops & startups

Start with Plus

Up to 2,500 active chatters / mo
50,000 text chat messages/month
Then $1 per 10,000 extra messages
1 year text chat history
5 GB included (+ $1/5 GB extra)
240 Voice call participant-minutes/month
120 Video call participant-minutes/month
240 Call recording minutes/month

Pro

Save 20% · $118/year

$49/month

$39.17/month

$470 billed once per year ($588 if paid monthly)

High-traffic marketplaces & apps

Start with Pro

Up to 15,000 active chatters / mo
500,000 text chat messages/month
Then $1 per 10,000 extra messages
3 years text chat history
25 GB included (+ $1/5 GB extra)
480 Voice call participant-minutes/month
240 Video call participant-minutes/month
480 Call recording minutes/month

Enterprise

Banks, logistics & regulated orgs

Contact sales

Unlimited
Unlimited text chat messages
Unlimited text chat history
Unlimited (custom storage tier)
Unlimited Voice call
Unlimited Video call
Included, unlimited
Dedicated infrastructure
Private cloud / self-hosted deployment
Custom webhook routing & dedicated support

Need a detailed comparison? View full pricing →

Developer experience

Built for backend teams first

Start with the API, add SDKs where they help. Docs, webhooks, and session flows are designed around how platform engineers actually integrate.

JavaScriptReactFlutterRESTWebSocketNode.js

Open documentation View pricing

webhook payload

{
  "type": "message.created",
  "tenantId": "acme",
  "roomId": "order_8f2a",
  "senderId": "user_42",   // your ID
  "body": "Driver is 2 min away"
}

Why Sendsar

Headless means you stay in control

If adding chat feels like bolting on someone else's product, you probably need infrastructure — not another app inside your app.

Typical chat SDK

Sendsar

Adopt our UI kit and user model

Keep your UI and map our rooms to your user IDs

Rebuild auth around our SDK

Mint session JWTs from the server you already run

Ship a full communication suite on day one

Start with two-party messaging, add calls when needed

Blog

Notes for platform builders

All posts →

Opinion

The Hidden Tax of "Building Your Own" Chat Backend

Building a real-time chat backend from scratch means signing up for a lifetime tax of fixing WebSocket connection drops, database scaling, and race conditions.

Team Flash Chat • Jun 13, 2026 • 5 min read

Comparison

Best Headless Chat APIs in 2026: Stream, Sendbird, CometChat & More Compared

Compare Stream, Sendbird, CometChat, Twilio, PubNub, and Flash Chat on integration, pricing, two-party messaging, and platform fit.

Team Flash Chat • Jun 10, 2026 • 8 min read

Ready to add chat without the rebuild?

Pick a plan above or message us on Telegram — we'll help with docs, sandbox access, and production setup.

support@sendsar.com

Get started View pricing