Two kinds of chat SDK
Messaging SDKs: users talk to each other
Tools like Stream, Sendbird and CometChat give you the building blocks for chat between your users: channels, typing indicators, reactions, moderation. You'd use them for a dating app, a marketplace or a community. You build the UI and the business logic yourself, and pricing usually follows monthly active users.
Support chat SDKs: users talk to you
Tools like Chatslane, Intercom and Helpshift give you a finished support chat: a screen in your app, an inbox for your team, push notifications and often AI answers. You add it in a day, not a sprint.
Which one do you need?
Ask one question: who is on the other side of the conversation? If it's another user, you need a messaging SDK. If it's you or your team, you need a support chat SDK.
You can build a support chat on top of a messaging SDK. It works, but you end up rebuilding an inbox, push logic, email fallback, user details and assignment. That's a product in itself.
What to check in a support chat SDK
- Native UI for your stack: SwiftUI/UIKit, Jetpack Compose, React Native/Expo, Flutter
- Size and dependencies: it shouldn't double your app size
- Push notifications for replies, with an email fallback
- Anonymous users by default, with a way to link your own user ID
- Photos and screenshots
- Theming so the chat looks like your app, including dark mode
- Device, app version and subscription details for the team
- Privacy: what data it collects, and what to declare in App Store privacy labels
Native vs web view
Some chat SDKs are a web page inside a web view. They're quick to ship but often feel slow, break with the keyboard, and look out of place. A native chat UI costs the vendor more to build, but your users feel the difference immediately. Check the demo app on a real device before you commit.
Adding a chat SDK with a coding agent
In 2026 most developers don't follow integration docs line by line anymore. They paste instructions into Claude Code, Cursor or Codex. A good SDK gives you a setup prompt that your agent can follow: install the package, initialize it with your key, add a "Contact us" button, and register for push.
That's how Chatslane works: you copy one prompt from the dashboard, your coding agent wires the chat into your Swift, Kotlin, React Native/Expo or Flutter app, and you send yourself a test message.
Pricing models to watch
Messaging SDKs usually charge per monthly active user, which gets expensive as you grow. Support tools often charge per seat or per AI resolution. For a small app team, a flat price is the easiest to plan around. Whatever you choose, model the cost at ten times your current users before you sign.
Frequently asked questions
What is the best chat SDK for iOS?
For chat between users, look at messaging SDKs like Stream or Sendbird. For support chat between users and your team, use a support SDK like Chatslane, which has a native Swift package.
Is there a chat SDK for React Native and Expo?
Yes. Chatslane works with React Native and Expo, and most messaging SDKs have React Native packages too.
Can I build a support chat with Firebase?
You can, but you'll also need an inbox for your team, push logic, email fallback and user details. A support chat SDK gives you all of that out of the box.
Does a chat SDK affect App Store privacy labels?
Yes. Declare what the SDK collects, such as messages, device info and identifiers. Chatslane has a guide that lists exactly what to declare.