# Private Messaging

Private messaging on COTI combines encrypted on-chain messages, a TypeScript SDK, a reward system for message activity, and onboarding flows for newly created wallets.

In this section you will find:

* an overview of the [`@coti-io/coti-sdk-private-messaging`](https://docs.coti.io/coti-documentation/private-messaging/typescript-sdk) package
* guides for [sending and reading messages](https://docs.coti.io/coti-documentation/private-messaging/messages)
* documentation for the [reward epoch system](https://docs.coti.io/coti-documentation/private-messaging/rewards)
* documentation for the [starter grant flow](https://docs.coti.io/coti-documentation/private-messaging/starter-grant)
* a reference for the available [skills](https://docs.coti.io/coti-documentation/private-messaging/skills)

## How private messaging works

The private messaging system stores encrypted message bodies on-chain while keeping routing metadata queryable.

* the message body is encrypted using COTI-compatible encryption before it is sent
* only the sender and recipient can decrypt the message content
* routing metadata such as `from`, `to`, `timestamp`, and `epoch` remains public
* long messages are automatically split into multiple encrypted chunks
* message activity contributes usage units that can later earn rewards

## What to read next

If you want to build with the SDK, start with [TypeScript SDK](https://docs.coti.io/coti-documentation/private-messaging/typescript-sdk).

If you want to understand the messaging flow itself, continue with [Sending and Reading Messages](https://docs.coti.io/coti-documentation/private-messaging/messages).

If you want to use the agent workflows, go to [Skills](https://docs.coti.io/coti-documentation/private-messaging/skills).