> ## Documentation Index
> Fetch the complete documentation index at: https://docs.x.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction to Chat API

> Overview of the X Chat API for sending and receiving end-to-end encrypted, signed direct messages on X with client-side encryption via the Chat XDK.

The **Chat API** lets you send and receive **end-to-end encrypted** direct messages on X. Message bodies are encrypted on the client; X routes ciphertext and cannot read plaintext content. Messages are also **signed** so recipients can verify the sender.

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## What you need in your app

| Piece                            | Responsibility                                                                                                              |
| :------------------------------- | :-------------------------------------------------------------------------------------------------------------------------- |
| **[Chat XDK](/xchat/xchat-xdk)** | Generate keys, encrypt/decrypt, sign/verify, optional passcode-protected secure key backup (Python, JS, Rust, Go, C#, Java) |
| **X API access**                 | Public keys, conversation keys, messages, events, media—via **[XDK](/xdks/python/overview)** (Python/TypeScript) or HTTPS   |
| **Delivery**                     | [Webhooks or activity stream](/xchat/real-time-events) for live events; events API for history                              |

Follow **[Getting Started](/xchat/getting-started)** for a full implementation. For concepts only, see the **[Cryptography primer](/xchat/cryptography-primer)**.

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## How encryption works (overview)

1. Create **identity** and **signing** keypairs; store private keys securely (secure key backup or protected blob).
2. **Publish public keys** so others can exchange conversation keys with you and verify signatures.
3. Share a **conversation key** by posting encrypted copies for each participant.
4. **Encrypt and sign** outbound messages; send only ciphertext to X.
5. **Receive** ciphertext via webhooks, stream, or event history.
6. **Verify and decrypt** with the Chat XDK.

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## Useful endpoints

Grouped under **API reference** in the sidebar, including:

* Public keys — register and fetch
* Conversations and messages — list/get conversations, add/rotate keys, events, send, typing, read, group membership
* Media — upload and download encrypted attachments ([guide](/xchat/media))

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## Auth notes

Use **OAuth 2.0 user context** with DM-related scopes (`dm.read`, `dm.write`, plus `users.read` / `tweet.read` as required; `media.write` for uploads). X Chat activity for a user requires that user’s authorization. Secure key backup configuration is returned on **your** public-key record (`juicebox_config` field)—see Getting Started.

***

## Next steps

1. [Cryptography primer](/xchat/cryptography-primer) — optional background on E2EE concepts
2. [Getting Started](/xchat/getting-started) — implement keys, send, and receive
3. [Chat XDK](/xchat/xchat-xdk) — encryption SDK reference
4. [Real-time events](/xchat/real-time-events), [Media](/xchat/media), or [Troubleshooting](/xchat/troubleshooting) when you need those topics