> ## 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.
# Getting Started with Chat API
> Step-by-step tutorial to build end-to-end encrypted X Chat messaging using the Chat XDK in Python, TypeScript, Go, Rust, C#, or Java.
Send and receive end-to-end encrypted direct messages on X: set up keys, initialize a conversation, send a message, and decrypt inbound traffic.
X Chat apps use two pieces together:
| Component | Role |
| :------------------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **[Chat XDK](/xchat/xchat-xdk)** | Encryption, decryption, signing, and private key storage (secure key backup or a key blob) |
| **X API** | Public keys, conversation keys, messages, and events—via the [Python](/xdks/python/overview) or [TypeScript](/xdks/typescript/overview) XDK, or HTTPS with a user access token |
**Prerequisites**
* [Developer account](https://developer.x.com/en/portal/petition/essential/basic-info) and an app configured for OAuth 2.0
* User access token with `dm.read`, `dm.write`, `tweet.read`, and `users.read`
***
## 1. Install dependencies
```bash theme={null}
pip install chatxdk xdk
```
The PyPI package is `chatxdk`; import it as `chat_xdk`. Requires Python 3.10+.
```bash theme={null}
npm install @xdevplatform/chat-xdk @xdevplatform/xdk
npm install juicebox-sdk # optional peer dependency — required for setup()/unlock() secure key backup
```
The compiled WASM engine ships inside `@xdevplatform/chat-xdk`—no build step. Requires Node.js 18+.
```toml theme={null}
[dependencies]
# chat-xdk-core is not yet on crates.io — use the git dependency
chat-xdk-core = { git = "https://github.com/xdevplatform/chat-xdk", tag = "v0.2.1" }
reqwest = { version = "0.12", features = ["blocking", "json"] }
serde_json = "1"
base64 = "0.22"
uuid = { version = "1", features = ["v4"] }
# Required until thrift 0.24 is released on crates.io
[patch.crates-io]
thrift = { git = "https://github.com/apache/thrift.git", rev = "deb36fa409849de45973b04ffc3ce49d277ca90a" }
```
```bash theme={null}
go get github.com/xdevplatform/chat-xdk/go/chatxdk
```
Precompiled static libraries are included (macOS arm64/amd64, Linux amd64 glibc/musl)—you need a C compiler but not Rust. Requires Go 1.21+.
```bash theme={null}
dotnet add package XDevPlatform.ChatXdk
```
The package is self-contained: native libraries for macOS (arm64, x64), Linux (x64), and Windows (x64) ship inside it. Requires .NET 8+.
```xml theme={null}
com.x
chatxdk
0.2.1
```
Available on Maven Central. The jar bundles the native library for macOS (arm64, x64), Linux (x64), and Windows (x64)—no `jna.library.path` setup needed. Import from `com.x.chatxdk`. Requires JDK 17+.
Create an API client with your **user** OAuth 2.0 access token:
```python theme={null}
from xdk import Client
client = Client(access_token="YOUR_OAUTH2_USER_TOKEN")
```
```typescript theme={null}
import { Client } from '@xdevplatform/xdk';
const client = new Client({ accessToken: 'YOUR_OAUTH2_USER_TOKEN' });
```
```rust theme={null}
let access_token = std::env::var("X_ACCESS_TOKEN")?;
let http = reqwest::blocking::Client::new();
let auth = format!("Bearer {access_token}");
```
```go theme={null}
accessToken := os.Getenv("X_ACCESS_TOKEN")
httpClient := &http.Client{Timeout: 30 * time.Second}
```
```csharp theme={null}
using var http = new HttpClient();
http.DefaultRequestHeaders.Authorization =
new System.Net.Http.Headers.AuthenticationHeaderValue(
"Bearer", Environment.GetEnvironmentVariable("X_ACCESS_TOKEN"));
```
```java theme={null}
String accessToken = System.getenv("X_ACCESS_TOKEN");
HttpClient http = HttpClient.newHttpClient();
```
***
## 2. Initialize the Chat XDK with existing keys
This step **loads keys you already have**—use it when this identity completed first-time setup before:
* **Secure key backup:** construct the SDK with the `juicebox_config` from your public-key record, then `unlock` with your passcode to recover the private keys (for example, on a new device).
* **Key blob:** `import_keys` with a blob you previously exported via `export_keys`.
Then set your registered public-key version (`public_key_version` on your record).
**Setting up for the first time?** Construct the SDK the same way but skip `unlock`/`import_keys`, and continue to [step 3](#3-create-and-register-keys-first-time-setup) to create, back up, and register your keys.
```python theme={null}
import json
from chat_xdk import Chat
resp = client.chat.get_user_public_keys(
"YOUR_USER_ID",
public_key_fields=[
"public_key_version", "public_key", "signing_public_key",
"identity_public_key_signature", "juicebox_config",
],
)
record = resp.data[0]
signing_key_version = str(record["public_key_version"])
chat = Chat(json.dumps(record["juicebox_config"]))
chat.unlock("YOUR_PASSCODE") # recovers keys stored by setup() during first-time setup (step 3)
chat.set_key_version(signing_key_version)
```
```typescript theme={null}
import { createChat } from '@xdevplatform/chat-xdk';
const resp = await client.chat.getUserPublicKeys('YOUR_USER_ID', {
publicKeyFields: [
'public_key_version', 'public_key', 'signing_public_key',
'identity_public_key_signature', 'juicebox_config',
],
});
const record = resp.data[0];
const signingKeyVersion = String(record.public_key_version);
const chat = await createChat({
juiceboxConfig: JSON.stringify(record.juicebox_config),
getAuthToken: async (realmId) => getRealmTokenFromYourBackend(realmId),
});
await chat.unlock('YOUR_PASSCODE');
chat.setKeyVersion(signingKeyVersion);
```
```rust theme={null}
use base64::{engine::general_purpose::STANDARD as B64, Engine};
use chat_xdk_core::ChatCore;
let mut chat = ChatCore::new();
let blob = B64.decode(std::env::var("PRIVATE_KEYS_B64")?)?;
let signing_key_version = std::env::var("SIGNING_KEY_VERSION").unwrap_or_else(|_| "1".into());
chat.import_keys(&blob)?;
chat.set_key_version(&signing_key_version);
```
```go theme={null}
import "github.com/xdevplatform/chat-xdk/go/chatxdk"
chat := chatxdk.New()
defer chat.Close()
blob, err := chatxdk.Base64ToBytes(os.Getenv("PRIVATE_KEYS_B64"))
if err != nil {
log.Fatal(err)
}
if err := chat.ImportKeys(blob); err != nil {
log.Fatal(err)
}
signingKeyVersion := os.Getenv("SIGNING_KEY_VERSION")
if signingKeyVersion == "" {
signingKeyVersion = "1"
}
chat.SetKeyVersion(signingKeyVersion)
```
```csharp theme={null}
using ChatXdk;
using var chat = new Chat();
var signingKeyVersion = Environment.GetEnvironmentVariable("SIGNING_KEY_VERSION") ?? "1";
chat.ImportKeys(Convert.FromBase64String(
Environment.GetEnvironmentVariable("PRIVATE_KEYS_B64")!));
chat.SetKeyVersion(signingKeyVersion);
```
```java theme={null}
import com.x.chatxdk.Chat;
String signingKeyVersion = Optional.ofNullable(System.getenv("SIGNING_KEY_VERSION")).orElse("1");
try (Chat chat = new Chat()) {
chat.importKeys(Base64.getDecoder().decode(System.getenv("PRIVATE_KEYS_B64")));
chat.setKeyVersion(signingKeyVersion);
}
```
Server and bot samples often use a **key blob** (`export_keys` / `import_keys`). Client apps often use **secure key backup** (`setup` / `unlock` with a passcode). See the [Chat XDK](/xchat/xchat-xdk) reference for both paths.
**Bringing your own keys?** `import_keys` only accepts the opaque blob produced by `export_keys` from the Chat XDK—it is a versioned, private serialization of the full key state, not raw or PEM-encoded P-256 keys. You cannot construct this blob yourself: generate keys through `generate_keypairs` ([step 3](#3-create-and-register-keys-first-time-setup)), export the blob once, and store it base64-encoded. Hand-crafted or modified blobs fail to import.
***
## 3. Create and register keys (first-time setup)
Skip this step if you loaded existing keys in [step 2](#2-initialize-the-chat-xdk-with-existing-keys). Otherwise, one-time setup for a new identity does **three things**:
1. **Create the keypairs** — `generate_keypairs` produces the identity and signing keypairs.
2. **Register the public keys** — POST the registration payload to the add-public-key endpoint so others can encrypt to you and verify your signatures.
3. **Store the private keys** — `setup` with a passcode writes them to secure key backup (clients), or `export_keys` returns a key blob for you to store securely (servers and bots).
```python theme={null}
from xdk.chat.models import AddUserPublicKeyRequest
registration = chat.generate_keypairs()
pk = registration.public_key
client.chat.add_user_public_key(
"YOUR_USER_ID",
AddUserPublicKeyRequest(
public_key={
"identity_public_key_signature": pk.identity_public_key_signature,
"public_key": pk.public_key,
"public_key_fingerprint": pk.public_key_fingerprint,
"registration_method": pk.registration_method,
"signing_public_key": pk.signing_public_key,
"signing_public_key_signature": pk.signing_public_key_signature,
},
version=registration.version,
generate_version=registration.generate_version,
),
)
chat.setup("YOUR_PASSCODE")
chat.set_key_version(str(registration.version or signing_key_version))
```
```typescript theme={null}
const registration = chat.generateKeypairs();
const pk = registration.publicKey;
await client.chat.addUserPublicKey('YOUR_USER_ID', {
public_key: {
identity_public_key_signature: pk.identityPublicKeySignature,
public_key: pk.publicKey,
public_key_fingerprint: pk.publicKeyFingerprint,
registration_method: pk.registrationMethod,
signing_public_key: pk.signingPublicKey,
signing_public_key_signature: pk.signingPublicKeySignature,
},
version: registration.version,
generate_version: registration.generateVersion,
});
await chat.setup('YOUR_PASSCODE');
chat.setKeyVersion(String(registration.version ?? signingKeyVersion));
```
```rust theme={null}
let registration = chat.generate_keypairs()?;
let body = serde_json::to_value(®istration)?;
let resp = http
.post(format!("https://api.x.com/2/users/{user_id}/public_keys"))
.header("Authorization", &auth)
.json(&body)
.send()?;
if !resp.status().is_success() {
anyhow::bail!("register keys: {}", resp.text()?);
}
let _blob = chat.export_keys()?; // store securely
```
```go theme={null}
registration, err := chat.GenerateKeypairs()
if err != nil {
log.Fatal(err)
}
regJSON, _ := json.Marshal(registration)
req, _ := http.NewRequest(http.MethodPost,
"https://api.x.com/2/users/"+userID+"/public_keys",
bytes.NewReader(regJSON))
req.Header.Set("Authorization", "Bearer "+accessToken)
req.Header.Set("Content-Type", "application/json")
resp, err := httpClient.Do(req)
if err != nil {
log.Fatal(err)
}
resp.Body.Close()
privateKeysB64, _ := chat.ExportKeys() // store securely
_ = privateKeysB64
chat.SetKeyVersion(signingKeyVersion)
```
```csharp theme={null}
var registration = chat.GenerateKeypairs();
var regJson = System.Text.Json.JsonSerializer.Serialize(registration);
using var content = new StringContent(regJson, Encoding.UTF8, "application/json");
using var regResp = await http.PostAsync(
$"https://api.x.com/2/users/{Uri.EscapeDataString(userId)}/public_keys", content);
regResp.EnsureSuccessStatusCode();
var blob = chat.ExportKeys(); // store securely
chat.SetKeyVersion(signingKeyVersion);
```
```java theme={null}
var registration = chat.generateKeypairs();
String regJson = new ObjectMapper().writeValueAsString(registration);
HttpRequest req = HttpRequest.newBuilder()
.uri(URI.create("https://api.x.com/2/users/" + userId + "/public_keys"))
.header("Authorization", "Bearer " + accessToken)
.header("Content-Type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString(regJson))
.build();
HttpResponse regResp = http.send(req, HttpResponse.BodyHandlers.ofString());
if (regResp.statusCode() >= 300) {
throw new RuntimeException("register keys: " + regResp.body());
}
byte[] blob = chat.exportKeys(); // store securely
chat.setKeyVersion(signingKeyVersion);
```
Use a strong passcode for secure key backup. Losing the passcode or an unprotected key blob can prevent decrypting past messages.
***
## 4. Set up conversation keys
Call **`prepare_conversation_key_change`** with your user ID, your signing key version, and every participant's identity public key. One call generates a fresh conversation key, encrypts it for each participant, and signs the change. POST the result to the **add conversation keys** endpoint (`POST /2/chat/conversations/{id}/keys`)—the body needs `conversation_key_version`, `conversation_participant_keys` (SDK `encrypted_key` → API `encrypted_conversation_key`), and **`action_signatures`** (required; the API rejects the call without them). Keep the **raw** conversation key for sending.
The response returns the canonical conversation id (`data.conversation_id`—the hyphen-joined pair for a 1:1, or the g-prefixed id for a group) and the key change's `data.sequence_id`. Use that returned id for subsequent requests instead of reconstructing it client-side. The same call also **rotates** keys later: pass the existing conversation id to `prepare_conversation_key_change` and POST with the newer key version. Rotate when you suspect the conversation key was exposed—rotation protects **future** messages only; messages encrypted under earlier key versions stay readable to anyone who holds those versions.
**Verify fetched keys before wrapping.** `prepare_conversation_key_change` encrypts the fresh conversation key to whatever public keys you pass. Check each fetched record first with `verify_key_binding(identity, signing, signature)`—passing the record's `public_key`, `signing_public_key`, and `identity_public_key_signature` fields from the public-keys API—so a substituted identity key cannot receive the conversation key.
```python theme={null}
def public_key_input(user_id: str) -> dict:
r = client.chat.get_user_public_keys(
user_id, public_key_fields=["public_key_version", "public_key"]
).data[0]
return {"user_id": user_id, "public_key": r["public_key"], "key_version": r["public_key_version"]}
prepared = chat.prepare_conversation_key_change(
"YOUR_USER_ID",
signing_key_version,
[public_key_input("YOUR_USER_ID"), public_key_input("RECIPIENT_USER_ID")],
# conversation_id=None for a new 1:1; pass the id to rotate later
)
resp = client.chat.add_conversation_keys(
"RECIPIENT_USER_ID",
{
"conversation_key_version": prepared["conversation_key_version"],
"conversation_participant_keys": [
{
"user_id": pk["user_id"],
"encrypted_conversation_key": pk["encrypted_key"],
"public_key_version": pk["public_key_version"],
}
for pk in prepared["participant_keys"]
],
"action_signatures": [
{
"message_id": sig["message_id"],
"encoded_message_event_detail": sig["encoded_message_event_detail"],
"message_event_signature": {
"signature": sig["signature"],
"public_key_version": sig["public_key_version"],
"signature_version": sig["signature_version"],
},
}
for sig in prepared["action_signatures"]
],
},
)
conversation_id = resp.data["conversation_id"] # canonical id for later requests
sequence_id = resp.data["sequence_id"]
conv_key = prepared["conversation_key"]
conv_key_version = prepared["conversation_key_version"]
```
```typescript theme={null}
async function publicKeyInput(userId: string) {
const r = (await client.chat.getUserPublicKeys(userId, {
publicKeyFields: ['public_key_version', 'public_key'],
})).data[0];
return { userId, publicKey: r.public_key, keyVersion: r.public_key_version };
}
// Omit conversationId for a new 1:1; pass the id to rotate later
const prepared = chat.prepareConversationKeyChange({
senderId: 'YOUR_USER_ID',
signingKeyVersion,
publicKeys: [
await publicKeyInput('YOUR_USER_ID'),
await publicKeyInput('RECIPIENT_USER_ID'),
],
});
const resp = await client.chat.addConversationKeys('RECIPIENT_USER_ID', {
conversation_key_version: prepared.conversationKeyVersion,
conversation_participant_keys: prepared.participantKeys.map((pk) => ({
user_id: pk.userId,
encrypted_conversation_key: pk.encryptedKey,
public_key_version: pk.publicKeyVersion,
})),
action_signatures: prepared.actionSignatures.map((sig) => ({
message_id: sig.messageId,
encoded_message_event_detail: sig.encodedMessageEventDetail,
message_event_signature: {
signature: sig.signature,
public_key_version: sig.publicKeyVersion,
signature_version: sig.signatureVersion,
},
})),
});
const conversationId = resp.data.conversation_id; // canonical id for later requests
const sequenceId = resp.data.sequence_id;
const convKey = prepared.conversationKey;
const convKeyVersion = prepared.conversationKeyVersion;
```
```rust theme={null}
// public_key_inputs: Vec from GET public keys
// (user_id, public_key, key_version ← public_key_version)
// new 1:1; set params.conversation_id = Some(id) to rotate later
let prepared = chat.prepare_conversation_key_change(
ConversationKeyChangeParams::new(&sender_id, &signing_key_version, public_key_inputs),
)?;
let participant_keys: Vec<_> = prepared
.participant_keys
.iter()
.map(|pk| {
serde_json::json!({
"user_id": pk.user_id,
"encrypted_conversation_key": pk.encrypted_key,
"public_key_version": pk.public_key_version,
})
})
.collect();
let action_signatures: Vec<_> = prepared
.action_signatures
.iter()
.map(|sig| {
serde_json::json!({
"message_id": sig.message_id,
"encoded_message_event_detail": sig.encoded_message_event_detail,
"message_event_signature": {
"signature": sig.signature,
"public_key_version": sig.public_key_version,
"signature_version": sig.signature_version,
},
})
})
.collect();
let body = serde_json::json!({
"conversation_key_version": prepared.conversation_key_version,
"conversation_participant_keys": participant_keys,
"action_signatures": action_signatures,
});
let resp: serde_json::Value = http
.post(format!("https://api.x.com/2/chat/conversations/{recipient_id}/keys"))
.header("Authorization", &auth)
.json(&body)
.send()?
.json()?;
// Canonical id for later requests
let conversation_id = resp["data"]["conversation_id"].as_str().unwrap().to_string();
// conversation_key is Option; encrypt_message wants owned bytes
let conv_key = prepared.conversation_key.expect("key present").to_bytes();
let conv_key_version = prepared.conversation_key_version;
```
```go theme={null}
// KeyVersion comes from the public_key_version field on each record
prepared, err := chat.PrepareConversationKeyChange(chatxdk.ConversationKeyChangeParams{
SenderID: myUserID,
SigningKeyVersion: signingKeyVersion,
PublicKeys: []chatxdk.PublicKeyInput{
{UserID: myUserID, PublicKey: myIdentityPubB64, KeyVersion: myKeyVersion},
{UserID: recipientID, PublicKey: theirIdentityPubB64, KeyVersion: theirKeyVersion},
},
// ConversationID empty for a new 1:1; pass the id to rotate later
})
var parts []map[string]string
for _, pk := range prepared.ParticipantKeys {
parts = append(parts, map[string]string{
"user_id": pk.UserID,
"encrypted_conversation_key": pk.EncryptedKey,
"public_key_version": pk.PublicKeyVersion,
})
}
var sigs []map[string]any
for _, sig := range prepared.ActionSignatures {
sigs = append(sigs, map[string]any{
"message_id": sig.MessageID,
"encoded_message_event_detail": sig.EncodedMessageEventDetail,
"message_event_signature": map[string]string{
"signature": sig.Signature,
"public_key_version": sig.PublicKeyVersion,
"signature_version": sig.SignatureVersion,
},
})
}
body, _ := json.Marshal(map[string]any{
"conversation_key_version": prepared.ConversationKeyVersion,
"conversation_participant_keys": parts,
"action_signatures": sigs,
})
req, _ := http.NewRequest(http.MethodPost,
"https://api.x.com/2/chat/conversations/"+recipientID+"/keys",
bytes.NewReader(body))
req.Header.Set("Authorization", "Bearer "+accessToken)
req.Header.Set("Content-Type", "application/json")
resp, err := httpClient.Do(req)
// Response data.conversation_id is the canonical id for later requests
// prepared.ConversationKey feeds EncryptMessage
_ = resp
```
```csharp theme={null}
// KeyVersion comes from the public_key_version field on each record
var prepared = chat.PrepareConversationKeyChange(new ConversationKeyChangeParams {
SenderId = myUserId,
SigningKeyVersion = signingKeyVersion,
PublicKeys = new[] {
new PublicKeyInput { UserId = myUserId, PublicKey = myPk, KeyVersion = myVer },
new PublicKeyInput { UserId = recipientId, PublicKey = theirPk, KeyVersion = theirVer },
},
}); // ConversationId null for a new 1:1; pass the id to rotate later
var keysBody = new {
conversation_key_version = prepared.ConversationKeyVersion,
conversation_participant_keys = prepared.ParticipantKeys.Select(pk => new {
user_id = pk.UserId,
encrypted_conversation_key = pk.EncryptedKey,
public_key_version = pk.PublicKeyVersion,
}),
action_signatures = prepared.ActionSignatures.Select(sig => new {
message_id = sig.MessageId,
encoded_message_event_detail = sig.EncodedMessageEventDetail,
message_event_signature = new {
signature = sig.Signature,
public_key_version = sig.PublicKeyVersion,
signature_version = sig.SignatureVersion,
},
}),
};
var json = System.Text.Json.JsonSerializer.Serialize(keysBody);
using var content = new StringContent(json, Encoding.UTF8, "application/json");
using var resp = await http.PostAsync(
$"https://api.x.com/2/chat/conversations/{Uri.EscapeDataString(recipientId)}/keys",
content);
resp.EnsureSuccessStatusCode();
var data = System.Text.Json.JsonDocument.Parse(await resp.Content.ReadAsStringAsync())
.RootElement.GetProperty("data");
string conversationId = data.GetProperty("conversation_id").GetString()!; // canonical id
byte[] convKey = prepared.ConversationKey!;
string convKeyVersion = prepared.ConversationKeyVersion;
```
```java theme={null}
// keyVersion comes from the public_key_version field on each record
PublicKeyInput mine = new PublicKeyInput();
mine.userId = myUserId; mine.publicKey = myIdentityPubB64; mine.keyVersion = myKeyVersion;
PublicKeyInput theirs = new PublicKeyInput();
theirs.userId = recipientId; theirs.publicKey = theirIdentityPubB64; theirs.keyVersion = theirKeyVersion;
ConversationKeyChangeParams keyParams = new ConversationKeyChangeParams();
keyParams.senderId = myUserId;
keyParams.signingKeyVersion = signingKeyVersion;
keyParams.publicKeys = List.of(mine, theirs);
// keyParams.conversationId null for a new 1:1; set the id to rotate later
PreparedConversationChange prepared = chat.prepareConversationKeyChange(keyParams);
List> parts = new ArrayList<>();
for (var pk : prepared.participantKeys) {
parts.add(Map.of(
"user_id", pk.userId,
"encrypted_conversation_key", pk.encryptedKey,
"public_key_version", pk.publicKeyVersion));
}
List> sigs = new ArrayList<>();
for (var sig : prepared.actionSignatures) {
sigs.add(Map.of(
"message_id", sig.messageId,
"encoded_message_event_detail", sig.encodedMessageEventDetail,
"message_event_signature", Map.of(
"signature", sig.signature,
"public_key_version", sig.publicKeyVersion,
"signature_version", sig.signatureVersion)));
}
ObjectMapper mapper = new ObjectMapper();
String body = mapper.writeValueAsString(Map.of(
"conversation_key_version", prepared.conversationKeyVersion,
"conversation_participant_keys", parts,
"action_signatures", sigs));
HttpRequest req = HttpRequest.newBuilder()
.uri(URI.create("https://api.x.com/2/chat/conversations/" + recipientId + "/keys"))
.header("Authorization", "Bearer " + accessToken)
.header("Content-Type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString(body))
.build();
HttpResponse resp = http.send(req, HttpResponse.BodyHandlers.ofString());
JsonNode data = mapper.readTree(resp.body()).path("data");
String conversationId = data.path("conversation_id").asText(); // canonical id
byte[] convKey = prepared.conversationKey;
String convKeyVersion = prepared.conversationKeyVersion;
```
***
## 5. Send a message
Encrypt with the **raw** conversation key bytes. On the send request, map:
| Chat XDK field | Request body field |
| :---------------------------------------------------------------------------- | :-------------------------------- |
| `encrypted_content` / `encryptedContent` / `EncryptedContent` | `encoded_message_create_event` |
| `encoded_event_signature` / `encodedEventSignature` / `EncodedEventSignature` | `encoded_message_event_signature` |
| Your generated id | `message_id` |
Use a **hyphenated** conversation id in the URL path when the API requires it (`:` → `-`). The SDK itself is flexible: `encrypt_message` and `encrypt_reply` accept the id in any form you hold—`A:B` from events, `A-B` from listings or URL paths (in either order), or just the recipient's user id—and canonicalize it before signing. Group ids (prefixed with `g`) pass through unchanged.
```python theme={null}
import uuid
from xdk.chat.models import SendMessageRequest
message_id = str(uuid.uuid4())
payload = chat.encrypt_message(
message_id,
"YOUR_USER_ID",
"CONVERSATION_ID",
conv_key,
"Hello!",
conv_key_version,
signing_key_version,
)
client.chat.send_message(
"RECIPIENT_USER_ID",
SendMessageRequest(
message_id=message_id,
encoded_message_create_event=payload.encrypted_content,
encoded_message_event_signature=payload.encoded_event_signature,
),
)
```
```typescript theme={null}
import { randomUUID } from 'crypto';
const messageId = randomUUID();
const payload = chat.encryptMessage({
messageId,
senderId: 'YOUR_USER_ID',
conversationId: 'CONVERSATION_ID',
conversationKey: convKey,
text: 'Hello!',
conversationKeyVersion: convKeyVersion,
signingKeyVersion,
});
await client.chat.sendMessage('RECIPIENT_USER_ID', {
message_id: messageId,
encoded_message_create_event: payload.encryptedContent,
encoded_message_event_signature: payload.encodedEventSignature,
});
```
```rust theme={null}
use chat_xdk_core::EncryptMessageParams;
let message_id = uuid::Uuid::new_v4().to_string();
let payload = chat.encrypt_message(EncryptMessageParams::new(
&message_id,
&sender_id,
&conversation_id,
conv_key,
"Hello!",
&conv_key_version,
&signing_key_version,
))?;
let body = serde_json::json!({
"message_id": message_id,
"encoded_message_create_event": payload.encrypted_content,
"encoded_message_event_signature": payload.encoded_event_signature,
});
let path_id = conversation_id.replace(':', "-");
http.post(format!("https://api.x.com/2/chat/conversations/{path_id}/messages"))
.header("Authorization", &auth)
.json(&body)
.send()?;
```
```go theme={null}
messageID := uuid.NewString()
payload, err := chat.EncryptMessage(chatxdk.EncryptMessageParams{
MessageID: messageID,
SenderID: senderID,
ConversationID: conversationID,
ConversationKey: convKey,
Text: "Hello!",
ConversationKeyVersion: convKeyVersion,
SigningKeyVersion: signingKeyVersion,
})
body, _ := json.Marshal(map[string]string{
"message_id": messageID,
"encoded_message_create_event": payload.EncryptedContent,
"encoded_message_event_signature": payload.EncodedEventSignature,
})
pathID := strings.ReplaceAll(conversationID, ":", "-")
req, _ := http.NewRequest(http.MethodPost,
"https://api.x.com/2/chat/conversations/"+pathID+"/messages",
bytes.NewReader(body))
req.Header.Set("Authorization", "Bearer "+accessToken)
req.Header.Set("Content-Type", "application/json")
resp, err := httpClient.Do(req)
_ = resp
```
```csharp theme={null}
var messageId = Guid.NewGuid().ToString();
var payload = chat.EncryptMessage(new EncryptMessageParams {
MessageId = messageId,
SenderId = senderId,
ConversationId = conversationId,
ConversationKey = convKey,
Text = "Hello!",
ConversationKeyVersion = convKeyVersion,
SigningKeyVersion = signingKeyVersion,
});
var sendJson = System.Text.Json.JsonSerializer.Serialize(new Dictionary {
["message_id"] = messageId,
["encoded_message_create_event"] = payload.EncryptedContent,
["encoded_message_event_signature"] = payload.EncodedEventSignature,
});
using var content = new StringContent(sendJson, Encoding.UTF8, "application/json");
var pathId = conversationId.Replace(':', '-');
using var resp = await http.PostAsync(
$"https://api.x.com/2/chat/conversations/{Uri.EscapeDataString(pathId)}/messages",
content);
resp.EnsureSuccessStatusCode();
```
```java theme={null}
EncryptMessageParams params = new EncryptMessageParams();
params.messageId = UUID.randomUUID().toString();
params.senderId = senderId;
params.conversationId = conversationId;
params.conversationKey = convKey;
params.text = "Hello!";
params.conversationKeyVersion = convKeyVersion;
params.signingKeyVersion = signingKeyVersion;
SendPayload payload = chat.encryptMessage(params);
String pathId = conversationId.replace(':', '-');
String sendJson = new ObjectMapper().writeValueAsString(Map.of(
"message_id", params.messageId,
"encoded_message_create_event", payload.encryptedContent,
"encoded_message_event_signature", payload.encodedEventSignature));
HttpRequest req = HttpRequest.newBuilder()
.uri(URI.create("https://api.x.com/2/chat/conversations/" + pathId + "/messages"))
.header("Authorization", "Bearer " + accessToken)
.header("Content-Type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString(sendJson))
.build();
http.send(req, HttpResponse.BodyHandlers.ofString());
```
***
## 6. Receive and decrypt
Use [webhooks or the activity stream](/xchat/real-time-events) for live traffic, or page conversation **events** for history.
* Live payload fields: `encoded_event`, optional `conversation_key_change_event`
* History: `GET /2/chat/conversations/{id}/events` — prefer **`decrypt_events`** on all events plus `meta.conversation_key_events`
* Pass the sender’s public keys into decrypt for signature verification (map API fields into `SigningKeyEntry`; see [Chat XDK](/xchat/xchat-xdk))
* JavaScript uses camelCase event types (`message`); other languages use `"Message"` and snake\_case fields in JSON
```python theme={null}
conversation_keys = {} # conversation_id -> { version: key_bytes }
def signing_keys_for(user_id: str) -> list[dict]:
resp = client.chat.get_user_public_keys(
user_id,
public_key_fields=[
"public_key_version", "public_key", "signing_public_key", "identity_public_key_signature",
],
)
return [
{
"user_id": user_id,
"public_key_version": r["public_key_version"],
"public_key": r["signing_public_key"],
"identity_public_key": r["public_key"],
"identity_public_key_signature": r["identity_public_key_signature"],
}
for r in resp.data
]
def handle_payload(payload: dict):
cid = payload["conversation_id"]
if payload.get("conversation_key_change_event"):
conversation_keys[cid] = chat.extract_conversation_keys(
[payload["conversation_key_change_event"]]
)["keys"]
event = chat.decrypt_event(
payload["encoded_event"],
conversation_keys.get(cid, {}),
signing_keys_for(payload["sender_id"]),
)
if event.get("type") == "Message" and event.get("content", {}).get("content_type") == "Text":
print(event["sender_id"], event["content"]["text"], event.get("verified"))
```
```typescript theme={null}
const conversationKeys = new Map>();
async function signingKeysFor(userId: string) {
const resp = await client.chat.getUserPublicKeys(userId, {
publicKeyFields: [
'public_key_version', 'public_key', 'signing_public_key', 'identity_public_key_signature',
],
});
return resp.data.map((r: {
public_key_version: string;
public_key: string;
signing_public_key: string;
identity_public_key_signature: string;
}) => ({
userId,
publicKeyVersion: r.public_key_version,
publicKey: r.signing_public_key,
identityPublicKey: r.public_key,
identityPublicKeySignature: r.identity_public_key_signature,
}));
}
async function handlePayload(payload: {
conversation_id: string;
encoded_event: string;
sender_id: string;
conversation_key_change_event?: string;
}) {
const cid = payload.conversation_id;
if (payload.conversation_key_change_event) {
conversationKeys.set(
cid,
chat.extractConversationKeys([payload.conversation_key_change_event]).keys,
);
}
const event = chat.decryptEvent(
payload.encoded_event,
conversationKeys.get(cid) ?? {},
await signingKeysFor(payload.sender_id),
);
if (event.type === 'message' && event.content?.contentType === 'text') {
console.log(event.senderId, event.content.text, event.verified);
}
}
```
```rust theme={null}
// Build Vec from GET /2/users/{id}/public_keys
// (public_key_version, public_key, signing_public_key, identity_public_key_signature)
if let Some(kc) = key_change_b64.as_deref() {
let extracted = chat.extract_conversation_keys(&[kc]);
conv_keys.extend(extracted.keys);
}
let event = chat.decrypt_event(&encoded_event, &conv_keys, &sender_signing_keys)?;
```
```go theme={null}
if keyChange != "" {
extracted, _ := chat.ExtractConversationKeys([]string{keyChange})
for v, k := range extracted.Keys {
convKeys[v] = k
}
}
event, err := chat.DecryptEvent(encodedEvent, convKeys, senderSigningKeys)
if err == nil && event.Type == "Message" {
fmt.Println(event.AsMessage().Text())
}
```
```csharp theme={null}
if (!string.IsNullOrEmpty(keyChangeB64))
{
var extracted = chat.ExtractConversationKeys(new[] { keyChangeB64 });
foreach (var kv in extracted.Keys)
convKeys[kv.Key] = kv.Value;
}
var evt = chat.DecryptEvent(encodedEvent, convKeys, senderSigningKeys);
if (evt.GetProperty("type").GetString() == "Message")
Console.WriteLine(evt.GetProperty("content").GetProperty("text").GetString());
```
```java theme={null}
if (keyChangeB64 != null && !keyChangeB64.isEmpty()) {
var extracted = chat.extractConversationKeys(List.of(keyChangeB64));
convKeys.putAll(extracted.keys);
}
JsonNode evt = chat.decryptEvent(encodedEvent, convKeys, senderSigningKeys);
if ("Message".equals(evt.path("type").asText())) {
System.out.println(evt.path("content").path("text").asText());
}
```
Complete poll-and-reply bots for every language: [chat-xdk/examples](https://github.com/xdevplatform/chat-xdk/tree/main/examples).
***
## Best practices
* Cache raw conversation keys and sender public keys; refresh on signature verification failures
* Deduplicate live deliveries with `event_uuid`
* Page event history until pagination is complete so key-change metadata is not missed
* Do not log passcodes, private keys, or message plaintext in production
* In web apps, keep OAuth tokens (and key backup realm token minting) on a server; prefer holding private keys only in the client Chat XDK
***
## Next steps
Methods and types for all language bindings
Encrypted images and file attachments
Multi-participant conversations and metadata
Webhooks and activity delivery