jvm

chat-xdk example bot (JVM)

An encrypted chat bot built on the com.x.chatxdk JVM binding (JNA over the Rust core). It reads incoming DMs, decrypts them, generates a reply, encrypts + signs it, and sends it back. Keys come from a local blob (or are generated + registered on first run); conversation state is in memory.

Layout

File	Purpose
ChatCore.java	All encryption logic — the only file that touches chatxdk.
XChatClient.java	The X Chat API I/O layer (plain HTTP).
Bot.java	The receive → decrypt → reply → encrypt → send loop.
Main.java	Entrypoint: config, key load/generate, run.
Register.java	One-time public-key registration (own main).
ChatCoreTest.java	Offline test driving the real binding (no mocks).

Prerequisites

• JDK 17+ and Maven
• The native chat_xdk_dotnet library and the installed chatxdk artifact:

# From the repo root: build the native library...
cargo build -p chat-xdk-dotnet --release
# ...and install the JVM binding into your local Maven repo:
cd crates/jvm/java/chatxdk && mvn install

The example's pom.xml points JNA at ../../target/release for the native lib.

Run it

cp .env.example .env
# First run with no keys prints a registration payload + a private blob:
mvn exec:java
# Paste CHAT_PRIVATE_KEYS_B64 into .env, register the public key with the X API,
# set X_ACCESS_TOKEN + CHAT_CONVERSATION_ID, then re-run.
mvn exec:java

The bot echoes messages back (pong for ping, otherwise You said: …). Customize Bot.generateReply in Bot.java to change the reply logic.

Registering your key (one-time)

Before a bot can send or receive, its public key must be registered on the account. This is a rate-limited write (only a few per 24h), so run it once:

X_ACCESS_TOKEN=... mvn exec:java -Dexec.mainClass=com.example.chatbot.Register -Dexec.args="--confirm"

It generates the identity, saves the private-key blob under state/ (mode 600) before the network call, then POSTs the public key. If it is interrupted, re-running resumes the same saved identity rather than minting a new one; if the key is already on the account it adopts that version and skips the POST; on HTTP 429 it stops and tells you when the window resets rather than retrying. Set CHAT_PIN to additionally back the keys up in Juicebox (best-effort — the local blob is already saved). When it finishes it prints the CHAT_PRIVATE_KEYS_B64 and CHAT_SIGNING_KEY_VERSION lines to paste into .env. state/ is gitignored — never commit key blobs.

Test it (offline, no credentials)

mvn test

The test imports the fixture private keys, checks the binding reproduces the committed public-key/signature vectors, and runs a real encrypt → decrypt round-trip plus a conversation-key ECIES round-trip.

License

MIT