veltix 1.6.7

The high-level TCP library Python never had — sync, thread-friendly, zero dependencies

Veltix

The high-level TCP library Python never had.

Sync, thread-friendly, zero dependencies : TCP done right.
Veltix handles framing, threading, handshake, routing, and reconnection
so you can focus on your application logic.

53k msg/s • 0.004ms latency • 84KB idle • 100% success rate

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Table of Contents

• Why Veltix
• Features
• Performance
• Installation
• Quick Start
• Integrated Logger
• Request/Response Pattern
• Built-in Ping/Pong
• Advanced Features
• Comparison
• Roadmap
• Migration Guide
• Examples
• Security
• Contributing
• License

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Built with Veltix

Projects using Veltix in production:

• Nexo — Fast LAN file transfer tool CLI + GUI. Uses Veltix's TCP server, client tags, route decorators, and send_and_wait() for reliable chunked file transfers with concurrent connection handling.

Built something with Veltix ? Open a PR or start a discussion to add your project.

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Why Veltix

Python's socket module is powerful but painful. You end up reimplementing framing, threading, reconnection, and protocol design every single time. Heavier alternatives like asyncio or Twisted solve this but force you into async/await or steep learning curves.

Veltix sits in between:

• No async required : sync, thread-based, works like you expect
• No boilerplate : framing, handshake, routing, reconnect are built-in
• No dependencies : pure Python stdlib, zero install friction
• FastAPI-style routing : @server.route(MY_TYPE) instead of if/elif chains

# This is all you need to get a working server
@server.route(CHAT)
def on_chat(response: Response, client: ClientInfo):
    print(f"{client.addr}: {response.content.decode()}")

Designed for: LAN tools, multiplayer games, real-time dashboards, custom protocols, IPC, remote tooling, file transfer.

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Features

Core

• Zero dependencies : pure Python stdlib
• Binary protocol with CRC32 integrity verification
• Automatic HELLO/HELLO_ACK handshake with version compatibility
• Thread-safe callback execution : slow handlers never block reception

API

• FastAPI-style routing : @server.route(MY_TYPE) / @client.route(MY_TYPE)
• send_and_wait() : built-in request/response correlation with timeout
• Built-in ping/pong : bidirectional latency measurement
• Client tags : attach arbitrary metadata to connected clients

Reliability

• Auto-reconnect : configurable retry with DisconnectState callbacks
• LOW / BALANCED / HIGH performance mode presets
• Swappable socket backends via SocketCore (Threading now, Selectors in v1.7.0, Rust in v3.0.0)

Developer Experience

• Integrated logger : colorized, file-rotating, thread-safe
• 208 tests, CI on Python 3.8 / 3.10 / 3.12 / 3.14

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Performance

Benchmarked on Python 3.14 — 12-core CPU, 30.5 GB RAM, Linux (loopback).

Metric	Result
Concurrent stress (100 clients)	52,655 msg/s — 100% success
Burst throughput	73,964 msg/s send / 53,976 msg/s recv
Average latency	0.004ms
Idle server memory	84 KB
FPS simulation (64 players @ 64Hz)	4,490 msg/s — 100% success

Full benchmark details, methodology, and how to run them yourself : PERFORMANCE.md

Installation

pip install veltix

Requirements: Python 3.8+, no additional dependencies.

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Quick Start

Server:

from veltix import Server, ServerConfig, ClientInfo, Response, MessageType, Request, Events

CHAT = MessageType(code=200, name="chat")

server = Server(ServerConfig(host="0.0.0.0", port=8080))
sender = server.get_sender()


def on_message(client: ClientInfo, response: Response):
    print(f"[{client.addr[0]}] {response.content.decode()}")
    sender.broadcast(Request(CHAT, response.content), server.get_all_clients_sockets())


server.set_callback(Events.ON_RECV, on_message)
server.start()

input("Press Enter to stop...")
server.close_all()

Client:

from veltix import Client, ClientConfig, Response, MessageType, Request, Events

CHAT = MessageType(code=200, name="chat")

client = Client(ClientConfig(server_addr="127.0.0.1", port=8080))

client.set_callback(Events.ON_RECV, lambda r: print(f"Server: {r.content.decode()}"))
client.connect()

client.get_sender().send(Request(CHAT, b"Hello Server!"))
input("Press Enter to disconnect...")
client.disconnect()

python server.py
python client.py  # In a separate terminal

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Roadmap

v1.6.6 : Version Compatibility & Reconnect Stability (May 2026) : Released

Version class, reconnect stability fixes, +111 tests, CI on Python 3.8-3.14

v1.6.7 : Architecture Refactor (May 2026) : Released

ClientContext Protocol, Rules system for RequestHandler, README rewrite

v1.7.0 : Selectors (June 2026) : Planned

AsyncSocket : selectors-based I/O, same API, 4-8x throughput improvement

Full roadmap

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Comparison

Feature	Veltix	socket	asyncio	Twisted
Simple API	✓	✗	~	✗
Zero dependencies	✓	✓	✓	✗
No async required	✓	✓	✗	✗
Message framing	✓	✗	✗	~
Message integrity	✓	✗	✗	✗
Automatic handshake	✓	✗	✗	✗
Request/Response	✓	✗	~	✓
Message routing	✓	✗	✗	~
Auto-reconnect	✓	✗	~	✓
Non-blocking callbacks	✓	✗	✓	✓
Built-in ping/pong	✓	✗	✗	✗
Client tags	✓	✗	✗	✗
Swappable backends	✓	✗	✗	✗
Integrated logger	✓	✗	~	✓

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Documentation

• Full documentation
• Advanced features
• Migration guide
• Roadmap
• Changelog
• Examples

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Contributing

Contributions are welcome. Please read CONTRIBUTING.md before submitting a pull request.

• Bug reports : Open an issue
• Discussions : Join the Discord
• Pull requests : Follow the contribution guide

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License

MIT License : see LICENSE for details.

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Links

• GitHub : NytroxDev/Veltix
• PyPI : pypi.org/project/veltix
• Documentation : https://nytroxdev.github.io/Veltix/
• Discord : discord.gg/NrEjSHtfMp