Protocol
Wire records, login, topic filters, QoS semantics, replay and encrypted session behaviour.
Publish Subscribe Streaming Protocol
Independent, lightweight streaming distribution
PSSP is an opaque-data publish/subscribe protocol. The broker accepts bytes, holds a bounded in-memory buffer for each topic, and distributes them to authorized subscribers without interpreting audio, video, images, files, control data, or synchronization data.
Scope boundary
This repository contains only the broker and the desktop management client. OX Firmware and WebService are future PSSP clients; no code from either project is embedded here.
Broker
Run, configure, secure, and deploy the standalone Rust/Tokio service.
Working flow
Visual connection, publish, buffering, fan-out, acknowledgement, and recovery flows.
Desktop client
Connect, authenticate, subscribe, publish QoS 1 data, and verify UDP heartbeat.
Troubleshooting
Diagnose startup, SQLite, credentials, TLS, AES-only pinning, ACL, UDP, and replay failures.
Applications
| Application | Location | Supported systems | Responsibility |
|---|---|---|---|
| PSSP Broker | Source: broker/Executable and run commands | Windows, Linux, macOS | Authentication, authorization, bounded topic caching, QoS 1 fan-out/replay, QoS 0 UDP handling. |
| PSSP Client | client/ | Windows, Linux, macOS | Desktop connection/login, topic inspection, test publishing, heartbeat validation, and diagnostics. |
QoS at a glance
Reliable application data
Use for audio, video, images, files, and all data that must not be silently lost. A broker PUBACK confirms acceptance. Subscribers send MSGACK after their durable handoff. Topic buffers provide bounded replay.
Best-effort liveness
Use normally for heartbeat and other loss-tolerant signals. There is no receipt, retry, subscriber acknowledgement, or replay. A UDP endpoint is tied to a live authenticated TCP session.
Security modes
| Mode | Configuration | Use |
|---|---|---|
| TLS + AES | TLS 1.3 enabled + PSSP AES-256-GCM enabled | Normal deployment. A new in-memory AES key is created for every authenticated connection. |
| AES only | TLS disabled + PSSP AES enabled + pinned Broker X25519 public key | No certificate transport layer. Each session derives AES locally through X25519 + HKDF; the symmetric key is never sent over the network. |
| Plain TCP/UDP | TLS/AES disabled + explicit allow_insecure_tcp_udp = true | Trusted local/private network only. Credentials and payloads are readable on the network. |
License
Proprietary software
Copyright © 2026 OX Recorder. All rights reserved. The PSSP broker, client, protocol documentation, and associated source are proprietary. No permission to copy, modify, distribute, sublicense, or use them is granted except under a separate written agreement with OX Recorder. Third-party components remain subject to their own license terms.