The CTS Zero Trust Engine
Absolute Data Control. Server-Driven UI.
Cel-Tech-Serv Pty Ltd has redefined enterprise software deployment. We have deprecated vulnerable, browser-based web applications and legacy perimeter VPNs. The CTS Zero Trust Engine operates as an impenetrable cryptographic gateway, serving native user interfaces directly to our universal rendering client.
Our History & Founders
Founded in 2009, Celcius Technical Services spent over a decade delivering uncompromising solutions across the telecommunications and electronic security sectors. Working in the trenches gave us a frontline view of the vulnerabilities inherent in traditional network deployments.
In 2025, recognising that traditional perimeter-based security was no longer sufficient against modern threats, we left the contracting game behind to focus entirely on specialised software development.
The driving force behind this evolution is our founder and lead developer, Paul "Fonsi" Fisher. With nearly 20 years of hands-on electronic security experience, Paul is the architectural brains of the operation. Embracing the unique analytical strengths, extreme attention to detail, and systemic thinking that come with being autistic, he saw right through the bloat and vulnerabilities of legacy platforms.
By pairing his rigorous field expertise with the advanced coding and problem-solving capabilities of Gemini AI, Paul engineered the ruthlessly lean, highly efficient, and impenetrable codebase that powers our enterprise suite today.
Paul "Fonsi" Fisher
Founder & Lead Developer
Gemini
AI Collaborator
A person dies twice in their lifetime: once when they leave this mortal coil, and a second time when their name is no longer spoken.
— Anonymous
Driven by this philosophy, Celcius Technical Services is built to endure, to protect, and to become a foundational, household name in Australian security.
The Server-Driven UI (SDUI) Paradigm
The core of our platform relies on the Agnostic Client Paradigm. The C# Avalonia desktop app functions purely as a standard, universal renderer. It securely connects to the Zero Trust Engine and draws the interface based on dynamically generated JSON payloads.
Because the client contains zero module-specific code, all proprietary business logic remains permanently locked on the server behind the Zero Trust gateway.
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Zero Web Browsers: No vulnerable HTML/JS injections. 100% native desktop rendering.
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Layer 3 Network Cloak: A hardened WireGuard tunnel provides the foundational transport layer, completely masking the infrastructure from the public web.
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Layer 7 Application Security: Once inside the encrypted tunnel, the gateway strictly enforces identity using time-limited, rolling bearer tokens for all API requests.
Actively Deployed Platforms
CTS Zero Trust Engine (ZTE)
Status: In Active Development (AGPL v3)The master Server-Driven UI (SDUI) orchestrator and cryptographic vault. It utilizes a Layer 3 WireGuard tunnel for secure network transport, while enforcing time-limited rolling bearer tokens at Layer 7 to authorize all internal microkernel traffic.
Development & Porting Pipeline
The following applications are currently being ported natively into the CTS Zero Trust Engine or are in the active architectural drafting phase.
OSL (Open Source Ledger)
Status: Being Ported (AGPL v3)High-performance C++ double-entry sovereign accounting engine designed for rapid data throughput. The Landlord Identity & Access Management (IAM) system has been fully migrated natively into this application.
OSVMS (Open Source VMS)
Status: Being Ported (AGPL v3)Uncompromising Zero Trust video surveillance. AI-driven, air-gappable, and engineered for bare-metal performance. Integrating natively into the SDUI gateway.
OSSC (Open Source Secure Central)
Status: Planned App (AGPL v3)A highly secure re-envisioning of MeshCentral. Built upon the foundational MeshCentral codebase, but completely rewritten from the ground up to eliminate web vulnerabilities.
OSL (Open Source Ledger) - Plugin Ecosystem
▶ Planned Plugins
GST/Australian Tax Plugin
Generates verified Australian tax compliance reporting directly from the C++ ledger. (Currently being ported)
Data Import Plugin
Facilitates the migration of legacy data from existing cloud providers into the Sovereign format. (Currently being ported)
Bank Reconciliation Plugin
Secure, local-first API designed for direct bank data ingest without third-party scraping. (Currently being ported)
LLM Auto-Translate Module
A future AI module designed for automated global transaction categorisation using localised LLM models within the OSL suite.
Advanced OCR Intelligence
Expanding our secure receipt capture capabilities to include multi-invoice batch processing natively rendered to the client.
OSVMS (Open Source VMS) - Plugin Ecosystem
▶ Planned Plugins
ONVIF Parser
Scans the network for ONVIF compliant cameras and automatically adds them to the VMS database.
Access Control
Adds native access control features to manage and secure future planned door controllers directly within the VMS.
OSPM (Open Source Plans Manager)
Status: Planned App (AGPL v3)A native module allowing desktop users to upload construction plans, draw device overlays, and plot proposed cabling routes with granular deployment tracking.
OSJM (Open Source Jobs Manager)
Status: Planned App (AGPL v3)A secure job tracking and dispatch management system operating strictly behind the Zero Trust gateway.
OSIM (Open Source Inventory Manager)
Status: Planned App (AGPL v3)A comprehensive hardware and inventory control system designed to track secure deployments and stock levels.
OSHM (Open Source Hospitality Manager)
Status: Planned App (AGPL v3)A comprehensive Point of Sale (POS) and hospitality management system engineered for restaurants, cafes, and retail. Operates entirely behind the Zero Trust gateway to secure transaction data and local network hardware.
OSIP (Open Source Interface Planner)
Status: Planned App (AGPL v3)A visual GUI tool designed for systems integrators to securely reach in and adjust the SDUI layouts of the apps. Because the Zero Trust Engine currently locks these layouts down by default, OSIP provides an authorized interface to dynamically alter components—such as OSHM point-of-sale terminals and waitstaff tablets—without writing raw code.
OSCAD (Open Source CAD)
Status: Planned App (AGPL v3)A complete, headless re-engineering of the FreeCAD geometry kernel. Stripped of legacy UI bloat and wired directly into the Server-Driven UI (SDUI) gateway, featuring an integrated CAM module for sovereign, air-gapped manufacturing and toolpath generation.
Enterprise Deployment & Support
Ready to reclaim your infrastructure? Reach out to Cel-Tech-Serv Pty Ltd to discuss sovereign deployment, Zero Trust hardware setups, or custom SDUI modules for your enterprise.
Support The Zero Trust Engine
The core architecture of the CTS Zero Trust Engine, along with OSVMS and the OSL Sovereign Accounting Suite, is actively developed and released under the AGPL v3 Open Source license.
If you deploy our sovereign infrastructure, please consider supporting our ongoing development.
Direct Contribution to Independent Development