We train AI models and specialised coding agents for organisations that need frontier capability inside secure environments.
In coalition with
Open Letter on Sovereign AI for the United Kingdom #
We have published an open letter, supported by a coalition of executives from critical national infrastructure.
Real benchmarks. Real results. #
Lumen is optimised for the outcomes that matter: shipping better code, faster, with fewer headaches.
GPT-5.4
Gemini 3.1 Pro
GPT-5.5
Kimi K2.6
Lumen Outpost
Read more about Niche-Bench Most AI models try to be everything to everyone. They write poetry, solve physics problems, and summarise novels.
Lumen does one thing: write exceptional software.
Our thesis is simple. A model trained exclusively on real production code, from real engineering teams will always beat a generalist at the task developers actually need.
That's why every training decision, every optimisation, every evaluation metric is grounded in a single objective: better code.
Less AI Slop
Optimised for maintainability, readability, and production-quality outputs, not bloated code generation.
Built for Real Systems
Designed to reason across complex architectures, legacy infrastructure, and long-lived codebases.
Beyond Mainstream Languages
Post-trained for enterprise and niche languages including COBOL, Fortran, Verilog, Rust, and complex SQL.
Use Cosine wherever you work #
Start in your terminal
Work within a terminal-native interface, with a local-to-remote execution model, external tool access via MCP, and multi-agent orchestration.
Collaborate in the Cloud
Run multiple coding tasks in parallel, plan large changes and collaborate across engineers, PMs, and stakeholders in a shared project.
Built to fit your security environment #
Start quickly in Cosine Cloud, or move into a dedicated tenant or fully air-gapped deployment when your infrastructure, data, and compliance requirements demand it.
Public Cloud
Fully managed Cosine for teams whose requirements fit our standard cloud controls.
Managed single-tenant cloud
A private Cosine environment operated for your organisation with enterprise controls.
Fully air-gapped
For organisations that need Cosine to run entirely inside their own security perimeter.
Three models. One philosophy. #
Lumen isn't a single model — it's a system designed for every layer of the development workflow.
Runs cheaply, operates on-device, and handles the heavy lifting around the coding loop.