The Coding Model That Actually Gets It
Deploy models where your data lives, with security, visibility, and ownership built in.
In coalition with
Major UK Institutions join Cosine's Sovereign AI coalition
Cosine has assembled a coalition of leading UK defense, infrastructure, financial, healthcare, and technology leaders to develop Sovereign AI.
Real benchmarks. Real results.
Lumen is optimized 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
Our thesis: specialists outperform generalists
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 optimization, every evaluation metric is grounded in a single objective: better code.
Less AI Slop
Optimized 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 organization 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.