Cosine
British sovereign-AI company building air-gapped, on-premise foundation models for defense and critical infrastructure.
Cosine is a British AI company founded in 2022, building sovereign, air-gapped foundation models built and operated entirely in the UK. Its coding models have topped independent benchmarks against OpenAI, Anthropic, Mistral and DeepSeek. Selected as a partner in the UK government's £500M Sovereign AI programme, it is building 'Lumen Sovereign,' Britain's first sovereign frontier model, with a coalition of UK industry (BT, Lloyds, Babcock and others).
Overview
- Headquarters
- London, United Kingdom
- Founded
- 2022
- Employees
- ~37
- Total funding
- $2.5M
- Stage
- Seed
- Status
- active
- Domains
- Sovereign AI, Foundation models, Air-gapped AI
Founders3
- FounderAlistair PullenCo-founder & CEO of Cosine; full-stack engineer who has built AI products since 2018 and previously founded Fancy (YC S20, acquired by GoPuff).
- FounderYang LiCo-founder & COO of Cosine; scaled Mobike to 220M users (acquired by Meituan for $55B), later Regional GM at Luno; Forbes 30 Under 30 (2021), Oxford.
- FounderSam StennerCo-founder & CTO of Cosine; Exeter CS; built the Fancy app (acquired by GoPuff) and contributed to the Vercel AI SDK; youngest person to publish a game on Steam (age 17).
Investors5
- FundLakestarPan-European VC backing visionary tech entrepreneurs from seed to scale.
- FundSOMA CapitalEarly-stage venture firm; investor in Cosine.
- FundUpHonest CapitalEarly-stage venture firm; co-led Cosine's seed round.
- FundFocalEarly-stage venture firm; participated in Cosine's seed round.
- FundY CombinatorTop startup accelerator actively backing defense technology companies.
Cap table0
Approximate ownership by holder. Indexed holders link to their records.
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Contracts0
No linked records yet.
Programs0
No linked records yet.
Frequently asked
- What does Cosine do?
- Cosine is a British AI company founded in 2022, building sovereign, air-gapped foundation models built and operated entirely in the UK. Its coding models have topped independent benchmarks against OpenAI, Anthropic, Mistral and DeepSeek. Selected as a partner in the UK government's £500M Sovereign AI programme, it is building 'Lumen Sovereign,' Britain's first sovereign frontier model, with a coalition of UK industry (BT, Lloyds, Babcock and others).
- Where is Cosine headquartered?
- Cosine is headquartered in London, United Kingdom and was founded in 2022.
- How much funding has Cosine raised?
- Cosine has raised $2.5M in disclosed funding.
- What does Cosine specialize in?
- Cosine works across Sovereign AI, Foundation models, Air-gapped AI.
Sources & citations4
Each claim links to its underlying source. Confidence reflects how directly the source supports the claim.
- 1
Founded 2022 by Alistair Pullen and Yang Li; selected for UK £500M Sovereign AI programme; air-gapped on-prem models for defense (BAE, Babcock, Leonardo, Thales)
Tech.eu: Cosine goes from benchmark leader to cornerstone of UK sovereign AI strategyVerified2026-04-17 - 2
Selected for the UK government's £500M Sovereign AI programme; building 'Lumen Sovereign,' Britain's first sovereign frontier model, with a UK industry coalition (BT, Lloyds, Babcock and others)
Tech.eu: Cosine secures industry backing for Britain's first sovereign frontier modelVerified2026-06-08 - 3
Raised a $2.5M seed round (August 2024) co-led by Uphonest Capital and SOMA Capital, with participation from Lakestar and Focal; Y Combinator-backed
Tech.eu: UK AI startup Cosine raises $2.5M for its AI developer outperforming human codersVerified2024-08-12 - 4
Reported to employ roughly 37 people (aggregator estimate)
Tracxn: Cosine - 2026 Company ProfileReported2026-05-26