Chai Discovery

What is Chai Discovery?

Chai Discovery develops AI models for molecular design and drug discovery, describing its platform as the computer-aided design suite for molecules. Chai-1 is a foundation model for biomolecular structure prediction, and Chai-2 targets drug-like antibody design against challenging targets. The company announced a $400M Series C in September 2026.

Key capabilities of Chai Discovery

• Structure prediction: Chai-1 predicts proteins, small molecules, DNA, RNA and glycosylations
• Antibody design: Chai-2 designs drug-like antibodies against hard targets
• Free web interface: Chai-1 hosted tool, free including commercial drug discovery use
• Open model weights: Chai-1 code and weights under Apache 2.0
• Pharma licensing: commercial agreements for enterprise partners
• API access: programmatic use of models

How Chai Discovery works

Scientists provide sequences and molecules and Chai models predict structures or generate candidate antibodies computationally. Candidates still need laboratory validation by research teams. Chai-1 can be run through the hosted web interface or locally from open weights.

Who uses Chai Discovery?

Pharmaceutical companies use Chai. The vendor names Novartis (antibody discovery collaboration), Pfizer (license agreement), Eli Lilly (software deployment deal) and argenx (immunology collaboration).

Chai Discovery pricing

Pricing is not published. Chai-1 is free through its hosted tool and as Apache 2.0 open weights, while Chai-2 and enterprise access are commercially licensed.

Chai Discovery alternatives

Chai Discovery is compared with Profluent and EvolutionaryScale, which build protein models, and with Modular MAX and fast.ai for machine learning infrastructure. AlphaFold is the best known structure prediction alternative.