Tencent's open-weight Hy4 preview, a 770B-parameter Mixture-of-Experts model with 49B active parameters and a 1M-token context window.

Hy4 preview works by combining 770B Mixture-of-Experts Architecture: Holds 770 billion total parameters while activating only 49 billion per token, so capacity scales without proportional inference cost., 1M-Token Context Window: Accepts inputs exceeding one million tokens, allowing whole codebases, long document sets or extended agent traces in a single prompt., Apache 2.0 Open Weights: Released under a permissive licence that allows commercial use, modification and redistribution with no separate agreement., Productivity Task Focus: Tuned for real-world coding, office work and scientific research rather than narrow benchmark optimisation., Multi-Product Availability: Accessible globally through Tencent's WorkBuddy, CodeBuddy, Yuanbao and ima applications in addition to the raw weights. to help users with Whole-Repository Code Work: Load an entire codebase into the million-token context to reason about refactors and cross-file dependencies at once., Long-Horizon Agent Tasks: Drive multi-step agent workflows where the full history of tool calls and intermediate results must stay in context., Self-Hosted Deployment: Run a frontier-scale open-weight model on private infrastructure where data cannot leave the organisation., Scientific Literature Analysis: Ingest large collections of papers or experimental logs and synthesise findings without chunking the input., Office Document Processing: Summarise, draft and restructure long reports, contracts and spreadsheets in enterprise workflows..

Key features include 770B Mixture-of-Experts Architecture: Holds 770 billion total parameters while activating only 49 billion per token, so capacity scales without proportional inference cost., 1M-Token Context Window: Accepts inputs exceeding one million tokens, allowing whole codebases, long document sets or extended agent traces in a single prompt., Apache 2.0 Open Weights: Released under a permissive licence that allows commercial use, modification and redistribution with no separate agreement., Productivity Task Focus: Tuned for real-world coding, office work and scientific research rather than narrow benchmark optimisation., Multi-Product Availability: Accessible globally through Tencent's WorkBuddy, CodeBuddy, Yuanbao and ima applications in addition to the raw weights..

Hy4 preview is useful for anyone interested in Whole-Repository Code Work: Load an entire codebase into the million-token context to reason about refactors and cross-file dependencies at once., Long-Horizon Agent Tasks: Drive multi-step agent workflows where the full history of tool calls and intermediate results must stay in context., Self-Hosted Deployment: Run a frontier-scale open-weight model on private infrastructure where data cannot leave the organisation., Scientific Literature Analysis: Ingest large collections of papers or experimental logs and synthesise findings without chunking the input., Office Document Processing: Summarise, draft and restructure long reports, contracts and spreadsheets in enterprise workflows..

Hy4 preview is free to use.

Visit https://hy.tencent.ai/ to sign up and explore Hy4 preview.