BAAI/AREX-Turbo

VISIONConcurrent Unit Cost:1Model Size:4.5BQuant:BF16Context Size:32kTool Calling:SupportedPublished:Jul 23, 2026License:apache-2.0Architecture:Transformer0.0K Open Weights Featherless Exclusive Cold

BAAI/AREX-Turbo is a 4 billion parameter dense language model developed by the Beijing Academy of Artificial Intelligence (BAAI), built on Qwen3.5-4B with a 262,144 token context length. It is part of the AREX family of deep research agents, specifically designed for long-horizon tasks requiring information search, evidence integration, constraint verification, and recursive self-improvement. This compact model offers lower-cost deployment for research-agent applications while retaining core research, verification, and context-management capabilities.

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AREX-Turbo: A Compact Deep Research Agent

AREX-Turbo is a 4 billion parameter dense model developed by the Beijing Academy of Artificial Intelligence (BAAI), built upon the Qwen3.5-4B backbone. It features an extensive 262,144 token context length and is designed as a compact member of the AREX family of deep research agents. The model is engineered for long-horizon tasks that involve searching across diverse sources, synthesizing information, verifying multiple constraints, and dynamically revising research plans based on incomplete evidence.

Key Capabilities

  • Recursive Self-Improvement: Employs an inner research loop for evidence integration and an outer self-improvement loop to evaluate and refine research trajectories.
  • Verification-Guided Research: Transforms unresolved constraints into targeted follow-up searches, enhancing research efficiency.
  • Autonomous Context Management: Automatically updates its research state with verified findings, rejected candidates, and evolving research plans.
  • Long-Horizon Tool Use: Supports multi-round interactions for searching, browsing, integrating evidence, and constructing answers.
  • Cost-Effective Deployment: Provides AREX's advanced research capabilities in a smaller 4B model, optimizing for lower serving costs and faster iteration.

When to Use AREX-Turbo

AREX-Turbo is particularly well-suited for research-agent applications where:

  • Long-horizon information seeking and evidence aggregation are critical.
  • Multi-constraint verification and tool-augmented reasoning are required.
  • Serving cost, latency, or iteration speed are important considerations for deployment.