Trinity Large Preview

Step 5 Preview

StepFun

Step 5 Preview is StepFun’s hosted flagship for agentic coding, research, professional knowledge work, and financial analysis. Its sparse mixture-of-experts architecture has 600B total parameters and 27B active per token. The documented API accepts text, images, and video, generates text, and supports a 1M-token context with up to 64K output. Tool calls, JSON Schema output, caching, and low, medium, or high reasoning effort support sustained workflows in an external application. It was publicly announced on September 20, 2026; September is used because earlier reported API availability dates are not resolved by a first-party dated changelog. Announced October 15 weights are future availability at this audit cutoff.

Trinity Large Thinking

Arcee AI

Trinity Large Thinking is Arcee AI’s reasoning-focused post-training of Trinity Large Base. The sparse mixture-of-experts model has 398B total parameters and approximately 13B active per token, with documented context extension to 512K. It generates explicit thinking traces and is trained for long-running agents, multi-turn tool calls, and coherent instruction following. Thinking tokens must remain in conversation history for supported agent behavior. API access and downloadable weights are available. The current model card specifies OpenMDW-1.1, despite Apache 2.0 wording in the original announcement; this record follows the current weight license.

Trinity Mini

Arcee AI

Trinity Mini is a distinct size tier in Arcee AI’s Trinity family of sparse language models trained from scratch. It combines a larger total weight capacity with relatively few active parameters per token. Mini targets efficient reasoning and tool-driven applications. Downloadable weights and deployment examples support private inference and customization. The current model card specifies OpenMDW-1.1; deployment rights should follow that release license.