stepfun-ai/Step-3.5-Flash

Health v2 · maintenance only

Flags: no_releases

Adoption not part of the score

2070 stars · 87 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

Step 3.5 Flash is an open-source 196B-parameter sparse Mixture-of-Experts foundation model (11B active per token) from StepFun, focused on fast reasoning and agentic capabilities. The repository provides model weights, deployment guidance, and cookbooks for running it locally and integrating it with agent platforms like OpenClaw, Claude Code, and Roo Code.

Use cases

• run a fast open-source reasoning model locally
• build coding agents that score high on SWE-bench
• self-host an LLM for tool-calling and long-horizon agent tasks
• serve an MoE model with high token throughput
• integrate an open model into Claude Code or Roo Code workflows
• deep research and multi-step task automation with an open model

When to choose

• you need an open-weights model with frontier-level reasoning and agentic tool use
• you want high generation throughput (100-350 tok/s) for real-time agent interaction
• you need strong software engineering performance (74.4% SWE-bench Verified) from a self-hosted model
• you want efficient long-context (256K) inference with modest active parameters

When to avoid

• you lack GPU infrastructure for a 196B-parameter model
• you need a small model for edge or CPU-only deployment
• you need native multimodal (image/video) input, which requires the newer Step 3.7 Flash
• you only need a hosted API and don't want to manage inference yourself

Facets

library · maturity active

llm-inference agent-framework machine-learning large-language-models artificial-intelligence python moe open-weights reasoning-model agentic-llm multi-token-prediction swe-bench coding-agent ai-agents gpu linux docker

Member repositories

For agents

markdown · JSON · MCP: product_card(name="stepfun-ai/Step-3.5-Flash")