Step-3.5-Flash-Base
StepFunfamily · Step3.5huggingface.co/stepfun-ai/Step-3.5-Flash-Base
Updated 4 h ago · first seen 12 Sept 2026
model_01M2AS5MASF5KXEJBK5TQ3KES8
Overview
Identity
- Canonical model
- Yesidentity confidence: highOne row per real model release. Artifacts (checkpoints, quantisations, conversions) and folded evaluation variants point here.
- Official checkpoints
- official_checkpoints = hf_repo identifiers carried by the model itself; artifacts are separate entities pointing here through canonical_id.
- Artifacts
- None recordedSeparate entities (checkpoint · quantization · conversion · packaging) pointing to this model through canonical_id.
- Provider deployments
- None recorded
- API aliases
- NoneIdentifiers under which providers and evaluators refer to this model.
- Folded evaluation variants
- 0Effort / thinking variants (…-high, …-non-reasoning) are result configurations of this model, not separate models. Their old URLs redirect here.
Openness
Open weights— weights downloadable under Apache-2.0; commercial use allowed; redistribution allowed; derivatives allowed; 4 dimensions unknown.
Weights downloadable under a permissive or Creative Commons licence allowing commercial use; code or data may be missing.
Weights
Yes
Inference code
—
Training code
—
Training data
—
Dataset
—
Commercial use
Yes
Redistribution
Yes
Derivatives
Yes
Licence: Apache License 2.0 (permissive · SPDX Apache-2.0)
dimensions marked null are unknown, not false
Key facts
- Release date
Source:Hugging Face Hub (public pages, model cards, papers)T2observed 4 d agomedium
- Model card
Source:Hugging Face Hub (public pages, model cards, papers)T2observed 4 d agomedium
Architecture
- Architecture
Source:Hugging Face Hub (public pages, model cards, papers)T2observed 4 d agomedium
- Model type
Source:Hugging Face Hub (public pages, model cards, papers)T2observed 4 d agomedium
- Parameters
Source:Hugging Face Hub (public pages, model cards, papers)T2observed 4 d agomedium
- Weights dtype
Source:Hugging Face Hub (public pages, model cards, papers)T2observed 4 d agomedium
- File size
Source:Hugging Face Hub (public pages, model cards, papers)T2observed 4 d agomedium
- Library name
Source:Hugging Face Hub (public pages, model cards, papers)T2observed 4 d agomedium
- Pipeline tag
Source:Hugging Face Hub (public pages, model cards, papers)T2observed 4 d agomedium
- Hugging Face repo
Source:Hugging Face Hub (public pages, model cards, papers)T2observed 4 d agomedium
Capabilities
Modalities
- Modalities
- text
- Input
- text
- Output
- text
Capabilities
Tool calling
Unavailable
Structured output
Unavailable
Reasoning
Unavailable
Vision
Unavailable
Audio
Unavailable
Fine-tuning available
Unavailable
No capability flags have been observed from a source yet — we do not infer them.
No structured attributes yet.
Hardware fit37
Assumptions (7)
- Estimated, not measured: weights = parameters × bytes/param × 1.15 runtime overhead (or the observed artifact file size when one is recorded).
- bytes/param: 4bit = 0.5, 8bit = 1.0, fp16 = 2.0 (uniform quantization, no per-layer exceptions).
- KV cache: 2 × layers × kv_heads × head_dim × 2 bytes × context × batch when the architecture is known; otherwise 0.5 GB per 8 192 tokens (× batch), independent of architecture (GQA/MLA models need less).
- A model 'fits' when the estimate is at most the device memory minus 2 GB reserved for the OS and framework.
- Mixture-of-experts models are estimated on total parameters (all experts must be resident); active parameters are ignored.
- Device memory uses the largest configuration when several are listed (e.g. Apple silicon tiers).
- Multi-GPU: device memories are summed; interconnect bandwidth, tensor-parallel replication and pipeline bubbles are not modelled.
Versions & Artifacts0
Version history
Licensefirst observation only
12 Sept 2026current
Opennessfirst observation only
12 Sept 2026current
Parametersfirst observation only
12 Sept 2026current
Each hop is a claim: click a value for its source, tier and observation time. Nothing is overwritten — a new observation closes the previous claim.
Artifacts 0
No artifact (checkpoint, quantisation, conversion or packaging) points to this model yet.
Papers2
- arXiv:2602.10604Active35
- arXiv:2601.05593Active35
Change history35
Viewing AI Atlas as of 15 Sept 2026 — attributes exactly as the atlas knew them on that day; later corrections are not shown.
Back to today →Attributes as of 15 Sept 2026 27 claims in force
- Release date
- 2 Mar 2026
- Openness
- open-weights
- License
- Apache-2.0
- Architecture
- Step3p5ForCausalLM
- Parameters
- 197.8B
- Modalities
- text
- Input modalities
- text
- Output modalities
- text
- File size
- 395.5 GB
- Hugging Face repo
- stepfun-ai/Step-3.5-Flash-Base
- Pipeline tag
- text-generation
- Downloads
- 330
- Likes
- 87
- Access
- open
- Commercial use allowed
- Yes
- Derivatives allowed
- Yes
- Last modified
- 2026-03-09T03:56:37+00:00
- Library name
- transformers
- License key
- Apache-2.0
- License raw
- apache-2.0
- Downloads all time
- 1,985
- Model type
- step3p5
- Redistribution allowed
- Yes
- Tags
- custom_code, safetensors, step3p5, text-generation, transformers
- Weights available
- Yes
- Weights dtype
- BF16, F32
Release daterelease_date1
Opennessopenness1
Licenselicense1
Architecturearchitecture1
Parametersparameter_count1
Modalitiesmodalities1
Input modalitiesmodalities_input1
Output modalitiesmodalities_output1
File sizefile_size_gb1
Hugging Face repohf_repo1
Pipeline tagpipeline_tag1
Model cardmodel_card_url1
Downloadsmetric.downloads5
Likesmetric.likes1
Accessaccess1
Commercial use allowedcommercial_use_allowed1
Derivatives allowedderivatives_allowed1
Last modifiedlast_modified1
Library namelibrary_name1
License keylicense_key1
License rawlicense_raw1
Downloads all timemetric.downloads_all_time5
Model typemodel_type1
Redistribution allowedredistribution_allowed1
Weights availableweights_available1
Weights dtypeweights_dtype1
Claims are temporal and append-only: a new observation closes the previous claim (valid_to) instead of overwriting it. Conflicting claims from different sources are kept side by side and flagged — never averaged. Methodology →
Provenance
Attributed facts
28
Source tiers
T228
Freshest observation
4 h ago
Conflicts
None
Source documents 2
Tier 1 = official/primary, 2 = quality secondary, 3 = community, 4 = unverified. Every snapshot is archived; see all sources and the methodology.
Data quality (59/100) measures how well AI Atlas knows this entity — completeness, primary-source ratio, freshness, conflicts — never how good the model is. Methodology →