Claim · 2025-07-31 · publication · Stated in source · Supported

StepFun's step3 Hugging Face repository, created on 28 July 2025, carried on 31 July 2025 a model card introducing Step3 as a mixture-of-experts multimodal reasoning model with 321 billion total and 38 billion active parameters.

One recorded claim. The claim panel gives its qualification, the source passages with their place in each source, and how it was checked.

What it connects

StepFun / 阶跃星辰 → published → step3 model card

Where it appears

No collection page holds this claim. It is listed with its records in the explorer.

Claim and evidence

StepFun / 阶跃星辰published ↓step3 model card

Machine-checked, not reviewed by an editorStated in sourceSupported

Supporting evidence: primary · 1 source

Date: 2025-07-31 · publication Records dated 2025 →

Scope and limitsThe card's description is the developer's own; benchmark tables in it are out of scope.

The evidence 01

primary sourceSupports the claim

step3 model card (README.md)

StepFun (stepfun-ai, Hugging Face) · 2025-07-31

Cite the original source

Cite the original document, not Selekoa. Check these details against it.

Source excerpt

“Mixture-of-Experts architecture with 321B total parameters and 38B active.”

Location in source README, "Introduction"

How it was read Retrieved directly from the publisher

Machine-checked · 2026-10-31

Source details and check notes

Authors: StepFun
Version: Dated page, retrieved on 2026-10-29 (SHA-256 243260dbd2d842c4748a113871014bd0dfc50190db89be1bc77cba1e2b0007a3) directly from the publisher. Version: 5fe5f2aff383cd9d0195ca7a8e673384ce30c228. README at the commit of 31 July 2025 ("Update README.md"), the first after the LICENSE file was created; the repository's initial commit is of 28 July 2025; later README edits (to 2 August 2025) not inspected.
Canonical address: Open the canonical source ↗
Accessed: 2026-10-29
Language: English (en)
Attribution: StepFun, “step3 model card (README.md)”, 2025-07-31.
Reuse: No open redistribution licence asserted. Bibliographic metadata, editorial paraphrases and short attributed quotations (at most 50 words each). Recheck terms before wider redistribution.
Check notes: Candidate pack passage, Chinese frontier-AI institutions, third collection (research/china-labs-3). The quotation (9 words) matched the text retrieved for the candidate pack on 2026-10-29 and again in a fresh retrieval the same day, read directly from the publisher. Matching ignored differences of whitespace, case, quotation marks, dashes and Unicode compatibility forms, so the source’s typography can differ. No human editorial review.

Status and meaning

Editorial status. Not reviewed by an editor. An exploratory record that no editor has accepted. This status does not say whether a person has read any linked passage. Each evidence record above shows how it was checked.

Relation. Publication of a specific document or version. Publication of a policy is not evidence of implementation.

Date. Date of the cited commit of the model card; the repository's initial commit is of 28 July 2025 and the weights were added on 31 July 2025. The arXiv report (25 July 2025) is a separate document. Not a verified moment of public availability.

Record ID c3-stepfun-step3-card