Model release

ESM3 open small (esm3-sm-open-v1)

ESM3 open small (esm3-sm-open-v1) is an open-weight model release in the ESM (EvolutionaryScale and Biohub protein models) family from Biohub (Chan Zuckerberg Biohub, Inc.)1 4 and EvolutionaryScale (original developer; now part of Biohub)5 7, version esm3-sm-open-v1, released Jun 25, 2024. Its weights can be downloaded by the public1 2 under the MIT License1 4 3.

The openly released small ESM3 model, which EvolutionaryScale describes as a 1.4B-parameter open model. ESM3 is a generative masked language model that takes partial prompts across protein sequence, structure, and function tracks and predicts all three. EvolutionaryScale released it in June 2024; Biohub now distributes it under the MIT license.5 3 1

Model hub: Model card (Hugging Face) (external site: huggingface.co)
Repository: GitHub repository (Biohub/esm) (external site: github.com)
Documentation: ESM3 README (external site: github.com)
Paper: ESM3 paper (Science, doi:10.1126/science.ads0018) (external site: science.org)

On AI on Hugging Face: biohub/esm3-sm-open-v1

Last reviewedSep 29, 2026Entry updated Sep 29, 2026Documented release Jun 25, 2024

Availability and license

Overall availability

Public

Downloadable from Hugging Face without gating. Biohub's README asks users to follow the Biohub Acceptable Use Policy.1 2 3

Availability fact review: not separately recorded

Availability is separate from permission: read the license before using or redistributing.

MIT License (external site: raw.githubusercontent.com)1 4 3
Applies to: Weights and code · SPDX MIT · on the rubric’s OSI-approved software-license list · fact-level rights review not recorded
Plain-language guide to the MIT License

The model card's text (its metadata has no license field) and the ESM3 README place the model under the MIT license, and the LICENSE file names Chan Zuckerberg Biohub, Inc. as copyright holder (2026). The EvolutionaryScale site still hosts an EvolutionaryScale, PBC Community License Agreement covering the ESM-3 open model code and weights that limits use to non-commercial purposes; the current Biohub materials state MIT, and the sources reviewed do not say when the terms changed. Biohub's README also asks users to follow its Acceptable Use Policy.1 2 3 4 6

Component reuse rights

A readable or downloadable component is not automatically reusable. These indicators concern recorded license evidence, not system certification.

weights: Unknown — no complete fact-level rights review
code: Unknown — no complete fact-level rights review
data: Unknown — no complete fact-level rights review
documentation: Unknown — no complete fact-level rights review

No complete system-rights review is recorded for this release.

Model-disclosure tier

Computed from the checklist below using USASI rubric v0.2. An editorial category, not a certification.

Open-weight

The model parameters for this release can be downloaded by the public. License terms may still restrict use, redistribution, or commercial use.

How tiers are computed

Public materials checklist

Items for a model under USASI rubric v0.2. Unknown means unassessed or insufficient evidence.

Public materials checklist for ESM3 open small (esm3-sm-open-v1)
Item	Status	Notes and evidence
WeightsCan the general public download the model parameters for this release?	Public	Downloadable from Hugging Face without gating.1 2
Inference codeIs code for running the model published?	Public	The esm package (pip install esm) loads the model locally; the ESM3 README gives an example.3 1
Training codeIs the code used to train the model published?	Unknown	The public repository covers local inference and API clients; no ESM3 training code was identified in the pages reviewed.
Training-data informationDoes the information cover provenance, scope, acquisition, selection, labeling, processing, and where data or alternatives can be obtained? Access alone does not establish completeness.	Unknown	Not assessed.
Training-data accessCan the training data be obtained? This is independent of information completeness and reuse rights; original unshareable data need not be downloadable.	Unknown	Not assessed.
Complete training pipelineIs the complete base-training and preprocessing pipeline published, including configuration? Fine-tuning code or an inference SDK alone is insufficient.	Unknown	Not assessed.
Legacy data assessment (v0.1)Historical assessment combining download access and disclosure. Preserved for traceability; excluded from the v0.2 tier calculation. See the new separate assessments above.	Partial	The card describes training on 2.78 billion natural proteins, augmented to 3.15 billion sequences, 236 million structures, and 539 million function-annotated proteins (771 billion tokens), with viral proteins and some USDA Select Agent proteins removed. The training set itself was not found as a download.1
Training recipeAre the training configuration and procedure documented in enough detail to follow?	Unknown	The ESM3 paper in Science describes the model; it was not reviewed for this record.
Evaluation materialsPublic = evaluation code or prompts that let others re-run the evaluations are published. Partial = results only.	Unknown	Not assessed.

What it is useful for

Designing or completing proteins from partial sequence, structure, and function prompts, run locally on a GPU or CPU with the esm package.1 3

Run and use notes

Documented facts only. No hardware or performance claims are made without a cited source and stated assumptions.

The ESM3 README loads the model with ESM3.from_pretrained("esm3-sm-open-v1") and runs it on "cuda" or "cpu".3

Organization context

Provenance and derivatives

Trained by EvolutionaryScale on natural protein sequences with synthetic augmentation; viral data and some proteins from organisms on the USDA Select Agents and Toxins list were removed, and the function decoder was filtered for potentially harmful keywords.1 5

Other releases in the ESM (EvolutionaryScale and Biohub protein models) family

ESMC 6B (ESM Cambrian)Model-disclosure tier (USASI rubric v0.2): Open-weight

ESM (EvolutionaryScale and Biohub protein models) family overview

What this catalog does not know

Unknown means the sources reviewed for this record do not document it. It is not evidence that something does not exist.

Training code: unknown.
Training-data information: unknown.
Training-data access: unknown.
Complete training pipeline: unknown.
Training recipe: unknown.
Evaluation materials: unknown.

Have a primary source? How to report a correction.

U.S. eligibility

Project eligibility rests on documented governing or maintaining entities, not on contributors.

Eligible · basis: U.S.-governed project

Developed by EvolutionaryScale, PBC (New York address in its former terms of use, effective January 15, 2025) and now published by Biohub, whose repository license names Chan Zuckerberg Biohub, Inc. The IRS lists Chan Zuckerberg Biohub Inc in Redwood City, California as a 501(c)(3) organization.8 5 4 9

Assessed Sep 29, 2026

Sources

1.
biohub/esm3-sm-open-v1 model card (external site: huggingface.co)
Biohub · Model card · accessed Sep 29, 2026
2.
biohub/esm3-sm-open-v1 (Hugging Face model API metadata) (external site: huggingface.co)
Hugging Face · Other · accessed Sep 29, 2026
3.
ESM3 README (Biohub/esm, _assets/ESM3_README.md) (external site: raw.githubusercontent.com)
Biohub · Documentation · accessed Sep 29, 2026
4.
Biohub/esm LICENSE.md (external site: raw.githubusercontent.com)
Chan Zuckerberg Biohub, Inc. · License · accessed Sep 29, 2026
5.
ESM3: Simulating 500 million years of evolution with a language model (external site: evolutionaryscale.ai)
EvolutionaryScale · Announcement · published Jun 25, 2024 · accessed Sep 29, 2026
6.
Community License Agreement | EvolutionaryScale (external site: evolutionaryscale.ai)
EvolutionaryScale · License · accessed Sep 29, 2026
7.
EvolutionaryScale (home page) (external site: evolutionaryscale.ai)
EvolutionaryScale · Official page · accessed Sep 29, 2026
8.
Terms of Use (historical) | EvolutionaryScale (external site: evolutionaryscale.ai)
EvolutionaryScale · Official page · accessed Sep 29, 2026
9.
Exempt Organizations Business Master File Extract - California (eo_ca.csv) (external site: irs.gov)
Internal Revenue Service · Filing · accessed Sep 29, 2026

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This listing is not an endorsement, a safety assessment, or a federal approval.

Cite this page

APA style

USASI. (2026, September 29). ESM3 open small (esm3-sm-open-v1). United States of America Superintelligence. https://unitedstatesofamericasuperintelligence.com/open/esm3-sm-open-v1/

BibTeX

@misc{usasi_esm3_sm_open_v1,
  author = {{USASI}},
  title = {ESM3 open small (esm3-sm-open-v1)},
  year = {2026},
  month = sep,
  howpublished = {\url{https://unitedstatesofamericasuperintelligence.com/open/esm3-sm-open-v1/}},
  note = {United States of America Superintelligence. Last updated 2026-09-29}
}

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