Structure prediction using OpenFold3, an open-weights PyTorch reproduction of AlphaFold3 from the AlQuraishi Lab. Use this skill when predicting protein/nucleic-acid/ligand complex structures with an Apache-2.0-licensed AF3 reimplementation.
Structure prediction using OpenFold3, an open-weights PyTorch reproduction of AlphaFold3 from the AlQuraishi Lab. Use this skill when predicting protein/nucleic-acid/ligand complex structures with an Apache-2.0-licensed AF3 reimplementation.
license
Apache-2.0
category
biomodels
requirements
["gpu"]
metadata
{"display-name":"OpenFold3","third_party":[{"kind":"weights","name":"OpenFold3","provider":"OpenFold Consortium","license":"Apache-2.0","terms_url":"https://github.com/aqlaboratory/openfold-3/blob/main/LICENSE"},{"kind":"service","name":"ColabFold MSA server (api.colabfold.com)","provider":"Steinegger Lab","info_url":"https://github.com/sokrypton/ColabFold/wiki"}]}
OpenFold3 Structure Prediction
Prerequisites
Requirement
Minimum
Recommended
Python
3.10+
3.11
CUDA
12.1+
12.4+
GPU VRAM
24GB
80GB (H100)
RAM
32GB
64GB
Disk (weights)
3GB
-
How to run
Installation
pip install 'openfold3[cuequivariance]==0.4.1'
The default attention kernel is DeepSpeed DS4Sci_EvoformerAttention. If
DeepSpeed is unavailable, switch to the cuEquivariance triangle kernels (no
build-from-source) by overriding the eval memory settings in
model_config.py (use_deepspeed_evo_attention: False,
use_cueq_triangle_kernels: True). Some pre-built environments already ship
this override; check before re-patching.
Weights
Apache-2.0, ~2.3 GB from HF OpenFold/OpenFold3. The repo is gated (auto-approval) — accept the access form on the HF model page and authenticate (huggingface-cli login or HF_TOKEN) before downloading:
run_openfold will also auto-download to $OPENFOLD_CACHE on first run if
egress is open and HF credentials are available (either HF_TOKEN or a prior
huggingface-cli login) with repo access granted. The interactive
setup_openfold helper exists but prompts on stdin; prefer the explicit
download above for non-interactive runs.
run_openfold discovers the checkpoint under $OPENFOLD_CACHE automatically.
Only pass --inference-ckpt-path <file.pt> if you have a non-standard layout
or multiple checkpoints and need to pin one explicitly.
For MSA + templates (slower, higher accuracy), drop the two false flags. The
MSA server is api.colabfold.com; template chain-ID remap hits
data.rcsb.org (GraphQL) — both must be reachable.
Query JSON format
OpenFold3 does not read FASTA. Queries are a JSON object validated by
InferenceQuerySet (pydantic, extra: forbid — unknown keys reject):
chain_ids is a list — repeat the same sequence across multiple chain IDs
for homo-oligomers. Per-chain paired_msa_file_paths / main_msa_file_paths
let you supply your own a3m instead of the server.
Key parameters
Flag
Default
Description
--num-diffusion-samples
5
Structures per (query, seed)
--num-model-seeds
1
Number of model seeds per query (multiplies output count alongside JSON seeds and diffusion samples)
--use-msa-server
true
ColabFold MMseqs2 server for MSA
--use-templates
true
ColabFold template search + RCSB remap
--inference-ckpt-path
auto-discovered under $OPENFOLD_CACHE
Override only — for non-standard layouts or to pin a specific checkpoint file