Binder design ranking using ipSAE (interprotein Score from Aligned Errors).

MITAuto-check passedResearch & Science

Install Ipsae

skills CLI
$ npx skills add adaptyvbio/protein-design-skills --skill ipsae -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install adaptyvbio/protein-design-skills ipsae --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/adaptyvbio/protein-design-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/ipsae .claude/skills/ipsae && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
ipsae
GitHub stars
163
Used in
4 other repos
Token cost
~1.2k tokens
SKILL.md length
272 words
Files
1
Skills in repo
24
Repo updated
First seen
Licence
MIT

At a glance

Binder design ranking using ipSAE (interprotein Score from Aligned Errors).

  • Ranking binder designs for experimental testing
  • SKILL.md covers Prerequisites, Overview, How to run and Key parameters, plus 7 more sections
  • Calls python, git and pip; reaches github.com
  • Filtering BindCraft

What it does

Ipsae is an agent skill from adaptyvbio/protein-design-skills. Binder design ranking using ipSAE (interprotein Score from Aligned Errors). Use this skill when: (1) Ranking binder designs for experimental testing, (2) Filtering BindCraft or RFdiffusion outputs, (3) Comparing AF2/AF3/Boltz predictions, (4) Predicting binding success rates, (5) Need better ranking than ipTM or iPAE. For structure prediction, use chai or alphafold. For QC thresholds, use protein-qc.

Its SKILL.md is about 1.2k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Research & Science, covering Protein structure and design. It works with AlphaFold. The repository describes itself as: Claude Code skills for protein design. The licence is MIT.

When your agent uses it

  • Ranking binder designs for experimental testing
  • Filtering BindCraft
  • RFdiffusion outputs
  • Comparing AF2/AF3/Boltz predictions

Example prompts

  • “/ipsae”

Requirements

  • Python 3

What it can do on your machine

Read from SKILL.md and the folder at commit 59dd633. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Shell commands in SKILL.md call:

    • python
    • git
    • pip

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Hosts in commands or code, which the agent is likely to contact:

    • github.com

    Also links to:

    • biorxiv.org

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Ipsae loads about 1.2k tokens when it runs. Until then it costs about 102 tokens; SKILL.md has 272 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~102
When it runs · the whole SKILL.md, loaded when a task matches
~1.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from adaptyvbio/protein-design-skills at commit 59dd633, republished under its MIT licence (© adaptyvbio). 272 words, ~1,247 tokens.

Download SKILL.mdSave it as .claude/skills/ipsae/SKILL.md (or your agent's skills folder).
name
ipsae
description
Binder design ranking using ipSAE (interprotein Score from Aligned Errors). Use this skill when: (1) Ranking binder designs for experimental testing, (2) Filtering BindCraft or RFdiffusion outputs, (3) Comparing AF2/AF3/Boltz predictions, (4) Predicting binding success rates, (5) Need better ranking than ipTM or iPAE. For structure prediction, use chai or alphafold. For QC thresholds, use protein-qc.
license
MIT
category
evaluation
tags
ranking, scoring, binding

ipSAE Binder Ranking

Prerequisites

RequirementMinimumRecommended
Python3.8+3.10
NumPy1.20+Latest
RAM8GB16GB

Overview

ipSAE (interprotein Score from Aligned Errors) is a scoring function for ranking protein-protein interactions predicted by AlphaFold2, AlphaFold3, and Boltz1. It separates true from false predicted complexes more reliably than ipTM, which dilutes interface confidence across disordered or accessory regions. In a separate binder meta-analysis (Overath et al. 2025), AF3 ipSAE_min gave a 1.4-fold gain in average precision over the ipAE score that RFdiffusion pipelines commonly filter on.

Paper: Dunbrack, "Rēs ipSAE loquuntur: What's wrong with AlphaFold's ipTM score and how to fix it", bioRxiv 2025.02.10.637595

How to run

Installation
bash
git clone https://github.com/DunbrackLab/IPSAE.git
cd IPSAE
pip install numpy
AlphaFold2
bash
python ipsae.py scores_rank_001.json unrelaxed_rank_001.pdb 15 15
AlphaFold3
bash
python ipsae.py fold_model_full_data_0.json fold_model_0.cif 10 10
Boltz1
bash
python ipsae.py pae_model_0.npz model_0.cif 10 10

Key parameters

ParameterDescriptionRecommended
PAE fileJSON (AF2/AF3) or NPZ (Boltz)Match predictor
Structure filePDB or CIF structureMatch PAE
PAE cutoffThreshold for contacts10-15
Distance cutoffMax CA-CA distance (A)10-15

Output format

Two output files are generated:

Chain-pair scores (_chains.csv):

chain_A,chain_B,ipSAE_min,pDockQ,pDockQ2,LIS,n_contacts,interface_dist
A,B,0.72,0.65,0.58,0.45,42,8.5

Residue-level scores (_residues.csv):

chain,resnum,pSAE,pLDDT
A,45,0.85,92.3
A,67,0.78,88.1

Sample output

Successful run
$ python ipsae.py scores_rank_001.json design_0.pdb 10 10
Processing design_0...
Found 2 chains: A, B
Computing ipSAE scores...

Results written to:
  design_0_chains.csv
  design_0_residues.csv

Summary:
  ipSAE_min: 0.72
  pDockQ: 0.65
  LIS: 0.45
  Interface contacts: 42

What good output looks like:

  • ipSAE_min > 0.61 (primary filter)
  • pDockQ > 0.5 (supporting metric)
  • Reasonable number of interface contacts (20-100)

Decision tree

Should I use ipSAE?
│
├─ What are you ranking?
│  ├─ Designed binders → ipSAE ✓
│  ├─ Natural complexes → ipTM is fine
│  └─ Single proteins → Not applicable
│
├─ What predictor did you use?
│  ├─ AlphaFold2 → ipSAE ✓
│  ├─ AlphaFold3 → ipSAE ✓
│  ├─ Boltz1 → ipSAE ✓
│  ├─ Chai → ipSAE (use PAE output)
│  └─ ESMFold → Not applicable (no PAE)
│
└─ Why ipSAE over ipTM?
   ├─ Different length constructs → ipSAE ✓
   ├─ Designs with disordered regions → ipSAE ✓
   └─ Standard complexes → Either works
MetricStandardStringentUse Case
ipSAE_min> 0.61> 0.70Primary filter
LIS> 0.35> 0.45Interface quality
pDockQ> 0.5> 0.6Supporting

Batch processing

python
import subprocess
import os
from pathlib import Path

def score_designs(pae_dir, struct_dir, output_dir):
    """Score all designs in a directory."""
    Path(output_dir).mkdir(exist_ok=True)

    for pae_file in Path(pae_dir).glob("*_scores*.json"):
        name = pae_file.stem.replace("_scores_rank_001", "")
        struct_file = Path(struct_dir) / f"{name}.pdb"

        if struct_file.exists():
            subprocess.run([
                "python", "ipsae.py",
                str(pae_file),
                str(struct_file),
                "10", "10"
            ])

Verify

bash
ls *_chains.csv | wc -l  # Should match number of predictions

Troubleshooting

Low scores for good designs: Check PAE/distance cutoffs Missing output: Verify PAE file format matches predictor Inconsistent scores: Use same cutoffs across all designs

Error interpretation
ErrorCauseFix
KeyError: 'pae'Wrong PAE formatCheck if AF2/AF3/Boltz format
FileNotFoundErrorStructure not foundVerify file paths
ValueError: no contactsNo interface detectedCheck chain IDs, reduce cutoffs

Next: Select top designs (ipSAE_min > 0.61) → experimental validation.

© adaptyvbio, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in skills/ipsae of adaptyvbio/protein-design-skills.

Open the folder on GitHubat commit 59dd633

Used in 4 other repositories

We found 6 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 4 other GitHub owners. This page covers the copy in adaptyvbio/protein-design-skills, which our catalogue first saw on October 7, 2026.

Compare with similar skills

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Alphafold Databasedavila7/claude-code-templates32k10 repos~4kAutomated safety check: PassMIT

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Works with

Questions about Ipsae

What does Ipsae do?

Binder design ranking using ipSAE (interprotein Score from Aligned Errors). Ipsae is an agent skill from adaptyvbio/protein-design-skills. Binder design ranking using ipSAE (interprotein Score from Aligned Errors).

When should I use Ipsae?

Ipsae fits situations like: ranking binder designs for experimental testing; filtering BindCraft; RFdiffusion outputs; comparing AF2/AF3/Boltz predictions.

How do I install Ipsae in Claude Code?

Run `npx skills add adaptyvbio/protein-design-skills --skill ipsae -a claude-code`. Or copy the skill folder (skills/ipsae in adaptyvbio/protein-design-skills) into .claude/skills/ipsae in your project. Claude Code loads it when a task matches its description.

How do I install Ipsae in Codex?

Run `npx skills add adaptyvbio/protein-design-skills --skill ipsae -a codex`. Or copy the skill folder (skills/ipsae in adaptyvbio/protein-design-skills) into .agents/skills/ipsae in your project. Codex loads it when a task matches its description.

Can I use Ipsae in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add adaptyvbio/protein-design-skills --skill ipsae -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/ipsae, .gemini/skills/ipsae, .github/skills/ipsae and .opencode/skills/ipsae in your project.

What does Ipsae need to run?

Going by SKILL.md and its folder, Ipsae needs the command-line tools its instructions call (python, git and pip). Our summary lists: Python 3.

Does Ipsae access the network?

SKILL.md names 2 domains. In commands or code: github.com; the agent is likely to contact it when it follows the instructions. As links in the text: biorxiv.org. This is read from the text; nothing was executed.

Is Ipsae safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Ipsae use?

Ipsae is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Ipsae use?

About 1.2k tokens (SKILL.md is roughly 5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Ipsae?

Skills that share tags, products or a category with Ipsae: Alphafold Database Fetch And Analyze (google-deepmind/science-skills, 3.2k stars), Biopipelines (locbp-uzh/biopipelines, 109 stars), Bio DB Tools (DrugClaw/DrugClaw, 125 stars) and Gget (davila7/claude-code-templates, 32k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Ipsae?

adaptyvbio (a GitHub organization) maintains it in adaptyvbio/protein-design-skills, which has 163 GitHub stars. The repository holds 24 skills in this directory. The repository was last updated on June 11, 2026.

Source: adaptyvbio/protein-design-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.