GEMEO Twin Stack — Application Layer for the GEMEO Patient World Model
The graph-native digital-twin application stack that runs on top of the GEMEO World Model. Six inference modes — trajectory, diagnosis, risk/survival, counterfactual, repurposing, cohort — wired together with auxiliary heads, KG embeddings, and a FastAPI surface. Research preview. Not a medical device.
Authors: Raras.ai team · Contact: dimas@raras.ai Source: github companion repo (raras.org) Paper v1 (Zenodo): DOI 10.5281/zenodo.20092131 🌍 World Model (the dynamics core this stack runs on top of): Raras-AI/gemeo-world-model 📱 Mobile decision-support sibling: Raras-AI/araras-gemma4 License: CC-BY-NC 4.0 + non-clinical-use rider (see LICENSE)
Note on naming. Previously released as
Raras-AI/gemeo-world-model(HF auto-redirects). Renamed togemeo-twin-stackbecause the actual world model — the generative dynamics core — is the Causal Diffusion Forcing transformer now living at the newgemeo-world-modelslug. This repo is the application layer (encoder, cohort, risk, whatif, repurpose, ask, ground_sus, api) that turns the world model into a usable digital twin with six inference modes.
What this is
This is the application layer of GEMEO — a module (≈22k LOC) that takes the GEMEO World Model (a Causal Diffusion Forcing transformer, published separately at Raras-AI/gemeo-world-model) and wires it together with auxiliary heads, KG embeddings, and tooling to produce a complete digital-twin product. Each inference mode has a clean Python API, a bootstrap implementation that runs today, and an optional learned slot that drops in when a checkpoint exists.
GEMEO Twin Stack (this repo)
├── Patient embedding (gemeo/encoder.py) HGT scaffolded; bootstrap = weighted KG embedding
├── Cohort retrieval (gemeo/cohort.py) kNN + Cypher overlap on PrimeKG
├── Subgraph reasoning (gemeo/subgraph.py) 1-hop sparsification (learned variant in train/)
├── Trajectory mode (gemeo/trajectory.py) ← calls into the GEMEO World Model
├── Diagnostic mode (deeprare_diagnosis.py + ← multi-agent over PrimeKG paths
│ fast_dx.py, ensemble)
├── Risk / survival (gemeo/risk.py) NeuralSurv trained on DATASUS SIM (c-index 0.70)
├── Drug repurposing (gemeo/repurpose.py) TxGNN slot + SUS auxiliary head
├── Counterfactual (gemeo/whatif.py) do-calculus mutator; uses world-model rollout
├── Active learning (gemeo/ask.py) info-gain over KG annotations
├── SUS grounding (gemeo/ground_sus.py) PCDT/CEAF/UF coverage check
└── FastAPI (gemeo/api.py) production /api/gemeo/* endpoints
GEMEO World Model (separate repo: Raras-AI/gemeo-world-model)
└── Causal Diffusion Forcing transformer (19.86M params)
The generative dynamics core. Trajectory + counterfactual modes
above delegate to it.
Headline numbers (real, audited)
| Mode | Metric | Value | Notes |
|---|---|---|---|
| Diagnosis (RareBench, 200 cases, v49) | R@1 canonical | 57.0% (114/200) | matches DeepRare phenotype-only published level |
| R@5 canonical | 81.5% | ||
| R@1 strict (ORPHA-code) | 39.5% | strict pattern matching | |
| timeout rate | 0.0% | ||
| Risk / survival (NeuralSurv, DATASUS SIM) | val c-index | 0.70 (best @ ep 30) | 4,624 SIM mortality records, 37,494 censoring samples |
| final c-index | 0.694 | after 100 epochs | |
| World Model backbone (gemeo-world-model) | val cross-entropy | 0.030 | per-token diffusion forcing |
| calibration ICI | 0.0006 | well calibrated | |
| training | 5.8 min on 1×H100 | $0.48 |
These are the audited, end-to-end numbers from the same swarm-py module — they are NOT promises or projections.
Six inference modes
1 · Trajectory (digital twin)
from gemeo import build_gemeo
twin = await build_gemeo(
case_text="5-year-old boy, progressive ataxia, telangiectasia, elevated AFP.",
patient_info={"age": 5, "sex": "M"},
context={"sus_region": "SP"},
)
twin.trajectory.horizons # 6/12/24-month event predictions
Backbone: bootstrap LLM-over-natural-history today, Causal Diffusion Forcing when the CDF checkpoint is mounted.
2 · Diagnosis
twin.diagnoses[:5] # top hypotheses ranked, with evidence chain
Three diagnostic engines wired in:
deeprare_diagnosis.py(DeepRare-style multi-agent over PrimeKG paths)fast_dx.py(low-latency phenotype → ORPHA ranking)ensemble_diagnostic.py(ensemble over the above)
Baseline RareBench numbers reported above. v49 corresponds to the checkpoint shipping in this repo.
3 · Risk / survival
twin.risk.survival_curve # months → P(alive), with bootstrap CI
artifacts/neuralsurv.pt (186 KB) — Bayesian-style neural survival head
over KG-walk features. Trained on DATASUS SIM (n=4,624 deaths,
n=37,494 censoring samples). See artifacts/neuralsurv_datasus_summary.json
for the per-ORPHA sanity check (e.g., ORPHA:586 / cystic fibrosis: 96.4%
alive at 12 m, 80.3% at 72 m).
4 · Counterfactual (what-if)
twin.what_if({"add_treatment": "ivacaftor"}) # mutated trajectory
Bootstrap = heuristic snapshot mutation; learned variant = CF-GNNExplainer slot.
5 · Drug repurposing
twin.drugs.candidates[:5] # KG-walk Disease→Gene→Drug, SUS-availability ranked
TxGNN slot + SUS auxiliary head (filters by CONITEC/PCDT coverage).
6 · Cohort + active learning
twin.cohort.members[:10] # patients-like-mine (kNN on PrimeKG)
twin.next_questions[:3] # information-gain ranked clinical questions
What's in this repo
src/gemeo/ # 22 k LOC, the world-model module
├── core.py, api.py, types.py # orchestrator + FastAPI + types
├── encoder.py, cohort.py, subgraph.py
├── trajectory.py, risk.py, whatif.py
├── repurpose.py, ask.py, ground_sus.py
├── deeprare_diagnosis-style modules # diagnostic mode wiring
├── train/ # HGT, TGNN, TxGNN, NeuralSurv training
├── datasus/ # DATASUS pull (SIH, APAC, SIM, CNS linkage)
└── cwm/ # earlier causal-world-model exploration
artifacts/
├── neuralsurv.pt # 186 KB, NeuralSurv risk head (c-index 0.70)
├── neuralsurv_datasus_summary.json # per-ORPHA survival sanity check
└── dt_fm.pt # 7.6 MB, decision-time foundation-model baseline
data_derived/ # ALL derived from PrimeKG (CC-BY 4.0)
├── fused_embeddings_fp16.npz # 43 MB, 3072-dim disease/HPO/gene embeddings
├── graph_embeddings.npz # 7 MB, 768-dim KG node embeddings
├── hetero_graph.json # 6 MB, edge index by relation
└── node_ids.json # 530 KB, id → ORPHA/HPO/HGNC mapping
benchmarks/
└── rarebench_v49_diagnose_200.json # 200-case RareBench eval, per-case results
examples/
└── quickstart.py # minimal usage
LICENSE
README.md ← this file
The GEMEO World Model (the Causal Diffusion Forcing dynamics core) is published separately at Raras-AI/gemeo-world-model (~80 MB) — keep that repo for the heavy ckpt, this repo for the application stack that runs on top of it.
Quickstart
import sys; sys.path.append("src")
from gemeo import build_gemeo
twin = await build_gemeo(
case_text="Menino, 5 anos, ataxia progressiva, telangiectasia, AFP elevado.",
patient_info={"age": 5, "sex": "M"},
context={"sus_region": "SP"},
)
twin.diagnoses[:3] # → e.g. Ataxia-Telangiectasia (ORPHA:100) at top
twin.cohort.members[:5] # patients-like-mine
twin.risk.survival_curve # months → P(alive)
twin.drugs.candidates[:3] # repurposing
twin.next_questions[:3] # active learning
twin.sus_check.pcdt_url # PCDT compliance link
For the FastAPI server (production layout — same as raras.org runs):
pip install -r requirements.txt
uvicorn gemeo.api:app --reload --port 8000
# POST /api/gemeo/build — create a twin
# POST /api/gemeo/{id}/evolve — add new clinical data
# POST /api/gemeo/{id}/whatif — counterfactual
# GET /api/gemeo/{id}/{cohort,subgraph,trajectory,risk,drugs,trials,next-questions,sus,viz}
Data, ethics, governance
- Source: Brazilian DATASUS subsystems (SIH-RD, APAC-SIA, BPA-I, SIM).
- Linkage: CNS-hash deterministic (Tier 1 via APAC).
- De-identification: ages bucketed (5y); UF only (no município); k-anonymity ≥ 5.
- Ethics: Brazilian Res. CNS 466/2012 + 510/2016. LGPD-compliant.
- Not on this repo: PHI, raw CNS hashes, individual-level data. Only derived embeddings (PrimeKG), trained weights (NeuralSurv, DT-FM), source code, and aggregate metrics.
What's in development (and what Mayo would enable)
The architecture is mode-complete: every box has a working bootstrap or trained slot. The bottleneck is data substrate:
| Mode | SUS today | What Mayo / multimodal substrate unlocks |
|---|---|---|
| Trajectory | events only (no notes) | + 1.65 B clinical notes → richer event tokens |
| Diagnosis | R@1 57% canonical / 200 cases | + WES variants + HPO from notes → target R@1 ≥ 78% (DeepRare bar) |
| Risk | c-index 0.70 on 4,624 deaths | + longitudinal labs + meds → target c-index ≥ 0.80 |
| Counterfactual | heuristic | + trial-emulation labels → causal-grade what-if |
| Repurposing | TxGNN + SUS heuristics | + Mayo trial outcomes → real evidence ranking |
This is the basis of our Mayo Clinic Platform_Accelerate proposal: same world model, multimodal substrate.
Citation
@misc{gemeo_world_model_2026,
title = {GEMEO: A Patient World Model for Rare Disease, Grounded in
Brazilian SUS Data},
author = {Timmers, Dimas and the Raras.ai team},
year = {2026},
url = {https://huggingface.co/Raras-AI/gemeo-world-model},
note = {Research preview. Not a medical device.}
}
@misc{gemeo_v1_2026,
title = {GEMEO v1: A SUS-Grounded Patient Digital Twin for Rare-Disease
Trajectory Forecasting},
author = {Timmers, Dimas and Kawassaki, Alexandre},
year = {2026},
doi = {10.5281/zenodo.20092131},
url = {https://doi.org/10.5281/zenodo.20092131}
}
Building blocks (please also cite as appropriate)
- PrimeKG — Chandak, Huang, Zitnik. Nature Sci Data (2023).
- HGT — Hu et al., WWW 2020. Heterogeneous Graph Transformer.
- TGNN — Rossi et al., ICML 2020. Temporal Graph Networks.
- TxGNN — Huang et al., Nature Medicine 2024. A foundation model for clinician-centered drug repurposing.
- NeuralSurv — Lee et al., Stat. Med. 2021.
- Diffusion Forcing — Chen et al., NeurIPS 2024 (2407.01392).
- DeepRare — Nature 2026, s41586-025-10097-9.
- PhenoKG — arXiv 2506.13119 (Jun 2025).
- MEDS — Medical Event Data Standard v0.4.1, McDermott et al. 2024.
Changelog
- 2026-05 (this release) — Initial public release of the twin-stack application layer + NeuralSurv ckpt (c-index 0.70) + DT-FM baseline + PrimeKG-derived embeddings + RareBench v49 results.
- 2026-05-19 — Renamed from
Raras-AI/gemeo-world-model→Raras-AI/gemeo-twin-stack(HF auto-redirects). The sluggemeo-world-modelnow hosts the actual Causal Diffusion Forcing world model. - 2026-05 — GEMEO World Model v2 (CDF backbone) published at Raras-AI/gemeo-world-model.
- 2026-04 — GEMEO v1 paper published on Zenodo (DOI 10.5281/zenodo.20092131).
⚠️ Reminder: Research only. Not a medical device. No clinical use without physician oversight and applicable regulatory clearance.