Model

Personal Health Agent (PHA; Google multi-agent framework over wearable + medical data)

Year
2026
Form factor
Wrist
EHRTextactivity recordswearable time series (consumer wellness devices)Nature, 2026-10-21Open codeWeights: not released
Heydari, A. Ali et al., "The Anatomy of a Personal Health Agent", arXiv:2508.20148, CC BY 4.0
PreprintCatalog paper date: 2026Added to atlas: Oct 22, 2026Source

Activity counts measure attention, not model quality. Missing counts are unknown. Publication status follows the linked source; a listed venue alone does not confirm peer review.

Personal Health Agent is Google's open multi-agent framework for personal health questions over consumer wearable and medical context. An orchestrator coordinates data-science, domain-expert, and health-coach LLM sub-agents with iterative reflection. Apache-2.0 code is available; the paper runs used Gemini. Published in Nature 2026 (DOI 10.1038/s41586-026-11161-8).

Form factor
Wrist
Year
2026
Architecture

Orchestrator coordinating three LLM sub-agents (Data Science agent with sandboxed code execution over personal time series; Domain Expert agent with web search + Data Commons; Health Coach agent for multi-turn goal setting) with iterative reflection; baselines in the repo: Parallel (no orchestration) and PHIA (single ReAct agent). Model-agnostic; Gemini in the paper

Signals

EHR, Text, activity records, wearable time series (consumer wellness devices)

Pretraining data

n/a. Evaluated on WEAR-ME (n=1,165; 50-persona subset open for research use in the repo) and an n=2,000 symptom dataset

License

Apache-2.0 (personal_health_agent/LICENSE.txt). No weights: model-agnostic framework; the paper's runs used Gemini (closed).

At a glance
Type
Task model
Form factor
Wrist
Parameters
Not reported
Architecture
Orchestrator coordinating three LLM sub-agents (Data Science agent with sandboxed code execution over personal time series; Domain Expert agent with web search + Data Commons; Health Coach agent for multi-turn goal setting) with iterative reflection; baselines in the repo: Parallel (no orchestration) and PHIA (single ReAct agent). Model-agnostic; Gemini in the paper
Venue
Nature, 2026-10-21 (preprint arXiv 2508.20148)
Year
2026
Weights
Not released
Licence
Apache-2.0 (personal_health_agent/LICENSE.txt). No weights: model-agnostic framework; the paper's runs used Gemini (closed).
Caveats
Not reported
Datasets
Not reported
Added
Oct 22, 2026
Updated
Oct 26, 2026

Abstract

Health is a fundamental pillar of human wellness, and the rapid advancements in large language models (LLMs) have driven the development of a new generation of health agents. However, the application of health agents to fulfill the diverse needs of individuals in daily non-clinical settings is underexplored. In this work, we aim to build a comprehensive personal health agent that is able to reason about multimodal data from everyday consumer wellness devices and common personal health records, and provide personalized health recommendations. To understand end-users' needs when interacting with such an assistant, we conducted an in-depth analysis of web search and health forum queries, alongside qualitative insights from users and health experts gathered through a user-centered design process. Based on these findings, we identified three major categories of consumer health needs, each of which is supported by a specialist sub-agent: (1) a data science agent that analyzes personal time-series wearable and health record data, (2) a health domain expert agent that integrates users' health and contextual data to generate accurate, personalized insights, and (3) a health coach agent that synthesizes data insights, guiding users using a specified psychological strategy and tracking users' progress. Furthermore, we propose and develop the Personal Health Agent (PHA), a multi-agent framework that enables dynamic, personalized interactions to address individual health needs. To evaluate each sub-agent and the multi-agent system, we conducted automated and human evaluations across 10 benchmark tasks, involving more than 7,000 annotations and 1,100 hours of effort from health experts and end-users. Our work represents the most comprehensive evaluation of a health agent to date and establishes a strong foundation towards the futuristic vision of a personal health agent accessible to everyone.

Verbatim fromarXiv· arXiv metadata (abstracts are released under CC0)

How it works

How Personal Health Agent (PHA; Google multi-agent framework over wearable + medical data) works: Input signals → Model → Downstream tasksInput signals: EHR; Text (Language); activity records; wearable time series (consumer wellness devices). Pretraining data: n/a. Evaluated on WEAR-ME (n=1,165; 50-persona subset open for research use in the repo) and an n=2,000 symptom dataset. Model: Personal Health Agent (PHA; Google multi-agent framework over wearable + medical data) (Language-aligned).Input signalsEHREHRText: LanguageTextLanguageactivity recordsactivity recordswearable time series (consumer wellness devices)wearable time series…Pretraining data: n/a. Evaluated on WEAR-ME (n=1,165; 50-persona subset open for research use in the repo) and an n=2,000 symptom datasetPretraining datan/a. Evaluated on WEAR-ME (n=1,165…ModelPersonal Health Agent (PHA…Language-aligned
Pretraining data
n/a. Evaluated on WEAR-ME (n=1,165; 50-persona subset open for research use in the repo) and an n=2,000 symptom dataset
Architecture
Orchestrator coordinating three LLM sub-agents (Data Science agent with sandboxed code execution over personal time series; Domain Expert agent with web search + Data Commons; Health Coach agent for multi-turn goal setting) with iterative reflection; baselines in the repo: Parallel (no orchestration) and PHIA (single ReAct agent). Model-agnostic; Gemini in the paper
Inputs
EHR, Text, activity records, wearable time series (consumer wellness devices)
Approach
LLM agent · multi agent · personal health · health coach · data science agent · wearables

Datasets

No public datasets linked yet.

Cite

APA

Heydari, A. A., Gu, K., Srinivas, V., Yu, H., Paruchuri, A., Zhang, Z., Zhang, Y., He, Q., Palangi, H., Hammerquist, N., Metwally, A. A., Winslow, B., Kim, Y., Ayush, K., Yang, Y., Narayanswamy, G., Xu, M. A., Garrison, J., Schmidgall, S., . . . Xu, X. O. (2026). The anatomy of a personal health agent. Nature, 2026-10-21. https://doi.org/10.1038/s41586-026-11161-8

BibTeX

@article{heydari2026anatomy,
  title         = {{The anatomy of a personal health agent}},
  author        = {Heydari, A. Ali and Gu, Ken and Srinivas, Vidya and Yu, Hong and Paruchuri, Akshay and Zhang, Zhihan and Zhang, Yuwei and He, Qian and Palangi, Hamid and Hammerquist, Nova and Metwally, Ahmed A. and Winslow, Brent and Kim, Yubin and Ayush, Kumar and Yang, Yuzhe and Narayanswamy, Girish and Xu, Maxwell A. and Garrison, Jake and Schmidgall, Samuel and Lee, Amy Armento and Vafeiadou, Jenny and Graef, Ben and Galatzer-Levy, Isaac R. and Schenck, Erik and Barakat, Andrew and Perez, Javier and Shreibati, Jacqueline and Hernandez, John and Faranesh, Anthony Z. and Rezaei, Naghmeh and Prieto, Javier L. and Heneghan, Conor and Zhan, Jiening and Malhotra, Mark and Patel, Shwetak and Liu, Yun and Althoff, Tim and Liu, Xin and McDuff, Daniel and Xu, Xuhai Orson},
  year          = {2026},
  journal       = {Nature, 2026-10-21},
  doi           = {10.1038/s41586-026-11161-8},
  eprint        = {2508.20148},
  archivePrefix = {arXiv}
}

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History

  1. Record updated

  2. Added to the ChatPPG research hub

Signal: Text (uses signal)TextTextSignal: EHR (uses signal)EHREHRPersonal Health Agent (PHA; G…Personal Health A…
Signals 2
Text, EHR