Eir reads your data like a careful scientist, and shows its working.
Eir has your whole record in front of it: every biomarker, every lab panel, your meals, your training, your journal and your devices’ own limits. Ask it anything about your own physiology and it answers from that record, against your own baseline, with the evidence behind each statement and the data it used named under the answer. It checks its own advice before you see it. And it describes; a professional diagnoses.
Eir is named for the Norse goddess of healing.
Five things that make every answer traceable.
Every answer is computed from your own record: the measures your devices wrote, the labs you uploaded, what you logged. Eir reads a number the way VT reads it, against your own baseline rather than a population range, per device, and with the count and the method behind each figure. When your record cannot support an answer, Eir says so instead of guessing.
Each reply carries what it rested on: the window it compared, the sources it read, the study behind a claim. A statement you cannot trace back to your data or to a paper does not appear.
Every nutrition and supplement claim Eir makes, including its own recommendations, is screened against Diet-MisRAT, a peer-reviewed misinformation-risk framework (Ruani et al., Scientific Reports, 2026), for inaccuracy, incompleteness, deceptiveness and potential for harm, and the result is shown with the reply. As far as we know, no other consumer health platform audits its own advice this way.
Eir is an interpretation partner, not an alarm system. It tells you what moved, by how much, against what, and what in your own logs could explain it. When something is worth a professional’s eye, it says so and points you there, and it will not name a condition.
Eir reads your data fresh every time you open it, so an answer is only ever as current as your last sync. It does not keep a memory of earlier conversations today, which also means nothing you said in passing shapes what it tells you next.
Four exchanges, from one member’s record.
A scare dissolved by the right statistic; a real change confirmed by two devices and explained from the member’s own logs; a supplement question answered against the evidence, with the professional’s role stated plainly; and a plan tracked rather than promised. No condition is named anywhere, no number is invented, and every reply names what it read.
Most of the time you meet Eir inside a feature, reading one thing well.
Four focused Eirs sit where their data lives; they read, they do not chat.
Today’s capacity sits in Build. Overnight HRV was 46 ms against your 30-day median of 44, resting heart rate 52 against 53, and yesterday’s load was light.
A hard session today stays inside your usual recovery pattern; two in a row would not.
Your Sleep Health Index moved from 78 to 74 this week. Regularity did it: bedtimes spread across 95 minutes against your usual 40.
Last night’s score of 81 says the night was good; it says nothing about the week.
Everything sat within your usual range last night: overnight heart rate 53, breathing rate 14.9, temperature within 0.1 °C of your baseline.
You logged a late meal, so VT weighed last night’s heart rate less.
Your energy-expenditure estimate moved from 2,540 to 2,480 kcal a day, medium confidence.
Your scale and your food log agree within 3%; the move follows two lighter training weeks.
| What it reads | Where it lives | |
|---|---|---|
| Capacity Eir | What today’s capacity rests on: last night’s recovery against your baseline, your recent load, and what would change the reading | The Capacity screen |
| Sleep Eir | Why your Sleep Health Index moved this week, which component did it, and what last night’s score does and does not tell you | The Sleep screen |
| Symptom Eir | What moved overnight, how far outside your usual range, and which of your logs (training, a late meal, a short night) accounts for it | The daily overnight check |
| TDEE Eir | Why your energy-expenditure estimate changed, how confident it is, and whether your food log and your scale agree | The energy and Weight Loss Plan screens |
The fifth is Eir itself: the one with the whole picture, across every domain and every source, that you can ask questions of, follow up with, and argue with. The focused Eirs are the pages of the book; Eir has read all of it.
Some of Eir’s work happens without a conversation.
- Pre-visit reports. When you prepare a report for your doctor or coach, Eir drafts the summary of what changed, since when, and the questions worth asking, from the same evidence it shows you. You read it, edit it, and decide what goes.
- Supplement regimens. When you build a regimen, Eir proposes it from your labs, your biomarkers and your goal, screens every claim through Diet-MisRAT, and checks each addition against the rest of what you take.
- Lab results. Upload a lab report as a PDF or a photo and Eir reads it, extracts each result with its unit and reference range, and files it under the right panel beside everything else you track, for you to confirm.
- Ingredients. Add an ingredient the Meal Planner has not seen and Eir classifies it, NOVA class, glycemic index and load, and the nutrients the planner needs, so your meals carry the same information whether the ingredient came from the database or from you.
Four screens in the app’s own language, with synthetic data. Eir appears in each as the same small orb; the screens belong to their features.
Six lines it holds.
- Diagnose, or name a condition. It describes your measures; your doctor interprets your health.
- Alarm you. A change in your data is described with its size and its likely explanations, and if it is worth a professional’s eye, Eir says that plainly, once.
- Invent a number. If your record cannot answer a question, Eir tells you what is missing and how to record it.
- Blend your devices. A ring night and a watch night stay separate in Eir’s reading, as they do everywhere in VT.
- Give you advice it has not checked. Nutrition and supplement claims go through Diet-MisRAT first, every time.
- Carry a conversation over. Today each session starts from your record, not from what you said last time.
Eir runs on AI credits.
Every conversation uses some, and your plan sets how many you get each month; the focused reads your plan schedules are included. This is where the plans differ most: Free comes with a welcome allowance to meet Eir, Standard a working allowance for daily use, and Premium the largest. Credits can also be bought on their own, outside the monthly plan, whenever you want more. The allowances and prices are on the Pricing page. During the invitation-only beta, Eir is included.
Eir describes; a professional diagnoses. Vitality Tracker describes and tracks physiological measures recorded by your own consumer devices against your own history, for general wellness and for discussion with a health professional. It tracks measures, not disease, and does not diagnose, predict or monitor any disease.