Yet another Hacker News

60 points ricotico060 3 days ago 73 comments

m463 3 days ago | parent

Why can't we just connect a garmin watch (or edge or gps) to our ai machine, have it extract all the data with MTP or garmin format, and keep it local. Then ask questions.

Honestly I've been wondering if in the near future I can basically have a big machine and some sort of "ingest" program.

Then keep connect my devices to it, where it will backup all the data, and mine the backups for information I want.

Mine my iphone backups for text messages or contacts

mine all my devices for photos or videos

mine my watch or bike computer or gps or whatever else for where I've been and how I've exercised.

instead, everyone wants your data and imposes themselves in the middle.

exabrial 3 days ago | parent

doesn’t Garmin support completely local synchronization with their devices still?

m463 3 days ago | parent

they do - and this is why I buy their stuff.

but a lot of these folks are uploading everything to garmin connect and letting it have your data and do the work.

jawilson2 3 days ago | parent

If you do local sync, can you work with the files directly? I.e. if I don't want to upload to garmin connect, can I just tell Claude to use an API or reverse engineer the files? I've had a venu 4 for a few months, and finished my connect+ trial, and want to setup my own analytics.

djantje 2 days ago | parent

I just connected my Garmin watch to charge via usb, enabled disk access, going into folder GARMIN/Activity/ and uploaded one of the .fit files to claude web and asked a summary and graph, it seems I had a nice evening bike ride that day :)

gadders 2 days ago | parent

Yes, but it stays within Garmin. It's hard to get metrics from multiple devices in one place.

cgsmith 3 days ago | parent

This is similar to what I did. Just download the gpx and analyze that. Skips the Garmin API.

zknill 3 days ago | parent

GPS traces recorded on a watch can be pretty noisy. If you stand in the same spot for a while, you're not going to get the exact GPS position recorded for the entire time you're there. The same happens when you move, it's not a smooth trace.

Strava (and I assume to some extent Garmin) apply some smoothing to these raw GPX traces to try and improve the path, or remove some of the noise.

You'd be missing out on this post-processing by taking the data raw. Ofc you can implement something similar yourself, but I wanted to point out that these platforms are doing a little bit more than just displaying the GPX trace.

szszrk 2 days ago | parent

But how real of a problem that is?

I wander often on many smartwatch/sport tracking forums/subreddits, and it's fairly frequent that people ask how to deal with smoothing and get back raw data. Some love how Garmin smooths out a race track run for them and make gps trail stick perfectly to a lane. Some pull their hair out seeing their lake run being smoothed out to make it look like they jumped over fences and private properties.

I often find my garmin traces confusing as well, it's not objectively better.

nradov 1 day ago | parent

Some users may be confused about Garmin functionality. If you select the Track Run activity profile on a standard 400m track then it will generate a perfectly smooth and consistent route every time. This is only possible because it knows the exact shape of a standard track and can adjust the location data points to fit.

All fitness trackers (and mobile devices in general) do some level of smoothing on location data before recording it to an activity. There is no "raw data" to get back. The developers try to select smoothing algorithms that produce a good result in most cases but there will always be occasional discrepancies. This is usually due to poor signal quality including multipath reflections when the device doesn't have a clear line of sight to the sky due to structures or trees.

Garmin devices don't only use "GPS". They support multiple GNSS constellations including Glonass and Galileo, and depending on the selected mode may use all of those simultaneously to improve location accuracy.

asp_hornet 2 days ago | parent

When parsing high end Garmin and Apple fit files, it appears a lot of their smoothing is done before writing to the fit file. They’re in a very workable state straight out of the gate.

TYPE_FASTER 1 day ago | parent

Yes. The location data you get from CoreLocation has been processed already, in that it is the output of combining the inputs from the GPS, Wi-Fi access points, cell towers, magnetometer, accelerometer, and gyroscope sensors.

Workout data might take it a step further, as you tell it the type of workout, and I'm assuming WorkoutKit might do something like adjust the distance filter that specifies how far the device has to travel before triggering a location update event to minimize battery use during the workout.

sarjann 2 days ago | parent

https://stories.strava.com/articles/explaining-the-strava-ta...

Interesting article (which I think is relevant)

kyzrfranz 2 days ago | parent

Main problem is the sync and getting to the data. Speaking from experience here, been working on something for a while. This is the current state of the product pitch:

https://claude.ai/artifact/162zJUVejDdrAAw6yz9ETs

fyi - most of the functionality already working, but the key factor is how to get the data from the vendors.I currently rely on run-gap but i realise this is not a long-term solution. Last time i have checked intervals icu api I just couldn't stop throwing up for a few days -but this might be better in the mean time.

long term solution is to have something like rungap, server side without the ridiculous fees some of the vendors charge (terra, rook,...)

if anybody wants to test what I currently got, or just has some feedback - let me know.

gadders 2 days ago | parent

>>without the ridiculous fees some of the vendors charge (terra, rook,...)

They charge an absolute fortune.

levocardia 2 days ago | parent

You can literally connect your Garmin to your computer via USB and drag-and-drop the raw activity files and analyze them if you want. Works totally fine. But Garmin's cloud sync is convenient and cloud processing adds data like elevation (by cross-matching GPS to topo data).

anygivnthursday 2 days ago | parent

I used to use Garmin offline like that with GoldenCheetah[0], it was my weekly ritual to analyse progress.

[0]: https://www.goldencheetah.org/

iamacyborg 2 days ago | parent

This wouldn't sync over any of the data points that are calculated by the device, VO2 max, various sleeps cores, etc. Probably a good thing as those things are rarely all that useful.

nradov 1 day ago | parent

All of that data is on the device and can be copied as .FIT files. Some of the fields aren't publicly documented, though.

embedding-shape 2 days ago | parent

That only gives you the activities though, doesn't it? Not the 24/7 metrics the device is also collecting outside of started/stopped activities.

I've been trying to get developer access to my watch, but seems for months the Garmin Developer Program doesn't seem to accept any "requests". The only thing I've seen working, is the full account export, but that takes ~3 days for me from pressing the button until I get the email. Besides that, syncing via Bluetooth and reverse-engineer their own protocol that runs there, seems to be the only way, sadly.

Melatonic 1 day ago | parent

Can't you just connect via USB (oldschool method from before their devices even had Bluetooth) and dump the data the old fashioned way ?

thi2 1 day ago | parent

This does not work for golf, I tried to get the activity but could not find it.

howunfortunate 1 day ago | parent

I work for a company where this is relevant.

Leadership is very aware of this and is accordingly being very careful about how easy we make it for people to instantly offload all of the data they've entered that makes our product worth using vs. a competitor.

I'm not saying this is good, obviously as a consumer I'd like the opposite. All I'm saying is, don't expect companies to be naive about this. If you don't want to be "locked in", you'll likely have to pay for that in some other way.

Centigonal 1 day ago | parent

Appropriate username!

> If you don't want to be "locked in", you'll likely have to pay for that in some other way.

That "some other way" is almost never via the wallet. From Apple to Whoop to Snowflake to Oracle, the most expensive ecosystems are often the ones with the most lock-in. More often than not, the "some other way" you pay is by having to put up with janky UX and incomplete featuresets.

Melatonic 1 day ago | parent

Isn't that how all Garmin GPS devices have traditionally worked ?

NoPicklez 1 day ago | parent

You can do this, you can plug your Garmin device into your machine and pull all of the data off.

obilgic 2 days ago | parent

Just connect your garmin to intervals.icu

rcMgD2BwE72F 2 days ago | parent

Just connect your Garmin to GadgetBridge as and have a small script upload your files to intervals.icu. Your data will never touch a Garmin server.

This works perfectly for me. Couldn't be happier.

afrnz 21 hours ago | parent

+1 - great platform with easy to use API. I created a free hosted mcp for it at intervals.club

shrx 2 days ago | parent

I highly recommend GadgetBridge for anyone wanting to avoid Garmin's cloud services: https://gadgetbridge.org/

szszrk 2 days ago | parent

I love it as it supports some weird devices that were abandoned or require Chinese data residency for them to sync.

How is it working for you in Garmin for sleep tracking? I tried it a few years ago and loved it at first, but then noticed how incorrect sleep data was.

shrx 2 days ago | parent

I'm not using it for sleep tracking so I can't comment on that. I mostly use it with Garmin Instinct 3 Solar for recording and exporting gpx tracks of my hikes and bicycle trips.

TrueGeek 2 days ago | parent

I've been using the unofficial Garmin APIs as well, but instead of an MCP I wrote an app that waits until my watch syncs after I wake up and then grabs all of yesterdays data and puts it into a Notion db.

It's been working great. The Claude morning brief compares my sleep, HRV, training status, calendar, and weather and then tells me when and how hard to workout that day.

Krasnol 2 days ago | parent

SparkyFitness has an MCP and you can connect Garmin to it:

https://github.com/CodeWithCJ/SparkyFitness

teroshan 2 days ago | parent

> Imagine how great an Instagram MCP would be. You could create your own feed algorithm (such as the OG algorithm: just pictures from friends based on when they posted). Users would be able to filter out all the influencer content and ads Instagram throws on them. But Instagram would never do this.

This is why I don't understand why MCPs (or in other words open documented APIs right?) are being pushed so much.

What's the value in e.g. Amazon opening up their APIs to competitors, lowering the cost of scraping their data? Or allowing their consumers to more easily analyze dynamic pricing? Isn't the whole point to steer people towards closed proprietary apps that work in walled garden that prevent reverse-engineering and any kind of modification?

weird-eye-issue 2 days ago | parent

> e.g. Amazon opening up their APIs to competitors, lowering the cost of scraping their data?

Not a great example considering how easy it is to get Amazon data from both official and unofficial APIs (which is very cheap at scale)

weird-eye-issue 2 days ago | parent

I sync Garmin activities to Strava then use the Strava API in Claude Code. Although I think Strava just came out with an MCP. This works great but doesn't access things like sleep which I didn't need anyways

Its funny because I literally just used it, opened HN, then saw this post

quora 2 days ago | parent

I've recently done something simliar but for creating strength workouts via Claude.

The web and mobile based workout builder has a terrible UI if your workout changes between sessions so I've lifted some features from an app called liftosaur and got it to send activities to my watch. Unfortunately Garmin don't seem to care very much about strength training, so are missing a lot of pretty key exercises from their list, with no ability to create custom ones

hummuscience 2 days ago | parent

I am very happy with liftosaur and it's MCP for that!

leni536 2 days ago | parent

The idea of letting an LLM anywhere near my finances (and actually initiate transactions) terrifies me. And I like using LLMs.

Hamuko 2 days ago | parent

I'm more terrified about how much (personal) data people are feeding commercial LLMs. You send Claude your Garmin data and Anthropic will keep it for literally years. And then probably hand it over to law enforcement as soon as a subpoena hits.

I've been using a local LLM (Gemma) to tag my personal documents (invoices, receipts, etc.) and there's no way I'd ever send that data to Anthropic or OpenAI.

weird-eye-issue 2 days ago | parent

Yeah it's a tradeoff... I had Claude Code discover issues my CPA made that resulted in getting over $100k back in my taxes after they amended and fixed my returns. But I had to feed in a ton of personal information for that to work

Melatonic 1 day ago | parent

Now you gotta tell us what the trick was !

weird-eye-issue 1 day ago | parent

It wasn't a trick, it was just pretty standard stuff in my situation that they completely forgot to take advantage of like deductions related to living outside of the US and related to some previous year losses on a rental property that was sold that they completely forgot to deduct when it was sold you can claim those losses back. It swung the tax return I just filed from owing 30k to getting 30k back, plus they filed amendments for the last couple years to get some money back there as well totaling around 100k

andor 2 days ago | parent

Paying bills of the same 3 companies each week is also not something that requires a LLM. In other countries, it would simply be a direct debit transaction or a scheduled bank transfer.

leni536 1 day ago | parent

To be fair, direct debit also terrifies me. But I use that one.

faangguyindia 2 days ago | parent

Many people actually try to use Garmin or other trackers/smart watches for things they aren't good at.

For example, if you want to track your maintenance calories (TDEE, total daily expenditure), Garmin isn't going to be much useful.

jcul 2 days ago | parent

I've started exporting my sleep data from Garmin connect. And my expenditure, weight, nutrition, from macrofactor.

I add them to a spreadsheet along with other metrics I've been collecting manually for a long time, like tape, caliper measurements etc.

I do it weekly and then ask Claude to analyse the sheet.

It's super manual but just once a week and it can be really helpful / spots insights I often miss like how sleep affected something etc.

faangguyindia 2 days ago | parent

We use a neural network to predict maintenance calories.

We actually operate a MacroFactor competitor: MacroCodex (which is completely free). https://macrocodex.app/ we've like 17,000+ users so far.

It adapts much faster than MacroFactor, and it's completely free of subscriptions and ads.

Guaranteed weight gain or loss within 2-3 weeks, consider reading reviews if in doubt, many people will see results from the very first week on macrocodex!

Many people waste their time by adding "calorie burn" from different activities by tracking all of them individually in smartwatches or fitness bands.

Melatonic 1 day ago | parent

Do maintenance calories vary and change that much (excluding exercise variance) ?

faangguyindia 1 day ago | parent

Yes, it can vary by 200-300kcal on week to week basis on average

iamacyborg 2 days ago | parent

> For example, if you want to track your maintenance calories (TDEE, total daily expenditure), Garmin isn't going to be much useful.

Why not?

faangguyindia 2 days ago | parent

It's not accurate for this.

You can't use a sensor and stack calorie burn from bunch of activities and add them all up to workout maintenance calories.

The sensorless method we use is more reliable, https://macrocodex.app/knowledge/rethink/adaptive-tdee/

You can see the reviews and guaranteed results within 2-3 weeks, all for free.

lairv 2 days ago | parent

I would like the reverse of an MCP, a protocol so that everyday apps can push notify (given my authorization) my agents on specific events

For example after I complete a run on Strava I want my agents to know about it, they already have all the context, they know what weekly volume I'm aiming for and what I'm training for

weird-eye-issue 2 days ago | parent

That's not a reverse MCP, they are working on adding that sort of thing into MCP. In the meantime just run scheduled tasks or webhooks to pull data

ssgodderidge 2 days ago | parent

The approach is more agent skills + a CLI that hits publicly available APIs than an MCP, but still cool! I would love to see the code?

lormayna 2 days ago | parent

If you are using Intervals.icu (and you really should, it's an amazing project), you can connect it to Garmin and then use their own MCP server https://forum.intervals.icu/t/mcp-server-for-connecting-clau...

isolli 2 days ago | parent

Coros has one, just saying...

https://coros.com/stories/coros-metrics/c/mcp-testing

jordiori 2 days ago | parent

I've created a "running coach" agent that does something similar. It basically exports Garmin's data using the unofficial API into a sqlite db. Then, the agent has some tools to query the data directly in the database with SQL. It works pretty well.

dSebastien 2 days ago | parent

I created an AI skill for this a while ago: https://www.dsebastien.net/garmin-ai-skill/

Lhd 2 days ago | parent

Which "Using an unofficial Garmin MCP" were you using? and which problems you encountered that made you move on?

I've been using taxuspt/garmin_mcp[0] via claude desktop and recommend it. It reads my data and it is able to create and schedule workouts. I've decided to fork it because it was not able to create the type of workouts that i wanted (swim, bike, run and gym) and it also pushes into my garmin calendar which syncs directly to the watch/gps unit).

Claude's official strava connector[1] is able to read the data (garmin -> strava -> claude), yes. But my point of view for strava is that it's not really meant to be for workouts - it's a social media to give/receive kudos and see what your friends and 'influencers' are doing (i'm not really interested). All the metrics of cadence/vertical oscilation/sleep, for example, are not synced to strava and therefore not accessible.

[0]: https://github.com/taxuspt/garmin_mcp [1]: https://claude.com/marketplace/connectors/strava

methou 2 days ago | parent

There’s an unofficial Garmin connect Home Assistant extension, playing along with Prometheus exporter you can get a quite impressive dashboard. That’s what I did.

lukwoz 2 days ago | parent

At the moment I'm a happy user of Tredict (https://www.tredict.com/app/). It sits between Garmin Connect and my ChatGPT (they have a ChatGPT connector). Works just great for the training data - in seconds after finishing my training, it's also visible to my ChatGPT, with all the details like intervals, heart rate etc. It's a paid tool, but they offer a 2-month free trial so it's easy to validate for a given use case (and get dependent on it too. :) ).

No, I'm not affiliated with Tredict :) (but if you guys are reading it, good job)

Aldipower 1 day ago | parent

Yeah and overall it is a mature platform for endurance sport planning.

helsinkiandrew 2 days ago | parent

Claude (Opus5.5Medium) with "Claude in Chrome" can scan your activities in Strava and Garmin Connect websites and download GPX files without use of an MCP (perhaps not as quick).

I've found it can also give quite good suggestions for what kind of run to do after looking at my previous weeks activities on the Strava website.

Strongbad536 2 days ago | parent

Good stuff - i made one too that can deploy on cloudflare workers, originally based on garmin-givemydata:

- Syncs Garmin every 30 min into a database, so you don't hit garmin's API but rather my own

- Week/month trends for HRV, resting HR, sleep, training readiness, race predictions

- A "how am I today" brief: last night's sleep, HRV vs baseline, readiness, recent load

- Read-only SQL for the weird questions, like "does less sleep hurt my runs?"

My agents use it for daily briefs to me and when i ask about random health/exercise stuff - https://github.com/BrianVia/garmin-mcp-cloudflare-workers

kyzrfranz 2 days ago | parent

took it live, if you want to have a look if it works for you - go ahead :)

-> www.fitsel.app

I have been experimenting with using run-gap paid and my own agregation / mcp for a little over a year, and for me and my coach it works great. You'll get to dive into the numbers the way you prefer either via api or using any LLM which offers some new ways of looking at your data. And the whole thing is liberated from vendor specific interpretation. but thats just me, be curious to get some more thoughts on it.

khaki54 1 day ago | parent

I want this for the scuba version of the watch and frankly also the dog stuff too. I looked and yeah the ecosystem isn't very welcoming to integrate or build with.

vaultdweller101 1 day ago | parent

I created a Garmin CLI that just connects to Garmin Connect. My agent loves it. Now it is my coach which I anthropomorphize too much, but it has a lasting effect in the sense of keeping running. I also feel relieved to not use the awful iOS app or website anymore.

schwetim 1 day ago | parent

I would love to try your CLI

Melatonic 1 day ago | parent

You mean it connects to the "Garmin Connect" app on the watch ? What protocol / what device are you running it on ?

Also sounds like a great candidate for backing up (automatically) your Garmin data locally !

citruscomputing 1 day ago | parent

I wanted similar for my Oura ring, but all the MCP servers were unmaintained. Claude suggested a SQLite db with cron sync, built it, and it works pretty great. An MCP server would've been overkill, and slower probably too. Only downside so far is the Oura API doesn't expose some metrics I care about, like cumulative stress.

Currently experimenting with prompt-injecting my sleep score etc with a startup hook, so agents automatically give simpler responses when I'm not "all there." (Also using this data to make it suggest less complicated/demanding perfume samples to try on those days.) Curious if anyone else has cool use cases for feeding health data to the AI overlords.

Melatonic 1 day ago | parent

Have they published any data how they even calculate the "cumulative stress" metrics ? I would guess it's fairly straight forward