Garmin Connect IQ vs Health API vs Activity API

Connect IQ vs Health API at a glance#

One question decides it: does your code run on the watch, or on your server after the watch syncs?

The Health API and Activity API split by data, not by access: both come through the same partner program and push delivery, and your partnership agreement sets which of them you get.

What Connect IQ is#

Connect IQ is Garmin's platform for apps that run on its wearables. Garmin's connectiq-apps repository, whose README says it is "officially maintained by the Garmin Connect IQ team", lists these types:

In our reading, the data field is the type that overlaps most with the Health and Activity APIs, because it works on the activity itself. The same README describes Garmin Connect as giving users a dashboard and tools for reviewing their fitness activities, including custom data from Connect IQ apps, so a data field's values can show up in the user's own activity view in Garmin Connect.

The phone side: companion SDKs#

Garmin's iOS companion SDK README says: "The Connect IQ Mobile SDK allows companion iOS applications to be created that interact with Monkey C applications running on Garmin wearable devices." It gives two examples of what that enables: retrieving remote data, and offloading resource-intensive tasks from the wearable to the iOS device.

On Android, the Connect IQ SDK for Android is published on Maven Central as com.garmin.connectiq:ciq-companion-app-sdk. Its README describes two samples that work as a pair: Comm Android, a companion app that runs on the phone, and Comm Watch, the matching watch app, which sits in the samples folder of the Connect IQ SDK for devices. The Maven Central listing named 2.4.0 as the latest release when we read it on October 12, 2026; its metadata was last updated on March 27, 2026.

Both companion READMEs tie the download to Garmin's License Agreement, so read it before you ship. Nothing on this page is legal advice; confirm with counsel what the agreement means for your product.

What the Health API and Activity API are#

These are server-to-server feeds, not code that runs on the watch. After a user's device syncs, Garmin sends that user's data from its cloud to endpoints on your backend. What follows comes from our Garmin API integration guide as verified on July 9, 2026, except where a bullet names Garmin's own FAQ:

• Health API: all-day wellness metrics such as heart rate, steps, sleep, stress and Pulse Ox.
• Activity API: per-activity data; Garmin's page names running, cycling, swimming, yoga and strength training and gives no total count.
• Auth: OAuth 2.0 with PKCE, which gives you a per-user userAccessToken.
• Delivery: you register callback URLs and Garmin POSTs to them. Ping sends a notification carrying a callbackURL that you then GET; Push sends the full data inline as JSON. You do not poll, which changes how you design ingestion; see webhooks vs polling for fitness data.
• Access: the Garmin Connect Developer Program is approval-only, not self-serve. Garmin's program FAQ, read on October 22, 2026, describes Starter and Enterprise Access and says that once your request is approved you get the Garmin Developer Portal; it no longer states a review time, and personal-use questions now go to Garmin's separate Personal API. Our page on what to do about Garmin's approval gate covers the options.
• Other programs: a partnership may cover others, such as a Training or Women's Health API. Verify what yours includes.

Garmin's partner docs are gated, so verify hosts, scopes and summary-type names against the current partner docs rather than any public page.

What we could not verify about Connect IQ#

Garmin's developer site could not be reached from our environment on October 12, 2026, so everything about Connect IQ on this page comes from Garmin's GitHub repositories and Maven Central. We left these gaps open rather than guess; check each in Garmin's developer documentation before a design depends on it:

• Whether apps submitted to the Connect IQ Store go through a review, and how long it takes.
• Which sensors and metrics a Connect IQ app may read, and on which devices. We have no device compatibility list.
• Whether a Connect IQ app may send data to your own server directly.
• Whether custom data from a Connect IQ app is included in what the Activity API delivers.
• Costs or fees of any kind for Connect IQ.
• The current version of the Connect IQ SDK for devices.

Which one do you need?#

Our recommendation, by what you are building:

• A custom value computed during a run or ride, inside Garmin's own activity: a Connect IQ data field.
• Your own activity type on the watch: a Connect IQ device app, which Garmin says "can implement third party activities".
• Something on the home screen, or one glance away from it: a watch face or a widget.
• Watch features that need remote data or heavy processing: add a companion phone app built on Garmin's companion SDK for iOS or Android.
• All-day wellness for many users, in your backend: the Health API.
• Per-activity data for many users, in your backend: the Activity API.
• An on-watch experience and backend history: both, as two separate integrations. The server side depends on partner approval, so plan it around the reported sign-up hold.
• No route to partner approval: read Garmin API alternatives before you design around Garmin's server feeds.

If you also build for Apple Watch or Wear OS, our watchOS vs Wear OS development guide covers the matching on-watch layer there.

A fourth path for personal projects: garminconnect#

garminconnect is neither Connect IQ nor a Garmin API. It is an unofficial Python client for Garmin Connect's web services that signs in with the user's own credentials, and its README says "it does not pair with the Garmin Connect phone app or connect directly to a watch." In our reading it suits, at most, a personal script against your own account, and our Garmin approval page records that Garmin blocks third-party clients and that using them breaks its terms; for your own data, Garmin's official Personal API is now the better start. For an app that serves other people's data, our garminconnect library page points to Garmin's official program, and so do we.