Trust and data flow

Your permission, your route, your receiver, your agent configuration.

Health Bridge reads only the Apple Health categories the user permits, delivers them to a receiver the user controls, stores them there, and exposes bounded read-only MCP and CLI access only on the receiver machine.

Readable architecture, not legal policy

Two different documents: This page explains the product architecture in plain language. The Privacy Policy remains the legal statement about data handling.

Data flow

  1. Apple Health permissionThe companion requests read access through Apple's authorization sheet. The user chooses which supported categories to allow.
  2. iPhone companionThe app reads permitted observations and can retain limited connection, sync, and pending-delivery state on the device.
  3. User-configured routePermitted data crosses the network route that the user prepared for the physical iPhone to reach the receiver.
  4. Receiver and local interfacesThe receiver stores the delivered copy and provides bounded read-only MCP and CLI queries on that machine.

Trust boundaries

Apple and the device

HealthKit and iOS enforce authorization and background-execution behavior. Health Bridge cannot bypass denied categories or promise a specific delivery schedule.

The network route

The receiver URL is supplied by the user, not by Health Bridge. The operator is responsible for reachability, transport security, authentication, and exposure.

The receiver and storage

The receiver process and database run on infrastructure the user chooses. Health Bridge does not operate a central health-data store for this path.

The AI client

Adding a client gives another local process the ability to query the private database through bounded interfaces. Setup detects adapters but does not modify client configuration without an explicit choice.

What read-only means

  • The iPhone companion requests HealthKit read access; it does not add, edit, or delete Apple Health records.
  • The MCP server and direct CLI expose bounded query operations rather than write tools or raw SQL.
  • An AI client's own behavior is outside the bridge boundary. Review the client and model configuration before sharing context with it.

Read-only does not mean risk-free. Any process that can read private data must be chosen, configured, and protected deliberately.

Receiver and storage ownership

Pairing tells the companion where to send permitted data. The destination, receiver process, credentials, database, backups, and retention practices belong to the user's environment. A local computer, private network route, or user-managed host can still be misconfigured or compromised.

The operational install guide requires the receiver to be supervised and checked from both the receiver host and physical iPhone before pairing. It also warns against exposing the receiver port or pairing page publicly.

Revocation and deletion

  • Stop future HealthKit reads: change or revoke the app's permissions in Apple Health or iOS Settings.
  • Stop future delivery: disconnect the receiver or remove the app, following the controls described in support.
  • Remove pending device data: use the available clear-pending-data control, then remove the app if the entire local container should be deleted.
  • Delete the receiver copy: purge or delete data on the receiver and any backups you operate. Revoking HealthKit access does not remove data already delivered.

Non-medical scope

Health Bridge is a data plane. It does not diagnose, treat, coach, provide emergency guidance, or turn an AI agent into a medical service. Its interfaces return source-grounded data and provenance for the user-chosen client to handle.

Sources and related pages

Review the operational path only after the trust boundaries match the environment you intend to run.