Security of Offgrid Coder
Last updated: 10 November 2026 · applies to the iPad app and Offgrid Coder Companion for macOS
In short
- The language model computes on your iPad. Prompts and source code go to no server.
- The iPad only talks to the one Mac you paired yourself by cable – encrypted.
- The server only runs when you start it, and only while the app is in the foreground.
- The content of your requests appears in no log.
Pairing
- Pairing works only over the USB-C cable. The iPad shows an eight-digit code that is valid for 120 seconds and allows at most five attempts.
- During pairing the devices exchange a random 256-bit secret. It is kept in the keychain of both devices, is bound to each device and is not synced through iCloud.
- An iPad is paired with exactly one Mac. Unpairing deletes the secret.
Connection between Mac and iPad
- Every connection is encrypted with TLS 1.2 (ECDHE-PSK with ChaCha20-Poly1305). Without the secret from pairing no connection is established – not even from another Mac on the same cable.
- A new session key is derived from the secret for every server session.
- Only the operating system's own cryptography is used.
- The port for requests is only open while the server is running. After stopping, and after restarting the app, it is closed.
On the Mac
- The Companion only accepts requests from your own machine (127.0.0.1) and requires a local access token.
- Requests coming from web pages in a browser are rejected.
- Before the Companion changes the Continue configuration, it backs up the existing one and verifies the backup. “Rollback” restores it unchanged.
- The Companion is signed with a Developer ID and notarized by Apple. The checksum of the download is shown on the product page.
Models
- The catalog models are pinned to fixed versions. Every file is verified with SHA-256 after download and before each start; a damaged or modified model does not start.
- Before start-up the app checks whether the model fits into memory. A resource guard pauses the model when the device is hot, short on memory or low on battery.
What Offgrid Coder does not do
- No protection against someone with access to your devices. Whoever holds your unlocked iPad or is an administrator on your Mac can read along.
- Programs running under your user account on the Mac can read the local access token from the Continue configuration and send requests to the iPad.
- The pairing code is short. That is why pairing is restricted to the cable; a protocol that would make wireless pairing safe is not built in.
- Answers from a language model can be wrong – and they can be influenced by text inside the project, for example in third-party files or dependencies. Review generated code and suggested commands before you use them.
- No independent audit. Offgrid Coder has not yet been examined by an external party.
Reporting a vulnerability
Please report vulnerabilities in the app, the Companion or this website by email to info@zerfas.de, subject “Security report”. App version, iPadOS and macOS version and the steps to reproduce are helpful. Please do not send confidential source code.