Kiln protects the integrity of downloaded client code, session credentials, local settings, and the host system.

• APK files are untrusted until their v3 or v2 signing block, content digest, signer signature, leaf certificate fingerprint, and required ABI entries all verify.
• APKCombo catalog pages and download links are untrusted metadata. They may select a candidate, but cannot authorize installation. Kiln permits only the expected HTTPS catalog paths, limits response sizes, and still requires the pinned Roblox signature and exact package name.
• Archive paths are untrusted and must be rejected when absolute or when any component is ...
• Deep links and manifest content are untrusted input and never enter a shell.
• Session cookies belong in the desktop secret service when available and never in logs.

There is no override for signature failure, signer mismatch, unsupported signature algorithms, or a missing host ABI. A rejected downloaded APK is deleted. A manually selected APK remains the user's file but is never installed.

The pinned Roblox signing-certificate SHA-256 was extracted from a real com.roblox.client APK on 2026-08-21 and independently matched against the certificate fingerprint published by Roblox in its Digital Asset Links declaration. It is compiled into the verifier and has no runtime override. Kiln also rejects a signed APK unless its manifest package is exactly com.roblox.client.

Automatic checks run at most once every 24 hours when a verified client is already installed. Downloads happen directly on the user's machine and are never bundled with or redistributed by Kiln. If the catalog changes or is unavailable, the installed verified version is retained and manual import remains available.

Kiln does not patch, hook, rewrite, or inject into engine code. It does not use ptrace, manipulate game state, evade anti-cheat, spoof a specific device, or claim to prevent account enforcement.

Diagnostics redact usernames, home directories, cookies, and tokens. Runtime errors include a cause, technical detail, and actionable remedy.