An input method sees every keystroke, so IPAbet is built to need as little trust as possible, and to make what remains verifiable.

• The keystroke-handling binary runs under the macOS App Sandbox with zero network entitlements. The OS denies it network access; this is enforced by macOS, not promised by us.
• No third-party dependencies. The macOS input method is compiled from first-party Swift against system frameworks only — no package manager is involved in the binary users install. This is policy, not accident.
• Release builds contain no logging code. The debug logger is compiled out of releases entirely (verifiable with strings); debug builds are published only as GitHub prereleases.
• One binary in the bundle, ipabet-register, runs unsandboxed by necessity (input-source registration writes session preferences the sandbox would redirect). It is deliberately small; changes to it get extra scrutiny.

Every release is built on the maintainer's machine, install-tested in a disposable clean-VM gate, signed with a Developer ID certificate that never leaves that machine, notarized by Apple, and stapled. Gatekeeper will refuse a package that was not signed and notarized this way — including a tampered asset uploaded by a compromised GitHub account.

To verify a downloaded package yourself:

spctl -a -vv -t install IPAbet.pkg   # expect: accepted, Notarized Developer ID: Brian Kim (2R9XM4BRFZ)
shasum -a 256 IPAbet.pkg             # compare against the checksum in the release notes

Please report suspected vulnerabilities privately via GitHub's private vulnerability reporting on this repository rather than a public issue.