# Check Signature

> Verify Android APK signing certificates and compare signer fingerprints with apksigner

- Skill: `jason0404/check-signature` (Agent Skill)
- Install (CLI): `npx skillmds@latest add jason0404/check-signature`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jason0404/check-signature/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: jason0404 (https://skillmd.com/u/jason0404)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/jason0404/check-signature

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Verify signing for one or more `.apk` files.

## Workflow
1. Confirm supplied files exist and are APKs.
2. Locate `apksigner` cross-platform through PATH or Android SDK build-tools locations.
3. Invoke `android-apk-signing-verifier`.
4. Use `apksigner verify --print-certs` when available.
5. Report verification status, signer count and certificate SHA-256 digest where returned.
6. When comparing APKs, state whether the confirmed certificate fingerprints match.
7. Generate an HTML report only when requested.

## Safety
Never request or expose keystore passwords or private signing material. Do not claim which Play Console key a certificate represents unless that evidence was separately provided.