A clean Android age gate built with Java, JNI, and a native 18+ date check.
Chiki AgeGate is a fullscreen age-verification gate for Android apps. It asks the user whether they are a minor or 18+, then checks the selected birth date through native C++ code before allowing the app to continue.
The whole interface is built in Java, so there is no XML layout maze and no giant UI dependency stack. The native side handles the date rules, prompt strings, and the local verification token.
It is an age gate, not an identity check. Keep that difference in mind before treating it like legal compliance magic.
Alright, check this out — here's Chiki AgeGate in action.
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- Shows a non-cancelable fullscreen verification dialog.
- Offers clear minor and 18+ choices.
- Closes the app when the user selects the minor option.
- Uses a custom year, month, and day picker.
- Checks leap years, valid calendar dates, future dates, and the user's current age.
- Requires the user to be at least 18 years old.
- Keeps the selected birth date in memory only; the actual date is not saved to preferences.
- Stores only a local verified-state token after a successful check.
- Obfuscates native strings with
EasyObfuse. - Uses random native prompt text so the opening message is not always identical.
- Supports an optional second birth-date confirmation flow.
- Includes smooth entry, exit, picker, logo, and invalid-choice animations.
- Uses a custom logo and font from Android assets, with built-in fallbacks.
- Requires two back presses within a short window before leaving the main gate.
- Styles
NumberPickeracross different Android implementations without XML themes.
App opens
↓
Was this installation already verified?
├─ Yes → continue
└─ No → show Chiki AgeGate
↓
User says "minor"?
├─ Yes → close the app
└─ No → select birth date
↓
Native 18+ check
├─ Fail → show feedback and stay locked
└─ Pass → save verified token and continue
Use this layout unless your build setup already has its own structure:
app/
└── src/
└── main/
├── java/
│ └── com/chiki/makigate/
│ └── ChikiVerification.java
├── cpp/
│ ├── ChikiVerification.cpp
│ └── EasyObfuse.h
└── assets/
└── chiki/
└── age_verify/
├── logo.png
└── font.ttf
The banner used by this README belongs here:
banner/chiki-agegate-banner.png
- Android project with Java support
- Android NDK and JNI
- C++11 or newer
- CMake, ndk-build, or another compatible native build setup
- A generated native library named
libmakigate.so ChikiVerification.javaChikiVerification.cppEasyObfuse.h
The Java class loads the native library with:
System.loadLibrary("makigate");Your native target therefore needs to be named makigate.
Call the verifier from an Activity:
import com.chiki.makigate.ChikiVerification;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ChikiVerification.verify(this);
}The method signature is:
public static void verify(Activity activity);The matching Smali call is:
invoke-static {p0}, Lcom/chiki/makigate/ChikiVerification;->verify(Landroid/app/Activity;)VThere is no move-result here because verify(Activity) returns void. This example also assumes p0 contains the current Activity, which is normally true inside a non-static Activity method such as onCreate.
If the Activity is stored in another register, replace p0 with that register.
The current Java class declares these native methods:
public static native String nRkVxQpLm();
public static native boolean zMpwQbLrS(int year, int month, int day);
public static native boolean qTrLxVmNp(int year);
public static native String pXvNqRtKm(String plain);
public static native String vLmQrXpNz(String encrypted);Their JNI exports are tied to this exact class path:
com.chiki.makigate.ChikiVerification
Changing the package, class name, or native method names means changing the matching JNI symbols in ChikiVerification.cpp too. JNI is very literal; one wrong character and it simply refuses to cooperate.
For release builds, keep the bridge class from being renamed by R8/ProGuard:
-keep class com.chiki.makigate.ChikiVerification { *; }
Chiki AgeGate looks for these files:
assets/chiki/age_verify/logo.png
assets/chiki/age_verify/font.ttf
logo.png is center-cropped into a circular image. When the logo is missing, the UI falls back to a generated purple circle.
font.ttf is used for the creator title. When it cannot be loaded, Android's default bold typeface is used instead.
Tapping the logo currently opens the hardcoded community link inside openLogoLink(). Replace that URL with your own page, group, or project link before publishing a fork.
| Setting | Current value |
|---|---|
| Minimum age | 18 |
| Earliest accepted birth year | 1980 |
| Native library | makigate |
| Preference file | maki_gate_enc |
| Preference key | vrf |
| Double-back exit window | 1800 ms |
| Random prompt count | 7 |
| Second date confirmation | Disabled |
The earliest birth year exists in both Java and C++:
private static final int MIN_BIRTH_YEAR = 1980;static const int kMinimumBirthYear = 1980;Change both values together. Updating only one side will create inconsistent behavior between the picker and the native validator.
The Java side already contains a second-step flow that asks the user to enter the same birth date again. Right now, it is disabled because the native method below always returns JNI_FALSE:
Java_com_chiki_makigate_ChikiVerification_qTrLxVmNp(...)That means successful users normally verify once and continue. The second picker can be enabled later by changing the native policy behind that method.
After a successful check, Chiki AgeGate stores an obfuscated verified token in private SharedPreferences.
The actual birth date is not written to preferences. It is used for the current verification flow and then discarded.
The stored token is wrapped with a lightweight native XOR-and-Base64 routine. That keeps it out of plain text, but it is not strong cryptography and should not be advertised as tamper-proof storage.
Chiki AgeGate performs its birth-date check locally. It does not upload the entered date or require a network request for verification. The only external action in the supplied code is the creator-logo link, which opens after the user taps the logo.
This project is a client-side age gate. A determined person can lie about a birth date, reset local app data, patch the APK, or modify the verification flow. Use it as a clear access barrier and user-facing confirmation step—not as proof of identity, a government-ID check, or a guarantee of compliance with every law or platform policy.
For stronger protection, pair it with whatever makes sense for your app:
- Server-side account rules
- Platform parental controls
- Region-aware compliance logic
- Code obfuscation and integrity checks
- Clear privacy and content notices
- A proper legal review for the countries you actually serve
- Pressing Nah, I'm a minor clears the verification flag and closes the process.
- A failed or underage date keeps the picker open and plays a short shake animation.
- Pressing Back on the main gate once shows a warning; pressing it again within
1800 msexits. - Pressing Back inside the date picker returns to the main gate.
- Once the verified token is accepted, later calls to
verify()return immediately. - Clearing the app's local data resets the verification state.
The easiest parts to change are:
- Banner, logo, and font
- Creator title and subtitle
- Button labels
- Dialog colors and gradients
- Random native prompts
- Minimum age
- Earliest accepted birth year
- Community/project link
- Preference file and key
- Exit timing
- Second confirmation policy
Keep Java and C++ constants synchronized whenever the same rule exists on both sides.
Chiki AgeGate uses the Chiki AgeGate License. Read the full terms in LICENSE.
This is a source-available license, not an OSI-approved open-source license. You may study, use, and modify the project under its terms, but you may not erase the original credit, pretend the original work is yours, or redistribute a renamed copy without proper attribution.
Created by ridhoae303.
© 2026 ridhoae303. All rights reserved except where permission is granted in the license.