Android and tbdex

This shows the tbdex SDK working in Android in a simple mobile app with Kotlin. See MainActivity.kt for the main code showing tbdex APIs. Also includes an AndroidKeyManager implementation that uses the Android Keystore to store that tbdex uses for DIDs and VCs.

This can serve as a starter app for tbdex on android. I think I have said android enough times now.

Running

• Open this in Android Studio and run it with a emulator, it generates and shows a DID and will print out a verifiable credential.

To run with a PFI to test it end to end:

• Run a local tunnel to the tbdex server: cloudflared tunnel --url http://localhost:9000.
• Take note of the public https url provided in step 1, and set it to HOST environment variable.
• Take that same url and set it as the pfiServer in MainActivity.kt : private val pfiServer = host
• Follow instructions to start this PFI: https://github.com/TBD54566975/example-pfi-aud-usd-tbdex
• Run the app and you will see an offer loaded from the PFI, and then it will place an order.
• Check the logcat logs to see the result of the tbdex workflow including order status and completion.

Android specific tips

• exclude META-INF/DEPENDENCIES
• exclude other things like protobuf, bouncy castle etc so that it uses android shipped versions.
• Check out the build.gradle.kts file for more info.
• Allow plaintext for json-schema.org (see below) in your Android config

Plaintext for json-schema.org

If you get the error: com.networknt.schema.JsonSchemaException: java.io.IOException: Cleartext HTTP traffic to json-schema.org not permitted Then to the following:

Create file res/xml/network_security_config.xml

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">api.example.com(to be adjusted)</domain>
    </domain-config>
</network-security-config>

And add to AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest ...>
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        ...
        android:networkSecurityConfig="@xml/network_security_config"
        ...>
        ...
    </application>
</manifest>

(thanks to https://stackoverflow.com/questions/45940861/android-8-cleartext-http-traffic-not-permitted)

TODO:

• ✅ Add an RFQ and order placement
• Migrate AndroidKeyManager to web5-kt
• Package both web5-kt and tbdex-kt with an android option where the provided dependencies are already excluded to simplify usage.