Android apps with a coding agent

A coding agent can test your Android app’s sign-up the way a person would: build it, run it in the Android Emulator, fill the form with a Proxy Mail QA test address, then enter the code or open the link from the email. Proxy Mail QA gives the agent the address and the email’s code or link; the agent drives the emulator with its own tools, usually adb.

Every setup below starts with Proxy Mail QA connected to the agent: paste the one-prompt setup, or connect the MCP server by hand.

Claude Code, Codex or Cursor with adb

Any agent that can run shell commands can drive the emulator through adb from the Android SDK’s platform tools. Start an emulator from Android Studio’s Device Manager (or emulator -avd with its name), open your project in the agent with Proxy Mail QA connected, and ask:

Build the debug app, install it on the running emulator and open it. Sign up with a new Proxy Mail QA test address, using the password it gives you, then enter the verification code from the email and check the app shows the account as verified. Take a screenshot at each step.

The agent then typically:

1. Builds and installs with ./gradlew installDebug, and opens the app with adb shell am start.
2. Calls create_address with password: true.
3. Finds the fields from adb shell uiautomator dump (or a screenshot from adb exec-out screencap -p), taps them with adb shell input tap and types with adb shell input text.
4. Submits, then calls wait_for_code or wait_for_link.
5. Types the code, or opens the link in the app with adb shell am start -a android.intent.action.VIEW -d and the link, so your App Link or custom scheme handles it.
6. Takes a screenshot and checks the screen shows the account as verified.

adb shell input text needs spaces written as %s and some characters escaped, so ask the agent to check each field after typing, especially passwords.

Android Studio’s Gemini agent

Android Studio’s agent mode can use remote MCP servers (Google’s guide). In Settings → Tools → AI → MCP Servers, select Enable MCP Servers and add:

mcp.json

{
  "mcpServers": {
    "proxymail-qa": {
      "httpUrl": "https://api.proxymail.qa/mcp"
    }
  }
}

Choose Start Login to sign in through your browser. Android Studio doesn’t support MCP prompt templates, so ask in plain words rather than choosing a prompt such as test_signup_flow. We haven’t tested Android Studio’s agent ourselves yet; if its sign-in doesn’t complete, use Claude Code or Codex alongside Android Studio instead.

What else to ask for

• A dev server on your computer. The emulator reaches your computer at 10.0.2.2, so a dev build’s links to 10.0.2.2:3000 are expected. Ask the agent to mark it as a dev environment (mark_dev_host), and check_email passes those links instead of failing them.
• App Links. After the link arrives, check_email with expect_host set to your App Link domain checks the link goes there, and count_emails catches a second email sent by mistake. If the link opens Chrome instead of the app, the domain’s assetlinks.json or the app’s intent filter is the usual cause.
• A code split into boxes. The agent taps the first box and types the whole code, then checks every digit landed before going on.
• A longer sign-up form. For a username with rules, a date of birth or a country, form_values gives a value for each field from a new address made for it.
• The same account next time. Ask the agent to record where the account is used (environment, such as staging, and tags such as android) when it creates it, so list_addresses finds it again. With an API key allowed to read saved passwords, get_sign_in returns the account and its password in one call.
• A report. The agent calls start_run first and finish_run at the end, which returns the report in Markdown.

Offers and marketing emails

• The coupon. After signing up for an offer in the app, wait_for_code with kind: coupon returns the coupon with its discount, end date and how long it took. The agent types it into the app’s promo field.
• Checkout, with test payments only. Use Google Play’s license testers and test cards, or the app’s own test mode, never a real card or a real purchase. The agent records what the app did with record_coupon_result.
• A coupon as a link that opens the app, such as myapp://redeem?code=…: wait_for_link with app: true returns it, and the agent opens it with adb shell am start -a android.intent.action.VIEW -d and the link.
• One offer per person. Signing up again with a version of the same address (get_address_variants), then check_offers, shows whether the app gave the offer twice.
• Awkward names and passwords. get_name_variants and get_password_variants give values for the form’s other fields (apostrophes, accents, other scripts, each symbol class, the field’s limits); the agent types each in and reports what the app did.
• Consent and unsubscribing. The agent records what it chose at sign-up with record_consent, unsubscribes from the app’s settings or the email’s link, calls mark_unsubscribed, and later check_unsubscribe lists any marketing that came after.

Writing it as a test instead

To keep the check as a UI test that runs in CI, see Android (Espresso), or Maestro for a flow that also covers iOS.