Automate Signup Testing With a Temp Mail REST API and Python SDK

Testing a signup flow by hand (generate an address, submit the form, switch tabs, wait, copy the code, switch back) is fine the first time. By the tenth time, it's the part of your job you dread most, and it's exactly the kind of repetitive, well-defined task that should be a script instead of a habit.

The shape of the automation

Every version of this follows the same four steps regardless of language or tooling: create a disposable inbox, submit your app's signup form using that address, wait for the verification email to arrive, extract the code or link from it and complete the flow. The only thing that changes between a five-line prototype and a maintainable test suite is how much of steps one, three, and four you're handling yourself versus letting the API do for you.

Starting from raw requests

You can do this with nothing but an HTTP client: POST /aliases/ to create an inbox, submit your form with the returned address, then GET /aliases/{alias}/otp/ to pull the extracted verification code directly. No regex, no manually parsing the email body; the extraction already happened server-side. That's genuinely enough for a quick script.

Where the Python SDK actually helps

Once this pattern shows up in more than one test, hand-rolled HTTP calls start costing you in duplicated error handling and inconsistent timeout logic across files. The zephbox Python package wraps the same endpoints in a typed client: client.create_and_wait_for_otp(timeout=20) collapses the whole create-submit-wait-extract sequence (minus your own form submission, which is app-specific) into one call that raises a real exception if nothing arrives in time, something a test suite can assert on directly instead of parsing a raw HTTP status code.

Fitting it into an existing suite

Because the SDK is just a thin Python client, it drops into whatever test runner you're already using, whether that's pytest, unittest, or a CI job calling a script directly, without needing a browser automation layer or a mock email server. The inbox is real, the mail is real, and the assertion is on real extracted data, which catches integration bugs a mocked inbox never would.

Full reference in the API documentation. If you're automating this from an AI agent rather than a test script, see the MCP server instead — same underlying API, different calling convention.