Time to first hello world (TTFHW), also called time to first call (TTFC), measures how long a new user takes to make their first API call. It is an acquisition metric: a developer may sign up, obtain an API key, and try the API in a sandbox before deciding whether to integrate it into an application. section 11.1.3
To track TTFHW, connect the start and end of that journey:
- Record the user's sign-up event and its time. section 11.1.4
- Associate the user's first API call with that sign-up, then inspect the elapsed time in a user lookup or funnel report. section 11.1.3 section 11.1.4
Product Catalog API simulation
A GitHub Actions workflow simulates developer sign-ups and API calls and sends their events to Moesif. The resulting reports show sign-ups, individual TTFHW values, and a funnel result. In one run, six users who made an API call after signing up had a reported TTFHW of 6 minutes 19 seconds. The simulation produces values in minutes; real-world intervals may span days, weeks, or months. section 11.1.4
Keep TTFHW distinct from time to first transaction (TTFT), which concerns a first production API call. A quick sandbox call shows that a developer reached an initial result; it does not establish production use. section 11.1.3
