The most important API metric is time to first call

Published July 12, 2021

Joyce Lin
Contributor

Joyce Lin is head of developer relations at Postman.

API publishers among Postman’s community of more than 15 million are working toward more seamless and integrated developer experiences for their APIs. Distilled from hundreds of one-on-one discussions, I recently shared a study on increasing adoption of an API with a public workspace in Postman. One of the biggest reasons to use a public workspace is to enhance developer onboarding with a faster time to first call (TTFC), the most important metric you’ll need for a public API.

If you are not investing in TTFC as your most important API metric, you are limiting the size of your potential developer base throughout your remaining adoption funnel.

To understand a developer’s journey, let’s first take a look at factors influencing how much time and energy they are willing to invest in learning your technology and making it work.

Urgency: Is the developer actively searching for a solution to an existing problem? Or did they hear about your technology in passing and have a mild curiosity?
Constraints: Is the developer trying to meet a deadline? Or do they have unlimited time and budget to explore the possibilities?
Alternatives: Is the developer required by their organization to use this solution? Or are they choosing from many providers and considering other ways to solve their problem?

Developer journey to an API

With that context in mind, the following stages describe the developer journey of encountering a new API:

Step 1: Browse

A developer browses your website and documentation to figure out what your API offers. Some people gloss over this step, preferring to learn what your tech offers interactively in the next steps. But judgments are formed at this very early stage, likely while comparing your product among alternatives. For example, if your documentation and onboarding process appears comparatively unorganized and riddled with errors, perhaps it is a reflection of your technology.

Step 2: Signup

Signing up for an account is a developer’s first commitment. It signals their intent to do something with your API. Frequently going hand-in-hand with the next step, signing up is required to generate an API key.

Step 3: First API call

Making the first API call is the first payoff a developer receives and is oftentimes when developers begin more deeply understanding how the API fits into their world. Stripe and Algolia embed interactive guides within their developer documentation to enable first API calls. Stripe and Twitter also use Postman public workspaces for interactive onboarding. Since many developers already use Postman, experiencing an API in familiar territory gets them one step closer to implementation.