What is the unit of value in APIs?

Building a platform to power a marketplace of APIs is interesting both from a product and a technical perspective. Platforms have three major components:

• Producers: participants that create items that are traded in the marketplace.
• Consumers: participants that acquire items available in the marketplace.
• Unit of value: the items that are traded in the marketplace.

So, for example, in the case of Airbnb, producers are anyone listing their properties to rent, consumers are anyone that rents a property, and the unit of value is a listed property.

What is the unit of value in APIs? If you were to create an API marketplace, what would you target as the unit of value?

I believe the unit of value in APIs is a single capability and not the whole API (unless the entire API consists of a single capability). Single capabilities are often mapped to individual API operations. However, they can also be a group of operations orchestrated in a flow.

Single API capabilities are easy to understand by consumers. They’re easy to mix with other capabilities from the same API or even from other APIs. They’re also easy to integrate with products and easy to consume from various interfaces. Capabilities are, in fact, what consumers are looking for.

Single API capabilities can also have different names, depending on the company promoting them as the unit of value.

• Actions: Google and Apple use this word to describe what their voice assistants provide. Behind the scenes, each action is powered by a capability. IFTTT, Zapier, and other products also use this word to describe what you can do with API capabilities.
• Skills: how Amazon calls the things you can do with its voice assistant. Each skill is powered by a capability.
• Plugins: this is how tools like ChatGPT call the things you can do with external APIs. They recommend that plugins be concise with a limited amount of API operations.

Ultimately, consumers want the capabilities provided by the APIs, not the APIs themselves. Consumers prefer capabilities that are small, easy to understand and use, and easy to mix with other capabilities.