I keep hearing this on customer calls: "We aren't building the API for developers. We're building it for agents". These are new APIs designed specifically for agent consumption. The difference matters—agents will fail to use APIs that aren't properly designed. Sideko is proposing a cool workflow for teams building this way:

• First, design your API surface in OpenAPI

• Use Sideko to get a live mock server and a Python SDK

• Create an agent toolkit

• Give the agent tasks and measure performance in the mock environment

The immediate feedback from agents trying to use the API shapes the design and helps you iterate. All done before writing any API server code.