Definition
Plain language
A packaged toolkit a developer (or an AI agent) uses to call an external service through well-defined functions.
As stated in the literature
A Software Development Kit, a library and set of tools exposing a system's functionality to developers or agents through structured APIs.
Why it matters: SDKs are how agents reach external services in practice, so the design of an SDK shapes what an agent can easily do and what's effectively out of reach.
For example, the OpenAI Python SDK gives a developer (or an AI agent) a single `client.chat.completions.create(...)` call that handles all the HTTP details.
Heard on the show
“They register a poisoning tool through a commercial agentic SDK using its official tool-definition API.”Episode 039 — When Smarter Agents Get Fooled by Three Extra Nodes in a Database