Genkit
Google‘s open-source framework for building full-stack, AI-powered / agentic applications — a library you embed in an app, positioned as the lower-altitude counterpart to adk. Its pitch: the gap between a single model call and a real agent (message history, tool loops, streaming, persistence) is infrastructure developers keep rebuilding, so Genkit “packages all of that behind one interface.”
What it offers (per the post)
- Agents API — define server-side agents with a system prompt, tools, and custom state. The same
chat()interface works whether the agent runs locally or remotely. - State / persistence — configurable session stores (in-memory, file, Firestore, or custom), distinguishing message history from custom application state and from generated artifacts. This is the memory/durability layer as a first-class, pluggable concern.
- HTTP-servable agents — agents are directly exposed over HTTP, with snapshot and abort companions.
- Full-stack client — a JS/TS remote agent client with an API identical to the backend agent, so front-end and back-end share one interface.
- Tool orchestration — interruption for human-in-the-loop workflows (the HITL checkpoint instinct) and delegation middleware for coordinating specialist agents (Genkit’s take on orchestration / the composable middleware unit).
- Developer UI — an Agent Runner to test conversations without writing client code.
- Languages — TypeScript, Go, Dart, and Python.
Genkit vs ADK
The post draws the line explicitly: adk is “purpose-built for complex agent topologies” and ships a managed runtime; Genkit is a library for embedding agents inside an application. So Google now fields two agent frameworks at different altitudes — an embeddable app library (Genkit) and a managed multi-agent runtime (ADK) — rather than one. That mirrors the broader harness-vs-runtime split this spoke tracks.
Tier
T1 — first-party Google engineering blog, authoritative about Genkit’s design. Promotional in framing (a “build with Genkit” guide), so feature emphasis is the vendor’s.