Google Agent Development Kit (ADK) for TypeScript (github.com)

Google has released the Agent Development Kit (ADK) for TypeScript, an open-source, code-first toolkit (package: @google/adk, v0.1.0) for building, evaluating, and deploying advanced AI agents tightly integrated with Google Cloud. ADK emphasizes developer control: you define agent behavior, orchestration, tools and multi-agent hierarchies directly in TypeScript for better debugging, testing, versioning and deployment. A rich tool ecosystem supports pre-built tools, custom functions and OpenAPI integrations (example: LlmAgent using model "gemini-2.5-flash" with a GOOGLE_SEARCH tool), and ADK plans remote agent-to-agent communication via the A2A protocol. Technically, ADK is in early, pre-GA status — mostly stable but subject to breaking changes and not recommended for production. It’s distributed via npm/yarn and requires zod ^3.22.4 as a peer dependency. The repo uses esbuild and provides build scripts (build, build:bundle, build:watch) to produce CommonJS, ESM and bundled outputs. General community contributions are currently closed (organized teams may be considered), and the project is released under Apache 2.0 and governed by Google’s Pre-GA terms. For AI/ML builders, ADK promises fine-grained, code-centric agent development and multi-agent composition, but adopt cautiously while APIs and governance mature.