Comparisons / Anthropic Agent SDK vs Google ADK
Anthropic Agent SDK vs Google ADK: Which Agent Framework to Use?
The Anthropic Agent SDK packages Claude Code's agent loop as a library. Google's Agent Development Kit (ADK) is an open-source framework for building multi-agent systems. Here is how they compare — paradigm, ecosystem, and the use cases each one is actually built for.
By the numbers
Anthropic Agent SDK
3.1k
582
Python
MIT
2023-01-17
Anthropic
Google, Spark Capital
Yes
Google ADK
18.7k
3.2k
Python
Apache-2.0
2025-04-01
Google/Alphabet
Vertex AI
Yes
GitHub stats as of April 2026. Stars indicate community interest, not necessarily quality or fit for your use case.
| Concept | Anthropic Agent SDK | Google ADK |
|---|---|---|
| Agent | Claude agent with built-in tools, MCP servers, and system prompt | `LlmAgent` class with model, instructions, and `sub_agents` list |
| Tools | Built-in tools (`bash`, file read/write, web) + MCP server connections | `FunctionTool`, built-in tools (Search, Code Exec), third-party integrations |
| Agent Loop | SDK's internal agentic loop with automatic tool dispatch | `Runner.run()` with automatic tool dispatch and sub-agent delegation |
| Sub-Agents | Agents invoke other agents as tools via the SDK | — |
| Lifecycle Hooks | 18 hook events: pre/post tool call, message, error, etc. | — |
| MCP Integration | One-line MCP server config for Playwright, Slack, GitHub, etc. | — |
| Multi-Agent | — | Hierarchical agent tree with root agent delegating to specialized sub-agents |
| Workflows | — | `SequentialAgent`, `ParallelAgent`, `LoopAgent` workflow primitives |
| Session | — | Session and State service with typed channels and persistence |
Anthropic Agent SDK vs Google ADK, head to head
Anthropic Agent SDK The Anthropic Agent SDK packages Claude Code's agent loop as a library.
Google ADK Google's Agent Development Kit (ADK) is an open-source framework for building multi-agent systems.
Both wrap the same underlying agent pattern — an LLM call, a tool dispatch, a loop — in different abstractions. The choice between them is mostly about which mental model and ecosystem fits the team you have, not which one is technically more capable.
Pick Anthropic Agent SDK if
Pick Anthropic Agent SDK if the Anthropic Agent SDK's real value is packaging Claude Code's battle-tested agent loop with built-in tools and MCP integration. If you want a production agent that reads files, runs commands, and connects to services, it saves significant plumbing. For understanding how agents work, the plain version is more instructive. Anthropic Agent SDK is the right fit when the tradeoffs in its intro line up with how your team actually wants to work day-to-day; Google ADK would force you to translate.
Pick Google ADK if
Pick Google ADK if aDK earns its complexity when you need multi-agent orchestration on Google Cloud with Vertex AI deployment. If you're using Gemini and need production-grade agent infrastructure, it's well-designed. For single-agent use cases or non-Google stacks, plain Python keeps things simpler. Google ADK is the right fit when the tradeoffs in its intro line up with how your team actually wants to work day-to-day; Anthropic Agent SDK would force you to translate.
What both add
Both Anthropic Agent SDK and Google ADK pull in a class hierarchy and a dependency tree to wrap what is, at the core, an HTTP POST in a while loop. If your use case is straightforward — one provider, a handful of tools, a single agent — the framework cost may exceed the framework benefit. The lesson below shows the same pattern in ~60 lines without either dependency.
Or build your own in 60 lines
Both Anthropic Agent SDK and Google ADK implement the same 8 patterns. An agent is a function. Tools are a dict. The loop is a while loop. The whole thing composes in ~60 lines of Python.
No framework. No dependencies. No opinions. Just the code.
Build it from scratch →