adk-agent-builder
Builds ADK (Agent Development Kit) Python agents: LLM agents with tools, graph workflows of function and agent nodes, conditional routing, fan-out and join, schema-validated delegation between agents, human-in-the-loop pauses, and pytest coverage for all of it. Use when asked to create an agent or a workflow, add a tool to one, branch or loop between nodes, run steps in parallel, pause for user approval, or test an agent. Don't use for explaining how ADK works internally or designing its core components (use adk-architecture), for an agent that already runs but misbehaves (use adk-debug), for authoring a sample under contributing/ (use adk-sample-creator), or for naming, typing, and formatting conventions (use adk-style).
- Installs
- 459
- Last 24h
- +35
- Trending rank
- #4122
- Security
- Not audited
Install
Works with every agent the skills CLI supports.
npx skills add https://github.com/google/adk-python --skill adk-agent-builder- 01
Install
Run the command in your project. The CLI asks which agents to install for.
- 02
Describe the task
Ask your agent for something this skill covers. It loads adk-agent-builder automatically when relevant.
- 03
Review the result
The agent follows the SKILL.md steps, scripts and references bundled with the skill.
SKILL.md
The instructions your agent reads when the skill is triggered.
ADK Agent Builder
Read only the reference that matches the task. Loading the whole tree costs context and buries the part that matters.
Every API below was checked against google-adk 2.6.2. If a symbol is missing
at runtime, read the source under src/google/adk/ rather than guessing a
neighbouring name.
Start here
| Task | Reference |
|---|---|
First agent, environment, adk CLI | getting-started.md |
| Which import path is the canonical one | import-paths.md |
| The rules that cause most runtime failures | best-practices.md |
Building blocks
- tool-catalog.md — function tools, MCP, OpenAPI,
Google API toolsets, built-in tools, custom
BaseToolandBaseToolset. - function-nodes.md — plain functions as nodes:
parameter resolution, generators,
node_inputtyping rules. - llm-agent-nodes.md — an
LlmAgentused as a workflow node: output types, instruction templates,output_schema, auto-wrapping behavior. - task-mode.md —
mode='task'andmode='single_turn'delegation with schema-validated input and output.
Graph orchestration
- routing-and-conditions.md — routed edges, dict routing maps, default routes, self-loops, revision loops.
- parallel-and-fanout.md — fan-out edges,
JoinNodefan-in,parallel_worker=Truelist processing. - dynamic-nodes.md — scheduling nodes at runtime
with
ctx.run_node()and imperative workflow construction. - human-in-the-loop.md —
RequestInput, resume behavior, resumable vs replayed sessions. - advanced-patterns.md — nested workflows,
retries, custom
BaseNodesubclasses, graph validation rules. - multi-agent.md — chat-transfer hierarchies, and
the deprecated
SequentialAgent/LoopAgent/ParallelAgentshells thatWorkflowreplaces.
Runtime and verification
- state-and-events.md — the
Contextobject,Eventfields, and how state flows between nodes. - session-and-state.md — session services, artifacts, memory, and state key scoping.
- callbacks-and-plugins.md — the six agent callbacks and app-level plugins.
- testing.md —
pytestwithInMemoryRunner, faking a model, asserting on node output.
FAQ
What does the adk-agent-builder skill do?
Builds ADK (Agent Development Kit) Python agents: LLM agents with tools, graph workflows of function and agent nodes, conditional routing, fan-out and join, schema-validated delegation between agents, human-in-the-loop pauses, and pytest coverage for all of it. Use when asked to create an agent or a workflow, add a tool to one, branch or loop between nodes, run steps in parallel, pause for user approval, or test an agent. Don't use for explaining how ADK works internally or designing its core components (use adk-architecture), for an agent that already runs but misbehaves (use adk-debug), for authoring a sample under contributing/ (use adk-sample-creator), or for naming, typing, and formatting conventions (use adk-style).
How do I install adk-agent-builder?
Run npx skills add https://github.com/google/adk-python --skill adk-agent-builder in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/adk-agent-builder/ (personal) or .claude/skills/adk-agent-builder/ (project).
Which AI agents can use adk-agent-builder?
Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.
Is adk-agent-builder safe to install?
No partner security audit is available yet. Skills can run commands and scripts, so read the SKILL.md and any bundled files before installing.
Who maintains adk-agent-builder?
It is published by google in google/adk-python. It has 459 recorded installs.
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Open the skill to read its SKILL.md instructions.
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