ADK Code Reference
Activate /google-agents-cli-workflow first for required development phases and scaffolding steps.
1. Study Recipes (No Project Needed)
Read the topic index in references/samples.md before answering "how do I build X". Worked implementations exist for: sandboxed/per-user code execution, agent-loadable SKILL.md skills, cross-session memory, approval gates before risky actions, tool guardrails, per-user credentials, and scheduled/event-driven runs.
The index only gives you a name; the recipe is the code. Clone it and read its AGENTS.md before you implement anything it covers. Hand-writing a Docker or E2B sandbox wrapper, a skill loader, a moderation callback or a memory store — for a capability the index lists — means you stopped at the name.
2. Prerequisites for Writing Code
Do NOT write agent code until a project is scaffolded.
- Verify project: run
agents-cli info (proceed if config exists).
- New project: run
agents-cli scaffold create <name>.
- Existing code: run
agents-cli scaffold enhance ..
Language Support: This reference covers the Python ADK SDK. Support for other languages coming soon.
Quick Reference — Most Common Patterns
from google.adk.agents import Agent
def get_weather(city: str) -> dict:
"""Get current weather for a city."""
return {"city": city, "temp": "22°C", "condition": "sunny"}
root_agent = Agent(
name="my_agent",
model="gemini-3.7-flash",
instruction="You are a helpful assistant that ...",
tools=[get_weather],
)
References
Use cheatsheets for common patterns. For deep knowledge, fetch the docs index or inspect the installed package.
| Reference |
When to read |
references/samples.md |
Topic-indexed catalog of ADK reference recipes. Read in workflow Phase 1 — before scaffolding and before writing code — maps a capability to the recipe that implements it. |
references/adk-python.md |
Core ADK API: Agent, tools, callbacks, plugins, state, artifacts, multi-agent systems, SequentialAgent / ParallelAgent / LoopAgent, custom BaseAgent, ManagedAgent (server-hosted first-party agents), A2A protocol, A2UI. Default for most agents. |
references/adk-workflows.md |
Graph-based Workflow API (ADK 2.0): nodes, edges, fan-out/fan-in, HITL, parallel processing. Use when you need explicit graph topology. |
curl https://adk.dev/llms.txt |
Docs index (every page title + URL). Fetch it, then WebFetch the specific page for anything beyond the cheatsheets. |
| Installed ADK package |
Exact signatures and symbols — inspect the source (see "Inspecting ADK Source Code" in references/adk-python.md). |
Related Skills
/google-agents-cli-workflow — Development workflow, coding guidelines, and operational rules/google-agents-cli-scaffold — Project creation and enhancement with agents-cli scaffold create / scaffold enhance/google-agents-cli-eval — Evaluation methodology, dataset schema, and the eval-fix loop/google-agents-cli-deploy — Deployment targets, CI/CD pipelines, and production workflows
1---2name: google-agents-cli-adk-code3description: This skill should be used when the user wants to "write agent code", "build an agent with ADK", "add a tool", "create a callback", "define an agent", "use state management", or needs ADK (Agent Development Kit) Python API patterns and code examples. Part of the Google ADK skills suite. It provides a quick reference for agent types, tool definitions, orchestration patterns, callbacks, state management, and reference recipes to study. Do NOT use for scaffolding (use google-agents-cli-scaffold) or deployment (use google-agents-cli-deploy).4---5
6# ADK Code Reference
7
8Activate `/google-agents-cli-workflow` first for required development phases and scaffolding steps.
9
10## 1. Study Recipes (No Project Needed)
11
12**Read the topic index in `references/samples.md` before answering "how do I build X".** Worked implementations exist for: sandboxed/per-user code execution, agent-loadable `SKILL.md` skills, cross-session memory, approval gates before risky actions, tool guardrails, per-user credentials, and scheduled/event-driven runs.
13
14The index only gives you a name; the recipe is the code. Clone it and read its `AGENTS.md` before you implement anything it covers. Hand-writing a Docker or E2B sandbox wrapper, a skill loader, a moderation callback or a memory store — for a capability the index lists — means you stopped at the name.
15
16## 2. Prerequisites for Writing Code
17
18Do NOT write agent code until a project is scaffolded.
19
201. Verify project: run `agents-cli info` (proceed if config exists).
212. New project: run `agents-cli scaffold create <name>`.
223. Existing code: run `agents-cli scaffold enhance .`.
23
24> **Language Support:** This reference covers the Python ADK SDK. Support for other languages coming soon.
25
26## Quick Reference — Most Common Patterns
27
28```python
29from google.adk.agents import Agent
30
31def get_weather(city: str) -> dict:
32 """Get current weather for a city."""
33 return {"city": city, "temp": "22°C", "condition": "sunny"}
34
35root_agent = Agent(
36 name="my_agent",
37 model="gemini-3.7-flash",
38 instruction="You are a helpful assistant that ...",
39 tools=[get_weather],
40)
41```
42
43---
44
45## References
46
47Use cheatsheets for common patterns. For deep knowledge, fetch the docs index or inspect the installed package.
48
49| Reference | When to read |
50|------|-------------|
51| `references/samples.md` | **Topic-indexed catalog of ADK reference recipes.** Read in workflow Phase 1 — before scaffolding and before writing code — maps a capability to the recipe that implements it. |
52| `references/adk-python.md` | Core ADK API: `Agent`, tools, callbacks, plugins, state, artifacts, multi-agent systems, `SequentialAgent` / `ParallelAgent` / `LoopAgent`, custom `BaseAgent`, `ManagedAgent` (server-hosted first-party agents), A2A protocol, A2UI. Default for most agents. |
53| `references/adk-workflows.md` | Graph-based Workflow API (ADK 2.0): nodes, edges, fan-out/fan-in, HITL, parallel processing. Use when you need explicit graph topology. |
54| `curl https://adk.dev/llms.txt` | Docs index (every page title + URL). Fetch it, then `WebFetch` the specific page for anything beyond the cheatsheets. |
55| Installed ADK package | Exact signatures and symbols — inspect the source (see "Inspecting ADK Source Code" in `references/adk-python.md`). |
56
57## Related Skills
58
59- `/google-agents-cli-workflow` — Development workflow, coding guidelines, and operational rules
60- `/google-agents-cli-scaffold` — Project creation and enhancement with `agents-cli scaffold create` / `scaffold enhance`
61- `/google-agents-cli-eval` — Evaluation methodology, dataset schema, and the eval-fix loop
62- `/google-agents-cli-deploy` — Deployment targets, CI/CD pipelines, and production workflows
Google