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.agents/skills/adk-sample-creator/SKILL.md

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+---
+name: adk-sample-creator
+description: Author new samples for the ADK Python repository. Use this skill when the user wants to create a new sample demonstrating a feature or agent pattern (e.g., dynamic nodes, standalone agents, fan-out/fan-in) or when adding examples to subdirectories under `contributing/`.
+---
+
+# ADK Sample Creator
+
+This skill helps you create new samples for the ADK Python repository. You should search for subdirectories under `contributing` (such as `new_workflow_samples`, `workflow_samples`, etc.) and confirm with the user which folder they want to use before creating the sample.
+
+> [!TIP]
+
+> Before creating samples, you can use the `adk-style` skill to learn about ADK 2.0 architecture knowledge and best practices.
+
+A sample consists of:
+
+1.  A directory per sample.
+2.  An `agent.py` file defining the agent or workflow logic.
+3.  A `README.md` file explaining the sample.
+
+## Guidelines
+
+### 1. Folder Name
+
+Use snake_case for the folder name (e.g., `dynamic_nodes`, `fan_out_fan_in`).
+
+### 2. `agent.py` Content
+
+The `agent.py` should focus on demonstrating a specific feature or agent pattern. Use absolute imports for testing convenience.
+
+> [!IMPORTANT]
+> **Model Selection**: Do not set the `model` parameter explicitly (e.g., `model="gemini-2.5-flash"`) on `Agent` instances in sample agents. Instead, let them default to the system-configured model, unless a specific model is explicitly requested by the user.
+
+Choose one of the following patterns:
+
+#### Pattern A: Workflows (for complex graphs)
+
+Use this when you need multiple nodes, routing, or parallel execution.
+
+**Imports:**
+
+```python
+from google.adk import Agent
+from google.adk import Context
+from google.adk.workflow import node
+from google.adk.workflow import JoinNode
+from google.adk.workflow._workflow_class import Workflow
+```
+
+**Anatomy:**
+
+```python
+my_agent = Agent(name="my_agent", ...)
+
+@node()
+async def my_node(node_input: str):
+    return "result"
+
+root_agent = Workflow(
+    name="root_wf",
+    edges=[("START", my_node)],
+)
+```
+
+#### Pattern B: Standalone Agents (for single-agent or simple tool use)
+
+Use this when you don't need a graph and the agent handles the loop.
+
+**Imports:**
+
+```python
+from google.adk import Agent
+from google.adk.tools import google_search  # example
+```
+
+**Anatomy:**
+
+```python
+root_agent = Agent(
+    name="standalone_assistant",
+    instruction="You are a helpful assistant.",
+    description="An assistant that can help with queries.",
+    tools=[google_search],
+)
+```
+
+### 3. `README.md` Content
+
+Each sample should have a `README.md` with the following structure:
+
+- **Overview**: What the sample does.
+- **Sample Inputs**: Examples of inputs to test with. Each prompt must be wrapped in backticks. If a prompt has an explanation, always add a blank line between the prompt and the explanation, and indent the explanation by two spaces.
+- **Graph**: Visualization of the graph flow (Mermaid recommended). For Workflow root agents, visualize the graph flow of nodes. For LlmAgent root agents that orchestrate tools or sub-agents, visualize the topology of the agent and its tools/sub-agents instead of internal workflow nodes.
+- **How To**: Explanation of key techniques used (e.g., `ctx.run_node`).
+- **Related Guides**: Links to relevant developer guides in `docs/guides/` that explain the concepts or classes used.
+
+#### README Example Template:
+
+````markdown
+# ADK Sample Name
+
+## Overview
+
+Brief description.
+
+## Sample Inputs
+
+- `Prompt example 1`
+
+- `Prompt example 2`
+
+  *Explanation or expected behavior*
+
+## Graph
+
+For Workflow root agents:
+```mermaid
+graph TD
+    START --> MyNode
+```
+
+For LlmAgent root agents:
+```mermaid
+graph TD
+    MyAgent[my_agent] -->|calls| MyTool(my_tool)
+```
+
+## How To
+
+Explain the details.
+
+## Related Guides
+
+- [Guide Title](../../docs/guides/path/to/guide.md) - Brief description of what the guide covers.
+````
+
+## Examples
+
+### Dynamic Nodes
+Snippet from `dynamic_nodes/agent.py`:
+```python
+@node(rerun_on_resume=True)
+async def orchestrate(ctx: Context, node_input: str) -> str:
+    while True:
+        headline = await ctx.run_node(generate_headline)
+        # ...
+````
+
+### Fan Out Fan In
+
+Snippet from `fan_out_fan_in/agent.py`:
+
+```python
+root_agent = Workflow(
+    name="root_agent",
+    edges=[("START", (node_a, node_b), join_node, aggregate)],
+)
+```