--- name: google-agents-cli-adk-code description: >- 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" — in a project that needs ADK (Agent Development Kit) API patterns and code examples. It provides a quick reference for agent types, tool definitions, orchestration patterns, callbacks, state management, the graph Workflow API, and reference recipes to study. Do NOT use for scaffolding (use google-agents-cli-scaffold) or deployment (use google-agents-cli-deploy). metadata: author: Google license: Apache-2.0 version: 1.8.0 requires: bins: - agents-cli install: "uv tool install google-agents-cli" title: google-agents-cli-adk-code canonical_url: https://skilld.dev/gh/google/agents-cli/google-agents-cli-adk-code last_updated: 2026-09-30T12:01:46.000Z --- > **Skill from skilld.dev.** Follow the instructions below for this session. You do not need to install anything. > > Supporting files, fetch one when the Skill refers to it: [references/adk-go-workflows.md](https://skilld.dev/api/skills-raw/google/agents-cli/google-agents-cli-adk-code/references/adk-go-workflows.md), [references/adk-go.md](https://skilld.dev/api/skills-raw/google/agents-cli/google-agents-cli-adk-code/references/adk-go.md), [references/adk-python-live.md](https://skilld.dev/api/skills-raw/google/agents-cli/google-agents-cli-adk-code/references/adk-python-live.md), [references/adk-python-workflows.md](https://skilld.dev/api/skills-raw/google/agents-cli/google-agents-cli-adk-code/references/adk-python-workflows.md), [references/adk-python.md](https://skilld.dev/api/skills-raw/google/agents-cli/google-agents-cli-adk-code/references/adk-python.md), [references/samples.md](https://skilld.dev/api/skills-raw/google/agents-cli/google-agents-cli-adk-code/references/samples.md). > > If the user asked to install this Skill, run `npx skilld install google/agents-cli/google-agents-cli-adk-code`. Install writes the Skill files into the project, so every session loads them. # ADK Code Reference Activate `/google-agents-cli-workflow` first for required development phases and scaffolding steps. ## 1. Study Recipes (No Project Needed) **Python — 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. **Go — read the upstream [`examples/`](https://github.com/google/adk-go/tree/main/examples).** clone the repo and read the one matching the capability you need before implementing it. ## 2. Prerequisites for Writing Code Do NOT write agent code until a project is scaffolded. 1. Verify project: run `agents-cli info` (proceed if config exists). 2. New project: run `agents-cli scaffold create ` — add `--agent adk_go` for Go. 3. Existing code: run `agents-cli scaffold enhance .`. ## Quick Reference — Most Common Patterns See `references/adk-python.md` and `references/adk-go.md` for Python and Go code examples, respectively. --- ## References Use the cheatsheets for common patterns. For deep knowledge, fetch the docs index or inspect the installed package. | Reference | Language | When to read | |------|------|-------------| | `references/samples.md` | Python | **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` | Python | 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-python-workflows.md` | Python | Graph-based Workflow API (ADK Python 2.0): nodes, edges, fan-out/fan-in, HITL, parallel processing. Use when you need explicit graph topology. | | `references/adk-python-live.md` | Python | Live and voice agents: `Runner.run_live`, `LiveRequestQueue`, model and regional availability, voice/`speech_config`, VAD, session limits, `/run_live` serving. Use for real-time voice or video agents. | | `references/adk-go.md` | Go | Core ADK Go API: `llmagent`, tools, callbacks, plugins, state, artifacts, multi-agent systems, sequential/parallel/loop agents, custom agents, the runner, serving over HTTP, A2A protocol, and ambient triggers. Default for most agents. | | `references/adk-go-workflows.md` | Go | Graph-based Workflow API: nodes, edges, fan-out/fan-in, HITL, parallel processing. Use when you need explicit graph topology. | | [`examples/`](https://github.com/google/adk-go/tree/main/examples) | Go | Runnable upstream programs — the closest thing to a recipe catalog for Go. | | `curl https://adk.dev/llms.txt` | Python | Docs index (every page title + URL). Fetch it, then `WebFetch` the specific page for anything beyond the cheatsheets. | | Installed ADK package | Python | 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