---
title: "Three layers, one repo: a tour of google/adk-recipes"
description: "The google/adk-recipes repository serves as the single source of truth for ADK content across Google Cloud’s Agent Platform, including the Agents CLI, Agent Garden, and Gemini Enterprise app. It is organized into three top-level folders: core/ with reference patterns curated by the Agents CLI and DevRel teams, plugins/ with installable vertical skills packaged as Plugin Recipes conforming to the Agent Plugins v1.0.0 spec, and contrib/ with end-to-end deployable services in five languages. Every recipe ships a validated manifest.yaml and an AGENTS.md written primarily for AI coding assistants, and CI enforces the standards on every pull request. The core/ layer features Horizon, a reference harness for long-horizon memory agents that handles cross-session memory, per-user sandboxing, guardrails, and multi-step task orchestration. The retail Plugin Recipe includes product-search and virtual-tryon skills using Vector Search 2.0 and Gemini models, with deployable counterparts in contrib/ that can be surfaced on five deployment personas."
---

# Three layers, one repo: a tour of google/adk-recipes

[Google](https://yomu.fyi/company/google) · Pier Paolo Ippolito, Shahin Saadati · Oct 15, 2026

**Type:** Explainer

## Summary

The google/adk-recipes repository serves as the single source of truth for ADK content across Google Cloud’s Agent Platform, including the Agents CLI, Agent Garden, and Gemini Enterprise app. It is organized into three top-level folders: core/ with reference patterns curated by the Agents CLI and DevRel teams, plugins/ with installable vertical skills packaged as Plugin Recipes conforming to the Agent Plugins v1.0.0 spec, and contrib/ with end-to-end deployable services in five languages. Every recipe ships a validated manifest.yaml and an AGENTS.md written primarily for AI coding assistants, and CI enforces the standards on every pull request. The core/ layer features Horizon, a reference harness for long-horizon memory agents that handles cross-session memory, per-user sandboxing, guardrails, and multi-step task orchestration. The retail Plugin Recipe includes product-search and virtual-tryon skills using Vector Search 2.0 and Gemini models, with deployable counterparts in contrib/ that can be surfaced on five deployment personas.

## Takeaways

- The repository is split into three top-level folders: core/ for reference patterns, plugins/ for installable vertical skills packaged as Plugin Recipes, and contrib/ for end-to-end deployable services in five languages.
- Every recipe includes an AGENTS.md file written primarily for AI coding assistants, enabling automatic discovery and installation without requiring human reading.
- Horizon, in core/, provides a reference harness for building long-horizon memory agents with cross-session memory, per-user sandboxing, guardrails, and resumable multi-step tasks.

## FAQ

### What is the purpose of AGENTS.md in each recipe?

AGENTS.md is written primarily for AI coding assistants to describe the recipe and how to use it. It enables automatic discovery and installation by the assistant without requiring human reading.

### How does Horizon handle long-horizon agent interactions?

Horizon uses cross-session memory, per-user sandboxing, secrets management, guardrails against runaway behavior, and orchestration primitives to make multi-step tasks resumable across days of interaction.

### What is the structure of a Plugin Recipe like the retail plugin?

The retail Plugin Recipe consists of a top-level plugin.json manifest and skills folders, each containing a SKILL.md conversational installer, README.md, EVAL.yaml quality gates, and necessary scripts and assets.

**Tags:** [Agent Development Kit](https://yomu.fyi/topic/agent-development-kit), [AI Agents](https://yomu.fyi/topic/ai-agents), [BigQuery](https://yomu.fyi/topic/bigquery), [Google Cloud](https://yomu.fyi/topic/gcp), [Vector Search](https://yomu.fyi/topic/vector-search)

- Source: [Google](https://developers.googleblog.com/three-layers-one-repo-a-tour-of-googleadk-recipes)
- Source URL: https://developers.googleblog.com/three-layers-one-repo-a-tour-of-googleadk-recipes
- Ingested by Yomu: 2026-10-15T18:00:22.968Z

[Read original post](https://developers.googleblog.com/three-layers-one-repo-a-tour-of-googleadk-recipes)