Agent Development Kit is a Python framework for building, evaluating, deploying, and coordinating AI agents as software applications. Developers use it to compose workflows, delegate tasks between specialized agents, manage state, and connect agents to tools while choosing supported models and deployment environments. The catalogue add-ons provide workflows for using the toolkit.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add google/adk-python --skill adk-unit-designgit clone --depth 1 https://github.com/google/adk-pythonWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/google/adk-python/adk-unit-design)<a href="https://agentmods.dev/skills/google/adk-python/adk-unit-design"><img src="https://agentmods.dev/badge/skills/google/adk-python/adk-unit-design/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/google/adk-python/adk-unit-design"><img src="https://agentmods.dev/badge/skills/google/adk-python/adk-unit-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00181 | $0.00698 |
| Opus 5.5 | $0.00072 | $0.00279 |
| Sonnet 5.5 | $0.00036 | $0.00140 |
| Haiku 4.5 | $0.00018 | $0.00070 |
Grade A, and why
adk-unit-design scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.
ADK code unit design
A unit design documents a code unit as implemented, the way a unit test exercises it as implemented. Nothing proposed or aspirational belongs in one. The reader is deciding what they may safely change, so answer "what breaks if I touch this?" — not "how do I call this?".
Inputs
Require the source file, or a class or method named inside it. Also read, when they exist: the base classes and interfaces the unit implements, its unit tests (the best evidence of intended behaviour), and example usage.
Analyse before writing
Answer each of these from the source. Anything the code does not show stays out of the document — do not infer a design intent from a name.
- Purpose and intended use of the unit.
- Execution flow, and the data that flows in and out.
- Upstream dependencies, and which classes depend on this unit.
- Extension surfaces: abstract methods, hooks, callbacks, configurable fields.
- Constraints — what a subclass or caller must not change, and why.
- Operational limitations.
Where the document goes
Mirror the source path under docs/design/, one directory per unit, document
named index.md. Drop the leading underscore of a private module:
| Source | Design document |
|---|---|
src/google/adk/workflow/_function_node.py |
docs/design/workflow/function_node/index.md |
src/google/adk/events/event.py |
docs/design/events/event/index.md |
If a document already exists at that path, update it in place and keep the existing wording wherever the code has not changed, so the diff shows only what the change actually altered.
docs/design/ does not exist in this repository yet — the first design document
creates it. docs/guides/ is the established sibling tree; match its directory
shape.
Link to GitHub, not to local paths
These documents render on GitHub, where a local filesystem path is dead.
Rewrite {repo_root}/src/google/adk/{topic}/{unit}.py#L93 as
https://github.com/google/adk-python/blob/main/src/google/adk/{topic}/{unit}.py#L93.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 70 lines · 181 tokens per session scan A da8ca332ec3f
adk-unit-design is a skill published in the GitHub repository google/adk-python (21,885 stars, last pushed today), licensed Apache-2.0. It adds 181 tokens to every session and 698 once invoked, about $0.0007 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
rowboat-spaces
How to work as a member of Rowboat Spaces, the team chat where people and agents work together. Load it once per session, before acting on any request that reaches you from Rowboat; it covers your setup, mentions and hand-offs, the tools, and files.
mindmap
Create concise hierarchical mind maps as canonical Markdown with a static PNG download.
adk-go-self-review
Review an ADK Go change the way a maintainer will — a fresh-context pass over the whole diff, five lenses (correctness and tests, scope, simplicity, style, adk-python parity), and the mutation check that proves your tests pin the change. Use before opening a PR, before any later push that changes code, and when asked…
security-conductor
Operating procedure for the kirocrew-security-conductor agent. Use when a security conductor session is seeded, inspected or debugged. Run vulnerability discovery on one target as a supervised fleet — one auditor per attack surface, an independent verifier per finding, two human gates.
artifact-deploy
One-click deploy a user's pre-built app/artifact into their OWN AWS account and get a global public HTTPS link (Vercel-like), with a default TTL and promote-to-persistent. Use when the user says "deploy this", "ship this demo", "give me a public link", "share this externally", or "deploy to AWS".
explain-for
Explain a topic, code, error or design decision for one named audience (a 5-year-old, a manager, a designer, a grad student, a parent). Resolves who it is for, pins the ground truth first, then tunes vocabulary, analogy, tone and depth to that audience. Use when an audience is named.