AG Kit is a toolkit that gives Google Antigravity coding agents a structured workspace with rules, skills, specialist agents, workflows, persistent memory, orchestration, MCP guidance, and a safety hook. It is for building and operating agent workflows in Antigravity, and its catalogue entries provide parts of that workspace contract.
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 agentmods add skills/vudovn/ag-kit/tdd-workflownpx skills add vudovn/ag-kit --skill tdd-workflowgit clone --depth 1 https://github.com/vudovn/ag-kitWrote 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/vudovn/ag-kit/tdd-workflow)<a href="https://agentmods.dev/skills/vudovn/ag-kit/tdd-workflow"><img src="https://agentmods.dev/badge/skills/vudovn/ag-kit/tdd-workflow.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00021 | $0.00761 |
| Opus 5 | $0.00010 | $0.00380 |
| Sonnet 5 | $0.00004 | $0.00152 |
| Haiku 4.5 | $0.00002 | $0.00076 |
Grade A, and why
tdd-workflow 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 5d 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.
Copies of this mod
6 near-identical copies found in the catalogue:
- tdd-workflow — 91% identical, 2 lines differ
- tdd-workflow — 91% identical, 2 lines differ
- tdd-workflow — 91% identical, 2 lines differ
- tdd-workflow — 91% identical, 2 lines differ
- tdd-workflow — 91% identical, 2 lines differ
- tdd-workflow — 91% identical, 2 lines differ
How it starts
The opening of the file, as written. The whole thing — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.
TDD Workflow
Write tests first, code second.
1. The TDD Cycle
🔴 RED → Write failing test
↓
🟢 GREEN → Write minimal code to pass
↓
🔵 REFACTOR → Improve code quality
↓
Repeat...
2. The Three Laws of TDD
- Write production code only to make a failing test pass
- Write only enough test to demonstrate failure
- Write only enough code to make the test pass
3. RED Phase Principles
What to Write
| Focus | Example |
|---|---|
| Behavior | "should add two numbers" |
| Edge cases | "should handle empty input" |
| Error states | "should throw for invalid data" |
RED Phase Rules
- Test must fail first
- Test name describes expected behavior
- One assertion per test (ideally)
4. GREEN Phase Principles
Minimum Code
| Principle | Meaning |
|---|---|
| YAGNI | You Aren't Gonna Need It |
| Simplest thing | Write the minimum to pass |
| No optimization | Just make it work |
GREEN Phase Rules
- Don't write unneeded code
- Don't optimize yet
- Pass the test, nothing more
5. REFACTOR Phase Principles
What to Improve
| Area | Action |
|---|---|
| Duplication | Extract common code |
| Naming | Make intent clear |
| Structure | Improve organization |
| Complexity | Simplify logic |
REFACTOR Rules
- All tests must stay green
- Small incremental changes
- Commit after each refactor
6. AAA Pattern
Every test follows:
| Step | Purpose |
|---|---|
| Arrange | Set up test data |
| Act | Execute code under test |
| Assert | Verify expected outcome |
7. When to Use TDD
| Scenario | TDD Value |
|---|---|
| New feature | High |
| Bug fix | High (write test first) |
| Complex logic | High |
| Exploratory | Low (spike, then TDD) |
| UI layout | Low |
8. Test Prioritization
| Priority | Test Type |
|---|---|
| 1 | Happy path |
| 2 | Error cases |
| 3 | Edge cases |
| 4 | Performance |
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.
- 5d ago First seen · 152 lines · 21 tokens per session scan A c758378bc135
tdd-workflow is a skill published in the GitHub repository vudovn/ag-kit (8,168 stars, last pushed 5d ago), licensed MIT. It adds 21 tokens to every session and 761 once invoked, about $0.0001 per session on Opus 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.
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