tdd SKILL.md skillA
This file is byte-identical to the first copy the registry indexed. Same content hash, so the same checks give both the same grade.
tdd from gaia-harness/gaia is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add gaia-harness/gaia/tdd@git:20261102.65f04fePins git:20261102.65f04fe in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- gaia-harness/gaia
- Path
.claude/skills/tdd/SKILL.md- Versions recorded
- 11
- Latest version
- git:20261102.65f04fe, committed Nov 2, 2026
- First version recorded
- Oct 15, 2026
- Size
- 11,479 bytes
- Repository stars
- 26
- License
- MIT
Runs test-driven development with a red-green-refactor loop. Use when the user wants to build features or fix bugs using TDD, mentions "red-green-refactor", wants integration tests, or asks for test-first development.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Test-Driven Development
Contents: Selecting a Stack Reference; Philosophy; Anti-Pattern: Horizontal Slices; Workflow; Checklist Per Cycle.
## Selecting a Stack Reference
Before writing the first red test, consult the reference for your stack:
- **React / Vitest / MSW / Storybook** → the `tdd-react` skill (`apps/web/.claude/skills/tdd-react/SKILL.md`)
- **Shell / bats** → `.claude/skills/tdd/references/tests-shell.md`
Add a new stack reference (a skill or a `references/tests-{stack}.md`) when adopting a new stack. The stack reference covers concrete patterns, test layers, mocking rules, and good/bad examples specific to that environment.
## Philosophy
**Core principle**: tests verify behavior through public interfaces, not implementation details. Good tests are integration-style: they exercise real code paths through public APIs, read like a specification ("user submits a valid form and sees a success toast"), and survive refactors. A test that breaks on a behavior-preserving refactor is coupled to implementation.
## Anti-Pattern: Horizontal Slices
…Read the whole file at its exact version.
How to install
mdr add gaia-harness/gaia/tdd@sha256:96bad8dacc66807bThe line at the top of this page pins the label git:20261102.65f04fe, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_fxdkzr65c4gnjxip)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 11 versions of this file, between Oct 15, 2026 and Nov 2, 2026, about one every 2 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261102.65f04fe latest | 2026-11-02 | 65f04fe | 11,479 B | A | view · diff |
| git:20261101.cb266c4 | 2026-11-01 | cb266c4 | 11,479 B | A | view · diff |
| git:20261031.fd1c1ae | 2026-10-31 | fd1c1ae | 11,243 B | A | view · diff |
| git:20261028.f0e4b7b | 2026-10-28 | f0e4b7b | 12,235 B | A | view · diff |
| git:20261028.da676a7 | 2026-10-28 | da676a7 | 12,274 B | A | view · diff |
| git:20261027.d7a19d0 | 2026-10-27 | d7a19d0 | 12,062 B | A | view · diff |
| git:20261019.39d38f1 | 2026-10-19 | 39d38f1 | 11,992 B | A | view · diff |
| git:20261018.0b068ec | 2026-10-18 | 0b068ec | 13,522 B | A | view · diff |
| git:20261017.28a4e4e | 2026-10-17 | 28a4e4e | 13,296 B | A | view · diff |
| git:20261016.262936e | 2026-10-16 | 262936e | 13,182 B | A | view · diff |
| git:20261015.0d3145e | 2026-10-15 | 0d3145e | 13,215 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (11479 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
gaia-harness/gaia · 26 stars · license MIT · pushed 2026-11-03 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_fxdkzr65c4gnjxip GET https://markdownregistry.com/api/v1/resolve?ref=gaia-harness/gaia/tdd GET https://markdownregistry.com/api/v1/blob/96bad8dacc66807b9150d9a5321469e904cd143380cbfea9a5ea559f0a505f91
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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