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/mvschwarz/openrig/test-driven-developmentnpx skills add mvschwarz/openrig --skill test-driven-developmentgit clone --depth 1 https://github.com/mvschwarz/openrigWhat 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 | $0.00017 | $0.02748 |
| Opus 5 | $0.00009 | $0.01374 |
| Sonnet 5 | $0.00003 | $0.00550 |
| Haiku 4.5 | $0.00002 | $0.00275 |
Grade A, and why
test-driven-development 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 2d 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.
This is a copy
91% identical to test-driven-development — 18 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 386 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test-Driven Development (TDD)
Overview
Write the test first. Watch it fail. Write minimal code to pass.
Core principle: If you didn't watch the test fail, you don't know if it tests the right thing.
A strong default in service of shipping — not a law that outranks it. TDD earns its keep where a failing test pins down behavior you'd otherwise get wrong: core logic, contracts, tricky edge cases. Match it to stakes — reach for it where test-first genuinely de-risks the change; throwaway prototypes, one-line copy tweaks, and obvious glue don't need the ceremony. Don't dodge it with synonyms; equally, don't let it block you from shipping the working thing.
When to Use
Always:
- New features
- Bug fixes
- Refactoring
- Behavior changes
Exceptions (ask your human partner):
- Throwaway prototypes
- Generated code
- Configuration files
Thinking "skip TDD just this once"? Stop. That's rationalization.
Chunk size is a dial, and it points up (2026-08) — this is NOT "skip TDD". How much you build per red-green cycle is configurable, and with frontier agents handling hour-plus goal-oriented work it is much larger than the classic tiny ping-pong, and rising. Keep everything below — the Iron Law, red before green, two sets of eyes, the guard structure — fully intact; only the cadence / granularity loosens. You still write the failing test(s) first for the chunk; the chunk is simply bigger. Tiny back-and-forth is overhead, not virtue, once the SDLC's gates (QA, review, guards) bound a larger chunk's risk. Match the chunk to the task; treat it as a configured lever — never as license to write code before its test (that's the rationalization this skill exists to stop).
The Iron Law
NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST
Write code before the test? Delete it. Start over.
No exceptions:
- Don't keep it as "reference"
- Don't "adapt" it while writing tests
- Don't look at it
- Delete means delete
Implement fresh from tests. Period.
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.
- 2d ago First seen · 386 lines · 17 tokens per session scan A 14974a332763
test-driven-development is a skill published in the GitHub repository mvschwarz/openrig (64 stars, last pushed 2d ago), licensed Apache-2.0. It adds 17 tokens to every session and 2,748 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 91% identical to test-driven-development, differing in 18 lines, and is treated as a copy.
Other skills, from other repositories
autoprompt
Explicit-only useful-first orchestration. Invoke only when the user names autoprompt - typed as /autoprompt or in plain language such as "act in autoprompt mode" - to turn a mission into one executable roadmap, build dependency-safe lanes, and verify the result with independent reviewers. Do not infer invocation from…
autoprompt
Explicit-only useful-first orchestration. Invoke /autoprompt to turn a mission into one executable roadmap, build dependency-safe lanes, and verify the result with independent reviewers. Never infer invocation from ordinary requests. Never resume from leftover artifacts without an explicit resume instruction.
autoprompt
Explicit-only useful-first orchestration. Invoke /autoprompt to turn a mission into one executable roadmap, build dependency-safe lanes, and verify the result with independent reviewers. Never infer invocation from ordinary requests. Never resume from leftover artifacts without an explicit resume instruction.
ap-implementer
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ap-researcher
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ap-arbiter
L4 terminal leaf - ARBITER. Independent decision-maker for forks the loop cannot resolve on its own. Under UNATTENDED mode it ALWAYS rules and continues, NEVER escalates to the user. Output is a binding ruling logged to the ledger.