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/romiluz13/cc10x/buildingnpx skills add romiluz13/cc10x --skill buildinggit clone --depth 1 https://github.com/romiluz13/cc10xWhat 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 | $0.00053 | $0.02323 |
| Opus 5 | $0.00026 | $0.01162 |
| Sonnet 5 | $0.00011 | $0.00465 |
| Haiku 4.5 | $0.00005 | $0.00232 |
Grade A, and why
building 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 3d 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 — 172 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Building (Code Generation + TDD)
Iron Law: NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST.
Reference Files
Read only what's needed:
references/testing-patterns.md— test structure, isolation, naming; load when writing the first test of a cycle or a test feels awkward to structurereferences/test-data-and-mocks.md— mock discipline, test data factories; load when a test needs fixtures/factories or you are about to mock anythingreferences/integration-and-live-proof.md— integration test guidance, live verification; load when the slice crosses a service/DB/API boundary or the plan names live proof
Test Process Discipline
- Always use run mode:
CI=true npm test,npx vitest run(NOTnpx vitest),CI=true npx jest— watch mode never exits, so the agent hangs waiting for a prompt that never returns - Timeout guard:
timeout 60s npx vitest runif uncertain about CI=true - After TDD cycle:
pgrep -f "vitest|jest" || echo "Clean". Kill if found — orphaned watchers hold ports and re-run stale code, producing false greens in later cycles. - IDE vs CLI truth: If CLI tests pass with exit 0, trust CLI over IDE/LSP errors (stale cache)
RED → GREEN → REFACTOR
RED — Failing Test First
Write one failing test for the current slice. Run it. RED = a behavioral failure ("X is not a function", "expected 3, received undefined") — never a bare exit code.
False-RED guard (CRITICAL): Exit 1 from an import/syntax/collection ERROR is a broken harness, not a RED — fix the harness and re-run. Record the observed failure reason verbatim.
GREEN — Minimal Code
Write the minimum code to pass the test. No extra features, no abstractions for hypothetical futures. No unrelated test breakage. If existing tests break, fix the code not the tests.
REFACTOR — Clean Up
Improve code quality while keeping tests green. If tests fail during refactor, revert — a red test proves it wasn't a refactor, and debugging forward mixes two changes. Re-run after every refactor step.
What ships with it
3 files 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.
- 3d ago First seen · 172 lines · 53 tokens per session scan A b30fdc9a6cb2
building is a skill published in the GitHub repository romiluz13/cc10x (164 stars, last pushed 1mo ago), licensed MIT. It adds 53 tokens to every session and 2,323 once invoked, about $0.0003 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.
Other skills, from other repositories
test-driven-development
Use when implementing any feature or bugfix, before writing implementation code.
test-driven-development
TDD: enforce RED-GREEN-REFACTOR, tests before code.
create-request
Create, update, or scan per-task request tickets for progress tracking. These are date-prefixed non-lifecycle docs under requests/, NOT feature-level requirements (use /req-analyze for those). Use when: tracking task progress, updating completion status, scanning incomplete requests, checking request status dashboard.…
codex-setup
Initialize sd0x-dev-flow infrastructure for Codex CLI and other non-Claude agents. Generates AGENTS.md, installs the commit-msg hook, copies runner scripts. The pre-push gate is opt-in via --with-push-gate. Use when setting up a new project or after updating skills.
codex-code-review
Code review using Codex MCP. Use when: PR review, code audit, second opinion on changes. Not for: doc review (use doc-review), security audit (use security-review). Output: severity-grouped findings + merge gate.
meta-harness-terminal-bench-2
Run one iteration of AgentHarness evolution for Terminal-Bench 2.