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 majiayu000/spellbook --skill dev-architecture-playbookgit clone --depth 1 https://github.com/majiayu000/spellbookWrote 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/majiayu000/spellbook/dev-architecture-playbook)<a href="https://agentmods.dev/skills/majiayu000/spellbook/dev-architecture-playbook"><img src="https://agentmods.dev/badge/skills/majiayu000/spellbook/dev-architecture-playbook/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/majiayu000/spellbook/dev-architecture-playbook"><img src="https://agentmods.dev/badge/skills/majiayu000/spellbook/dev-architecture-playbook.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 | $0.00081 | $0.00736 |
| Opus 5 | $0.00041 | $0.00368 |
| Sonnet 5 | $0.00016 | $0.00147 |
| Haiku 4.5 | $0.00008 | $0.00074 |
Grade A, and why
dev-architecture-playbook 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 11d 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.
Dev Architecture Playbook
Purpose
Use this as the lifecycle router before starting broad product or architecture work. It chooses the minimum useful skill chain, defines gates, and prevents starting implementation before the required contracts exist.
Route
Classify the request first:
| Request | Primary Skills | Output |
|---|---|---|
| Idea, product direction, or market/user problem | product-discovery, prd-master |
Product brief, user stories, success metrics |
| Architecture or module boundaries | architecture-foundation, technical-spec, elegant-architecture |
Architecture spec, boundaries, rejected alternatives |
| API, auth, data, or schema contract | api-design, auth-security, database-patterns, data-contract-migrations |
Versioned contracts and migration plan |
| UI/product surface | frontend-design, ui-ux-pro-max, ui-design-system, playwright-automation |
UX flow, component plan, visual checks |
| Implementation workflow | flowguard, threads, systematic-debugging, comprehensive-testing |
Bounded execution, ownership, root-cause debugging, and verification |
| Quality and regression risk | comprehensive-testing, codebase-audit, vibeguard, project-health-auditor |
Test matrix and risk list |
| Release and operations | release-engineering, config-secrets-environments, performance-capacity, incident-slo-runbook, observability-sre, devops-excellence |
Rollout, config, capacity, SLO, runbook |
Required Gates
Do not treat the architecture as complete until these gates are explicit:
- Goal and non-goals.
- Domain model and ownership boundaries.
- External API, data, and config contracts.
- Security and permission model.
- Test strategy with command-level verification.
- Release, rollback, and migration gates.
- Observability, SLO, and incident response.
If a gate is irrelevant, state why. Do not silently skip data, security, or rollback gates for production systems.
Execution Pattern
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.
- 11d ago First seen · 70 lines · 81 tokens per session scan A 07237a4e7f35
dev-architecture-playbook is a skill published in the GitHub repository majiayu000/spellbook (278 stars, last pushed today), licensed MIT. It adds 81 tokens to every session and 736 once invoked, about $0.0004 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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