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 architecture-foundationgit 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/architecture-foundation)<a href="https://agentmods.dev/skills/majiayu000/spellbook/architecture-foundation"><img src="https://agentmods.dev/badge/skills/majiayu000/spellbook/architecture-foundation/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/architecture-foundation"><img src="https://agentmods.dev/badge/skills/majiayu000/spellbook/architecture-foundation.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 | $0.00064 | $0.01875 |
| Opus 5 | $0.00032 | $0.00937 |
| Sonnet 5 | $0.00013 | $0.00375 |
| Haiku 4.5 | $0.00006 | $0.00187 |
Grade A, and why
architecture-foundation 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 — 190 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Architecture Foundation
Overview
Use this skill to turn an architecture discussion into explicit boundaries, contracts, validation gates, and a small execution plan. The goal is not to copy an admired project, but to identify the project's shape and choose the minimum architecture that keeps ownership, effects, errors, and tests clear. For large existing repos, first explain the architecture they already have, then decide whether the work is boundary creation, boundary completion, or boundary deletion.
When To Use
- The user asks "what architecture should this use?", "is this stacked work?", "make a complete spec", "design the runtime", or "compare good libraries".
- The change touches runtime, state ownership, adapters, plugins, event loops, rendering, schedulers, persistence, or cross-module contracts.
- A repo has many issues/PRs that look individually valid but may not converge on one architecture.
- A mature repo has duplicated paths, compatibility shims, generated configs, workflow definitions, or docs that may disagree about the source of truth.
- A new skill, framework, library, or large feature needs a foundation guide before implementation.
Do not use this for small, local fixes where the existing architecture is obvious and no boundary decision is needed.
Workflow
- Search first.
- Inspect existing architecture docs, entrypoints, manifests, module trees, public APIs, open issues/PRs, and tests before proposing new structure.
- If the user names a reference project, verify current source or official docs before treating it as evidence.
- For existing repos, also inspect generated/config artifacts, migration files, background workers, cron jobs, adapters, and the largest files/tests.
- Classify the project shape.
- Simple library: stable API plus internal implementation.
- CLI or developer tool: command layer, core operations, IO adapters, reporter.
- API gateway or model router: transport, auth/accounting, routing policy, provider adapters, billing/settlement, observability.
- Long-running runtime: state root, scheduler, drivers, observability, shutdown.
- Lifecycle/composition framework: dependency graph, construction phase, runtime hooks, rollback, shutdown, and test harness.
- Event/cache/reconcile controller: watch/list input, cache/projection, queue/backpressure, worker/reconciler, retry, and drain.
- Config/module platform: canonical config, adapters, module lifecycle, reload order, rollback, cleanup, and plugin host interfaces.
- UI or app shell: state ownership, event protocol, renderer/platform boundary, headless tests.
- Service framework: domain core, application services, transport, storage, middleware, error-to-response boundary.
- Agent or workflow system: task model, scheduler, provider adapters, event log, replay/test harness.
What ships with it
4 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.
- 11d ago First seen · 190 lines · 64 tokens per session scan A 37bdec7d1e5c
architecture-foundation is a skill published in the GitHub repository majiayu000/spellbook (278 stars, last pushed today), licensed MIT. It adds 64 tokens to every session and 1,875 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.
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