aspens

npx aspens doc init --recommended

Why aspens?

Without aspens	With aspens
Agents miss conventions and architectural boundaries	Agents start from repo-specific instructions
New sessions waste time rediscovering key files	Skills point to the right files, patterns, and rules
Context files drift after code changes	Aspens syncs them from the codebase
Teams keep correcting the same mistakes manually	Critical conventions and anti-patterns stay in generated context

What it does

Scan

Map the repo: domains, hub files, import graph, tech stack. Deterministic — no LLM, instant, free.

Generate

Write instructions and skills for Claude Code, Codex, or both. Parallel discovery and generation.

Sync

Keep generated context fresh. On each commit, aspens reads the diff and updates only what changed.

Prove

Verify coverage, freshness, and drift with aspens doc impact. Know your context is working.

Start here

npx aspens doc init --recommended
npx aspens doc impact

Generate context, then verify it covers your repo.

What are skills?

Concise markdown files (~35 lines) that give coding agents the context they need to write correct code: key files, patterns, conventions, and critical rules.

---
name: billing
description: Stripe billing — subscriptions, usage tracking, webhooks
---

## Activation
This skill triggers when editing billing/payment-related files:
- `**/billing*.ts`
- `**/stripe*.ts`

---

## Key Files
- `src/services/billing/stripe.ts` — Stripe SDK wrapper
- `src/services/billing/usage.ts` — Usage counters and limit checks

## Key Concepts
- **Webhook-driven:** Subscription state changes come from Stripe webhooks
- **Usage gating:** `checkLimit(userId, type)` returns structured 429 error data

## Critical Rules
- Webhook endpoint has NO auth middleware — verified by Stripe signature only
- Cancel = `cancel_at_period_end: true` (user keeps access until period end)

Requirements

• Node.js 20+
• Claude Code CLI or Codex CLI (at least one backend)

License

MIT — view on GitHub.