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 rules/beettlle/pi-spine/engineering-philosophygit clone --depth 1 https://github.com/beettlle/pi-spineWrote 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/rules/beettlle/pi-spine/engineering-philosophy)<a href="https://agentmods.dev/rules/beettlle/pi-spine/engineering-philosophy"><img src="https://agentmods.dev/badge/rules/beettlle/pi-spine/engineering-philosophy.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00000 | $0.02929 |
| Opus 5 | $0.00000 | $0.01465 |
| Sonnet 5 | $0.00000 | $0.00586 |
| Haiku 4.5 | $0.00000 | $0.00293 |
Grade A, and why
engineering-philosophy 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 4d 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 — 271 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Engineering Philosophy
Design goals: Priority is Safety, then Performance, then Developer Experience.
Core Beliefs
1.1 Simplicity is a Feature (CRIT)
CRITICAL: Every line of code is a liability. The best code is code you didn't write.
❌ Bad: class Service { func get() { return repo.get() } } (unnecessary layer)
✅ Good: Delete unnecessary layers, prefer deletion over addition
⚠️ Why: Complexity kills maintainability, increases bugs, slows development
🔧 Fix: Fight complexity; delete code that doesn't add value
📍 See: general-llm-anti-patterns.mdc section 1.1 (Ghost Layer Prevention)
Detect: Unnecessary abstractions, wrapper classes, code that adds no value
1.1a Simplicity is the Hardest Revision
CRITICAL: Real simplicity comes from iteration and "throw one away," not from the first attempt.
❌ Bad: Shipping first draft as "simple", no revision passes, assuming simple = quick
✅ Good: Multiple passes to simplify; revise until design is minimal and clear
⚠️ Why: First attempt is rarely simplest; iteration reveals the super idea that solves axes together
🔧 Fix: Budget revision time; simplify after it works
📍 See: engineering-philosophy.mdc section 1.3 (Make it Work, Make it Right, Make it Fast)
Detect: One-pass "simple" solutions, no design revision, complexity defended as "good enough"
1.1b Zero Showstopper Policy
CRITICAL: Don't ship known critical bugs or unbounded risks; fix showstoppers before merge.
❌ Bad: Merging with known unbounded loops, unbounded queues, or critical correctness bugs "to fix later"
✅ Good: Bounded loops/queues, fail-fast on limits, fix showstoppers in design or implementation before merge
⚠️ Why: The second time may not transpire; shipping known critical debt undermines progress
🔧 Fix: Enforce bounded iteration and fail-fast; resolve critical issues before merge
📍 See: general-llm-anti-patterns.mdc section 2.4 (Bounded loops and queues)
Detect: Unbounded loops or queues, known critical bugs deferred, merge with "we'll fix later" on showstoppers
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.
- 4d ago First seen · 271 lines · 0 tokens per session scan A a687a7ddf83e
engineering-philosophy is a cursor rule published in the GitHub repository beettlle/pi-spine (3 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 2,929 tokens. 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 2026-08-31.
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