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 elbwalker/walkerOS --skill walkeros-understanding-developmentgit clone --depth 1 https://github.com/elbwalker/walkerOSWrote 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/elbwalker/walkeros/walkeros-understanding-development)<a href="https://agentmods.dev/skills/elbwalker/walkeros/walkeros-understanding-development"><img src="https://agentmods.dev/badge/skills/elbwalker/walkeros/walkeros-understanding-development/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/elbwalker/walkeros/walkeros-understanding-development"><img src="https://agentmods.dev/badge/skills/elbwalker/walkeros/walkeros-understanding-development.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 | $0.00041 | $0.01493 |
| Opus 5.5 | $0.00016 | $0.00597 |
| Sonnet 5.5 | $0.00008 | $0.00299 |
| Haiku 4.5 | $0.00004 | $0.00149 |
Grade A, and why
walkeros-understanding-development 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 18d 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 — 176 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Understanding walkerOS Development
Overview
walkerOS follows extreme programming principles with strict conventions. This skill is your foundation before writing any code.
Core principle: DRY, KISS, YAGNI. Test first. Verify before claiming complete.
Commands
| Command | Purpose |
|---|---|
npm install |
Install all dependencies |
npm run dev |
Watch mode for all packages |
npm run build |
Build all packages |
npm run format |
Prettier formatting |
Verification cheatsheet:
- While iterating (L1, touched package):
npm run verify:touched -- <pkg> - At plan completion (L2, affected since
origin/main):npm run verify:affected
See /workspaces/developer/AGENT.md rule 11 for the full doctrine.
XP Principles (Non-Negotiable)
| Principle | In Practice |
|---|---|
| DRY | Use @walkeros/core utilities, don't reimplement |
| KISS | Minimal code to solve the problem |
| YAGNI | Only implement what's requested |
| TDD | Test first, watch it fail, then implement |
No any |
Never use any in production code (tests are exception) |
Folder Structure
packages/
├── core/ # Platform-agnostic types, utilities, schemas
├── collector/ # Central event processing engine
├── config/ # Shared config (eslint, jest, tsconfig, tsup)
├── web/
│ ├── core/ # Web-specific utilities
│ ├── sources/ # browser, dataLayer
│ └── destinations/ # gtag, meta, api, piwikpro, plausible
└── server/
├── core/ # Server-specific utilities
├── sources/ # gcp
└── destinations/ # aws, gcp, meta
apps/
├── walkerjs/ # Zero-config browser file for GTM
├── quickstart/ # Code examples (source of truth for patterns)
└── demos/ # Demo applications
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.
- 18d ago Changed 9df1d037ab93
- 1mo ago First seen · 176 lines · 41 tokens per session scan A 4adefe45cfeb
walkeros-understanding-development is a skill published in the GitHub repository elbwalker/walkerOS (348 stars, last pushed today), licensed MIT. It adds 41 tokens to every session and 1,493 once invoked, about $0.0002 per session on Opus 5.5. 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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