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 painhardcore/pstack --skill principle-guard-the-context-windowgit clone --depth 1 https://github.com/painhardcore/pstackWrote 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/painhardcore/pstack/principle-guard-the-context-window)<a href="https://agentmods.dev/skills/painhardcore/pstack/principle-guard-the-context-window"><img src="https://agentmods.dev/badge/skills/painhardcore/pstack/principle-guard-the-context-window/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/painhardcore/pstack/principle-guard-the-context-window"><img src="https://agentmods.dev/badge/skills/painhardcore/pstack/principle-guard-the-context-window.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00046 | $0.00235 |
| Opus 5.5 | $0.00018 | $0.00094 |
| Sonnet 5.5 | $0.00009 | $0.00047 |
| Haiku 4.5 | $0.00005 | $0.00023 |
Grade A, and why
principle-guard-the-context-window 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 1mo 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.
This is a copy
95% identical to principle-guard-the-context-window — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
What it actually says
Guard the Context Window
The context window is finite and non-renewable within a session. Every token that enters should earn its place.
Why: Context overflow degrades reasoning quality, creates compression artifacts, and halts progress. Unlike compute or time, context spent inside a session cannot be reclaimed.
Pattern:
- Isolate large payloads. Route verbose outputs, screenshots, and large documents to subagents. The main context gets summaries, not raw data.
- Don't read what you won't use. Read selectively based on relevance. If a file isn't needed for the current task, skip it.
- Keep frequently used content inline. Templates and references used on every invocation belong in the skill file, not in separate files that cost a read each time.
- Size phases and cap scope. Limit files per phase, set turn budgets, account for mechanism costs.
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.
- 1mo ago First seen · 17 lines · 46 tokens per session scan A 17301d7bd38c
principle-guard-the-context-window is a skill published in the GitHub repository painhardcore/pstack (12 stars, last pushed 9d ago), licensed MIT. It adds 46 tokens to every session and 235 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 95% identical to principle-guard-the-context-window, differing in 8 lines, and is treated as a copy.
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apply
Use when a staged proposal has been reviewed and signed off — REVIEW.md Step 3 ticked reviewed or provisional — and is ready to promote into the live contextualizer.
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maintaining-project-context
Use when completing development phases or branches to identify and update CLAUDE.md or AGENTS.md files that may have become stale - analyzes what changed, determines affected contracts and documentation, and coordinates updates.
lore-ingest
Use when the user runs /lore:lore-ingest — find files in the lore's raw/ inbox that are new or changed since their last ledger entry, distill or surgically update wiki pages by content type, update log.md, regenerate the index, and commit.