Context Engineer AI Skill - Selin
Engineer the context window: token budgeting, ordering, compression, and eviction that keeps quality up.
Claude skill package instant downloadselin-context-engineer.skill
Get this skill and 2,500+ others
$9/mo or $59 a year
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One file, paid once. No updates, no connector.
Costs about the same as 2 months of Library.
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How it works
Ask it something hard.
Or have every skill inside your AI.
Questions before you buy? A person answers, usually the same day: hello@kissmyskills.com
// the file itself
The first lines of the file your AI will read, exactly as delivered. Nothing rewritten for the page.
You are Selin, a Senior Context Engineer who counts tokens per region with a real tokenizer, budgets system prompt, tools, memory and history, and compresses before truncating. You have been activated to make the context window earn every token.
// what's inside
Agent builders hitting the token ceiling or watching quality drop as history grows.
// two ways to get it
$9/mo cancel anytime, or $59 a year
$19 one payment
Already on Library or Both? This one is included, no need to buy the file.
// ask your assistant
Go to kissmyskills.com/pages/connector and set up the "Context Engineer AI Skill - Selin" skill (handle: selin-context-engineer) for me
Paste it into Claude, ChatGPT, Claude Code, Cursor or Codex. Your AI walks you through connecting KissMySkills (about 3 minutes, 7-day free trial) and loads the skill. What your AI will read →
Drop Selin into Claude and get a senior context engineer who treats the context window as a scarce, ordered token budget and makes every token earn its place.
Selin engineers the context window: token accounting across system prompt, tools, retrieved snippets, memory and history; context assembly and templating; positional placement (lost-in-the-middle, primacy and recency); compression and summarization before truncation; retrieved-context selection and dedup; tool-result trimming; memory injection; multi-turn history windowing and eviction; structured context; and prompt caching. Measure whether the model actually uses the context. Always evaluate on a held-out set in dev/staging before production.
What you get
How to install
Download the .skill package → open Claude → paste SKILL.md into your Project Instructions or system prompt → describe your requirement → Selin builds the answer. Includes a full worked example so you see exactly what you get.
After checkout, the download link lands in your inbox. Save the .skill file: Claude takes it as it is.
Any AI chat you already use: Claude, ChatGPT, Gemini, Grok, Copilot or another.
Claude: Settings → Capabilities → Skills, upload the .skill file. ChatGPT, Gemini and others: open the .skill file like a .zip archive and paste SKILL.md into custom instructions or Project instructions.
Your AI is now configured as a specialist. Ask it anything inside its domain.
No technical knowledge required.
With Library there is nothing to download. Connect your AI once, then just ask: "Load Context Engineer AI Skill from KissMySkills."
Engineer the context window: token budgeting, ordering, compression, and eviction that keeps quality up. Load it once into Claude Projects and you get a configured Context Engineer without re-explaining context at the start of every session. Build and evaluate against a held-out test set in a development or staging environment, add guardrails, cost and rate limits, and human review, and roll out behind evals and monitoring before serving agents or LLM features in production.
Download the .skill package (it contains SKILL.md), paste the contents into Claude Projects Instructions or your AI's system prompt, add your own context and start your first session. Works with Claude, ChatGPT, or any AI chat that accepts system prompts.
Works with Claude (recommended), ChatGPT, Gemini, Perplexity and Copilot, and any AI chat that accepts system prompts. Claude Projects gives the best results.
Without a skill file your AI starts every session as a general assistant. With Selin loaded it applies Context Engineer methodology from the first message, with consistent quality every time. Build and evaluate against a held-out test set in a development or staging environment, add guardrails, cost and rate limits, and human review, and roll out behind evals and monitoring before serving agents or LLM features in production.
This one and 2,500+ others, inside Claude, ChatGPT, Claude Code, Codex or Cursor. Cancel anytime.