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 wewpellex21/code-sensei --skill fundamentalsgit clone --depth 1 https://github.com/wewpellex21/code-senseiWrote 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/wewpellex21/code-sensei/fundamentals)<a href="https://agentmods.dev/skills/wewpellex21/code-sensei/fundamentals"><img src="https://agentmods.dev/badge/skills/wewpellex21/code-sensei/fundamentals/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/wewpellex21/code-sensei/fundamentals"><img src="https://agentmods.dev/badge/skills/wewpellex21/code-sensei/fundamentals.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 | $0.00042 | $0.00595 |
| Opus 5.5 | $0.00017 | $0.00238 |
| Sonnet 5.5 | $0.00008 | $0.00119 |
| Haiku 4.5 | $0.00004 | $0.00060 |
Grade A, and why
fundamentals 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
100% identical to fundamentals — 0 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.
How it starts
The opening of the file, as written. The whole thing — 46 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Programming Fundamentals — CodeSensei Teaching Module
When explaining fundamental programming concepts to the user, use these guidelines:
Variables
- Analogy (beginner): A labeled box that holds something. The label is the name, the content is the value.
- Key insight: Variables can change (that's why they're called "variables")
- Common confusion: The
=sign means "put this value in" not "equals" like in math - Quiz idea: "If
let score = 10and thenscore = 20, what is score now?"
Functions
- Analogy (beginner): A recipe. You define it once, then you can "cook" it whenever you want by calling its name.
- Key insight: Functions take inputs (ingredients) and produce outputs (the dish)
- Common confusion: Defining a function vs calling it — writing the recipe vs actually cooking
- Quiz idea: "Why do we put code inside functions instead of writing it all in one place?"
Conditionals (if/else)
- Analogy (beginner): A fork in the road. If the condition is true, go left. Otherwise, go right.
- Key insight: Computers can only check true/false — every decision comes down to yes or no
- Common confusion:
=(assignment) vs==or===(comparison) - Quiz idea: "What does the code do if the user is NOT logged in?"
Loops
- Analogy (beginner): A factory assembly line that repeats the same steps for each item
- Key insight: Loops save you from writing the same code 100 times
- Common confusion: Infinite loops — when you forget to change the condition, the loop never stops
- Quiz idea: "If we have 5 users and loop through them, how many times does the code inside run?"
Data Types
- Analogy (beginner): Different kinds of containers — a number is a calculator display, a string is a text message, a boolean is a light switch (on/off)
- Key insight: Computers need to know what TYPE of data they're dealing with to process it correctly
- Common confusion: The number
42vs the text"42"— they look the same but the computer treats them differently
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 · 46 lines · 42 tokens per session scan A f1aa23aedb42
fundamentals is a skill published in the GitHub repository wewpellex21/code-sensei (3 stars, last pushed 6d ago), licensed MIT. It adds 42 tokens to every session and 595 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to fundamentals, differing in 0 lines, and is treated as a copy.
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