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 skills/wewpellex21/code-sensei/fundamentalsnpx 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.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 | $0.00042 | $0.00595 |
| Opus 5 | $0.00021 | $0.00298 |
| Sonnet 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 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.
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.
- 4d 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 today), licensed MIT. It adds 42 tokens to every session and 595 once invoked, about $0.0002 per session on Opus 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.
Other skills, from other repositories
researchers-historical
Researches archives, contemporary accounts, and timeline reconstruction. Use when the album subject involves historical events that need primary source verification.
book-to-skill
Use when the user names one book, course, paper, or source document and asks to distill it into a reusable skill. Classifies the source as procedure or reference, writes an attributed SKILL.md, and proves its routing. Not for a folder of sources — use map-corpus.
drill
Use when a concept needs practising rather than explaining: run a scaffolded exercise from worked example to independent problem, quiz the learner, run spaced recall over what they cleared, or probe for the gaps blocking what they want next. For explanation, use explain-concept; for an end-to-end build, use capstone.
scaffold-exercises
Use when a course needs numbered problem, solution, and explainer scaffolds. Creates type-specific files with non-colliding names, populates them, and validates with the course linter. Not for a CLI or Next.js project scaffold — use scaffold-cli or scaffold-nextjs.
explain-concept
Use when a concept needs making clear rather than practising: build the intuition, explain why it exists and what it replaced, trace where it came from, draw it, or contrast it against what it gets confused with. For exercises and grading, use drill.
capstone
Use when the user is ready to apply what they learned to something real: scope a project sized to what they have cleared, write the brief with milestones and a done test, then judge the finished work against it. For single-concept exercises and quizzes, use drill.