ai-engineering-from-scratch: Instructions file for Codex

AGENTS.md

ai-engineering-from-scratch AGENTS.md is an instructions file for Codex, OpenCode from rohitg00/ai-engineering-from-scratch. It costs 4,136 tokens per session, scanned A, original, MIT.

A set of contributor instructions for the ai-engineering-from-scratch programming curriculum. It explains the repository layout, working philosophy, lesson requirements, and rules for keeping its hundreds of lessons consistent.

In plain words
What is it for?
Use it when editing lessons, documentation, quizzes, code, reusable outputs, the roadmap, or the public README in that repository.
Why use it?
It gives coding agents the project context they need before changing lessons or opening a pull request. This reduces inconsistent structure, missing lesson materials, and violations of the curriculum's build-from-first-principles approach.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md. Also seen: reads .claude/ paths; mentions Claude Code; mentions AGENTS.md.

This is rohitg00/ai-engineering-from-scratch's own configuration. It tells Codex and OpenCode how to work on ai-engineering-from-scratch itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything ai-engineering-from-scratch configures →

About the project

AI Engineering from Scratch is a free, open-source curriculum that teaches people to build AI systems through lessons and reusable artifacts such as prompts, skills, agents, and MCP servers. It is for learners who want practical foundations or want to create AI applications, and the catalogue skills support parts of that curriculum.

rohitg00/ai-engineering-from-scratch · 77,007 stars · on GitHub · aiengineeringfromscratch.com

Reuse

Borrowing it

Nothing to install: this file belongs to rohitg00/ai-engineering-from-scratch. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/rohitg00/ai-engineering-from-scratch/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/rohitg00/ai-engineering-from-scratch

Made for: Codex, OpenCode.

Wrote 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.

agentmods badge for ai-engineering-from-scratch AGENTS.md

README.md
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Your own site
<a href="https://agentmods.dev/instructions/rohitg00/ai-engineering-from-scratch/agents-md"><img src="https://agentmods.dev/badge/instructions/rohitg00/ai-engineering-from-scratch/agents-md/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.

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<a href="https://agentmods.dev/instructions/rohitg00/ai-engineering-from-scratch/agents-md"><img src="https://agentmods.dev/badge/instructions/rohitg00/ai-engineering-from-scratch/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 4,136 This file is loaded in full into every session.
When invoked 4,136 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.04136 $0.04136
Opus 5.5 $0.01654 $0.01654
Sonnet 5.5 $0.00827 $0.00827
Haiku 4.5 $0.00414 $0.00414

Measured 2d ago against content hash f30a4f59dba4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

ai-engineering-from-scratch AGENTS.md 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 2d 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.

AGENTS.md · 349 lines

How it starts

The opening of the file, as written. The whole thing — 349 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

Operating manual for contributors and AI agents touching this repo. Read it before opening a PR.

The repo is a curriculum, not a SaaS app. The lessons are the product. Every rule below keeps 542 lessons coherent over time.


Philosophy

542 lessons. 20 phases. Every algorithm built from raw math before a single framework gets imported. You write backprop, the tokenizer, the attention mechanism, and the agent loop by hand in Python, TypeScript, Rust, or Julia. Then you run the same operation through the production library so the framework stops being a black box. The "Build It / Use It" split is the spine. Each lesson ships a reusable artifact you can plug into your daily workflow.


Repo layout

phases/
  NN-phase-slug/
    NN-lesson-slug/
      docs/en.md              # lesson explainer
      code/                   # implementation + tests
      quiz.json               # 6 questions
      outputs/                # reusable artifact (skill / prompt / agent / MCP server)
README.md                     # public face; lesson counts auto-synced
ROADMAP.md                    # phase/lesson status
glossary/terms.md             # canonical term definitions
site/
  build.js                    # parses README + ROADMAP + glossary -> data.js
  data.js                     # generated; rebuilt by CI on main push
certifications/claude/
  program.json                # program metadata, source policy, official links
  tracks/*.json               # exam blueprint, ordered route, study plans
  lessons/NN-slug/            # shared certification lesson contract
  assessments/<exam-code>/    # original diagnostics and full mocks
manuals/
  AUTHORING.md                # manual contract: shape, figures, capture kit, prose limits
  <id>/manual.json            # pinned subject, palette, parts and sections
  <id>/sections/*.md          # one file per section
  <id>/figures/*.svg          # static figures; figure kit sources in figures/src/
  <id>/capture/               # offline capture kit and the records it wrote
scripts/                      # automation
.github/workflows/
  curriculum.yml              # invariant + auto-sync workflow

Read the full file on GitHub · 349 lines

Changes

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.

  1. 2d ago Changed · +15 lines · +376 tokens per session f30a4f59dba4
  2. 14d ago Changed · +3 lines · +129 tokens per session fcebb777e98f
  3. 23d ago Changed 5c5d3980ffff
  4. 25d ago Changed 49f024b89260
  5. 27d ago Changed · +8 lines · +235 tokens per session 27fabcd65289
  6. 1mo ago Changed · +11 lines · +232 tokens per session 59d6183d5edc
  7. 1mo ago Changed · +2 lines · +63 tokens per session 24a1cb3e1111
  8. 1mo ago Changed 9aabea3913cb
  9. 2mo ago First seen · 310 lines · 3,101 tokens per session scan A d4bc4cccea16

Subscribe to this mod's changes

ai-engineering-from-scratch AGENTS.md is an instructions file published in the GitHub repository rohitg00/ai-engineering-from-scratch (77,007 stars, last pushed yesterday), licensed MIT. It adds 4,136 tokens to every session, about $0.0165 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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