project-onboarding

project-onboarding is a skill for Codex from yuri-semenenko/ai-engineering-workspace. It costs 42 tokens per session (934 once invoked), scanned A, original, MIT.

A guide for creating or updating AGENTS.md, a repository file that tells coding agents how the project is organized and operated.

In plain words
What is it for?
Use it when onboarding an agent to a repository or documenting its build, test, migration, database, environment, authentication, and CI workflows.
Why use it?
It captures project-specific commands, workflows, boundaries, and pitfalls so an agent can work correctly without relying on guesses or repeated explanations.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: mentions CLAUDE.md; mentions Claude Code; mentions AGENTS.md.

Good fit Use it when onboarding an agent to a repository or documenting its build, test, migration, database, environment, authentication, and CI workflows.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/yuri-semenenko/ai-engineering-workspace/project-onboarding
Install

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.

Any agent
npx skills add yuri-semenenko/ai-engineering-workspace --skill project-onboarding
Clone the repo
git clone --depth 1 https://github.com/yuri-semenenko/ai-engineering-workspace

Made for: Codex.

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 project-onboarding

README.md
[![agentmods](https://agentmods.dev/badge/skills/yuri-semenenko/ai-engineering-workspace/project-onboarding/github.svg)](https://agentmods.dev/skills/yuri-semenenko/ai-engineering-workspace/project-onboarding)
Your own site
<a href="https://agentmods.dev/skills/yuri-semenenko/ai-engineering-workspace/project-onboarding"><img src="https://agentmods.dev/badge/skills/yuri-semenenko/ai-engineering-workspace/project-onboarding/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.

agentmods 80×15 button for project-onboarding

Your own site · 80×15
<a href="https://agentmods.dev/skills/yuri-semenenko/ai-engineering-workspace/project-onboarding"><img src="https://agentmods.dev/badge/skills/yuri-semenenko/ai-engineering-workspace/project-onboarding.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 934 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00042 $0.00934
Opus 5 $0.00021 $0.00467
Sonnet 5 $0.00008 $0.00187
Haiku 4.5 $0.00004 $0.00093

Measured 3d ago against content hash f88730da0ee8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

project-onboarding 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 3d 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.

codex/skills/project-onboarding/SKILL.md · 75 lines

How it starts

The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Project Onboarding

Create or update a repository's root AGENTS.md: the tool-agnostic contract for how agents work in that repository.

AGENTS.md is a context router, not a codebase dump. It answers four questions and nothing else: what would a competent agent not know about this repository, what mistake is likely without this instruction, where should it read next, and how is a change verified here. If a fact is derivable from package.json or a directory listing, leave it out.

Boundaries

  • Never copy the persona, general engineering methodology, or a whole skill into the project contract. Those are global and shared; this file is repository-specific.
  • Never invent a command. Every command comes from package.json, workspace config, Makefile, CI workflow, or existing developer docs. If discovery cannot settle a value, leave a <placeholder> and say so in the report.
  • Target 80-150 lines. Longer than that and it stops being read — a repository whose own subject is agent configuration is a known exception to that budget.

Process

  1. Inspect read-only first. Do not write anything during discovery.
  2. Read what already exists: root and nested AGENTS.md, CLAUDE.md, .github/copilot-instructions.md, GEMINI.md, .cursor/rules/, README, CONTRIBUTING, package.json (plus workspace config), test and lint config, migration directories, and CI workflows.
  3. Identify from evidence: package manager and lockfile, repository layout (single package or workspaces), the build/test/lint/type-check/dev commands and the single-test invocation, architecture boundaries, generated files, protected or vendored paths, and the environment variables required to boot.
  4. Separate verified facts from inferences. A command read from a script entry is verified; a command guessed from a framework convention is an inference and must be labelled as one.
  5. Detect an existing contract. Check the root and every nested AGENTS.md.
  6. Prepare an update, never an overwrite. Human-authored content stays. Patch stale sections, fill gaps, and leave anything you cannot verify alone.
  7. Present material ambiguities and conflicts before writing — two plausible test commands, instructions that contradict the code, a stale command that no longer exists.
  8. Get explicit approval, then write. Show the proposed diff, or the full file for a new one, and wait for a go-ahead before touching the repository.
  9. Recommend a nested AGENTS.md only when a package or service genuinely has different local rules. Agents read the nearest file, so a nested copy that repeats the root only costs context and drifts.
  10. Validate every referenced path against the working tree before writing. A contract that links to a file that does not exist is worse than silence.
  11. Wire up the tools the repository actually uses. Codex and Copilot read AGENTS.md directly, and Gemini CLI does when context.fileName lists it. Claude Code does not: it reads CLAUDE.md, so add a CLAUDE.md whose body is @AGENTS.md rather than a second copy of the rules.
  12. Report what was created, what was changed, what was inferred rather than verified, and what stayed unresolved.

Read the full file on GitHub · 75 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 3d ago Changed · +39 lines f88730da0ee8
  2. 8d ago First seen · 36 lines · 42 tokens per session scan A 4730cac2e839

Subscribe to this mod's changes

project-onboarding is a skill published in the GitHub repository yuri-semenenko/ai-engineering-workspace (1 stars, last pushed 8d ago), licensed MIT. It adds 42 tokens to every session and 934 once invoked, about $0.0002 per session on Opus 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 2026-08-31.