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.
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 rohitg00/ai-engineering-from-scratch --skill migration-review-skillgit clone --depth 1 https://github.com/rohitg00/ai-engineering-from-scratchWrote 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/rohitg00/ai-engineering-from-scratch/migration-review-skill)<a href="https://agentmods.dev/skills/rohitg00/ai-engineering-from-scratch/migration-review-skill"><img src="https://agentmods.dev/badge/skills/rohitg00/ai-engineering-from-scratch/migration-review-skill/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/rohitg00/ai-engineering-from-scratch/migration-review-skill"><img src="https://agentmods.dev/badge/skills/rohitg00/ai-engineering-from-scratch/migration-review-skill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00035 | $0.00276 |
| Opus 5 | $0.00017 | $0.00138 |
| Sonnet 5 | $0.00007 | $0.00055 |
| Haiku 4.5 | $0.00003 | $0.00028 |
Grade A, and why
migration-review 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 10d 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.
What it actually says
Migration Review
Review only the migration files named in $ARGUMENTS and the code needed to
verify their compatibility. This Skill does not authorize applying a migration.
- Run
python3 ${CLAUDE_SKILL_DIR}/scripts/check_scope.py $ARGUMENTS. - Stop if the checker rejects any path outside
migrations/. - Read references/review-checklist.md.
- Inspect each accepted file and its schema assumptions.
- Report forward behavior, rollback limits, lock risk, data-volume risk, verification evidence, and unresolved blockers.
Return these headings: Scope, Evidence, Risks, Rollback, Blockers, and
Decision. Use Decision: blocked whenever required evidence is missing.
The bundled checker is scripts/check_scope.py. The
allowed-tools entry pre-approves only that command for the invocation turn; it
does not remove other tools or replace project permission rules.
What ships with it
2 files 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.
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.
- 10d ago First seen · 25 lines · 35 tokens per session scan A 5e5e0cb4bcd5
migration-review is a skill published in the GitHub repository rohitg00/ai-engineering-from-scratch (53,293 stars, last pushed 2d ago), licensed MIT. It adds 35 tokens to every session and 276 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 2026-08-30.
Other skills, from other repositories
migration-review
A review workflow for database migration files, which change the structure or data rules of a database. It checks the requested migration files and the code needed to assess their compatibility.
database-migration-service-expertise
AWS Database Migration Service (DMS) operational review and troubleshooting skill. Conducts best practices validation, health assessments, performance diagnostics, cost optimization reviews, and migration cutover guidance. Triggers on requests like "DMS review", "DMS health check", "DMS troubleshooting", "migration…
db-migration-review
Review and clean up auto-generated database migration files after running make migrate-create. Identifies and removes unrelated Atlas schema drift such as dropped partial indexes, no-op index recreations, and other operations not related to the intended migration. Use when creating database migrations, running make…
postgresql-expert-best-practices-code-review
PostgreSQL database design, migration, and performance optimization best practices. This skill should be used when writing, reviewing, or refactoring database schemas, migrations, or query patterns. Triggers on tasks involving PostgreSQL databases, schema design, migration optimization, or data modeling.
sqlalchemy-alembic-expert-best-practices-code-review
SQLAlchemy ORM and Alembic migration best practices for building safe, performant database schemas. This skill should be used when writing, reviewing, or refactoring SQLAlchemy models, Alembic migrations, or database query patterns. Triggers on tasks involving SQLAlchemy ORM, Alembic migrations, database schema…
review-implement-phase
Implements triaged review actions, commits focused fixes, and posts Done plus resolves threads. Use when the user wants only the implementation phase of the review-framework workflow.