ai-engineering-from-scratch: Skill for Claude Code

Write a manual

A manual explains one subject, such as a protocol, a file format, or a runtime, at one exact version. A lesson teaches a concept and moves on. A manual stays with one system until the reader can predict what it does in a case the manual never showed.

This skill gives the full method. It covers research, ranked sources, and a register of conflicts between sources. It also covers an offline capture kit, a fixed section shape, prose limits, and an audit that must report TOTAL 0. It works in any repository. Inside the AI Engineering from Scratch repo, the tooling already exists, and manuals/a2a-101/ is the worked example.

When to use

• The reader must predict the behavior of one system, at one version, in cases you did not show.
• The subject has a specification, a schema, or a source tree that you can pin to a commit.
• You can run the subject, or a faithful stand-in, offline and record its requests and responses.
• The result is 60 to 100 pages with figures, and other people will maintain it.

When not to use

• You teach a general concept, such as attention or retrieval. Write a lesson instead.
• The subject has no version to pin, or changes every week.
• You cannot run the subject and cannot record its output. A manual without captures is an essay.
• You want a short how-to. A manual of fewer than about 15 sections does not need this shape.

Size of a 101 manual

Item	Target
pages	60 to 100
parts	6 to 8, plus one reference part
sections	about 25
figures	30 to 40
outcomes in manual.json	at least 3
takeaways per section	exactly 1 block, with at least 2 items

The worked example has 7 parts, 28 sections, 7 reference sections, and 31 figures.

Method

1. Pin the subject. Record the version, source URL, commit, release date, and verified date.
2. Rank the sources. List them in authority order: schema or proto, specification, project docs, reference SDK, capture kit.
3. Vendor what the license allows. Copy each quotable source unchanged into research/sources/, with its license file beside it.
4. Write the fact brief. Index every rule you will use by section and line number, in research/. See references/research-and-sources.md.
5. Open the conflict register. Give each disagreement between two sources an id (D1, D2, ...) as you find it.
6. Build the capture kit. Drive the subject offline and write deterministic files to capture/out/. See references/capture-kit.md.
7. Plan the contents from the specification. Name each section after one thing the reader can find in the spec.
8. Write manual.json. Fill the pin, outcomes, palette, ranked sources, quote sources, capture commands, and parts. See references/manual-json.md.
9. Write the front matter. Title it "How to read this manual" and follow the order in "Front matter" below.
10. Write one section at a time. Use the section shape below. Cut every listing from a capture file.
11. Draw each figure from a capture. Follow the figure must-haves below and the sibling blueprint-figure skill.
12. Build and audit. Fix every finding until the audit prints TOTAL 0. See references/audit.md.
13. Size commits by judgment. A section with its figures and the captures it adds is a good unit.