Colophon

Who this is for — readers who want to know how a book about agentic development was itself made.

Read this if — you are curious what the split of labour actually looked like.
Skip this if — you came for the engineering; the Golden Path has more of it.

Takeaways

1. The books are built by the same pipeline they describe: spec, canary, harness, preflight.
2. Attribution is machine-readable — model credit lives in commit trailers, not in prose.
3. The agents got things wrong here too, and the wrong things are named below.

Last updated: 2026-08-09.

How This Book Was Made

Everything you are reading is plain Markdown in src/, compiled by mdBook and printed to PDF by headless Chromium. The slide decks that accompany the library are compiled by a single-file Go program, scripts/build_slides.go, which also generates each book’s stylesheet from spec/config.yaml and refuses to build if a forbidden term appears in any source file. One command builds the shelf; one command, make preflight, decides whether it was allowed to.

The typography, accent colors, margins, and slide transitions of all three books are spec values, not stylesheet values. Changing the violet you see in these headings is a one-line edit in spec/config.yaml — the mechanism, and the bug it shipped with, is the subject of The Golden Path.

(Versions as recorded in the tools: registry of spec/config.yaml.)

Who Wrote What

The human — Uwe Jugel — wrote the thesis, the structure, the arguments, the decisions, and every judgement call about what belongs in the spec, what belongs in a rule, and what belongs in an ADR. The models drafted, refactored, wrote tests, and did the mechanical work of turning notes and Git history into prose.

Attribution is recorded where it can be queried rather than claimed. At the time of writing, 16 of this repository’s 37 commits carry a Co-Authored-By: trailer naming the model that worked on them; the earlier commits predate the convention. Run the count yourself:

git log --format='%H %(trailers:key=Co-authored-by,valueonly)' | awk 'NF>1' | wc -l
git rev-list --count HEAD

Which models may be named at all is itself governed by the models: registry in spec/config.yaml — the build aborts on any model name that is not in it, which is why this page will not quietly drift into naming something that never worked here. The registry records Claude Fable 5 for technical writing and general agentic work, Claude Sonnet 5 for the module refactors and the final book compilation, Claude Opus 4.8 for the image pipelines, and Claude Sonnet 4.6, Gemini 3.1 Pro, and Gemini 3.5 Flash for the emojig TUI work chronicled in the Emojig Chronology.

What the Agents Got Wrong

A colophon in a book with this thesis owes the reader the failures, not just the credits. Three, all documented elsewhere in the repository:

1. A one-line YAML parse that was right for every case but the real one. strings.Trim(…, "\"'") handled quoted values perfectly and mangled every value with a trailing comment — including the accent color of every book. It passed review, passed the build, and shipped. Post-mortem and fix: The Golden Path.
2. Two correct stylesheets that disagreed about authority. A hand-written theme and a spec-generated baseline both defined the same selectors; the book rendered as a colour hybrid with every test green. Resolved by a decision record rather than by code.
3. A review that critiqued a table of contents. An AI reviewer recommended adding diagrams to the two chapters that already had them, and missed the four chapters that had none. It is a useful reminder of what agent output looks like when nothing in the loop forces contact with the source: fluent, confident, and about a book that does not exist.

The first two were caught by a human noticing that a page looked wrong, then converted into permanent checks. The third was caught by counting. All three are the same lesson from different angles: an agent’s output is a hypothesis, and the only thing that makes it knowledge is a check.

Acknowledgments

The dedications belong at the end of The Solo Fleet, Reviewed, where they were written, not here.