I
The thesis
Prompts are software. Why that framing unlocks everything that follows, and why the current state of "prompt engineering" is closer to superstition than to engineering.
II
What cognition actually is in an LLM
Tokens, attention, RLHF, modes of failure. What the substrate you're engineering on top of actually is, mechanistically, so you can design for its real properties.
III
The four primitives
Prompt, brain, blueprint, circuit -- abstracted from Brainboot's branding. The taxonomy of composable cognitive work, and why each tier exists.
IV
Typed I/O for cognition
Why putting Zod schemas on the edges of a brain changes its failure shape. How type contracts make cognition testable in the way functions are testable.
V
Invariants as the unit of engineering
Every brain has properties that must hold. Building them in as enforced runtime checks instead of hoping for them is the difference between software and wishful thinking.
VI
Composition
Why a brain graph is not just a chained prompt. How to design sub-brain handoffs, budget propagation, and error surfaces across compositions.
VII
Cost as a design input
The model cascade, prompt caching, batch economics. Why the pricing decision comes before the architecture decision, not after.
VIII
Test harnesses for probabilistic systems
How to test a function whose output is non-deterministic but whose properties are not. The role of property-based tests in the cognitive engineering stack.
IX
The garden principle
Why every commercial AI product must grow its user, and how that rule makes itself visible in the architecture when you honor it.
X
What is still hard
Open research. Honest limits. Where the framework runs out of traction and what would have to change upstream in the model layer for it to stop running out.
XI
What this replaces
The honest comparison to agents, LangChain, prompt marketplaces, and every other existing thing the framework relates to. What this is, what it isn't, what it subsumes, what it doesn't.
XII
Where this is going
The 3-year vision. The creator economy for brain authors, the Brainboot Index, and the question of what happens to software engineering when a non-trivial fraction of it is cognitive engineering.