Appendix A — Appendix: The Evidence Trio Templates

The three documents every project keeps. Copy them at project start; the discipline is filling them at the moment of the event, not after.

Lab companion: Lab 14, The Paper Trail: the trio as a checked artefact rather than a good intention, with the reference linter in this book’s tools/trio_lint.py.

A.1 SPEC.md

# SPEC — <project name> v<n>

Purpose: <one sentence — what this is for>

Inputs: <every input, with type, range, and format>
Behaviour: <numbered rules; every rule specific enough to test>
Out of scope: <explicitly not doing, this version>

Done means:
- [ ] <runnable check 1>
- [ ] <runnable check 2>

A.2 DECISIONS.md

# Decisions

| Date | Decision | Why | Revisit when |
|---|---|---|---|
| 2026-09-16 | Use plain files, no database | One user, data must be human-editable | More than one user appears |

A.3 CRITIQUE.md

# Critique

## Position
<what you chose and would choose again>

## Why
<the reason that names a person and a situation>

## What I gave up
<the admitted cost of the choice>

## What would change my mind
<the condition that reverses it>