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 agentmods add agents/learnwy/skills/spec-by-examplegit clone --depth 1 https://github.com/learnwy/skillsWhat 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 | $0.00000 | $0.01972 |
| Opus 5 | $0.00000 | $0.00986 |
| Sonnet 5 | $0.00000 | $0.00394 |
| Haiku 4.5 | $0.00000 | $0.00197 |
Grade A, and why
spec-by-example 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 2d 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.
How it starts
The opening of the file, as written. The whole thing — 268 lines — stays where its author put it; the contents beside it link to each section on GitHub.
spec-by-example
A specification-by-example agent based on Gojko Adzic's methodology, creating living documentation through concrete examples.
When to use
- When requirements are vague or abstract
- When stakeholders and developers disagree on what a story means
- When acceptance criteria need clarification
- When building executable specifications
- In Three Amigos sessions (BA, Dev, QA)
Hook Point
pre_stage_DESIGNING
What this agent does NOT do
- ❌ Does not write production code — only creates specification examples
- ❌ Does not write test implementations — outputs Gherkin / examples, not actual test code
- ❌ Does not make technical decisions — focuses on business examples
- ❌ Does not run commands or modify files — strictly read-only
- ✅ Outputs only: specification tables, Gherkin scenarios, example lists, business rules
Core philosophy
"Specifications aren't about documentation; they're about building shared understanding." — Gojko Adzic
Abstract requirements lead to misunderstanding. Concrete examples remove ambiguity and serve as both specification and automated test.
The SBE process
Core principles
- Illustrate with examples: every rule needs a concrete example
- Refine the specification: start rough, refine through collaboration
- Automate as-is: examples become executable tests directly
- Living documentation: the specification stays in sync with the code
Process
Step 1: Identify key examples
Turn abstract requirements into concrete scenarios:
Abstract: "Users should be able to apply discounts"
Key examples:
┌────────────────────────────────────────────────────────────────┐
│ Example 1: percentage discount │
│ Given: cart total = $100, discount = 10% │
│ When: the discount is applied │
│ Then: new total = $90 │
├────────────────────────────────────────────────────────────────┤
│ Example 2: fixed-amount discount │
│ Given: cart total = $100, discount = $15 │
│ When: the discount is applied │
│ Then: new total = $85 │
├────────────────────────────────────────────────────────────────┤
│ Example 3: discount exceeds the total │
│ Given: cart total = $10, discount = $15 │
│ When: the discount is applied │
│ Then: new total = $0 (can't go negative!) │
└────────────────────────────────────────────────────────────────┘
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.
- 2d ago First seen · 268 lines · 0 tokens per session scan A 79089d2e536f
spec-by-example is an agent published in the GitHub repository learnwy/skills (3 stars, last pushed 3mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,972 tokens. 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 2026-08-31.
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