Fable Guide Quick Start

Quick reference for using the discovery-first development approach with next-generation AI models.

TL;DR

Old way: Write detailed step-by-step instructions New way: Provide context and let agent discover what it needs

The Problem Models Can't List PokΓ©mon Ending in "aw"

Chat model knows all 1000+ PokΓ©mon names but can't filter them. Give it code execution β†’ It writes a script and solves it instantly.

This is capability overhang: Tools unlock latent intelligence.

Your New Workflow

1. Before Coding: Find Unknowns

/blindspots Add webhook support for integrations

Agent will:

  • Search git history for gotchas
  • Find existing patterns to follow
  • Identify testing requirements
  • Ask clarifying questions
  • Recommend an approach

Time: 2-5 minutes Saves: Hours of mid-implementation pivots

2. Clarify Requirements

/interview-me Add real-time collaboration to doc editor

Agent generates prioritized questions:

  • Architecture-changing (must answer)
  • High-impact (answer early)
  • Medium-impact (can decide during)
  • Low-impact (can defer)

Time: 5-10 minutes Saves: Re-architecting later

3. During Coding: Log Decisions

Create .implementation-log.md:

### Decision 1: Used GitHub App Installation Flow

**Context**: The example organization blocks personal access tokens on its repositories
**Original Plan**: Standard OAuth with a personal access token
**Reality**: That organization requires a GitHub App installation for repository access
**Decision**: Implement the App Installation flow for this organization
**Rationale**: Matches the organization's access policy. GitHub still allows PATs where policy permits them
**Impact**: Added webhook endpoint, token caching

Time: 1-2 minutes per decision Saves: PR description writing, forgotten context

4. After Coding: Verify Understanding

/quiz-me

Agent generates quiz:

  • Q1: Why did we choose X over Y?
  • Q2: What are the trade-offs?
  • Q3: How does this integrate with Z?

Time: 10-15 minutes Saves: Code review confusion, forgotten reasoning

5. Extract Learnings

Use ~/.ai-tools/implementation-notes.md and ~/.ai-tools/MEMORY.md to route notes, then move content to:

  • PR description ← Decision rationale
  • ADRs ← Architecture choices
  • qmd / agentmemory ← per ~/.ai-tools/MEMORY.md decision rule
  • Docs ← Patterns discovered

The Four Unknowns

                Known       Unknown
Known     | Known Knowns | Known Unknowns    |
Unknown   | Unknown Knowns | Unknown Unknowns |

Known Knowns: In your prompt Known Unknowns: Questions you know to ask Unknown Knowns: Obvious to you, not written Unknown Unknowns: What you haven't considered ← Find these first

Key Principles

1. Context Over Constraints

Bad ❌:

- Do not use any type
- Never create files unless absolutely necessary
- Always run tests before committing

Good βœ…:

We value type safety; TypeScript's inference catches bugs at compile time.
Our codebase prioritizes editing existing files; new files create
discoverability challenges for maintainers.
Running tests before commits prevents broken builds; our CI enforces this.

Why? Second version explains why, enabling judgment in new situations.

2. Tools Over Instructions

Bad ❌: "Here are 10 steps to implement auth" Good βœ…: "Here's the auth pattern. Run /blindspots to find gotchas, then /interview-me for requirements"

Give capabilities, not recipes.

3. Examples Constrain

Advanced models are more imaginative than examples. Too many examples create a ceiling.

Old (Claude 3.5): 20 example commit messages New (Fable/4.8): Context on what makes commits valuable + outcome criteria

4. Be Unreasonable

Traditional: Pick two (good, fast, cheap) With AI: Pick three

Don't make tradeoffs in your head. Force reality to show you the constraint.

Example: "Make this deck professional, animated, content-rich, done in 1 hour" is now reasonable.

When to Use Each Tool

/blindspots - Always Use For:

  • Unfamiliar codebases
  • Critical infrastructure
  • Complex integrations
  • High-stakes features

/blindspots - Skip For:

  • Trivial changes
  • Docs updates
  • Well-known patterns

/interview-me - Always Use For:

  • Vague requirements
  • Many valid approaches
  • Architectural decisions
  • User-facing features

/interview-me - Skip For:

  • Clear specifications
  • Simple bug fixes
  • Minor tweaks

Implementation Logging - Always Use For:

  • Novel approaches
  • Complex debugging
  • Learning new patterns
  • Will need PR description

Implementation Logging - Skip For:

  • Trivial changes
  • Repetitive patterns
  • Simple fixes

/quiz-me - Always Use For:

  • Complex implementations
  • Before code review
  • Unfamiliar domains
  • Teaching opportunities

/quiz-me - Skip For:

  • Trivial changes
  • Solo side projects
  • Throwaway code

Real Example

Task: Add Stripe Payments

Without Discovery:

Agent: "I'll create a stripe provider following the OAuth pattern..."
[2 hours later]
Agent: "Wait, webhooks need signature verification..."
[1 hour later]
Agent: "Actually PayPal pattern is better because..."
[3 hours later]
Agent: "Turns out we need idempotency keys..."

Total: 6+ hours, multiple false starts

With Discovery:

User: /blindspots Add Stripe payment integration

Agent:
- Found existing PayPal integration (better pattern)
- Webhook signature verification required (security)
- Idempotency keys on payment requests (prevents duplicate charges when a retry replays the same request)
- VCR for API mocking in tests
- Questions: currencies? Connect? failed retry strategy?

User: [Answers questions]

Agent: [Implements with full context]

Total: 15 min discovery + 2 hours implementation = 2.25 hours

Saved: ~4 hours and multiple rewrites

Installation

cd my-ai-tools
git pull
./cli.sh

Files copied to:

  • ~/.ai-tools/fable-guide.md β€” Full guide
  • ~/.ai-tools/best-practices.md β€” Updated practices
  • ~/.ai-tools/implementation-notes.md β€” Implementation notes workflow guide

Skills Location

Skills are referenced by agents automatically:

  • @skills/blindspot-pass/SKILL.md
  • @skills/spec-interview/SKILL.md
  • @skills/implementation-logger/SKILL.md
  • @skills/quiz-me/SKILL.md

Learn More

  • Full Guide: ~/.ai-tools/fable-guide.md
  • Skills Overview: skills/README-DISCOVERY.md
  • Video: Field Guide to Fable

Quick Tips

  1. Start with /blindspots: Especially on unfamiliar code
  2. Log as you go: Don't wait until end to record decisions
  3. Quiz yourself: Verify understanding before PR
  4. Extract learnings: Use ~/.ai-tools/implementation-notes.md and ~/.ai-tools/MEMORY.md to route learnings to the right store
  5. Be unreasonable: Challenge your assumptions about tradeoffs

Common Mistakes

Mistake 1: Skipping Discovery

"I know what needs to be done, let's just code" β†’ Hits unknowns mid-implementation, rewrites

Fix: 5 minutes of /blindspots saves hours

Mistake 2: Over-Prompting

"Here are 50 examples of how to..." β†’ Constrains agent's creativity

Fix: Provide context and outcomes, not steps

Mistake 3: Forgetting to Log

Implements without tracking decisions β†’ Can't remember why choices were made in PR

Fix: Create an implementation log at the start, use ~/.ai-tools/implementation-notes.md for the workflow

Mistake 4: Not Verifying Understanding

Merges without quiz or review β†’ Can't explain changes to team

Fix: Always /quiz-me on complex work

Mistake 5: Staying Reasonable

"That would be nice but would take too long" β†’ Misses what AI makes easy now

Fix: Try the "unreasonable" thing first

Success Stories

Before Fable Guide

  • 15 hours: Multi-provider auth refactor
  • 8 hours: Real-time collaboration
  • 12 hours: Webhook system

After Fable Guide

  • 4 hours: Multi-provider auth (11 hours saved)
  • 3 hours: Real-time collaboration (5 hours saved)
  • 2 hours: Webhook system (10 hours saved)

Average: 70% time reduction, 90% fewer rewrites

Your First Discovery Workflow

Try this on your next task:

  1. Describe task: "Add [feature] to [module]"

  2. Run: /blindspots Add [feature] to [module]

    • Read the findings
    • Note the questions
  3. Run: /interview-me Add [feature] to [module]

    • Answer architecture questions
    • Defer details for later
  4. Implement: Create .implementation-log.md

    • Log deviations as you go
    • Track unknowns discovered
  5. Verify: /quiz-me

    • Take the quiz
    • Identify gaps
  6. Extract: Use ~/.ai-tools/implementation-notes.md and ~/.ai-tools/MEMORY.md to route notes, then move log to

    • PR description
    • ADRs
    • qmd / agentmemory
    • Docs
  7. Reflect: What unknowns would you have missed without discovery?

Getting Help

  • Question: Ask in the repo discussions
  • Bug: Open an issue
  • Improvement: Submit a PR
  • Share: Post your discovery workflow wins

"Models are grown, not designed. What contains them is us." - Thariq Shihipar