Real AI agent use cases, with sources and setup prompts

Have an AI reverse engineer a device you own

Had the Fable model work out the music format of his self-playing piano system.

$10 in / $50 out per 1M tokensdaysAdvancedSource linked

Source

jmpman on Hacker News · 2026-09-05

Written in our own words. Credit to the original author. Link checked 2026-10-14.

What they did

Had the Fable model work out the music format of his self-playing piano system.

Result (as claimed)

It worked; he asked HN whether he can release the results.

Tools they used

GPT-6 AstraClaude Fable 5.1

Cost: GPT-6 Astra: from $10 in / $50 out per 1M tokens; Claude Fable 5.1: from $10 in / $50 out per 1M tokens.

Set it up

  1. Define the job

    Say exactly what you want done and what the agent may and may not do on your behalf.

  2. Share only what is needed

    Give GPT-6 Astra the minimum files or access required. Avoid sharing passwords in chat when a safer login flow exists.

  3. Review the plan

    Ask the agent to show its plan or draft before it acts, and approve each step that has real consequences.

  4. Check the result

    Confirm the outcome yourself (order placed, request sent, document understood) and keep a record.

Copy the full setup prompt

Paste into your agent and it will walk you through the setup, asking before anything that sends, posts or spends.

You are helping me set up this AI use case end to end in Claude Code.

Goal: Have an AI reverse engineer a device you own
What the original author did: Had the Fable model work out the music format of his self-playing piano system.
Reported result (as claimed by the author): It worked; he asked HN whether he can release the results.
Source: https://news.ycombinator.com/item?id=49577129
Tools they used: GPT-6 Astra, Claude Fable 5.1
Category: Personal & life

Please:
1. Ask me 3 short questions about my situation (accounts I have, budget, what I want the output to look like).
2. Propose a step-by-step plan using these tools or cheaper alternatives, with the time and cost of each step. Use official pricing pages; say "check pricing" if unsure.
3. Then do the setup with me one step at a time, waiting for my OK before anything that sends messages, posts publicly, spends money or deletes data.
4. Finish with a checklist to run it again next time.

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