Prompt Builder ·
Included in The AI Stack
Turn a rough idea into a prompt that gets usable answers.
Prompt Builder takes your goal, audience and constraints and assembles the structure that gets better output from any AI model, with an AI-refined version beside it.
## Role You are a senior B2B cold-email copywriter who has sold done-for-you automation services to local, owner-operated businesses. You give direct, practical, specific answers. ## Task Write one cold email to the owner of an independent gym, offering a done-for-you AI system that texts every new lead (web form, Instagram DM, missed call) within 60 seconds. ## Context <context> - I run a one-person AI automation agency: [your name / agency name]. - Offer: done-for-you setup of an AI text-back system that responds to every new lead within 60 seconds, 24/7, and books trials/tours straight into their calendar. - Proof I can cite: [case study, result, or local client — e.g. "a gym in [city] booked 14 extra trials in 30 days"]. If none, write the email without fabricating proof. - Price/terms: [e.g. $X setup + $Y/month, or omit]. - How I found them: [e.g. filled out their web form and got no reply for 3 days / saw their Google reviews]. - My contact: [phone / booking link]. </context> ## Audience Owner of an independent, single-location gym. Busy, on the floor most of the day, skeptical of agencies and of being pitched. Speaks in terms of leads, trials, memberships, no-shows, front-desk coverage — not "funnels," "pipelines," or "AI-powered solutions." ## Tone Direct and friendly. Peer-to-peer, not vendor-to-prospect. Short sentences. No hype, no flattery, no pressure. ## Constraints - Email body under 120 words (subject line not counted). - Subject line under 7 words, lowercase or sentence case, no clickbait. - No buzzwords: avoid "revolutionize," "cutting-edge," "synergy," "AI-powered," "game-changer," "leverage," "solutions." - Exactly one ask — a single, low-friction CTA (e.g. a yes/no reply or a 10-minute call). - Open with a specific, concrete observation about their gym or their lead response, not "I hope this finds you well." - Prefer concrete specifics (numbers, timeframes, named steps) over general claims. - Do not invent results, client names, or statistics. If something essential is missing or ambiguous, state your assumption in one line above the email, then continue. - Plain text only — no bullet points, no emojis, no links beyond one optional booking link. ## Output format Assumption (one line, only if needed) Subject: [subject line] [email body] ## Before you answer Check your draft against the task and every constraint: word count, one ask only, no banned words, no invented proof, specific opener. Fix anything that fails, then respond with the final version only.
$99/month · Cancel anytime · Every Tool included
Same input. Real output.
This is one real run of Prompt Builder on October 1, 2026, exactly as it came out. The data is live, so yours will be different.
Without it
- Type a one-line prompt
- Get generic filler back
- Rewrite it by trial and error
- Lose the version that finally worked
With Prompt Builder: what went in
- What do you want the AI to do?
- Write a cold email to a local gym owner offering to automate their lead follow-up with AI
- Who is it for?
- Owner of an independent gym: busy, skeptical of agencies
- Output format
- Subject line, then the email body
- Constraints
- Under 120 words. No buzzwords. One clear ask.
- Tone
- Direct and friendly
- Background context
- I run a one-person AI automation agency. The offer is a done-for-you system that texts every new lead within 60 seconds.
- Refine with AI after building
- Yes
What came out
## Role You are a senior B2B cold-email copywriter who has sold done-for-you automation services to local, owner-operated businesses. You give direct, practical, specific answers. ## Task Write one cold email to the owner of an independent gym, offering a done-for-you AI system that texts every new lead (web form, Instagram DM, missed call) within 60 seconds. ## Context <context> - I run a one-person AI automation agency: [your name / agency name]. - Offer: done-for-you setup of an AI text-back system that responds to every new lead within 60 seconds, 24/7, and books trials/tours straight into their calendar. - Proof I can cite: [case study, result, or local client — e.g. "a gym in [city] booked 14 extra trials in 30 days"]. If none, write the email without fabricating proof. - Price/terms: [e.g. $X setup + $Y/month, or omit]. - How I found them: [e.g. filled out their web form and got no reply for 3 days / saw their Google reviews]. - My contact: [phone / booking link]. </context> ## Audience Owner of an independent, single-location gym. Busy, on the floor most of the day, skeptical of agencies and of being pitched. Speaks in terms of leads, trials, memberships, no-shows, front-desk coverage — not "funnels," "pipelines," or "AI-powered solutions." ## Tone Direct and friendly. Peer-to-peer, not vendor-to-prospect. Short sentences. No hype, no flattery, no pressure. ## Constraints - Email body under 120 words (subject line not counted). - Subject line under 7 words, lowercase or sentence case, no clickbait. - No buzzwords: avoid "revolutionize," "cutting-edge," "synergy," "AI-powered," "game-changer," "leverage," "solutions." - Exactly one ask — a single, low-friction CTA (e.g. a yes/no reply or a 10-minute call). - Open with a specific, concrete observation about their gym or their lead response, not "I hope this finds you well." - Prefer concrete specifics (numbers, timeframes, named steps) over general claims. - Do not invent results, client names, or statistics. If something essential is missing or ambiguous, state your assumption in one line above the email, then continue. - Plain text only — no bullet points, no emojis, no links beyond one optional booking link. ## Output format Assumption (one line, only if needed) Subject: [subject line] [email body] ## Before you answer Check your draft against the task and every constraint: word count, one ask only, no banned words, no invented proof, specific opener. Fix anything that fails, then respond with the final version only.
- 8
- structured sections built
- ~241
- tokens, estimated for you
- 14s
- including the AI-refined version
How it works
- 1
Describe what you want
Your goal, plus anything you know: audience, context, constraints, tone, output format, examples.
- 2
It builds the structure
Role, task, context, constraints, examples and output format, in the order models respond to best.
- 3
Copy and use it
A copy-ready prompt with a character and token estimate, and optionally an AI-refined version side by side.
Who it's for
Anyone using ChatGPT or Claude for work
Your answers come back generic and you're not sure what to add.
Freelancers and agencies
You need repeatable prompts for client work, not one-off luck.
Builders
You're writing prompts into a product and want a consistent structure to start from.
Prefer to learn the method by hand first? Read the free guide: Start an AI Automation Agency, Ship a Landing Page With AI in an Afternoon.
What it does
- Structured sections: role, task, context, audience, tone, constraints, output format
- Optional AI-refined version, side by side with the original
- Character and token estimate
- Works with any model: copy it anywhere
- Saved runs you can star and reopen
What you need
- Runs in your browser on phone, tablet or computer. Nothing to install.
- No API keys or extra subscriptions: usage is included in the membership.
- The prompt works in any AI model you already use. You don't need a paid AI subscription to build one.
- Up to 200 runs a day.
Prompt Builder is included in The AI Stack
$99 a month, billed monthly until you cancel. No separate charge for Prompt Builder, no usage fees.
Also in your membership
- 4 more Tools: GitHub Discovery, Trend Radar, Script Generator, Page Scraper
- Every Blueprint: step-by-step systems to help you build
- Selected source code and components (first releases coming soon)
- The member community: ask questions, get help, share progress
By joining you agree to the Terms and Privacy Policy. Cancel any time. Refund Policy.
Already a member? Log in and you'll go straight to Prompt Builder.
Ready-to-Launch Businesses are not part of the membership. They're separate and by application.
Questions
Which AI models does it work with?
Any. It produces plain text you paste into ChatGPT, Claude, Gemini or your own app.
Do I need my own AI subscription?
Not to build prompts: the AI refinement runs on our side and is included. You'll want whichever model you plan to paste the prompt into.
Is my input kept private?
Your runs are saved to your account so you can reopen them. See the Privacy Policy for how data is handled.
What does it cost?
Prompt Builder is part of The AI Stack membership: $99 a month, billed monthly until you cancel. There's no separate charge for this Tool and no usage fees on top.
Is there a limit?
Up to 200 runs a day, which resets daily.
What happens after I pay?
Checkout creates your account with the email you pay with and takes you straight into Prompt Builder. If the payment takes a moment to confirm, you'll see that and can refresh safely: you're never charged twice.
Can I cancel?
Yes, any time from your billing settings. You keep access until the end of the month you've paid for. Our Refund Policy explains refunds.
Do I get the source code?
Using Prompt Builder is included. The membership also includes selected source code and components under our licence (see License). Ready-to-Launch Businesses are separate and by application.
Where do I get help?
Ask in the member community, which is included, or email support@jointheaistack.com.
Policies: Refund Policy, Terms, Privacy, License.
Turn a rough idea into a prompt that gets usable answers.
Get Prompt Builder$99/month · Cancel anytime · Lands you straight in Prompt Builder