Give ChatGPT and Claude Persistent Context with 3 Markdown Files

If you use ChatGPT or Claude for real work, you've probably typed some version of this dozens of times:

"I'm building a tool for freelancers that... our tone is friendly but not cheesy... please don't use buzzwords..."

Every new chat starts from zero. The model doesn't know your product, your audience, or the things you hate seeing in its output. So you either re-explain everything (slow) or skip it and get generic results (worse).

The fix is boring and effective: keep your context in three small Markdown files and paste or attach them at the start of a session.

• product.md — what you're building, for whom, and why
• voice.md — how you sound
• rules.md — hard constraints and output format

Here's how to write each one, with templates you can copy right now.

Why Markdown files instead of "memory" features?

Built-in memory and custom instructions are useful, but they have limits:

• Portability. A file works in ChatGPT, Claude, an API script, or your code editor's AI assistant. Switching tools costs you nothing.
• Version control. Put the files in a Git repo or a notes folder and you can see how your positioning changed over time.
• Precision. You decide exactly what the model sees. There's no guessing about what it "remembered" from a chat three weeks ago.
• Scope. You can keep different sets for different projects without them bleeding into each other.

Markdown specifically works well because models handle headings and bullet lists reliably, and the files stay readable for you too.

File 1: product.md

This is the single source of truth about what you sell. Keep it short — one screen is plenty. If it's too long, the important parts get diluted.

# Product Context

## One-liner
InvoiceSnap turns a finished project into a sendable invoice in under a minute.

## Who it's for
- Solo freelancers (designers, developers, copywriters)
- Billing 2–10 clients per month
- Currently using spreadsheets or Word templates

## Problem
Invoicing is tedious, gets postponed, and delays getting paid.

## What it does
- Creates invoices from a short project summary
- Remembers client details and payment terms
- Exports PDF and sends by email

## What it does NOT do
- No accounting, tax filing, or payroll
- No team features

## Pricing
(example) Single plan, monthly.

## Current focus
Getting the first 20 paying users. Priority: landing page copy and cold outreach.

Two sections punch above their weight here:

• "What it does NOT do" stops the model from inventing features in your marketing copy.
• "Current focus" tells the model what matters this week, so its suggestions stay relevant. Update this line often.

File 2: voice.md

Without guidance, models default to a polished, slightly overexcited corporate voice. voice.md pulls them toward how you actually write.

# Voice & Tone

## In three words
Direct. Friendly. Practical.

## Do
- Write like you're explaining to a smart friend
- Short sentences. Short paragraphs.
- Use concrete examples over abstract claims
- Address the reader as "you"

## Don't
- No hype words: "revolutionary", "game-changing", "unlock", "supercharge"
- No exclamation marks in headlines
- No emojis unless explicitly asked
- Don't open with "In today's fast-paced world..."

## Sample of my writing
> Invoicing shouldn't take longer than the last task on the project.
> Paste what you did, check the numbers, hit send. That's it.

The sample paragraph is the most important part. Models imitate examples far better than they follow adjectives. Paste two or three sentences you've written and liked — an email, a tweet, a landing page line.

File 3: rules.md

This is where you put non-negotiables: facts the model must not invent, and how you want output formatted.

# Rules

## Accuracy
- Never invent statistics, testimonials, customer counts, or partnerships.
- If a number is needed and I haven't given one, write [NUMBER] as a placeholder.
- Mark any sample figures clearly as "(example)".
- If you're unsure about a fact, say so instead of guessing.

## Output
- Default language: US English
- Use Markdown headings and bullet lists
- Give 3 variations when I ask for copy (headlines, subject lines, CTAs)
- Keep emails under 120 words unless told otherwise

## Process
- If my request is ambiguous, ask at most 2 clarifying questions, then proceed.
- When I say "tighten", cut length by ~30% without losing meaning.

The accuracy rules alone are worth the effort. The placeholder convention ([NUMBER]) means you can scan output and immediately see what needs real data, instead of discovering a made-up "93% of freelancers" in something you already sent.

The workflow: 5 minutes to set up, seconds to reuse

1. Create the files once. Put them in a folder like ai-context/. Fill in the templates above with your own details. Resist the urge to write an essay; aim for under 300 words per file.

2. Start each session with a context message. In ChatGPT or Claude, attach the three files (or paste them) with a short opener:

Here is context about my product, my voice, and my rules.
Read all three files. Don't reply with a summary — just say "Ready."
Then wait for my first task.

The "just say Ready" line saves you from a long recap you'll never read.

3. Give a specific task.

Write a cold outreach email to a freelance designer who
currently invoices with a Google Docs template.
Follow voice.md and rules.md.

4. Iterate, then feed learnings back. If you correct the model the same way twice ("stop saying 'streamline'"), that correction belongs in voice.md or rules.md. Your files get better every week.

5. Use project features if you have them. ChatGPT Projects and Claude Projects let you attach files once so every chat in that project starts with them. The files stay the same — only the delivery gets easier.

Tips from using this setup

• Keep files small. A tight 200-word product.md beats a 2,000-word one. If a section doesn't change the output, delete it.
• Separate stable from changing info. Your product description changes rarely; "Current focus" changes weekly. Put the volatile stuff at the bottom so it's easy to find and edit.
• One set per project. Client work, your side project, and your newsletter each deserve their own three files.
• Test with a known task. After editing a file, rerun a task you've done before (say, "write 3 headlines") and compare. That's the quickest way to see whether a change helped.
• Don't store secrets. No API keys, passwords, or private client data in files you paste into a chat.

Wrapping up

Persistent context isn't a feature you need to wait for. Three Markdown files — what you sell, how you sound, and what the model must never do — make ChatGPT and Claude noticeably more useful from the first message. Copy the templates above, spend five minutes filling them in, and use them on your next task.

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If you'd rather start from ready-made templates, PromptWorks has an AI Starter for Solo Founders pack: 40 prompts with usage context, a short guide, and checklists, as Markdown files.