PromptPatch: first app from GantryWorks

Your prompts,
never lost
again.

GantryWorks builds focused extensions for AI-heavy work. PromptPatch is the first: save every prompt you write on Claude, ChatGPT or OpenAI, track versions, compare changes, and copy what works.

Add to Chrome — free trial See how it works →
Works on
Claude
ChatGPT
OpenAI
claude.ai/new
N
Rewrite this email to sound more direct and professional. Remove filler phrases and get to the point in the first sentence. Keep it under 100 words.
C
Subject: Decision needed by Friday

Hi Sarah, we need your sign-off on the revised budget before end of week. The main change is a £12K design increase for the additional sprint…
PromptPatch
Email tone rewriter
Claude Sonnet
✓ Version 3 saved.
§ 01
GantryWorks
A growing collection of small, sharp tools for AI operators.
App 01
PromptPatch keeps useful prompts out of chat history and inside a reusable local library.
Next
Future extensions will target the same standard: self-serve, privacy-aware, narrow enough to be excellent.
Principle
No demos. No custom onboarding. Just focused products that solve repeated workflow pain.
02
The problem

You wrote it perfectly
once. Then lost it.

Great prompts take hours to craft. One wrong click, a browser refresh, a new conversation — and they're gone. You rebuild from scratch, never quite landing the same result.

Slack #ai-prompts
"does anyone have that prompt for writing OKRs? I lost mine again"
Notion doc
"PROMPT EXPERIMENTS v7 (use this one, not the others)"
notes.txt
"the email rewrite prompt that actually worked was somewhere in thread 4"
Clipboard
"I copied it but then copied something else 😭"
§ 02
PromptPatch

Three steps.
Zero friction.

1

Write. Click save.

The PromptPatch panel sits quietly on every AI platform. When you write something worth keeping, one click saves it with title, model, and timestamp.

2

Iterate. Version automatically.

Every save creates a new version. Full lineage — v1, v2, v3 — so you can always compare what changed between iterations.

3

Reuse. Across any platform.

Open your library, find the prompt, copy it. Works on Claude, ChatGPT, OpenAI. Export the whole library to Markdown or JSON any time.

Prompt library
Rewrite this email to sound more direct and professional. Remove filler phrases and get to the point in the first sentence. Keep it under 100 words.
v1
v2
v3
claude.ai · Claude Sonnet · 187 tokens · 3 versions
§ 03
Version compare

See exactly
what changed.

Every time you refine a prompt, PromptPatch saves the diff. Line-by-line comparison shows what you added, removed, and why the new version performs differently.

Compare any two versions side by side
Token count delta — see if your prompt got leaner
Full version history, unlimited iterations
Email tone rewriter
v2 → v3
Changes in version 3
−Please be thorough and provide context for each change.
+Remove filler phrases and get to the point in the first sentence.
−There is no word limit.
+Keep it under 100 words.
v2 — 214 tokensv3 — 187 tokens
−12.6% more concise
v1
→
v2
→
v3
§ 04
PromptPatch features

Built for people who
take prompts seriously.

💾
Auto-capture
Detect and save prompts as you type, across every supported platform. No copy-paste required.
📋
Instant copy
One click to copy any saved prompt back into Claude, ChatGPT, or any other input.
⟷
Version diff
Line-level comparison between any two versions. See exactly what changed and why it performs differently.
📊
Token estimates
Live token count and estimated cost per prompt. Know what each version costs before you send it.
📦
Export anywhere
Export your full library to Markdown or JSON. Works with Notion, Obsidian, or any text editor.
🔒
Local-first
Your prompts are stored in your browser. Nothing leaves your device unless you explicitly export.
§ 05
PromptPatch platforms

One extension.
Every AI platform.

🟠
Claude
Full support for claude.ai. Captures prompts from all Claude models.
● Live
🟢
ChatGPT
Works on chatgpt.com with GPT-4o, GPT-4.1 and all other models.
● Live
⚫
OpenAI
Captures prompts from the OpenAI Playground and developer console.
● Live
§ 06
01
GantryWorks app
3
AI platforms
7
Day free trial
£0
Data sold
Pricing

Simple. Honest.
One price.

Annual subscription
£39
per year · cancel any time
  • Unlimited prompt saves and versions
  • Line-level version comparison
  • Works on Claude, ChatGPT and OpenAI
  • Token estimates and cost tracking
  • Export to Markdown and JSON
  • Local-first — your data stays on your device
  • All future features included
Start 7-day free trial
No credit card required for trial · £39/year after 7 days
§ 07
Common questions

FAQ.

Does PromptPatch send my prompts to a server?
+
No. Your prompts are stored locally in your browser using Chrome's built-in storage. Nothing is transmitted to our servers except licence verification. You can export and delete your library at any time.
Which AI platforms are supported?
+
PromptPatch currently works on claude.ai, chatgpt.com, and the OpenAI Playground. More platforms are on the roadmap — Gemini, Perplexity, and others coming soon.
What happens after the 7-day trial?
+
After 7 days, you'll need an active licence to continue saving new prompts. Your existing saved prompts are always accessible — you can copy and export them regardless of licence status.
Can I export my prompts if I cancel?
+
Yes. Export to Markdown or JSON any time directly from the extension. Your data is yours — we will never hold it hostage.
Is there a team or business plan?
+
Not yet. Team plans with shared libraries are on the roadmap. Email support@gantryworks.co if you want early access.
§ 08