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AI Prompt Templates with Variables: The Complete Guide

The best prompt isn't one you write once — it's one you can run a hundred times with the details swapped out. Meet the {{variable}}.

What is an AI prompt template with variables?

A prompt template is a saved prompt where the parts that change are marked as placeholders — variables — instead of hardcoded text. Written with double curly braces, they look like this:

Write a {{tone}} email to {{recipient}} about {{topic}}. Keep it under 120 words with a clear call to action.

When you run the template, you fill in tone, recipient and topic, and the completed prompt goes to ChatGPT, Claude or Gemini. One template, unlimited uses — and because the fixed part never changes, the quality of the output stays consistent every single time.

Why templates beat rewriting prompts from scratch

How to create a prompt template in Vault

  1. Save a prompt in Vault: AI Prompt Library as usual.
  2. Replace the parts that change with {{variable}} placeholders — Vault highlights them automatically as you type.
  3. Tap run. Vault detects every variable, shows a fill-in form, substitutes your answers, and launches the finished prompt in your AI app of choice — or copies it to the clipboard.
Naming tip: use short, self-explanatory variable names — {{audience}}, {{deadline}}, {{code}}. Future-you should know exactly what to type into each field without opening the full prompt.

Five copy-ready template examples

1. The everyday email

Write a {{tone}} email to {{recipient}} about {{topic}}. Under 120 words, one clear call to action.

2. Code review

Review this {{language}} code for bugs, readability and performance. Suggest concrete fixes:

{{code}}

3. Social media captions

Write 5 {{platform}} captions for a post about {{topic}}, aimed at {{audience}}. Vary the hooks; include hashtags.

4. Explain like I'm new

Explain {{concept}} to someone with no background in {{field}}. Use one analogy and one concrete example.

5. Meeting agenda

Create an agenda for a {{duration}} meeting about {{goal}} with {{attendees}}. Time-box each item.

Go further: chain templates into workflows

Vault also supports child prompts — follow-up prompts nested under a parent. Pair a "Draft the blog post" template with children like "Tighten the intro", "Write the meta description", "Suggest 5 titles", and you've effectively built your own custom GPT that runs the same multi-step workflow every time.

Build your first template in a minute

Vault highlights {{variables}} as you type and fills them in before every run. Free on iPhone, iPad & Mac.

Download on theApp Store