●MIT licensed · self-hostable

engineer your prompts.
not just write them.

Version, test, and compare prompts across GPT-4o and Claude side-by-side. Track costs per run. Find what actually works.

Start Free →★ View on GitHub
prompt-v3.txt
system: You are a helpful assistant.
        specialized in {domain}.

user: Summarize the following in {tone} tone:
        {content}

▶ GPT-4o · 142 tokens · $0.0014 · 890ms

features

Everything a prompt engineer needs

⬡

Template System

Variables with {curly_braces} — define inputs once, test across every variant automatically.

⇄

Multi-Model Compare

Run the same prompt against GPT-4o and Claude simultaneously. See outputs diff'd side-by-side.

$

Cost Tracking

Per-run token counts and USD cost. Know exactly what each prompt iteration is costing you.

◷

Version History

Every edit is stored. Roll back to any version, compare diffs, and audit what changed.

pricing

Simple. No surprises.

self-hosted

$0

forever. MIT license.

  • ✓ Full source code access
  • ✓ Unlimited prompts & runs
  • ✓ All models supported
  • ✓ Your own infrastructure
  • ✓ Community support
Clone on GitHub →
HOSTED

cloud

$19/mo

no ops, just prompts.

  • ✓ Everything in self-hosted
  • ✓ Managed PostgreSQL
  • ✓ Automatic backups
  • ✓ Zero-config deploy
  • ✓ Email support
Get Started →