Multi-AI Prompt Comparison Tool

Developers need to test prompts across multiple AI models (Claude, GPT, Gemini) to find the best responses, but copying prompts between each tool is tedious. This CLI tool runs the same prompt in parallel across models and synthesizes a comparison. Target users are AI/ML engineers and prompt engineers.

Prompt engineering has become a distinct workflow for a growing slice of developers, and the proliferation of capable frontier models in 2024-2025 means the "which model is best for my use case" question is genuinely unresolved and asked constantly. No single incumbent owns this space cleanly — PromptLayer handles logging and versioning but not side-by-side multi-model comparison as a first-class CLI experience. The $2k-10k/mo revenue band is realistic for a dev tool with a usage-based or seat-based pricing model, since AI/ML engineers are accustomed to paying for tooling and their employers absorb the cost without much friction. The biggest risk is commoditization: every major AI provider is building playground and comparison features directly into their products, and the window before this gets absorbed natively is probably narrow.