I'm building a prototype and need a cheap AI API to test with

If you want to keep prototype costs low, the cheapest “good enough” option is usually:

Best low-cost choices

1. OpenAI’s smaller models

   • Good for quick prototyping
   • Usually much cheaper than flagship models
   • Easy to integrate if you already want OpenAI-compatible APIs

2. Anthropic / Google / others’ smaller tiers

   • Can be cost-effective depending on your use case
   • Worth comparing if you need better quality on certain tasks

3. Hosted open-source model providers

   • Often the cheapest per token
   • Good for simple chat, classification, extraction, or summaries
   • Tradeoff: quality and consistency can be lower than top proprietary models

4. Local models

   • Cheapest at scale if you can run them yourself
   • Great for experimentation
   • Tradeoff: you handle infra, latency, and maintenance

Practical advice

If you’re just testing a prototype:

• Start with a small/cheap model
• Keep prompts short
• Cache responses where possible
• Set strict token limits
• Use a fallback model only if needed

If you want the absolute cheapest route

For many prototypes, the cheapest setup is:

• Small hosted open-source model for basic flows
• Or small proprietary model if you care more about reliability

If you want, I can give you a side-by-side list of the cheapest APIs right now for:

• chat
• embeddings
• image generation
• function calling
  and recommend the best one for your specific prototype.