Home › Stacks › AI App Prototype

Free AI App Prototype Stack

A chat or RAG prototype with an LLM API, vector search and product analytics. Every layer below is a tracked free tier, with its published limits and the date we last checked them. The tightest limit in the stack is usually the one you hit first.

Hosting: Vercel

• CDN requests1M / month
• Fast data transfer100 GB / month
• Function invocations1M / month
• Fluid Active CPU4 hours / month
• Provisioned memory360 GB-hrs / month
• Firewall custom rulesUp to 3

Catch: Hobby plan; team collaboration needs Pro ($20/mo).

Checked 13 Nov 2026 · vendor page · alternatives

LLM API: Groq

• gpt-oss-120b30 RPM, 1K RPD, 8K TPM, 200K TPD
• whisper-large-v320 RPM, 2K RPD
• ScopePer organization

Catch: Limits vary per model.

Checked 13 Nov 2026 · vendor page · other AI APIs free tiers

Second LLM API: Google Gemini API

• Input / output tokens (select Flash models)Free of charge on Free tier
• Rate limitsModel- and tier-specific; view in AI Studio
• RPD resetMidnight Pacific Time
• Content useFree-tier prompts may be used to improve products

Catch: Exact RPM/TPM/RPD vary by model and usage tier; check AI Studio. Flagship models (e.g. Gemini 4 Argon) are not on Free. Paid tier required for higher limits and some models.

Checked 13 Nov 2026 · vendor page · other AI APIs free tiers

Vector Search: Upstash Vector

• Databases1
• Queries / updates10,000 / day
• Vectors x dimensions200 million
• Max dimensions1,536
• Namespaces100
• Data / metadata size1 GB

Catch: Capped at 1,536 dimensions (paid plans go to 3,072+).

Checked 5 Nov 2026 · vendor page · other databases free tiers

Product Analytics: PostHog

• Analytics events1M / month
• Session replays5K / month
• Feature flag requests1M / month
• Exceptions100K / month
• Survey responses1,500 / month
• Logs10 GB

Catch: Allowance resets monthly, card or not. The no-card Free plan has 1 project and 1-year data retention, and usage stops at the limits (extra events are dropped); pay-as-you-go keeps the same free allowance and adds 6 projects.

Checked 13 Nov 2026 · vendor page · alternatives

This is one example combination, not a recommendation or sponsorship. Swap any layer for an alternative in the same category; confirm limits at each vendor before you build.