My Actual AI Stack for Building Apps in 2026 — All Free

#ai #api #gemini #programming

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I've shipped 7 Mac apps in the past year. Every AI feature in them runs on free tools.

Here's the exact stack — what I use, why, and where the limits are.

Cloud AI: Gemini API (Google AI Studio)

What: Gemini 2.5 Flash Preview via REST API
Cost: Free tier — 500 requests/day, no credit card
Use for: Log diagnosis, document analysis, text classification, anything needing strong reasoning

The free tier is genuinely sufficient for developer tools with intermittent AI use. I've never hit the daily limit in normal usage.

Get a key at aistudio.google.com — takes 2 minutes.

Local AI: Ollama

What: Run open-source LLMs locally
Cost: Free, open source
Use for: Privacy-sensitive processing, offline use, high-volume tasks

# Install
brew install ollama

# Pull a model
ollama pull gemma2

# Run
ollama run gemma2

Models I actually use:

gemma2 — good general reasoning, runs on 8GB RAM
qwen2.5-coder:1.5b — fast code autocomplete, tiny footprint
qwen3:8b — best quality/size ratio for chat

Local AI for Code: Ollama + Continue.dev

What: VS Code extension that uses your local Ollama models for autocomplete
Cost: Free
Use for: Code completion without sending code to any cloud

// .continue/config.json
{
  "models": [{
    "title": "Qwen 2.5 Coder",
    "provider": "ollama",
    "model": "qwen2.5-coder:1.5b"
  }],
  "tabAutocompleteModel": {
    "title": "Autocomplete",
    "provider": "ollama",
    "model": "qwen2.5-coder:1.5b"
  }
}

OCR: Apple Vision Framework

What: macOS built-in OCR engine
Cost: Free, ships with every Mac
Use for: Extracting text from scanned PDFs, images

No API call. No internet. Runs entirely on-device via a Swift sidecar in Tauri.

The decision rule

Data is sensitive (medical, legal, financial)?
  → Ollama or Apple Vision (local only)

Need strong reasoning, complex analysis?
  → Gemini API (with PII filtering)

Need code autocomplete?
  → Ollama + Continue.dev

Need OCR on Mac?
  → Apple Vision Framework