Setting Up API Keys

Postiller uses your own AI provider accounts to generate content. Here's how to get started with each provider.

Before You Start

  • You only need one provider to use Postiller. Pick whichever you prefer.
  • API keys are stored encrypted on your device. They never touch our servers.
  • Typical personal usage costs $1-5 per month. You pay providers directly.
  • On-device features (semantic search, summarization) are free and don't need API keys.
AI

OpenAI

GPT-4o, GPT-4o-mini, GPT-4 Turbo

Best for nuanced writing, complex reasoning, and versatile content generation. The most widely-used AI provider with excellent all-around capabilities.

Pricing: Pay-as-you-go. GPT-4o costs ~$5/1M input tokens, ~$15/1M output tokens. GPT-4o-mini is much cheaper at ~$0.15/1M input.

How to Get Your Key

  1. 1Go to platform.openai.com and sign up or log in
  2. 2Navigate to API Keys in the left sidebar
  3. 3Click "Create new secret key"
  4. 4Give it a name (e.g., "Postiller") and copy the key
  5. 5Add a payment method under Billing to enable usage

Tip: Set usage limits under Settings → Limits to avoid unexpected charges.

Get API KeyView Documentation
A

Anthropic

Claude Sonnet, Claude Haiku, Claude Opus

Excellent at following style guidelines, longer-form content, and nuanced communication. Claude tends to produce more natural, less "AI-sounding" text.

Pricing: Pay-as-you-go. Claude Sonnet costs ~$3/1M input tokens, ~$15/1M output tokens. Claude Haiku is faster and cheaper.

How to Get Your Key

  1. 1Go to console.anthropic.com and create an account
  2. 2Complete the onboarding process
  3. 3Navigate to API Keys in your account settings
  4. 4Click "Create Key" and copy it immediately
  5. 5Add credits under Billing to enable usage

Tip: Anthropic requires prepaid credits. Start with $5-10 to test.

Get API KeyView Documentation
G

Google

Gemini Pro, Gemini Flash

Fast and cost-effective for everyday content generation. Gemini Flash is particularly good for quick tasks where speed matters more than maximum quality.

Pricing: Generous free tier available. Gemini Pro is ~$1.25/1M input tokens. Gemini Flash is even cheaper.

How to Get Your Key

  1. 1Go to aistudio.google.com
  2. 2Sign in with your Google account
  3. 3Click "Get API key" in the left sidebar
  4. 4Select or create a Google Cloud project
  5. 5Copy your API key

Tip: Google offers a free tier—great for testing before committing to paid usage.

Get API KeyView Documentation
X

xAI

Grok

Real-time knowledge and witty, unfiltered responses. Grok has access to recent information and tends to have a more conversational, less corporate tone.

Pricing: Pay-as-you-go pricing. Check x.ai for current rates.

How to Get Your Key

  1. 1Go to console.x.ai and create an account
  2. 2Navigate to the API section
  3. 3Generate a new API key
  4. 4Copy the key and store it securely
  5. 5Add payment information to enable usage

Tip: Grok is newer but improving rapidly. Good for content that benefits from current events context.

Get API KeyView Documentation

Which Provider Should I Choose?

If you're unsure, start with OpenAI. It has the most mature API, excellent documentation, and GPT-4o provides great results for most content types.

For more natural-sounding content, try Anthropic's Claude. It excels at matching specific writing styles and produces less "AI-sounding" text.

For budget-conscious usage, Google's Gemini offers a generous free tier and competitive pricing. Great for testing and lighter usage.

For current events and edgier content, xAI's Grok has real-time knowledge and a less filtered personality.

Model Assignment: Which Model for Which Task?

Different tasks have different requirements. Postiller lets you assign specific models to each task type, optimizing for quality where it matters and saving costs on routine operations.

Content Generation

Creating posts, threads, and long-form content

Recommended: GPT-4o, Claude Sonnet, or Gemini Pro. These excel at nuanced writing and following style guidelines. Worth the extra cost for your public content.

Summarization

Condensing bookmarks and articles into key points

Recommended: GPT-4o-mini, Claude Haiku, Gemini Flash, or On-Device. Summarization is straightforward—fast, cheap models work great here.

Tagging & Organization

Auto-categorizing content and suggesting hashtags

Recommended: GPT-4o-mini, Claude Haiku, or On-Device. Classification tasks don't need frontier models. Save your budget for content creation.

Semantic Search & Embeddings

Finding related content by meaning

Recommended: On-Device (free). Apple's foundation models handle embeddings beautifully with zero API cost. No reason to use paid models here.

Title Generation

Creating titles for bookmarks and posts

Recommended: GPT-4o-mini, Claude Haiku, or On-Device. Short-form generation that any model can handle well.

Pro tip: Start with on-device models for everything except content generation. You'll get fast results with zero API costs, then use your budget where it really matters—crafting great content.

Adding Keys to Postiller

Once you have your API key:

  1. 1Open Postiller and go to Settings
  2. 2Tap API Keys
  3. 3Select your provider and paste your key
  4. 4Tap Verify to confirm it works

Your key is encrypted and stored only on your device. You can remove or change it anytime.

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