Working withAI APIs
AI APIs let you add ChatGPT, Claude, or Gemini to your own apps. Instead of using a chat interface, your software talks directly to these AI models.
What Are AI APIs?
What is an AI API?
An API (Application Programming Interface) is a way for your app to talk to AI services. Instead of building your own AI, you send a request to OpenAI, Google, or Anthropic, and they send back the AI's response.
Why use an API instead of ChatGPT directly?
ChatGPT's website is for humans to chat. APIs let your software use the same AI automatically. You can build AI into your own apps, process thousands of requests, and integrate with your data.
Do I need to be a programmer?
Yes, using APIs requires some coding knowledge. But it's not as hard as you might think! With tools like Cursor, Replit, or no-code platforms, even beginners can make API calls.
The simple version: AI APIs are like a "brain-as-a-service." Send text in, get intelligence out. Just pay for what you use.
Key Concepts
Important terms you'll encounter when working with APIs.
API Key
A secret password that identifies you to the AI service. Never share it publicly!
Request
What you send to the API. Usually includes your prompt, which model to use, and settings.
Response
What the API sends back. Contains the AI's answer plus metadata like token usage.
Tokens
How AI measures text. Roughly 1 token ≈ 4 characters. You pay per token used.
Major AI API Providers
The big players in the AI API space.
OpenAI API
Models: GPT-4o, GPT-4, GPT-3.5-turbo, DALL-E 3
The most popular AI API. Powers ChatGPT. Great documentation.
Pricing: GPT-4o: ~$5/million tokens
Anthropic API
Models: Claude 3.5 Sonnet, Claude 3 Opus, Claude 3 Haiku
Known for safety and long context (200K tokens). Excellent for analysis.
Pricing: Sonnet: ~$3/million tokens
Google AI API
Models: Gemini 1.5 Pro, Gemini 1.5 Flash
Google's multimodal AI. Can process text, images, video, and audio.
Pricing: Free tier available
Mistral API
Models: Mistral Large, Mistral Small, Mixtral 8x7B
European AI provider. Fast, efficient, and open-weights options.
Pricing: Large: ~$4/million tokens
Simple Example
Here's how to call the OpenAI API in JavaScript.
JavaScript Example
// Send a message to ChatGPT via API
const response = await fetch('https://api.openai.com/v1/chat/completions', {
method: 'POST',
headers: {
'Content-Type': 'application/json',
'Authorization': 'Bearer YOUR_API_KEY'
},
body: JSON.stringify({
model: 'gpt-4o',
messages: [
{ role: 'user', content: 'What is the capital of France?' }
]
})
});
const data = await response.json();
console.log(data.choices[0].message.content);
// Output: "The capital of France is Paris."Warning: Never put API keys in your code! Use environment variables.
Getting Started
From zero to your first API call in 4 steps.
Create an Account
Sign up at platform.openai.com, console.anthropic.com, or ai.google.dev
Get Your API Key
Generate a secret API key. Store it securely — never commit to Git!
Add Credits
Most APIs are pay-as-you-go. Add $5-10 to start.
Make Your First Request
Use the code example below, a library, or a no-code tool like Zapier.
What Can You Build?
Real-world applications powered by AI APIs.
Chatbots & Assistants
Build customer support bots, virtual assistants, or interactive characters.
Content Generation
Automatically create blog posts, product descriptions, or marketing copy.
Data Analysis
Process documents, extract insights, summarize reports.
Code Generation
Help developers write, review, and debug code.
Translation
Translate content between languages while preserving context.
Moderation
Detect harmful content, spam, or policy violations.
Pricing Comparison
Prices per 1 million tokens (roughly 750,000 words).
OpenAI - GPT-4o
Input: $5.00 | Output: $15.00 | Context: 128K
OpenAI - GPT-3.5-turbo
Input: $0.50 | Output: $1.50 | Context: 16K
Anthropic - Claude 3.5 Sonnet
Input: $3.00 | Output: $15.00 | Context: 200K
Anthropic - Claude 3 Haiku
Input: $0.25 | Output: $1.25 | Context: 200K
Google - Gemini 1.5 Pro
Input: $7.00 | Output: $21.00 | Context: 2M
Google - Gemini 1.5 Flash
Input: $0.075 | Output: $0.30 | Context: 1M
Best Practices
Tips for using AI APIs safely and efficiently.
Never expose your API key
Use environment variables. Never put keys in frontend code.
Set spending limits
Configure usage limits in your dashboard to avoid surprise bills.
Handle errors gracefully
APIs can fail or rate-limit you. Always handle errors.
Cache when possible
If the same query comes up often, cache the response.
Use streaming
Stream tokens as they're generated for better UX.
Monitor usage
Track costs and performance. Set up alerts.
No-Code Options
Don't want to code? These tools let you use AI APIs visually.
Zapier
Connect AI to thousands of apps without code.
Make (Integromat)
Visual workflow builder with AI integrations.
Flowise
Drag-and-drop LLM flow builder. Open source.
Langflow
Visual interface for LangChain.
Ready to Build?
Start with small experiments. A simple chatbot or content generator can be built in an afternoon!