Getting Started: Claude.ai and the API

Ready to start using Claude? This lesson walks you through every way to access it — from the free web interface to the developer API. By the end, you'll have Claude up and running.

Option 1: Claude.ai (The Easiest Way)

The simplest way to use Claude is through the web interface at claude.ai.

Creating Your Account

1. Go to claude.ai
2. Click Sign Up
3. Choose a sign-up method:
   • Google account — Fastest option, one click
   • Email address — Create a password and verify your email
   • Apple account — Available if you prefer Apple sign-in
4. Complete the brief onboarding

Free vs Pro vs Team

Claude offers several pricing tiers:

Plan	Price	What You Get
Free	$0/month	Access to Claude Sonnet, limited daily messages
Pro	$20/month	Higher limits, access to Opus, Projects, priority access
Team	$25/user/month	Everything in Pro plus team collaboration and admin controls
Enterprise	Custom	SSO, extended context, custom usage limits

Start with Free. The free tier gives you access to Claude Sonnet, which is excellent for most tasks. You can upgrade to Pro later if you need higher limits or access to Opus.

Your First Conversation

Once you're signed in, you'll see a text input box. Here's how to have your first conversation:

Try this prompt:

I'm new to AI assistants. Can you explain what you can help me with,
and give me three specific examples of tasks I could try right now?

Claude will respond with practical suggestions tailored to a beginner. Notice how it structures its response clearly and avoids overwhelming you.

A few things to try next:

Summarize this article for me: [paste an article]

Help me write a professional email declining a meeting invitation

Explain how compound interest works like I'm 15 years old

Navigating the Interface

The Claude.ai interface is straightforward:

• New chat — Start a fresh conversation (top left)
• Chat history — Find previous conversations in the sidebar
• Model selector — Switch between Sonnet, Opus, and Haiku (if on Pro)
• File upload — Attach documents, images, or code files using the paperclip icon
• Artifacts panel — When Claude creates code or documents, they appear in a side panel

Option 2: Claude Mobile App

Claude is available on mobile for conversations on the go:

• iOS — Available on the App Store
• Android — Available on Google Play

The mobile app syncs with your claude.ai account, so your conversations carry over. It's great for:

• Quick questions while away from your computer
• Reading and discussing documents on your phone
• Voice dictation for hands-free prompting

Option 3: The Anthropic API (For Developers)

If you're a developer or want to integrate Claude into applications, Anthropic offers an API.

Getting API Access

1. Go to console.anthropic.com
2. Create an account (separate from your claude.ai account)
3. Add a payment method — API access is pay-per-use
4. Generate an API key from the dashboard

API Pricing Basics

API pricing is based on tokens (roughly 1 token = 0.75 words):

Model	Input Price	Output Price
Claude Sonnet	$3 / million tokens	$15 / million tokens
Claude Opus	$15 / million tokens	$75 / million tokens
Claude Haiku	$0.25 / million tokens	$1.25 / million tokens

For context, processing a 10-page document with Sonnet costs roughly $0.01–$0.03.

A Simple API Example

Here's what an API call looks like in Python:

import anthropic

client = anthropic.Anthropic(api_key="your-api-key")

message = client.messages.create(
    model="claude-sonnet-4-20250514",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "What is the capital of France?"}
    ]
)

print(message.content[0].text)

You don't need to learn the API to use Claude effectively — the web interface is perfectly capable for most users. The API is for building applications, automating workflows, or integrating Claude into your own tools.

Option 4: Third-Party Integrations

Claude is also available through various third-party platforms:

• Amazon Bedrock — Use Claude through AWS
• Google Cloud Vertex AI — Access Claude via Google Cloud
• Cursor, Windsurf, and other code editors — Claude powers AI features in development tools
• Slack — Claude can be added as a Slack bot for team use

Tips for Getting Started

Start Simple

Don't try to master everything at once. Begin with basic conversations and gradually explore features:

1. Week 1 — Ask questions, get help with writing
2. Week 2 — Try uploading documents for analysis
3. Week 3 — Explore Projects and custom instructions
4. Week 4 — Build workflows that combine multiple features

Write Naturally

You don't need special syntax or keywords. Talk to Claude like you'd talk to a knowledgeable colleague:

This works well:

I'm writing a quarterly report for my team. Can you help me
structure it? We had a good quarter with 15% revenue growth
but we missed our customer acquisition target.

You don't need:

SYSTEM: You are a business report writer. TASK: Generate
a quarterly report. PARAMETERS: revenue=15%, acquisition=missed

Simple, natural language gets excellent results from Claude.

Use the File Upload

One of Claude's most practical features is file upload. You can attach:

• PDFs and documents
• Images and screenshots
• Code files
• Spreadsheets (CSV)
• Text files

Simply click the paperclip icon and select your file. Claude will read it and you can ask questions about it.

Key Takeaways

• The easiest way to start is at claude.ai — sign up for free in under a minute
• The free tier gives you Claude Sonnet, which handles most tasks well
• Claude Pro ($20/month) adds higher limits, Opus access, and Projects
• Mobile apps are available on iOS and Android
• The API is pay-per-use for developers building applications
• Write naturally — Claude responds best to clear, conversational prompts
• Start simple and explore new features gradually over time