Anthropic / Claude API

Set up API access for Claude and other Anthropic models.

⏱ 5 minutes ai llm console.anthropic.com

getapi anthropic

Prerequisites

Variable	Description	Sensitive
`ANTHROPIC_API_KEY`	API key for authenticating requests to the Anthropic API	Secret

1 Info

We'll get you an Anthropic API key for using Claude models. You'll need to add a payment method or have existing credits -- the API is pay-per-use.
2 Open URL

Opening the Anthropic Console. Sign in or create an account if prompted.
https://console.anthropic.com
3 Choice
Do you have billing set up (payment method or credits)?
- Yes, billing is set up
  
  → Jumps to navigate_keys
- No / Not sure
  
  → Jumps to setup_billing
4 Open URL

Opening billing settings. Add a payment method or purchase credits to enable API access.
https://console.anthropic.com/settings/billing
5 Confirm

Billing set up?

Checkpoint — confirm before continuing
6 Open URL

Opening the API Keys page.
https://console.anthropic.com/settings/keys
7 Info

Click 'Create Key'. Give it a descriptive name (e.g., your project name).
8 Input

Copy your API key and paste it here (starts with sk-ant-):

→ ANTHROPIC_API_KEY

Starts with sk-ant-. At least 20 characters
9 Validate

Checking your API key works...

API key verified. You're ready to use Claude.

Couldn't verify the API key. Make sure billing is set up and the key is active.

API keys are shown only once when created. If you lose it, you'll need to create a new one.
The Anthropic API requires an 'anthropic-version' header (e.g., '2023-06-01'). Most client libraries handle this automatically.
New accounts start with lower rate limits (Tier 1). Limits increase automatically as you spend more.
Set a monthly spending limit in the Console to avoid unexpected charges.
Claude models have different pricing tiers. Claude Haiku is the cheapest; Claude Opus is the most capable and most expensive.
The API uses 'x-api-key' header for authentication, not the more common 'Authorization: Bearer' pattern.