How to Get a Claude API Key: Step-by-Step Guide

Claude is an advanced large language model developed by Anthropic, an AI safety research company founded in 2021 by former OpenAI researchers Dario Amodei and Daniela Amodei. Claude excels at natural language understanding, text generation, analysis, and performing complex tasks.

The Claude API (Application Programming Interface) allows developers and applications to communicate programmatically with the Claude model. An API key is a unique authentication code used to access this interface. You need a Claude API key to use the Claude-based AI therapist experience in OpenGnothia.

The Claude API works on a pay-as-you-go model, meaning you only pay for the amount of text you send and receive. Anthropic also offers starter credits for new users.

First, open your browser and navigate to console.anthropic.com. This is Anthropic's developer console where you manage your API keys.

Once you reach the page, click the "Sign Up" button. You'll need to provide an email address and create a password. Alternatively, you can sign up quickly using your Google account.

After filling out the registration form, click "Create Account". Anthropic will send a verification link to your email address.

Check your email inbox and find the verification email from Anthropic. Click the verification link to activate your account. If you can't see the email, check your spam/junk folder.

After verification, you'll be redirected to the Anthropic Console. On your first login, you may be asked for some basic information: your name, intended use (personal project, company, etc.). Fill in this information and continue.

In some cases, Anthropic may also request phone number verification. If so, enter your mobile number and type the code received via SMS into the verification field.

After logging into the Anthropic Console, click on the "API Keys" tab in the left menu. On this page, you can view your existing API keys and create new ones.

Click the "Create Key" button. Give your key a name, such as "OpenGnothia" or "My App". This name is only for you to distinguish between your keys.

Once your key is created, it will be displayed on screen. This key is a long string of characters starting with "sk-ant-". Copy your key immediately because you won't be able to see it again after leaving this page.

After creating your API key, it's crucial to store it in a safe place. Save your key in a password manager (1Password, Bitwarden, etc.) or store it in a secure notes application.

Never share your API key in public places. Sharing your key on platforms like GitHub repositories, forums, social media, or email creates a security risk. Anyone who obtains your key can make API calls on your account and increase your bill.

If you suspect your key has been compromised, you can immediately revoke the key from the Anthropic Console and create a new one. Revoking a key instantly invalidates all requests made with that key.

The Claude API operates on a pay-as-you-go model. Pricing varies based on the model you use and the number of tokens processed. A token is a unit of text roughly equivalent to 3/4 of a word.

Anthropic offers different Claude models: Claude Haiku (fastest and most affordable), Claude Sonnet (balanced), and Claude Opus (most capable). Each model has different prices per input and output token. Visit anthropic.com/pricing for current prices.

New accounts typically have a starter usage limit. This limit can be increased over time based on your account's usage history and payment information. You can access higher limits by adding your payment details and building your usage history.

My API key isn't working, what should I do? First, make sure you copied the key correctly — there should be no spaces at the beginning or end. Check the Anthropic Console to ensure your key hasn't been revoked. If it still doesn't work, try creating a new key.

I've exceeded my usage limit, what happens? If you exceed your usage limit, your API requests will be rejected (429 error). To increase your limit, add or update your payment information from the Anthropic Console. Limit increases usually happen automatically.

I lost my API key, how can I find it? Unfortunately, you cannot view the full value of an existing key again. Revoke the old key from the Anthropic Console and create a new one. Update the new key in your OpenGnothia settings.

Is there free usage available? Anthropic occasionally provides starter credits to new accounts. Check Anthropic's website for current promotions. Additionally, the low-cost Claude Haiku model can be used as a budget-friendly option.