Fixing Claude Code 403 API Errors

Experiencing a 403 API error with Claude Code can be frustrating. This error, often accompanied by the message "The security token included in the request is invalid," signals an issue with your API key or account authentication. This guide provides a comprehensive approach to troubleshooting and resolving this problem, drawing from your experiences and common solutions. We'll delve into identifying the active account, logging out and back in, and ensuring your setup is correct to avoid these errors and keep you coding smoothly.

Understanding the 403 API Error in Claude Code

The 403 Forbidden error is a status code indicating that the server understands the request but refuses to authorize it. In the context of Claude Code, this often boils down to an invalid or missing API key, incorrect account credentials, or access restrictions. The error message specifically points to a problem with the security token, which is essentially your API key. To effectively resolve this, we'll focus on account verification and authentication. The first step involves confirming the API key and checking the account associated with it. The API key is what allows you to access the Anthropic models. Without it, you can't use Claude Code.

This kind of error often occurs when your API key has expired, has been revoked, or doesn't have the necessary permissions to access the model you're trying to use. It could also be due to a configuration error within the Claude Code setup, such as an incorrect profile or environment variable not being set up correctly. The core of this issue comes down to the verification that the client application (Claude Code) correctly authenticates with the Anthropic API using a valid and authorized token. In many cases, it is a straightforward fix such as re-entering the API key or ensuring your environment variables are correctly configured. Before jumping into the steps, make sure you've double-checked your API key for typos and that it matches the key on your Anthropic account dashboard.

To troubleshoot, start by verifying your API key. Ensure the key is correct and active. Check your Claude Code configuration to make sure it's using the correct key. Consider checking for expired or revoked keys and confirm the key has the necessary permissions. If you've recently changed your API key, make sure you've updated the settings in Claude Code. Environment variables often provide the API key, so double-check those too. Look for any conflicting configurations that might be overriding your set API key. If you've been using multiple accounts, make sure the one you intended to use is the one that's connected to Claude Code. If you're still stuck, you could try updating Claude Code or consulting the Anthropic documentation for the latest updates and troubleshooting steps. Furthermore, if you are using any kind of proxies or VPNs, ensure that they are not interfering with your connection to the Anthropic API.

Determining the Account Claude Code is Using

One of the initial steps to resolve a 403 error is identifying which account Claude Code is attempting to use. This information is crucial for verifying the associated API key and ensuring it has the correct permissions. Unfortunately, Claude Code doesn't always make this information readily apparent through standard commands like /config or /doctor. The absence of clear account information in the documentation or command-line help can indeed complicate the troubleshooting process. However, several alternative methods can help you determine the active account and its associated configuration. Knowing the account helps in several ways: it allows verification of the API key, confirmation of the account permissions, and troubleshooting of any potential account-related issues. Understanding which account Claude Code is using ensures that you're working with the correct credentials and permissions.

Since /config and /doctor aren't providing the account information, you might need to look for clues in other places. Start by checking your environment variables. Claude Code often uses these variables (like ANTHROPIC_API_KEY) to store API keys. You can examine your system's environment variables to see if any are set that might be overriding the default configurations. Ensure that you are looking in the correct environment or terminal session where you are running Claude Code. This involves inspecting the environment in which Claude Code is running to find the API key being used. You should also check any configuration files that Claude Code might use, such as those related to the CLI, to see if the API key or account information is stored there. Another technique involves using the verbose mode when running Claude Code commands if such an option exists. This can reveal the configuration settings, including the account being used for authentication. If you're using any wrappers or scripts to run Claude Code, these could be setting the API key as well, so inspect them carefully.

Another approach is to temporarily set a known invalid API key. Run a command that interacts with the Claude Code API. If you receive an error related to the invalid key, it suggests that the environment is picking up your intentionally incorrect key. Try this with a command, such as one that lists available models or initiates a chat session. If the error still persists, the configuration might be using a different key. In such cases, thoroughly examine all the configuration files and environment variables, ensuring that no old or conflicting API keys exist. Once you pinpoint the account, you can proceed to the next step, which is logging out and logging back in.

Logging Out and Logging Back In (If Possible)

Once you've identified the account Claude Code is using, the next step is to log out and log back in, which can often resolve authentication issues. However, the exact process of logging out and logging back in might not be explicitly documented for Claude Code. This often requires a few workarounds. Since a direct logout command is missing, one way is to remove or invalidate the current API key. You can do this by deleting the API key from your environment variables or any configuration files that store it. After removing the key, try running a command that requires authentication. Claude Code should prompt you to enter a new API key, thereby allowing you to log in with a different account. This method ensures that the old key is no longer in use, which forces the system to recognize the new key on the next command. Another approach is to explicitly set the ANTHROPIC_API_KEY to the desired API key in the environment before running Claude Code. The goal is to provide a clean and valid API key to prevent the 403 error.

Another potential method involves re-installing or updating the Claude Code application, as it can sometimes reset the configuration and clear any cached authentication credentials. Ensure that you've backed up any custom configurations before reinstalling. After the reinstallation, enter the new API key to log into the desired account. If the issue stems from an incorrect profile, you might need to manually edit the configuration files to point to the correct account or profile. These files are typically located in the user's home directory. Locate these files and change the settings to the desired account information. Another potential strategy is to try creating a new profile with the correct account details. Some tools support the concept of profiles for storing different configurations. Check to see if Claude Code supports this feature. This will allow you to switch between accounts without constantly changing the API key.

In addition, check for any third-party tools or scripts that may be managing your API keys. Make sure they are updated and configured with your intended account. Also, confirm that your network configuration isn’t interfering with the authentication process. Certain network setups, such as firewalls, might block requests to the Anthropic API. Be sure to verify your proxy settings and ensure they are correctly set up.

Additional Troubleshooting Steps

If the above steps don't resolve the 403 error, further troubleshooting steps can help isolate and fix the problem. Here are some methods to try, from checking the basics to more advanced solutions. Begin by verifying your internet connection. A stable internet connection is essential for Claude Code to communicate with the Anthropic API. Ensure your network isn't blocking requests to Anthropic's servers. If you're using a proxy server or VPN, verify that it's configured correctly and isn't interfering with the API requests. Test your API key on the Anthropic website or a simple script to make sure it's valid and active. Confirm that your API key has the necessary permissions for the tasks you're trying to perform. The key may not have the right access to the model. Also, consider any rate limits. If you've exceeded the rate limits for your API key, you will get a 403 error. Check your usage dashboard on the Anthropic website to see if you have reached any limits. The Anthropic documentation contains specific error codes, troubleshooting tips, and best practices. If problems persist, consult the documentation to find solutions to your particular issue. Check for updates to Claude Code. Outdated versions may have bugs or compatibility issues that cause 403 errors. In addition, look at the GitHub repository or the support channels of Claude Code. Others might have encountered similar problems, and you can find solutions there. Sometimes, a simple restart of the application or your computer can resolve temporary issues. Try restarting your computer. If none of these steps work, it may be an issue with the Anthropic API itself. Check the Anthropic status page or contact their support for more information.

Also, consider issues with your IDE or editor. Certain IDEs and code editors have their own configuration settings for API keys. Double-check these settings to ensure they align with the configurations in Claude Code. Some IDE extensions might override the settings, leading to authentication errors. Verify your configurations and update them if needed.

Conclusion

Resolving the 403 API error in Claude Code often involves a methodical approach to account verification and authentication. By identifying the active account, logging out and logging back in (or simulating the process), and thoroughly troubleshooting, you can get back to coding without interruption. Remember to check your API key, environment variables, and configurations and to follow the official documentation for the latest updates and troubleshooting steps. Regularly review your account settings and API key permissions to ensure continued access. Persistent issues might indicate deeper problems with your setup or the Anthropic API, requiring more targeted solutions. By methodically addressing these issues, you will likely overcome the 403 error and continue working efficiently with Claude Code.

For further help, check the Anthropic API documentation.