As cloud services continue to grow in popularity, particularly Amazon Web Services (AWS), developers are increasingly tasked with understanding the platform’s intricacies. One of the most common issues developers face when working with AWS is the “botocore.exceptions.NoCredentialsError: Unable to locate credentials” error. In this blog post, we will delve into the root causes and solutions for this issue, helping you save time and effort while working with AWS services.

Understanding the botocore.exceptions.NoCredentialsError

The botocore.exceptions.NoCredentialsError is an exception raised by the botocore library, which provides low-level core functionality for the AWS SDK for Python (Boto3). This exception occurs when the library cannot find valid AWS credentials in any of the available sources. AWS credentials consist of an Access Key ID and Secret Access Key, both of which are required to authenticate and authorize access to AWS services.

The Significance of AWS Credentials

Credentials play a vital role in security and access control when working with AWS services. They ensure that only authorized personnel can access your AWS resources, preventing unauthorized access or modifications. AWS has stringent security measures in place, and credentials are a key component in maintaining the integrity and security of your cloud infrastructure.

Common Causes of the NoCredentialsError

There are several reasons why you might encounter the botocore.exceptions.NoCredentialsError. Some of the most common causes include:

  • Missing or incorrect environment variables
  • Incorrect or incomplete AWS CLI configuration
  • Absent or incorrectly set AWS credentials in your application code
  • Incorrect IAM role permissions or role assumption

Now that we understand the common causes, let’s explore solutions to fix the NoCredentialsError.

Solution 1: Setting Environment Variables

AWS SDKs and the AWS CLI look for AWS credentials in the environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY. To set these variables, use the following commands:

For Linux, macOS, or Unix:

export AWS_ACCESS_KEY_ID=your_access_key export AWS_SECRET_ACCESS_KEY=your_secret_key

For Windows:

set AWS_ACCESS_KEY_ID=your_access_key set AWS_SECRET_ACCESS_KEY=your_secret_key

Make sure to replace your_access_key and your_secret_key with your actual AWS Access Key ID and Secret Access Key.

Solution 2: Configuring the AWS CLI

If you have installed the AWS CLI, you can configure it to store your credentials. Use the following command to set up the AWS CLI with your credentials:

aws configure

You will be prompted to enter your Access Key ID, Secret Access Key, default region name, and default output format. Once entered, the AWS CLI stores the credentials in the ~/.aws/credentials file (or %UserProfile%\.aws/credentials on Windows).

Solution 3: Embedding Credentials in Your Application Code

Although not recommended for production environments, you can temporarily embed AWS credentials directly in your application code for testing and development purposes. Using Boto3, you can set the credentials as follows:

import boto3 session = boto3.Session( aws_access_key_id='your_access_key', aws_secret_access_key='your_secret_key', )

Make sure to replace your_access_key and your_secret_key with your actual AWS Access Key ID and Secret Access Key. Remember to remove the hardcoded credentials before deploying your application to production.

Solution 4: Configuring IAM Roles and Permissions

For applications running on AWS resources, such as EC2 instances or Lambda functions, it is recommended to use IAM roles to grant permissions to access AWS services. To resolve the NoCredentialsError in this case, ensure that the IAM role associated with your resource has the necessary permissions to access the required AWS services.

Follow these steps to create and attach an IAM role to your resource:

Creating an IAM Role

  1. Log in to the AWS Management Console and navigate to the IAM service.
  2. Click on “Roles” in the left navigation pane and then click on “Create role.”
  3. Choose the appropriate service (e.g., EC2 or Lambda) and click “Next: Permissions.”
  4. Attach the necessary policies to grant the required permissions to your role. You can use AWS managed policies or create custom policies.
  5. Review your role settings and click “Create role.”

Attaching the IAM Role to Your Resource

For EC2 instances:

  1. Navigate to the EC2 console and select the instance that requires the IAM role.
  2. Click on “Actions” and then “Instance Settings.”
  3. Choose “Attach/Replace IAM Role” and select the role you created earlier.
  4. Click “Apply” to attach the IAM role to the instance.

For Lambda functions:

  1. Navigate to the Lambda console and select the function that requires the IAM role.
  2. In the “Function” panel, click “Edit” next to “Execution role.”
  3. Choose “Use an existing role” and select the role you created earlier.
  4. Click “Save” to attach the IAM role to the Lambda function.

With the IAM role attached to your resource, your application should now have the necessary permissions to access AWS services without encountering the NoCredentialsError.

Best Practices for Managing AWS Credentials

While resolving the NoCredentialsError is important, it is equally important to follow best practices when managing AWS credentials to ensure the security of your cloud infrastructure. Here are some recommendations:

  • Avoid hardcoding credentials in your application code or configuration files. Instead, use environment variables, the AWS CLI, or IAM roles.
  • Use IAM roles and instance profiles for applications running on AWS resources to automatically manage and rotate credentials.
  • Regularly rotate your access keys, especially when team members leave the organization or when a key is suspected of being compromised.
  • Use the principle of least privilege when granting permissions through IAM policies. Only allow access to the AWS services and resources required for your application to function correctly.
  • Enable AWS Multi-Factor Authentication (MFA) for added security.


The botocore.exceptions.NoCredentialsError can be a stumbling block for developers working with AWS, but understanding its causes and applying the solutions discussed in this blog post will help you resolve the issue quickly and efficiently. By following the best practices for managing AWS credentials, you can maintain a secure and robust cloud infrastructure, ensuring the success of your projects on the AWS platform.

Disclaimer: The code snippets and examples provided on this blog are for educational and informational purposes only. You are free to use, modify, and distribute the code as you see fit, but I make no warranties or guarantees regarding its accuracy or suitability for any specific purpose. By using the code from this blog, you agree that I will not be held responsible for any issues or damages that may arise from its use. Always exercise caution and thoroughly test any code in your own development environment before using it in a production setting.

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