Botocore.Exceptions.NoCredentialsError: Unable to Locate Credentials – Causes and Fixes

The error “botocore.exceptions.NoCredentialsError: Unable to locate credentials” is one of the most common AWS-related errors in Python applications. It usually appears when working with the AWS SDK for Python (boto3) and indicates that the application cannot find valid AWS credentials required to authenticate API requests.

This issue is common in:

1. Local development environments
2. EC2 instances
3. Docker containers
4. CI/CD pipelines
5. Lambda functions

Although the error looks technical, it is generally caused by missing or incorrectly configured AWS credentials. Understanding how AWS credential resolution works is the key to fixing the issue properly.

What Does “Unable to Locate Credentials” Mean?

This error means that the AWS SDK (boto3 / botocore) attempted to authenticate with AWS services but could not find valid credentials anywhere in the configured credential chain.

Example error:

botocore.exceptions.NoCredentialsError:

Unable to locate credentials

Without credentials, AWS services cannot verify the application’s identity, so requests to services such as S3, DynamoDB, Lambda, or EC2 fail immediately.

Why Does This Error Occur?

AWS SDKs use a credential resolution chain to automatically locate authentication credentials. If no valid credentials are found in any supported location, this error occurs.

In most cases, the issue is not with the code itself but with how the environment is configured.

export AWS_ACCESS_KEY_ID=YOUR_KEY
export AWS_SECRET_ACCESS_KEY=YOUR_SECRET

How AWS Credential Resolution Works?

AWS SDKs search for credentials in a specific order called the credential provider chain.

The SDK checks:

1. Environment variables
2. AWS credentials file
3. AWS config file
4. IAM roles (EC2/Lambda)
5. ECS task roles
6. Other credential providers

If no valid credentials are found in any of these locations, the SDK throws the NoCredentialsError.

How to Fix “Unable to Locate Credentials”?

Fixing the issue usually involves configuring AWS credentials correctly and ensuring the environment can access them.

The exact solution depends on where the application is running.

aws configure

~/.aws/credentials

[default]
aws_access_key_id=YOUR_ACCESS_KEY
aws_secret_access_key=YOUR_SECRET_KEY

aws sts get-caller-identity

export AWS_ACCESS_KEY_ID=YOUR_KEY
export AWS_SECRET_ACCESS_KEY=YOUR_SECRET

setx AWS_ACCESS_KEY_ID "YOUR_KEY"
setx AWS_SECRET_ACCESS_KEY "YOUR_SECRET"

import boto3
session = boto3.Session(profile_name='dev')
s3 = session.client('s3')

import boto3
s3 = boto3.client('s3')
response = s3.list_buckets()
print(response)

Common Scenarios Where This Error Appears

This issue frequently occurs in modern DevOps and cloud workflows.

docker run -e AWS_ACCESS_KEY_ID=KEY \
-e AWS_SECRET_ACCESS_KEY=SECRET app
print(response)

env:
AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}

Best Practices to Avoid Credential Errors

Following proper AWS security and configuration practices helps avoid authentication issues.

aws_access_key_id = "AKIA..."

aws configure --profile staging

How Moon Technolabs Helps with AWS and DevOps Solutions?

Moon Technolabs helps businesses build secure cloud-native applications and DevOps workflows using AWS best practices. The focus is on infrastructure automation, credential security, CI/CD optimization, and scalable cloud architecture.

By implementing proper IAM policies, environment management, and secure deployment strategies, organizations can reduce authentication issues and maintain reliable AWS operations.

Conclusion

The “botocore.exceptions.NoCredentialsError: Unable to locate credentials” error occurs when AWS SDKs cannot find valid authentication credentials. Although common, the issue is usually straightforward to fix through proper credential configuration and environment setup.

By understanding how AWS credential resolution works and following secure credential management practices, developers can avoid authentication issues and build more stable cloud applications.