Resolving the Missing Authentication Token Error When Sending a GET Request with a Dot in AWS Lambda

Learn how to tackle the `Missing Authentication Token` error when using a dot (`.`) in GET request URLs from AWS Lambda to API Gateway. --- This video is based on the question https://stackoverflow.com/q/66563628/ asked by the user 'Haha' ( https://stackoverflow.com/u/11561121/ ) and on the answer https://stackoverflow.com/a/68907295/ provided by the user 'Haha' ( https://stackoverflow.com/u/11561121/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Unable to send a GET request containing "." query parameter using Lambda Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/licensing The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Resolving the Missing Authentication Token Error When Sending a GET Request with a Dot in AWS Lambda When working with AWS Lambda and API Gateway, you may encounter some tricky issues, particularly when it comes to formatting your requests. A specific problem arises when you attempt to send a GET request that includes a dot (.) in the query parameters. This situation often results in the frustrating Missing Authentication Token error, especially when everything seems to work just fine via tools like Postman. In this guide, we’ll explore the problem and provide insights into possible workarounds. Understanding the Problem Imagine you have an API Gateway set up with a series of query parameters, and you need to call this API from your AWS Lambda function. When you successfully invoke the API using a well-structured URL on Postman, such as: [[See Video to Reveal this Text or Code Snippet]] You receive the expected results. However, when you attempt to make the same GET request from within Lambda code using the Python requests library: [[See Video to Reveal this Text or Code Snippet]] You are met with the perplexing Missing Authentication Token message. This indicates that something is going wrong in the request process when executed within Lambda versus the API Gateway directly. Why This Error Occurs AWS API Gateway is designed to interpret certain characters in a URL in specific ways. A dot (.) can be misunderstood by API Gateway when parsing the request path, resulting in authentication errors. As a result, your Lambda function is unable to correctly authenticate and access the intended resource. Possible Workarounds Unfortunately, there is no direct solution to this issue when you're reliant on the dot character as part of your request. However, here are a couple of alternative approaches to consider: 1. Replace the Dot with a Placeholder Since you must send a dot but face challenges in doing so, one workable solution is to replace the dot in your URL with a placeholder string that your code can later interpret accurately. Example: Use the word dot in place of . in your URL like this: [[See Video to Reveal this Text or Code Snippet]] In Your Code: After retrieving the response, you can substitute the placeholder back to a dot as necessary. 2. Handle Dot Logic in Processing You may create an intermediate processing logic to translate placeholder names back into a dot after the request has been made. While this increases the complexity of your application slightly, it ensures that your API remains functional without compromising its design. Conclusion Even though dealing with the Missing Authentication Token when using a dot in a GET request represents a common hurdle in AWS, it’s manageable with the right approach. While there is no direct fix available, strategically replacing the dot with a placeholder that can be processed later within your Lambda function effectively circumvents the authentication issue. Remember that developing a solution can sometimes involve a little creativity to work within service constraints, and this will serve your needs well in maintaining smooth functioning of your APIs. If you face similar issues or have different questions about AWS integration, feel free to share!