AWS Lambda (sdk) UnsupportedMediaTypeException

The content type of the request is not supported.

Understanding AWS Lambda and Its Purpose

AWS Lambda is a serverless compute service that allows you to run code without provisioning or managing servers. It automatically scales your application by running code in response to each trigger, such as changes in data, shifts in system state, or user actions. Lambda supports a variety of programming languages, making it a versatile tool for developers looking to build scalable applications.

Identifying the Symptom: UnsupportedMediaTypeException

When working with AWS Lambda, you might encounter the UnsupportedMediaTypeException. This error typically occurs when the content type of the request sent to a Lambda function is not supported. As a result, the function fails to process the request, leading to an interruption in the workflow.

Exploring the Issue: What Causes UnsupportedMediaTypeException?

The UnsupportedMediaTypeException is triggered when the content type specified in the request header does not match any of the supported types by the Lambda function. This mismatch can occur due to incorrect content type settings or unsupported formats being used in the request.

Common Scenarios Leading to the Error

  • Sending a request with a content type that is not explicitly handled by the Lambda function.
  • Using an incorrect or misspelled content type in the request header.
  • Attempting to process binary data without proper configuration.

Steps to Fix the UnsupportedMediaTypeException

To resolve the UnsupportedMediaTypeException, follow these steps:

Step 1: Verify the Content Type

Ensure that the content type specified in your request header matches one of the supported types by your Lambda function. Common content types include application/json, text/plain, and application/xml. Check your API documentation or Lambda function configuration to confirm the supported types.

curl -X POST https://your-api-endpoint \
-H "Content-Type: application/json" \
-d '{"key":"value"}'

Step 2: Update the Lambda Function Configuration

If your Lambda function needs to handle additional content types, update its configuration to include these types. You can do this by modifying the function's code to parse and process the new content types appropriately.

Step 3: Use API Gateway for Content Type Mapping

If you are using AWS API Gateway with your Lambda function, configure it to map incoming content types to the ones your function can handle. This can be done in the API Gateway console under the 'Integration Request' settings.

Learn more about API Gateway mapping templates

Conclusion

By ensuring that your request content types are correctly specified and supported by your Lambda function, you can effectively resolve the UnsupportedMediaTypeException. Proper configuration and validation of content types are crucial for seamless Lambda function execution. For further reading, refer to the AWS Lambda Developer Guide.

Try DrDroid: AI Agent for Debugging

80+ monitoring tool integrations
Long term memory about your stack
Locally run Mac App available

Thank you for your submission

We have sent the cheatsheet on your email!
Oops! Something went wrong while submitting the form.
Read more
Time to stop copy pasting your errors onto Google!

Try DrDroid: AI Agent for Fixing Production Errors

80+ monitoring tool integrations
Long term memory about your stack
Locally run Mac App available

Thankyou for your submission

We have sent the cheatsheet on your email!
Oops! Something went wrong while submitting the form.

Thank you for your submission

We have sent the cheatsheet on your email!
Oops! Something went wrong while submitting the form.
Read more
Time to stop copy pasting your errors onto Google!

MORE ISSUES

Deep Sea Tech Inc. — Made with ❤️ in Bangalore & San Francisco 🏢

Doctor Droid