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implementing Cross-Region AWS Lambda Function Invocation from API Gateway

👀 Views: 2801 💬 Answers: 1 📅 Created: 2025-06-07
aws lambda api-gateway cross-region JavaScript

I've been researching this but I'm sure I'm missing something obvious here, but I'm trying to invoke an AWS Lambda function located in a different region from my API Gateway, but I'm running into issues... The API Gateway is set up in `us-east-1`, and the Lambda function is in `us-west-2`. Despite following the documentation, I'm getting a `502 Bad Gateway` behavior. I have the Lambda function configured with the correct permissions, and the API Gateway's integration type is set to use 'Lambda Function'. Here's the configuration for the integration: ```json { "type": "AWS_PROXY", "httpMethod": "POST", "uri": "arn:aws:apigateway:us-west-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-west-2:123456789012:function:myLambdaFunction/invocations" } ``` I also ensured that cross-region invocation is enabled on the Lambda function by adding this policy: ```json { "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Principal": { "Service": "apigateway.amazonaws.com" }, "Action": "lambda:InvokeFunction", "Resource": "arn:aws:lambda:us-west-2:123456789012:function:myLambdaFunction" } ] } ``` When I check the CloudWatch logs for the Lambda function, I see the invocation attempt, but it just shows that the function was invoked and nothing more. I’ve also tried using a direct test invocation from the Lambda console, and that works fine. What could be causing this `502 Bad Gateway` behavior when invoking the Lambda from the API Gateway? Is there something I'm missing in the setup that relates to cross-region functionality? For context: I'm using Javascript on macOS. Thanks in advance!