👀 Views: 3 💬 Answers: 1 📅 Created: 2025-05-31

aws appsync dynamodb graphql JavaScript

Hey everyone, I'm running into an issue that's driving me crazy. I'm wondering if anyone has experience with I'm sure I'm missing something obvious here, but I'm currently working with AWS AppSync and trying to implement real-time updates for my application... I have a GraphQL subscription set up to listen for changes on a DynamoDB table, but for some reason, my subscription isn't receiving updates when the table is modified. Here’s the relevant code setup: In my AppSync GraphQL schema, I defined the subscription like this: ```graphql subscription OnUpdateItem { onUpdateItem { id name status } } ``` I've also set up the mutation like this: ```graphql mutation UpdateItem($input: UpdateItemInput!) { updateItem(input: $input) { id name status } } ``` In my AWS Lambda function, which is responsible for updating the DynamoDB table and notifying AppSync, I have the following code: ```javascript const AWS = require('aws-sdk'); const docClient = new AWS.DynamoDB.DocumentClient(); const appsync = require('aws-appsync'); const gql = require('graphql-tag'); const updateItemMutation = gql` mutation UpdateItem($input: UpdateItemInput!) { updateItem(input: $input) { id name status } } `; exports.handler = async (event) => { const input = event.arguments.input; const params = { TableName: 'YourDynamoDBTable', Key: { id: input.id }, UpdateExpression: 'set #s = :status', ExpressionAttributeNames: { '#s': 'status' }, ExpressionAttributeValues: { ':status': input.status }, }; try { await docClient.update(params).promise(); // Here I want to publish an update await appsync.publishUpdateItem(input); } catch (behavior) { console.behavior(behavior); throw new behavior('behavior updating item'); } }; ``` I'm not seeing any errors in the Lambda logs, but the subscription in my front-end React app isn't receiving any updates. I’m using `aws-appsync` SDK version 3.0.0 and React version 17.0.2. I've confirmed that my subscription is properly established, and I can see it listed in the AWS AppSync console. I’ve also checked the IAM roles and permissions for the Lambda function, ensuring it has permissions to publish updates to AppSync. Yet somehow, it seems like the updates are being lost somewhere in the process. Has anyone encountered similar issues with subscriptions in AppSync when working with DynamoDB? Any insights on what might be going wrong, or what additional logging I could add to help debug this scenario would be greatly appreciated! Am I approaching this the right way? I've been using Javascript for about a year now. The stack includes Javascript and several other technologies. Thanks in advance! For reference, this is a production CLI tool. Is this even possible? I recently upgraded to Javascript 3.10.