How to Deploy InstantDM Webhooks on AWS Lambda (Serverless)

AWS Lambda lets you run code without managing servers. Deploy a webhook handler that processes InstantDM events, scales automatically, and costs nearly nothing at low volume.

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Why AWS Lambda?

• Zero infrastructure - no servers to manage, patch, or scale
• Pay per request - first 1M requests/month are free
• Auto-scaling - handles traffic spikes without configuration
• AWS ecosystem - easy integration with DynamoDB, SES, SQS, and more

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What You'll Need

Requirement	Details
InstantDM account	Trendsetter+ plan with API access
AWS account	Free tier eligible
AWS CLI	Installed and configured

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Lambda Function

// index.mjs
export const handler = async (event) => {
  const body = JSON.parse(event.body);
  const { event: eventType, timestamp, data } = body;
  
  console.log(`Event: ${eventType} from @${data.username}`);
  
  if (eventType === 'flow_completed') {
    const name = data.response_variables?.full_name || 'there';
    
    // Send a follow-up DM
    await fetch('https://api.instantdm.com/api-webhook', {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${process.env.INSTANTDM_API_KEY}`,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        action: 'send_message',
        type: 'text',
        recipient_id: data.instagram_user_id,
        message: `Thanks ${name}! We'll follow up shortly.`,
      }),
    });
    
    // Save to DynamoDB (optional)
    // await saveToDynamoDB(data);
  }
  
  return { statusCode: 200, body: JSON.stringify({ status: 'ok' }) };
};

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Setup with API Gateway

1. Create the Lambda function in AWS Console.
2. Add an API Gateway trigger (HTTP API).
3. Copy the API Gateway URL.
4. Paste it into InstantDM Settings → API → Webhook URL.
5. Set the INSTANTDM_API_KEY environment variable in Lambda.

Using SAM (Serverless Application Model)

# template.yaml
AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31

Resources:
  WebhookFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      Runtime: nodejs20.x
      Timeout: 30
      Environment:
        Variables:
          INSTANTDM_API_KEY: !Ref InstantDMApiKey
      Events:
        Webhook:
          Type: HttpApi
          Properties:
            Path: /webhook
            Method: POST

Parameters:
  InstantDMApiKey:
    Type: String
    NoEcho: true

Deploy:

sam build && sam deploy --guided

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Saving to DynamoDB

import { DynamoDBClient, PutItemCommand } from '@aws-sdk/client-dynamodb';

const dynamo = new DynamoDBClient({});

async function saveToDynamoDB(data) {
  await dynamo.send(new PutItemCommand({
    TableName: 'instagram-leads',
    Item: {
      id: { S: `${data.instagram_user_id}-${Date.now()}` },
      username: { S: data.username },
      email: { S: data.response_variables?.email || '' },
      flow_name: { S: data.flow_name || '' },
      timestamp: { S: new Date().toISOString() },
    },
  }));
}

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Troubleshooting

Issue	Solution
Lambda timing out	Increase timeout to 30 seconds. Check that external API calls aren't hanging.
502 Bad Gateway	Lambda must return { statusCode, body } format. Check the response structure.
Environment variable empty	Set it in Lambda Configuration → Environment variables, not in code.
Cold start latency	Use provisioned concurrency for consistent response times, or accept 1-2s cold starts.

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What's Next

• Deploy to Vercel for a simpler serverless option.
• Use Cloudflare Workers for edge computing.
• Read the Node.js backend guide for a traditional server.
• Explore the full API docs at instantdm.com/instagram-api-docs.