Server Source code Package

AWS Lambda

AWS Lambda source for walkerOS. Works across API Gateway REST (v1), API Gateway HTTP (v2), Lambda Function URLs, and direct invocation. Auto-detects the API Gateway version, supports optional pixel tracking with a 1x1 GIF response, and exposes a built-in health check endpoint. The @walkeros/server-source-aws package also ships sourceSqs for ingesting from SQS queues; this page covers the Lambda handler only.

Where this fits

The AWS Lambda source is a server source in the walkerOS flow:

It receives events via HTTP and forwards them to your destinations.

Installation

npm install @walkeros/server-source-aws

Integrated

import { sourceLambda } from '@walkeros/server-source-aws';
import { startFlow } from '@walkeros/collector';

let handler: any;

async function init() {
if (handler) return handler;

const { sources } = await startFlow({
  sources: {
    lambda: {
      code: sourceLambda,
      config: {
        settings: { cors: true, healthPath: '/health' },
      },
    },
  },
  destinations: {
    // Your destinations
  },
});

handler = sources.lambda.push;
return handler;
}

export const main = async (event: any, context: any) => {
const h = await init();
return h(event, context);
};

export { main as handler };

Bundled

Add to your flow.json sources:

"sources": {
"lambda": {
  "package": "@walkeros/server-source-aws",
  "config": {
    "settings": {
      "cors": true,
      "healthPath": "/health"
    }
  }
}
}

Server sources require platform-specific handlers. For containerized deployments, see Docker.

See bundled mode setup | CLI reference

Configuration

This source uses the standard source config wrapper (consent, data, env, id, ...). For the shared fields see source configuration. Package-specific fields live under config.settings and are listed below.

Settings

Property	Type	Description	More
cors	boolean | object	CORS configuration: false = disabled, true = allow all origins, object = custom configuration
timeout	integer	Request timeout in milliseconds (max: 900000 for Lambda)
enablePixelTracking	boolean	Enable GET requests with 1x1 transparent GIF response for pixel tracking
healthPath	string	Health check endpoint path (e.g., /health)

Mapping

This package does not define custom rule-level settings. For the standard rule fields (consent, condition, data, batch, name, policy) see mapping.

Examples

API Gateway v1 POST

A REST API Gateway v1 POST request with a JSON body is converted into a walker elb event.

Event

{
  "httpMethod": "POST",
  "path": "/collect",
  "requestContext": {
    "requestId": "req-789",
    "identity": {
      "sourceIp": "203.0.113.42"
    }
  },
  "queryStringParameters": null,
  "body": "{\"event\":\"page view\",\"data\":{\"title\":\"Home\"}}",
  "isBase64Encoded": false
}

Out

elb({
  "name": "page view",
  "data": {
    "title": "Home"
  }
})

Lambda GET

An API Gateway v2 HTTP GET with query parameters is parsed into an elb event payload.

Event

{
  "version": "2.0",
  "requestContext": {
    "http": {
      "method": "GET",
      "path": "/collect"
    },
    "requestId": "req-456"
  },
  "rawQueryString": "e=page+view&d=%7B%22title%22%3A%22Home%22%7D",
  "isBase64Encoded": false
}

Out

elb({
  "e": "page view",
  "d": "{\"title\":\"Home\"}"
})

Lambda POST

An API Gateway v2 HTTP POST with a JSON body is converted into a walker elb event.

Event

{
  "version": "2.0",
  "requestContext": {
    "http": {
      "method": "POST",
      "path": "/collect"
    },
    "requestId": "req-123"
  },
  "body": "{\"event\":\"page view\",\"data\":{\"title\":\"Home\"}}",
  "isBase64Encoded": false
}

Out

elb({
  "name": "page view",
  "data": {
    "title": "Home"
  }
})

Ingest metadata

Extract request metadata from Lambda events and forward it through the pipeline.

config.ingest must use the map operator. Keys are output field names; values are direct field paths on the Lambda event (no prefix). A bare object like { ip: 'requestContext.identity.sourceIp' } is silently inert: without the map operator the source passes the whole event through and no field is extracted.

const { sources } = await startFlow({
sources: {
  lambda: {
    code: sourceLambda,
    config: {
      settings: { cors: true },
      ingest: {
        map: {
          ip: { key: 'requestContext.identity.sourceIp' },  // v1
          ua: { key: 'requestContext.identity.userAgent' }, // v1
          // Or for API Gateway v2:
          // ip: { key: 'requestContext.http.sourceIp' },
          // ua: { key: 'requestContext.http.userAgent' },
        },
      },
    },
  },
},
});

Available ingest paths

API Gateway v1 (REST API):

Path	Description
requestContext.identity.sourceIp	Client IP address
requestContext.identity.userAgent	User agent string
headers.*	HTTP headers
httpMethod	HTTP method

API Gateway v2 (HTTP API) / Function URLs:

Path	Description
requestContext.http.sourceIp	Client IP address
requestContext.http.userAgent	User agent string
requestContext.http.method	HTTP method
headers.*	HTTP headers

Supported platforms

Platform	Status
API Gateway REST API (v1)	Supported
API Gateway HTTP API (v2)	Supported
Lambda Function URLs	Supported
Direct Lambda invocation	Supported