Kinesis Firehose

AWS Documentation

• Using AWS Lambda with Amazon Kinesis Data Firehose

Example JSON

import middy from '@middy/core'
import eventBatchParser, { parseJson } from '@middy/event-batch-parser'
import eventBatchResponse from '@middy/event-batch-response'
import eventBatchHandler from '@middy/event-batch-handler'

const recordHandler = async (record, context) => {
  // record.data is the parsed JSON payload; return the transformed payload
  // (auto-base64-encoded) or { result: 'Dropped', data: '' } to drop a record;
  // throw to mark it as ProcessingFailed
}
const lambdaHandler = eventBatchHandler(recordHandler)

export const handler = middy()
  .use(eventBatchParser({ body: parseJson() }))
  .use(eventBatchResponse())
  .handler(lambdaHandler)

Example Avro

import middy from '@middy/core'
import eventBatchParser, { parseAvro } from '@middy/event-batch-parser'
import eventBatchResponse from '@middy/event-batch-response'
import eventBatchHandler from '@middy/event-batch-handler'

const schema = { type: 'record', name: 'Record', fields: [
  { name: 'id', type: 'string' },
  { name: 'payload', type: 'string' },
] }

const recordHandler = async (record, context) => {
  // record.data is the decoded Avro object
}
const lambdaHandler = eventBatchHandler(recordHandler)

export const handler = middy()
  .use(eventBatchParser({ body: parseAvro({ schema }) }))
  .use(eventBatchResponse())
  .handler(lambdaHandler)

For dynamic schemas resolved via @middy/glue-schema-registry, omit schema and chain the registry middleware.

Example Protobuf

Per-record schemas are resolved dynamically from the AWS Glue Schema Registry. Each Glue-framed record carries a SchemaVersionId that the registry middleware fetches (and caches) before parseProtobuf runs.

import middy from '@middy/core'
import glueSchemaRegistry from '@middy/glue-schema-registry'
import eventBatchParser, { parseProtobuf } from '@middy/event-batch-parser'
import eventBatchResponse from '@middy/event-batch-response'
import eventBatchHandler from '@middy/event-batch-handler'

const recordHandler = async (record, context) => {
  // record.data is the decoded Protobuf message (as JSON)
}
const lambdaHandler = eventBatchHandler(recordHandler)

export const handler = middy()
  .use(glueSchemaRegistry())
  .use(eventBatchParser({ body: parseProtobuf(), glueSchemaRegistry: {} }))
  .use(eventBatchResponse())
  .handler(lambdaHandler)

Last updated: 2026-05-17