SDK adapters

Adapters convert normal single-request handlers into batch handlers compatible with the gateway. Two adapters are available: Node (khone-lambda-adapter) and Rust (khone-lambda-adapter).

Node adapter

Package: khone-lambda-adapter (CommonJS; main: dist/index.js).

Buffered

const { batchAdapter } = require("khone-lambda-adapter");

exports.handler = batchAdapter(async function handler(event) {
  return { statusCode: 200, body: "ok" };
});

batchAdapter(handler, options?) accepts an options object:

Option	Type	Default	Description
`concurrency`	number	`16`	Maximum concurrent in-flight handler invocations across the batch.

Streaming

const { batchAdapterStream } = require("khone-lambda-adapter");

exports.handler = batchAdapterStream(handler);

Interleaved streaming is enabled with:

exports.handler = batchAdapterStream(handler, { interleaved: true });

batchAdapterStream(handler, options?) options:

Option	Type	Default	Description
`concurrency`	number	`16`	Maximum concurrent in-flight handler invocations.
`interleaved`	boolean	`false`	Emit `head`/`chunk`/`end`/`error` records per request.
`streamifyResponse`	function	`globalThis.awslambda.streamifyResponse`	Override the runtime streaming wrapper.

Streaming requires awslambda.streamifyResponse from the AWS managed Node.js runtime, or an explicit streamifyResponse override. The adapter throws if neither is available.

Rust adapter

Crate: khone-lambda-adapter (publish = false; depend via git or path).

Buffered

use khone_lambda_adapter::{batch_adapter, HandlerResponse};

let adapter = batch_adapter(handler).with_concurrency(16);
let response = adapter.handle(event, &ctx).await;

batch_adapter(handler) returns a BatchAdapter with:

.with_concurrency(usize) — defaults to 16.

Streaming

use khone_lambda_adapter::batch_adapter_stream;

let adapter = batch_adapter_stream(handler).with_interleaved(true);

batch_adapter_stream(handler) returns a BatchAdapterStream with:

.with_concurrency(usize) — defaults to 16.
.with_interleaved(bool) — defaults to false.

Response mapping

Each batch item becomes an API Gateway HTTP API v2 event.
requestContext.requestId is the response correlation id.
Handler errors become per-item 500 responses with content-type: text/plain and internal error as the body.
headers, cookies, body, and isBase64Encoded follow the standard Lambda response shape.
The Rust adapter clamps statusCode == 0 to 200 for safety.