cloudfront-functions — CloudFront Functions & KeyValueStore

A zero-dependency, in-process emulator for the AWS CloudFront Functions control plane and CloudFront KeyValueStore (with a simple data-plane key/value API).

Property	Value
Port	4713
Protocol	REST / XML (+ JSON data plane)
API Version	2020-05-31
Health	`GET /_parlel/health`
Reset	`POST /_parlel/reset`

Default connection

AWS_ENDPOINT_URL=http://127.0.0.1:4713
AWS_REGION=us-east-1
AWS_ACCESS_KEY_ID=parlel
AWS_SECRET_ACCESS_KEY=parlel

Supported operations

Operation	Path
CreateFunction	`POST /2020-05-31/function`
ListFunctions	`GET /2020-05-31/function`
DescribeFunction	`GET /2020-05-31/function/{name}`
PublishFunction	`POST /2020-05-31/function/{name}/publish`
TestFunction	`POST /2020-05-31/test-function`
DeleteFunction	`DELETE /2020-05-31/function/{name}`
CreateKeyValueStore	`POST /2020-05-31/key-value-store`
ListKeyValueStores	`GET /2020-05-31/key-value-store`

KeyValueStore data plane (parlel extension)

Operation	Path
PutKey	`PUT /2020-05-31/key-value-store/{name}/keys/{k}`
GetKey	`GET /2020-05-31/key-value-store/{name}/keys/{k}`
DeleteKey	`DELETE /2020-05-31/key-value-store/{name}/keys/{k}`
ListKeys	`GET /2020-05-31/key-value-store/{name}/keys`

TestFunction actually executes the function code with a synthetic event, returning FunctionOutput, so you can validate handler logic.

SDK usage example

import {
  CloudFrontClient,
  CreateFunctionCommand,
  TestFunctionCommand,
} from "@aws-sdk/client-cloudfront";

const cf = new CloudFrontClient({
  endpoint: "http://127.0.0.1:4713",
  region: "us-east-1",
  credentials: { accessKeyId: "parlel", secretAccessKey: "parlel" },
});

await cf.send(
  new CreateFunctionCommand({
    Name: "redirect",
    FunctionConfig: { Comment: "", Runtime: "cloudfront-js-2.0" },
    FunctionCode: Buffer.from(
      "function handler(event){ event.request.uri='/index.html'; return event.request; }",
    ),
  }),
);

Access via MCP / preview URL

Point any AWS SDK or MCP tool at the allocated preview URL via AWS_ENDPOINT_URL.

Surface coverage

This emulator faithfully replicates the API surface most application code and agents exercise. Anything below the supported lines is either an intentional design choice for a fast, zero-cost local emulator (✓ By design) or a candidate for a future release (⟳ Roadmap) — never a silent inaccuracy.

Legend: ✅ fully supported · ◐ accepted (stored, not strictly enforced) · ✓ by design · ⟳ on the roadmap.

Area	Limitation
Runtime	`TestFunction` uses `node:Function`, not the real CF runtime
UpdateFunction	Not implemented
ETag concurrency	ETag returned but not enforced on update/publish
Associations	Function-to-distribution associations not tracked
State	In-memory only; lost on restart

Configuration — `test.env`

Copy these into your test.env (used by the bridge sidecar flow). Tokens are Parlel's seeded test credentials — any non-empty value is accepted by the emulator, so you rarely need to change them. Swap in real credentials only when pointing at the live service in prod.env.

AWS_ACCESS_KEY_ID=parlel
AWS_SECRET_ACCESS_KEY=parlel
AWS_REGION=us-east-1
AWS_ENDPOINT_URL=http://parlel-bridge:4713