AWS Emulator

S3, SQS, Cognito, IAM, and STS emulation with AWS SDK-compatible S3 paths. S3 uploads and downloads preserve arbitrary binary payloads, including raw byte lengths and ETags. SQS supports AWS JSON 1.0 and XML Query protocols; IAM and STS use XML Query. All state is in-memory.

Start

Local listeners bind to 127.0.0.1 by default. For access from containers or other machines, pass --host 0.0.0.0 to the CLI or hostname: '0.0.0.0' to createEmulator. Configure --base-url or baseUrl for advertised URLs reachable by those clients.

# AWS only
npx emulate --service aws

# Default port (when run alone)
# http://localhost:4000

Or programmatically: