echo

name	echo
version	1.0.0
description	Echoes the input message back, optionally transforming its case.
inputs	[{"name":"message","type":"string","description":"The message to echo back","required":true},{"name":"transform","type":"string","description":"Optional case transform: 'upper', 'lower', or 'none'","required":false}]
outputs	[{"name":"echoed","type":"string","description":"The (optionally transformed) echoed message"},{"name":"length","type":"integer","description":"Character length of the echoed message"}]
capabilities	["stateless","streaming"]
dependencies	[]
resources	{"vcpu":1,"memory_mib":64,"boot_timeout_ms":300}

Overview

The echo agent is the simplest possible unikernel skill — it exists primarily as a health-check and integration-test target for the fabric.

Given an input message string, it returns the message unchanged (or case-transformed if the optional transform field is provided), along with the character length.

Behaviour

• If transform is "upper", return message.upper()
• If transform is "lower", return message.lower()
• For any other value (including absent), return message unchanged

Example

Request:

{
  "message": "Hello, Fabric!",
  "transform": "upper"
}

Response:

{
  "echoed": "HELLO, FABRIC!",
  "length": 14
}

Error Handling

If message is empty, return HTTP 422 with {"error": "message must not be empty"}.