Template Serializer

Compose custom message bodies using ${...} placeholders resolved against raw Keycloak event properties.

Configuration

kete.routes.<name>.serializer.kind=template
kete.routes.<name>.serializer.template-file-text=User ${userId} logged in from ${ipAddress}

Required Properties

Property	Description
kind	template
One of:
template-file-text	Inline template string
template-file-base64	Base64-encoded template
template-file-path	Path to template file on disk

Exactly one template source must be set. This follows the same triple-source pattern used by TLS certificates and credentials throughout KETE.

Optional Properties

Property	Default	Description
content-type	text/plain	MIME type sent as the contenttype header
variable-escape	none	Global escape mode applied to all variables

Template Variables

For User Events (Event):

Variable	Source	Example
${id}	Event ID	evt-abc-123
${type}	Event type name	LOGIN
${realmId}	Realm ID	my-realm
${realmName}	Realm display name	My Realm
${clientId}	Client ID	my-app
${userId}	User ID	abc-123-def
${sessionId}	Session ID	sess-456
${ipAddress}	IP address	192.168.1.1
${error}	Error string (if any)	invalid_user_credentials
${time}	Epoch milliseconds	1707500000000
${details.<key>}	Event detail by key	${details.username} → john

Event detail keys support both raw (${details.redirect_uri}) and camelCase (${details.redirectUri}) forms.

For Admin Events (AdminEvent):

Variable	Source	Example
${id}	Event ID	adm-abc-123
${operationType}	Operation type name	CREATE
${resourceType}	Resource type (raw string)	USER
${realmId}	Realm ID	my-realm
${realmName}	Realm display name	My Realm
${resourcePath}	Resource path	users/abc-123
${representation}	JSON representation	{"username":"john"}
${error}	Error string (if any)
${time}	Epoch milliseconds	1707500000000
${authDetails.realmId}	Auth realm	master
${authDetails.realmName}	Auth realm display name	Master Realm
${authDetails.clientId}	Auth client	admin-cli
${authDetails.userId}	Auth user	admin-uuid
${authDetails.ipAddress}	Auth IP	10.0.0.1

Undefined variables resolve to an empty string.

Variable Escaping

Set a global escape mode with variable-escape, then override individual variables with the :filter suffix:

Filter	Aliases	Description
none		Raw passthrough (default)
json	json-encode	JSON string escaping (" → \", \n → \\n, etc.)
xml	xml-encode	XML entity escaping (< → &lt;, & → &amp;, etc.)
url	url-encode	URL percent-encoding
csv	csv-quote	CSV quoting (wraps in quotes if value contains ,, ", or newlines)
b64	base64	Base64 encoding

Unrecognized filter names are treated as none (raw passthrough).

Per-variable override:

# Global: JSON-escape all variables
kete.routes.myroute.serializer.variable-escape=json

# Template: ${time:none} opts out of JSON escaping for this variable
kete.routes.myroute.serializer.template-file-text={"user": "${userId}", "time": ${time:none}}

Example Output

SMS Alert (plain text)

Config:

kete.routes.sms.serializer.kind=template
kete.routes.sms.serializer.template-file-text=ALERT: ${userId} ${type} from ${ipAddress} in ${realmId}

Output:

ALERT: abc-123-def LOGIN from 192.168.1.1 in production

Slack Webhook (JSON payload)

Config:

kete.routes.slack.serializer.kind=template
kete.routes.slack.serializer.content-type=application/json
kete.routes.slack.serializer.variable-escape=json
kete.routes.slack.serializer.template-file-text={"text": "User ${userId} performed ${type} in ${realmId}"}

Output:

{"text": "User abc-123-def performed LOGIN in production"}

Admin Alert (HTML)

Config:

kete.routes.admin.serializer.kind=template
kete.routes.admin.serializer.content-type=text/html
kete.routes.admin.serializer.variable-escape=xml
kete.routes.admin.serializer.template-file-text=<h2>Admin Action</h2><p><b>${authDetails.userId}</b> performed <b>${operationType}</b> on <b>${resourceType}</b></p><p>Path: ${resourcePath}</p>

Output:

<h2>Admin Action</h2><p><b>admin-uuid</b> performed <b>CREATE</b> on <b>USER</b></p><p>Path: users/abc-123</p>

Lightweight IoT (pipe-delimited)

Config:

kete.routes.iot.serializer.kind=template
kete.routes.iot.serializer.template-file-text=${type}|${userId}|${realmId}

Output:

LOGIN|abc-123-def|production