Built-in Extensions¶

Lace ships two built-in extensions with every executor distribution. They are bundled as .laceext files and referenced in lace.config with the builtin: prefix.

What "built-in" means¶

Built-in extensions are regular .laceext files that use the same rule language and extension system as any author-written extension. The only difference is distribution: they ship alongside the executor binary and can be referenced as builtin:<name> instead of a file path.

Built-in extensions are not active by default. They must be listed in lace.config to take effect:

[extensions.laceNotifications]
laceext = "builtin:laceNotifications"

[extensions.laceBaseline]
laceext = "builtin:laceBaseline"

Included extensions¶

laceNotifications ¶

Notification dispatch for assertion failures and timeouts. When a scope, condition, or call fails, this extension emits structured notification events into result.actions.notifications. The backend is responsible for delivering these notifications via its configured transport (email, Slack, webhook, etc.).

Key features:

Registers notification and silentOnRepeat options on scopes, conditions, and timeouts
Emits notification_event entries with text, template, or structured payloads
Supports op_map for conditional notification selection based on failure type
Exposes pushNotification() for other extensions to inject notifications
Suppresses repeated alerts with silentOnRepeat (default: true)

laceBaseline ¶

Rolling average timing baseline and spike detection. Tracks 7 HTTP response timing metrics across runs and dispatches notifications when a metric deviates significantly from its baseline.