DeReg REST API

The DeReg API exposes registered schema metadata using read-only Arrow IPC endpoints.

DeReg stands for Decision Registry. It is the registry of compiled DeQL definitions for a system: aggregates, commands, events, decisions, projections, templates, and event stores. Because DeReg can be exported and then loaded into another environment, it is also the portability layer for moving a DeQL system definition across environments.

Block Collections

Method	Route
GET	/api/dereg/aggregates
GET	/api/dereg/commands
GET	/api/dereg/events
GET	/api/dereg/decisions
GET	/api/dereg/projections
GET	/api/dereg/templates
GET	/api/dereg/eventstores

Single-Definition Lookups

Method	Route
GET	/api/dereg/aggregates/{name}
GET	/api/dereg/commands/{name}
GET	/api/dereg/events/{name}
GET	/api/dereg/decisions/{name}
GET	/api/dereg/projections/{name}
GET	/api/dereg/templates/{name}
GET	/api/dereg/eventstores/{name}

Detail Endpoints

Method	Route
GET	/api/dereg/aggregates/{name}/fields
GET	/api/dereg/commands/{name}/fields
GET	/api/dereg/events/{name}/fields
GET	/api/dereg/decisions/{name}/emits
GET	/api/dereg/templates/{name}/params
GET	/api/dereg/templates/{name}/instances

Behavior

• All responses are Arrow IPC unless an execution layer error is returned as JSON.
• Unknown block groups or sub-resources return 404.
• Invalid names return 400.
• Single-row lookups return 404 if no rows are found.

Internal Mapping

These routes are backed by DeReg meta tables such as:

• aggregate definitions and fields
• command definitions and fields
• event definitions and fields
• decision definitions and emitted-event metadata
• projection definitions
• template definitions, parameters, and instances
• event store definitions