intersystems_openapi3

A CLI tool that generates InterSystems IRIS CSP REST backend classes from an OpenAPI 3.1.x specification. Point it at a valid JSON spec and it produces two ready-to-import ObjectScript class files — a dispatch class that handles routing and validation, and an implementation stub where you fill in the business logic.

Requirements

• Python 3.10+
• A valid OpenAPI 3.1.x spec in JSON format

Installation

pip install intersystems_openapi3

Usage

Generate classes from a spec (output alongside the spec file):

intersystems_openapi3 /path/to/spec.json

Write output to a specific directory:

intersystems_openapi3 /path/to/spec.json -o /path/to/output/

Use a custom name for the generated classes:

intersystems_openapi3 /path/to/spec.json -n MyRestService

Other flags:

intersystems_openapi3 --version
intersystems_openapi3 --help

Output

Two ObjectScript class files are generated in the output directory:

File	Description
{MyRestService}.disp.cls	Dispatch class — handles URL routing, parameter validation, request body checks, and Accept header validation. Do not edit.
{MyRestService}.impl.cls	Implementation class — one stub method per operation. Add your business logic here.

Import both files into your InterSystems IRIS instance to set up the REST API.

What gets generated

For each operation in the spec, the tool produces:

• Typed method signatures — parameters are annotated with ObjectScript types derived from the OpenAPI schema (%String, %Integer, %Float, %Boolean)
• Parameter validation — enforces constraints such as minLength, maxLength, pattern, minimum, maximum, and format-specific bounds (int32, int64)
• Request body handling — validates that required bodies are present and checks Content-Type against declared media types
• Response media type validation — validates Accept headers against declared response schemas
• Auto-assigned operation IDs — if your spec omits operationId, one is generated from the HTTP method and path

Example

Given a spec with a GET /users/{id} operation, the tool generates a dispatch method that validates the id path parameter and calls through to an implementation stub:

/// GET /users/{id}
ClassMethod GetUsersId(id As %String) As %Status
{
    // Add your business logic here
    Quit $$$OK
}