diff --git a/tf-aws-rest-api-gateway/main.tf b/tf-aws-rest-api-gateway/main.tf
index b3dbebe..ded5d8d 100644
--- a/tf-aws-rest-api-gateway/main.tf
+++ b/tf-aws-rest-api-gateway/main.tf
@@ -4,8 +4,15 @@ terraform {
 }
 
 locals {
-  create_log_group       = var.logging_level != "OFF"
-  log_group_arn          = local.create_log_group ? module.cloudwatch_log_group.log_group_arn : null
+  create_log_group = var.logging_level != "OFF"
+  log_group_arn    = local.create_log_group ? module.cloudwatch_log_group.log_group_arn : null
+  stage_name       = var.stage_name != "" ? var.stage_name : module.name.environment
+}
+
+data "template_file" "this" {
+  template = var.api_template
+
+  vars = var.api_template_vars
 }
 
 module "name" {
@@ -20,7 +27,7 @@ module "name" {
 
 resource "aws_api_gateway_rest_api" "this" {
   name = module.name.id
-  body = jsonencode(var.openapi_config)
+  body = data.template_file.this.rendered
   tags = module.name.tags
 
   endpoint_configuration {
@@ -51,7 +58,7 @@ resource "aws_api_gateway_deployment" "this" {
 resource "aws_api_gateway_stage" "this" {
   deployment_id        = aws_api_gateway_deployment.this.id
   rest_api_id          = aws_api_gateway_rest_api.this.id
-  stage_name           = var.stage_name != "" ? var.stage_name : module.this.stage
+  stage_name           = local.stage_name
   xray_tracing_enabled = var.xray_tracing_enabled
   tags                 = module.name.tags
 
@@ -68,7 +75,7 @@ resource "aws_api_gateway_stage" "this" {
 resource "aws_cloudwatch_log_group" "this" {
   count = local.create_log_group ? 1 : 0
 
-  name              = "${aws_api_gateway_rest_api.this.id}/${var.stage_name}"
+  name              = "${aws_api_gateway_rest_api.this.id}/${local.stage_name}"
   retention_in_days = var.cloudwatch_logs_retention_in_days
 }
 
diff --git a/tf-aws-rest-api-gateway/variables.tf b/tf-aws-rest-api-gateway/variables.tf
index c0411cf..a5cee9b 100644
--- a/tf-aws-rest-api-gateway/variables.tf
+++ b/tf-aws-rest-api-gateway/variables.tf
@@ -45,12 +45,16 @@ variable "tags" {
   description = "Additional custom tags (e.g. `{'Billing': 'Department_1'}`)."
 }
 
-# See https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-swagger-extensions.html for additional 
-# configuration information.
-variable "openapi_config" {
-  description = "The OpenAPI specification for the API"
-  type        = any
+variable "api_template" {
+  type        = string
+  default     = null
+  description = "API Gateway OpenAPI 3 template file"
+}
+
+variable "api_template_vars" {
+  type        = map(string)
   default     = {}
+  description = "Variables required in the OpenAPI template file"
 }
 
 variable "endpoint_type" {