diff --git a/packages/kbn-generate-oas/src/generate_oas.ts b/packages/kbn-generate-oas/src/generate_oas.ts
index 2263014d046c1..2abcfc1eeed34 100644
--- a/packages/kbn-generate-oas/src/generate_oas.ts
+++ b/packages/kbn-generate-oas/src/generate_oas.ts
@@ -128,12 +128,8 @@ const prepareRoutes = <R extends { path: string; options: { access?: 'public' |
     routes
       // TODO: Make this smarter?
       .filter(pathStartsWith ? (route) => route.path.startsWith(pathStartsWith) : () => true)
-      // TODO: Figure out how we can scope which routes we generate OAS for
-      // .filter((route) => route.options.access === 'public')
-      .map((route) => ({
-        ...route,
-        path: route.path.replace('?', ''),
-      }))
+    // TODO: Figure out how we can scope which routes we generate OAS for
+    // .filter((route) => route.options.access === 'public')
   );
 };
 
@@ -186,7 +182,7 @@ const processVersionedRouter = (
         },
       };
 
-      paths[route.path] = { ...paths[route.path], ...path };
+      assignToPathsObject(paths, route.path, path);
     } catch (e) {
       // Enrich the error message with a bit more context
       e.message = `Error generating OpenAPI for route '${route.path}' using version '${version}': ${e.message}`;
@@ -259,8 +255,7 @@ const processRouter = (appRouter: Router, pathStartsWith?: string): OpenAPIV3.Pa
           operationId: getOperationId(route.path),
         },
       };
-
-      paths[route.path] = { ...paths[route.path], ...path };
+      assignToPathsObject(paths, route.path, path);
     } catch (e) {
       // Enrich the error message with a bit more context
       e.message = `Error generating OpenAPI for route '${route.path}': ${e.message}`;
@@ -270,6 +265,15 @@ const processRouter = (appRouter: Router, pathStartsWith?: string): OpenAPIV3.Pa
   return paths;
 };
 
+const assignToPathsObject = (
+  paths: OpenAPIV3.PathsObject,
+  path: string,
+  pathObject: OpenAPIV3.PathItemObject
+): void => {
+  const pathName = path.replace('?', '');
+  paths[pathName] = { ...paths[pathName], ...pathObject };
+};
+
 const getOpenApiPathsObject = (
   appRouter: Router | CoreVersionedRouter,
   pathStartsWith?: string
diff --git a/packages/kbn-generate-oas/src/oas_converters/index.ts b/packages/kbn-generate-oas/src/oas_converters/index.ts
index fc25b14915946..7434ed4f60b75 100644
--- a/packages/kbn-generate-oas/src/oas_converters/index.ts
+++ b/packages/kbn-generate-oas/src/oas_converters/index.ts
@@ -7,7 +7,7 @@
  */
 
 import type { OpenAPIV3 } from 'openapi-types';
-import { OpenAPIConverter } from '../type';
+import { KnownParameters, OpenAPIConverter } from '../type';
 
 import { zodConverter } from './zod';
 import { kbnConfigSchemaConverter } from './kbn_config_schema/kbn_config_schema';
@@ -24,7 +24,7 @@ export const convert = (schema: unknown): OpenAPIV3.SchemaObject => {
 
 export const convertPathParameters = (
   schema: unknown,
-  pathParameters: string[]
+  pathParameters: KnownParameters
 ): OpenAPIV3.ParameterObject[] => {
   return getConverter(schema).convertPathParameters(schema, pathParameters);
 };
diff --git a/packages/kbn-generate-oas/src/oas_converters/kbn_config_schema/kbn_config_schema.ts b/packages/kbn-generate-oas/src/oas_converters/kbn_config_schema/kbn_config_schema.ts
index 1dbec10b69adf..66c9a76b0704a 100644
--- a/packages/kbn-generate-oas/src/oas_converters/kbn_config_schema/kbn_config_schema.ts
+++ b/packages/kbn-generate-oas/src/oas_converters/kbn_config_schema/kbn_config_schema.ts
@@ -11,7 +11,7 @@ import joi from 'joi';
 import { isConfigSchema, Type } from '@kbn/config-schema';
 import { get } from 'lodash';
 import type { OpenAPIV3 } from 'openapi-types';
-import type { OpenAPIConverter } from '../../type';
+import type { KnownParameters, OpenAPIConverter } from '../../type';
 import { isReferenceObject } from '../common';
 import * as mutations from './post_process_mutations';
 
@@ -115,6 +115,7 @@ const convert = (kbnConfigSchema: unknown): OpenAPIV3.BaseSchemaObject => {
 
 const convertObjectMembersToParameterObjects = (
   schema: joi.Schema,
+  knownParameters: KnownParameters = {},
   isPathParameter = false
 ): OpenAPIV3.ParameterObject[] => {
   let properties: Exclude<OpenAPIV3.SchemaObject['properties'], undefined>;
@@ -129,7 +130,6 @@ const convertObjectMembersToParameterObjects = (
     throw createError(`Expected record, object or nullable object type, but got '${schema.type}'`);
   }
 
-  const isRequired = isSchemaRequired(schema);
   return Object.entries(properties).map(([schemaKey, schemaObject]) => {
     const isSubSchemaRequired = isSchemaRequired(schemaObject);
     if (isReferenceObject(schemaObject)) {
@@ -141,7 +141,7 @@ const convertObjectMembersToParameterObjects = (
     return {
       name: schemaKey,
       in: isPathParameter ? 'path' : 'query',
-      required: isPathParameter || (isRequired && isSubSchemaRequired),
+      required: isPathParameter ? !knownParameters[schemaKey].optional : isSubSchemaRequired,
       schema: openApiSchemaObject,
       description,
     };
@@ -150,12 +150,12 @@ const convertObjectMembersToParameterObjects = (
 
 const convertQuery = (kbnConfigSchema: unknown): OpenAPIV3.ParameterObject[] => {
   const schema = unwrapKbnConfigSchema(kbnConfigSchema);
-  return convertObjectMembersToParameterObjects(schema, false);
+  return convertObjectMembersToParameterObjects(schema, {}, false);
 };
 
 const convertPathParameters = (
   kbnConfigSchema: unknown,
-  pathParameters: string[]
+  knownParameters: { [paramName: string]: { optional: boolean } }
 ): OpenAPIV3.ParameterObject[] => {
   const schema = unwrapKbnConfigSchema(kbnConfigSchema);
 
@@ -170,7 +170,7 @@ const convertPathParameters = (
     throw createError('Input parser for path params expected to be an object schema');
   }
 
-  return convertObjectMembersToParameterObjects(schema, true);
+  return convertObjectMembersToParameterObjects(schema, knownParameters, true);
 };
 
 const is = (schema: unknown): boolean => {
diff --git a/packages/kbn-generate-oas/src/oas_converters/zod.ts b/packages/kbn-generate-oas/src/oas_converters/zod.ts
index 944ab7f604f3d..5678974418485 100644
--- a/packages/kbn-generate-oas/src/oas_converters/zod.ts
+++ b/packages/kbn-generate-oas/src/oas_converters/zod.ts
@@ -9,7 +9,7 @@
 import { z } from '@kbn/zod';
 import type { OpenAPIV3 } from 'openapi-types';
 import zodToJsonSchema from 'zod-to-json-schema';
-import { OpenAPIConverter } from '../type';
+import { KnownParameters, OpenAPIConverter } from '../type';
 import { validatePathParameters } from './common';
 
 // Adapted from from https://github.com/jlalmes/trpc-openapi/blob/aea45441af785518df35c2bc173ae2ea6271e489/src/utils/zod.ts#L1
@@ -142,7 +142,8 @@ const instanceofZodTypeCoercible = (_type: z.ZodTypeAny): _type is ZodTypeCoerci
 const convertObjectMembersToParameterObjects = (
   shape: z.ZodRawShape,
   isRequired: boolean,
-  isPathParameter = false
+  isPathParameter = false,
+  knownParameters: KnownParameters = {}
 ): OpenAPIV3.ParameterObject[] => {
   return Object.entries(shape).map(([shapeKey, subShape]) => {
     const isSubShapeRequired = !subShape.isOptional();
@@ -164,7 +165,7 @@ const convertObjectMembersToParameterObjects = (
     return {
       name: shapeKey,
       in: isPathParameter ? 'path' : 'query',
-      required: isPathParameter || (isRequired && isSubShapeRequired),
+      required: isPathParameter ? !knownParameters[shapeKey]?.optional : isSubShapeRequired,
       schema: openApiSchemaObject,
       description,
     };
@@ -184,11 +185,13 @@ const convertQuery = (schema: unknown): OpenAPIV3.ParameterObject[] => {
 
 const convertPathParameters = (
   schema: unknown,
-  pathParameters: string[]
+  knownParameters: KnownParameters
 ): OpenAPIV3.ParameterObject[] => {
   assertInstanceOfZodType(schema);
   const unwrappedSchema = unwrapZodType(schema, true);
-  if (pathParameters.length === 0 && instanceofZodTypeLikeVoid(unwrappedSchema)) {
+  const paramKeys = Object.keys(knownParameters);
+  const paramsCount = paramKeys.length;
+  if (paramsCount === 0 && instanceofZodTypeLikeVoid(unwrappedSchema)) {
     return [];
   }
   if (!instanceofZodTypeObject(unwrappedSchema)) {
@@ -196,7 +199,7 @@ const convertPathParameters = (
   }
   const shape = unwrappedSchema.shape;
   const schemaKeys = Object.keys(shape);
-  validatePathParameters(pathParameters, schemaKeys);
+  validatePathParameters(paramKeys, schemaKeys);
   const isRequired = !schema.isOptional();
   return convertObjectMembersToParameterObjects(shape, isRequired, true);
 };
diff --git a/packages/kbn-generate-oas/src/type.ts b/packages/kbn-generate-oas/src/type.ts
index 82cdbfd51ce55..21284ebf053ba 100644
--- a/packages/kbn-generate-oas/src/type.ts
+++ b/packages/kbn-generate-oas/src/type.ts
@@ -8,8 +8,15 @@
 
 import type { OpenAPIV3 } from 'openapi-types';
 
+export interface KnownParameters {
+  [paramName: string]: { optional: boolean };
+}
+
 export interface OpenAPIConverter {
-  convertPathParameters(schema: unknown, pathParameters: string[]): OpenAPIV3.ParameterObject[];
+  convertPathParameters(
+    schema: unknown,
+    knownPathParameters: KnownParameters
+  ): OpenAPIV3.ParameterObject[];
 
   convertQuery(schema: unknown): OpenAPIV3.ParameterObject[];
 
diff --git a/packages/kbn-generate-oas/src/util.ts b/packages/kbn-generate-oas/src/util.ts
index ce6df5589707b..010dbc36e647e 100644
--- a/packages/kbn-generate-oas/src/util.ts
+++ b/packages/kbn-generate-oas/src/util.ts
@@ -8,10 +8,14 @@
 
 import { VersionedRouterRoute } from '@kbn/core-http-router-server-internal/src/versioned_router/types';
 import { RouterRoute, RouteValidatorConfig } from '@kbn/core-http-server';
+import { KnownParameters } from './type';
 
-// https://github.com/jlalmes/trpc-openapi/blob/aea45441af785518df35c2bc173ae2ea6271e489/src/utils/path.ts#L5
-export const getPathParameters = (path: string): string[] => {
-  return Array.from(path.matchAll(/\{(.+?)\}/g)).map(([_, key]) => key!);
+export const getPathParameters = (path: string): KnownParameters => {
+  return Array.from(path.matchAll(/\{(.+?)\}/g)).reduce<KnownParameters>((acc, [_, key]) => {
+    const optional = key.endsWith('?');
+    acc[optional ? key.slice(0, key.length - 1) : key] = { optional };
+    return acc;
+  }, {});
 };
 
 export const extractValidationSchemaFromVersionedHandler = (