diff --git a/README.md b/README.md
index 04d81196..4d35178e 100644
--- a/README.md
+++ b/README.md
@@ -50,6 +50,7 @@ This project implements an [MCP server](https://spec.modelcontextprotocol.io/) f
 - All database operations now use `data_source_id` instead of `database_id`
 - Search filter values changed from `["page", "database"]` to `["page", "data_source"]`
 - Page creation now supports both `page_id` and `database_id` parents (for data sources)
+- Data source creation payload now uses `initial_data_source.properties` instead of top-level `properties`
 
 ### Do I need to migrate?
 
@@ -61,7 +62,7 @@ If you have hardcoded tool names or prompts that reference the old database tool
 | -------------- | --------------- | ---------------- |
 | `post-database-query` | `query-data-source` | `database_id` → `data_source_id` |
 | `update-a-database` | `update-a-data-source` | `database_id` → `data_source_id` |
-| `create-a-database` | `create-a-data-source` | No change (uses `parent.page_id`) |
+| `create-a-database` | `create-a-data-source` | payload uses `initial_data_source.properties` |
 
 > **Note:** `retrieve-a-database` is still available and returns database metadata including the list of data source IDs. Use `retrieve-a-data-source` to get the schema and properties of a specific data source.
 
diff --git a/scripts/notion-openapi.json b/scripts/notion-openapi.json
index 18669f22..d6525a7e 100644
--- a/scripts/notion-openapi.json
+++ b/scripts/notion-openapi.json
@@ -1812,7 +1812,9 @@
         },
         "deprecated": false,
         "security": []
-      },
+      }
+    },
+    "/v1/databases/{data_source_id}": {
       "patch": {
         "summary": "Update a data source",
         "description": "Update properties of a data source",
@@ -1904,7 +1906,7 @@
         "security": []
       }
     },
-    "/v1/data_sources": {
+    "/v1/databases": {
       "post": {
         "summary": "Create a data source",
         "description": "Create a new data source (database)",
@@ -1924,15 +1926,23 @@
                 "type": "object",
                 "required": [
                   "parent",
-                  "properties"
+                  "initial_data_source"
                 ],
                 "properties": {
                   "parent": {
                     "$ref": "#/components/schemas/pageIdParentRequest"
                   },
-                  "properties": {
+                  "initial_data_source": {
                     "type": "object",
-                    "description": "Property schema of data source"
+                    "required": [
+                      "properties"
+                    ],
+                    "properties": {
+                      "properties": {
+                        "type": "object",
+                        "description": "Property schema of data source"
+                      }
+                    }
                   },
                   "title": {
                     "type": "array",
@@ -2214,4 +2224,4 @@
       }
     }
   }
-}
\ No newline at end of file
+}
diff --git a/src/openapi-mcp-server/openapi/__tests__/notion-openapi-data-source.test.ts b/src/openapi-mcp-server/openapi/__tests__/notion-openapi-data-source.test.ts
new file mode 100644
index 00000000..50c2c14e
--- /dev/null
+++ b/src/openapi-mcp-server/openapi/__tests__/notion-openapi-data-source.test.ts
@@ -0,0 +1,62 @@
+import fs from 'node:fs'
+import path from 'node:path'
+import { fileURLToPath } from 'node:url'
+import { describe, expect, it } from 'vitest'
+
+type NotionOpenApiSpec = {
+  paths: Record<string, Record<string, { operationId?: string; requestBody?: any }>>
+}
+
+function loadSpec(): NotionOpenApiSpec {
+  const filename = fileURLToPath(import.meta.url)
+  const directory = path.dirname(filename)
+  const specPath = path.resolve(directory, '../../../../scripts/notion-openapi.json')
+  return JSON.parse(fs.readFileSync(specPath, 'utf-8')) as NotionOpenApiSpec
+}
+
+function findOperationPath(spec: NotionOpenApiSpec, operationId: string): { path: string; method: string; operation: any } | null {
+  for (const [pathName, pathItem] of Object.entries(spec.paths)) {
+    for (const [method, operation] of Object.entries(pathItem)) {
+      if (operation?.operationId === operationId) {
+        return { path: pathName, method, operation }
+      }
+    }
+  }
+  return null
+}
+
+describe('Notion OpenAPI data-source compatibility', () => {
+  it('maps create-a-data-source to the databases endpoint', () => {
+    const spec = loadSpec()
+    const op = findOperationPath(spec, 'create-a-data-source')
+
+    expect(op).not.toBeNull()
+    expect(op?.method).toBe('post')
+    expect(op?.path).toBe('/v1/databases')
+  })
+
+  it('maps update-a-data-source to the databases endpoint', () => {
+    const spec = loadSpec()
+    const op = findOperationPath(spec, 'update-a-data-source')
+
+    expect(op).not.toBeNull()
+    expect(op?.method).toBe('patch')
+    expect(op?.path).toBe('/v1/databases/{data_source_id}')
+  })
+
+  it('accepts create payload via initial_data_source.properties', () => {
+    const spec = loadSpec()
+    const op = findOperationPath(spec, 'create-a-data-source')
+    const schema = op?.operation?.requestBody?.content?.['application/json']?.schema
+
+    expect(schema).toBeDefined()
+    expect(schema.required).toContain('parent')
+    expect(schema.required).toContain('initial_data_source')
+    expect(schema.required).not.toContain('properties')
+
+    expect(schema.properties.initial_data_source).toBeDefined()
+    expect(schema.properties.initial_data_source.type).toBe('object')
+    expect(schema.properties.initial_data_source.properties).toBeDefined()
+    expect(schema.properties.initial_data_source.properties.properties).toBeDefined()
+  })
+})