diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8d16acc8a4..c4db3af158 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to
 ### Added
 
 - ✨(frontend) add duplicate action to doc tree #1175
+- ✨(api) add API route to fetch document content #1206
 
 ### Changed
 
diff --git a/src/backend/core/api/viewsets.py b/src/backend/core/api/viewsets.py
index 7919033e16..bdeba5a23d 100644
--- a/src/backend/core/api/viewsets.py
+++ b/src/backend/core/api/viewsets.py
@@ -1,6 +1,7 @@
 """API endpoints"""
 # pylint: disable=too-many-lines
 
+import base64
 import json
 import logging
 import uuid
@@ -37,6 +38,15 @@
 from core import authentication, choices, enums, models
 from core.services.ai_services import AIService
 from core.services.collaboration_services import CollaborationService
+from core.services.converter_services import (
+    ServiceUnavailableError as YProviderServiceUnavailableError,
+)
+from core.services.converter_services import (
+    ValidationError as YProviderValidationError,
+)
+from core.services.converter_services import (
+    YdocConverter,
+)
 from core.tasks.mail import send_ask_for_access_mail
 from core.utils import extract_attachments, filter_descendants
 
@@ -1443,6 +1453,69 @@ def cors_proxy(self, request, *args, **kwargs):
                 status=status.HTTP_500_INTERNAL_SERVER_ERROR,
             )
 
+    @drf.decorators.action(
+        detail=True,
+        methods=["get"],
+        url_path="content",
+        name="Get document content in different formats",
+    )
+    def content(self, request, pk=None):
+        """
+        Retrieve document content in different formats (JSON, Markdown, HTML).
+
+        Query parameters:
+        - content_format: The desired output format (json, markdown, html)
+
+        Returns:
+            JSON response with content in the specified format.
+        """
+
+        document = self.get_object()
+
+        content_format = request.query_params.get("content_format", "json").lower()
+        if content_format not in {"json", "markdown", "html"}:
+            raise drf.exceptions.ValidationError(
+                "Invalid format. Must be one of: json, markdown, html"
+            )
+
+        # Get the base64 content from the document
+        content = None
+        base64_content = document.content
+        if base64_content is not None:
+            # Convert using the y-provider service
+            try:
+                yprovider = YdocConverter()
+                result = yprovider.convert(
+                    base64.b64decode(base64_content),
+                    "application/vnd.yjs.doc",
+                    {
+                        "markdown": "text/markdown",
+                        "html": "text/html",
+                        "json": "application/json",
+                    }[content_format],
+                )
+                content = result
+            except YProviderValidationError as e:
+                return drf_response.Response(
+                    {"error": str(e)}, status=status.HTTP_400_BAD_REQUEST
+                )
+            except YProviderServiceUnavailableError as e:
+                logger.error("Error getting content for document %s: %s", pk, e)
+                return drf_response.Response(
+                    {"error": "Failed to get document content"},
+                    status=status.HTTP_500_INTERNAL_SERVER_ERROR,
+                )
+
+        return drf_response.Response(
+            {
+                "id": str(document.id),
+                "title": document.title,
+                "content": content,
+                "created_at": document.created_at,
+                "updated_at": document.updated_at,
+            }
+        )
+
 
 class DocumentAccessViewSet(
     ResourceAccessViewsetMixin,
diff --git a/src/backend/core/models.py b/src/backend/core/models.py
index d6e79c5100..1098bbe940 100644
--- a/src/backend/core/models.py
+++ b/src/backend/core/models.py
@@ -786,6 +786,7 @@ def get_abilities(self, user):
             "children_list": can_get,
             "children_create": can_update and user.is_authenticated,
             "collaboration_auth": can_get,
+            "content": can_get,
             "cors_proxy": can_get,
             "descendants": can_get,
             "destroy": is_owner,
diff --git a/src/backend/core/services/converter_services.py b/src/backend/core/services/converter_services.py
index d6a6dbf4b1..9c79a7192d 100644
--- a/src/backend/core/services/converter_services.py
+++ b/src/backend/core/services/converter_services.py
@@ -1,4 +1,4 @@
-"""Converter services."""
+"""Y-Provider API services."""
 
 from base64 import b64encode
 
@@ -28,25 +28,44 @@ def auth_header(self):
         # Note: Yprovider microservice accepts only raw token, which is not recommended
         return f"Bearer {settings.Y_PROVIDER_API_KEY}"
 
-    def convert(self, text):
+    def _request(self, url, data, content_type, accept):
+        """Make a request to the Y-Provider API."""
+        response = requests.post(
+            url,
+            data=data,
+            headers={
+                "Authorization": self.auth_header,
+                "Content-Type": content_type,
+                "Accept": accept,
+            },
+            timeout=settings.CONVERSION_API_TIMEOUT,
+            verify=settings.CONVERSION_API_SECURE,
+        )
+        response.raise_for_status()
+        return response
+
+    def convert(
+        self, text, content_type="text/markdown", accept="application/vnd.yjs.doc"
+    ):
         """Convert a Markdown text into our internal format using an external microservice."""
 
         if not text:
             raise ValidationError("Input text cannot be empty")
 
         try:
-            response = requests.post(
+            response = self._request(
                 f"{settings.Y_PROVIDER_API_BASE_URL}{settings.CONVERSION_API_ENDPOINT}/",
-                data=text,
-                headers={
-                    "Authorization": self.auth_header,
-                    "Content-Type": "text/markdown",
-                },
-                timeout=settings.CONVERSION_API_TIMEOUT,
-                verify=settings.CONVERSION_API_SECURE,
+                text,
+                content_type,
+                accept,
             )
-            response.raise_for_status()
-            return b64encode(response.content).decode("utf-8")
+            if accept == "application/vnd.yjs.doc":
+                return b64encode(response.content).decode("utf-8")
+            if accept in {"text/markdown", "text/html"}:
+                return response.text
+            if accept == "application/json":
+                return response.json()
+            raise ValidationError("Unsupported format")
         except requests.RequestException as err:
             raise ServiceUnavailableError(
                 "Failed to connect to conversion service",
diff --git a/src/backend/core/tests/documents/test_api_documents_content.py b/src/backend/core/tests/documents/test_api_documents_content.py
new file mode 100644
index 0000000000..459bf5a0ce
--- /dev/null
+++ b/src/backend/core/tests/documents/test_api_documents_content.py
@@ -0,0 +1,176 @@
+"""
+Tests for Documents API endpoint in impress's core app: content
+"""
+
+import base64
+from unittest.mock import patch
+
+import pytest
+import requests
+from rest_framework import status
+from rest_framework.test import APIClient
+
+from core import factories
+
+pytestmark = pytest.mark.django_db
+
+
+@pytest.mark.parametrize(
+    "reach, role",
+    [
+        ("public", "reader"),
+        ("public", "editor"),
+    ],
+)
+@patch("core.services.converter_services.YdocConverter.convert")
+def test_api_documents_content_public(mock_content, reach, role):
+    """Anonymous users should be allowed to access content of public documents."""
+    document = factories.DocumentFactory(link_reach=reach, link_role=role)
+    mock_content.return_value = {"some": "data"}
+
+    response = APIClient().get(f"/api/v1.0/documents/{document.id!s}/content/")
+
+    assert response.status_code == status.HTTP_200_OK
+    data = response.json()
+    assert data["id"] == str(document.id)
+    assert data["title"] == document.title
+    assert data["content"] == {"some": "data"}
+    mock_content.assert_called_once_with(
+        base64.b64decode(document.content),
+        "application/vnd.yjs.doc",
+        "application/json",
+    )
+
+
+@pytest.mark.parametrize(
+    "reach, doc_role, user_role",
+    [
+        ("restricted", "reader", "reader"),
+        ("restricted", "reader", "editor"),
+        ("restricted", "reader", "administrator"),
+        ("restricted", "reader", "owner"),
+        ("restricted", "editor", "reader"),
+        ("restricted", "editor", "editor"),
+        ("restricted", "editor", "administrator"),
+        ("restricted", "editor", "owner"),
+        ("authenticated", "reader", None),
+        ("authenticated", "editor", None),
+    ],
+)
+@patch("core.services.converter_services.YdocConverter.convert")
+def test_api_documents_content_not_public(mock_content, reach, doc_role, user_role):
+    """Authenticated users need access to get non-public document content."""
+    user = factories.UserFactory()
+    document = factories.DocumentFactory(link_reach=reach, link_role=doc_role)
+    mock_content.return_value = {"some": "data"}
+
+    # First anonymous request should fail
+    client = APIClient()
+    response = client.get(f"/api/v1.0/documents/{document.id!s}/content/")
+
+    assert response.status_code == status.HTTP_401_UNAUTHORIZED
+    mock_content.assert_not_called()
+
+    # Login and try again
+    client.force_login(user)
+    response = client.get(f"/api/v1.0/documents/{document.id!s}/content/")
+
+    # If restricted, we still should not have access
+    if user_role is not None:
+        assert response.status_code == status.HTTP_403_FORBIDDEN
+        mock_content.assert_not_called()
+
+        # Create an access as a reader. This should unlock the access.
+        factories.UserDocumentAccessFactory(
+            document=document, user=user, role=user_role
+        )
+
+        response = client.get(f"/api/v1.0/documents/{document.id!s}/content/")
+
+    assert response.status_code == status.HTTP_200_OK
+    data = response.json()
+    assert data["id"] == str(document.id)
+    assert data["title"] == document.title
+    assert data["content"] == {"some": "data"}
+    mock_content.assert_called_once_with(
+        base64.b64decode(document.content),
+        "application/vnd.yjs.doc",
+        "application/json",
+    )
+
+
+@pytest.mark.parametrize(
+    "content_format, accept",
+    [
+        ("markdown", "text/markdown"),
+        ("html", "text/html"),
+        ("json", "application/json"),
+    ],
+)
+@patch("core.services.converter_services.YdocConverter.convert")
+def test_api_documents_content_format(mock_content, content_format, accept):
+    """Test that the content endpoint returns a specific format."""
+    document = factories.DocumentFactory(link_reach="public")
+    mock_content.return_value = {"some": "data"}
+
+    response = APIClient().get(
+        f"/api/v1.0/documents/{document.id!s}/content/?content_format={content_format}"
+    )
+
+    assert response.status_code == status.HTTP_200_OK
+    data = response.json()
+    assert data["id"] == str(document.id)
+    assert data["title"] == document.title
+    assert data["content"] == {"some": "data"}
+    mock_content.assert_called_once_with(
+        base64.b64decode(document.content), "application/vnd.yjs.doc", accept
+    )
+
+
+@patch("core.services.converter_services.YdocConverter._request")
+def test_api_documents_content_invalid_format(mock_request):
+    """Test that the content endpoint rejects invalid formats."""
+    document = factories.DocumentFactory(link_reach="public")
+
+    response = APIClient().get(
+        f"/api/v1.0/documents/{document.id!s}/content/?content_format=invalid"
+    )
+    assert response.status_code == status.HTTP_400_BAD_REQUEST
+    mock_request.assert_not_called()
+
+
+@patch("core.services.converter_services.YdocConverter._request")
+def test_api_documents_content_yservice_error(mock_request):
+    """Test that service errors are handled properly."""
+    document = factories.DocumentFactory(link_reach="public")
+    mock_request.side_effect = requests.RequestException()
+
+    response = APIClient().get(f"/api/v1.0/documents/{document.id!s}/content/")
+    mock_request.assert_called_once()
+    assert response.status_code == status.HTTP_500_INTERNAL_SERVER_ERROR
+
+
+@patch("core.services.converter_services.YdocConverter._request")
+def test_api_documents_content_nonexistent_document(mock_request):
+    """Test that accessing a nonexistent document returns 404."""
+    client = APIClient()
+    response = client.get(
+        "/api/v1.0/documents/00000000-0000-0000-0000-000000000000/content/"
+    )
+    assert response.status_code == status.HTTP_404_NOT_FOUND
+    mock_request.assert_not_called()
+
+
+@patch("core.services.converter_services.YdocConverter._request")
+def test_api_documents_content_empty_document(mock_request):
+    """Test that accessing an empty document returns empty content."""
+    document = factories.DocumentFactory(link_reach="public", content="")
+
+    response = APIClient().get(f"/api/v1.0/documents/{document.id!s}/content/")
+
+    assert response.status_code == status.HTTP_200_OK
+    data = response.json()
+    assert data["id"] == str(document.id)
+    assert data["title"] == document.title
+    assert data["content"] is None
+    mock_request.assert_not_called()
diff --git a/src/backend/core/tests/documents/test_api_documents_retrieve.py b/src/backend/core/tests/documents/test_api_documents_retrieve.py
index b229adb5c9..63880f2e69 100644
--- a/src/backend/core/tests/documents/test_api_documents_retrieve.py
+++ b/src/backend/core/tests/documents/test_api_documents_retrieve.py
@@ -37,6 +37,7 @@ def test_api_documents_retrieve_anonymous_public_standalone():
             "children_list": True,
             "collaboration_auth": True,
             "cors_proxy": True,
+            "content": True,
             "descendants": True,
             "destroy": False,
             "duplicate": False,
@@ -112,6 +113,7 @@ def test_api_documents_retrieve_anonymous_public_parent():
             "collaboration_auth": True,
             "descendants": True,
             "cors_proxy": True,
+            "content": True,
             "destroy": False,
             "duplicate": False,
             # Anonymous user can't favorite a document even with read access
@@ -216,6 +218,7 @@ def test_api_documents_retrieve_authenticated_unrelated_public_or_authenticated(
             "collaboration_auth": True,
             "descendants": True,
             "cors_proxy": True,
+            "content": True,
             "destroy": False,
             "duplicate": True,
             "favorite": True,
@@ -297,6 +300,7 @@ def test_api_documents_retrieve_authenticated_public_or_authenticated_parent(rea
             "collaboration_auth": True,
             "descendants": True,
             "cors_proxy": True,
+            "content": True,
             "destroy": False,
             "duplicate": True,
             "favorite": True,
@@ -490,6 +494,7 @@ def test_api_documents_retrieve_authenticated_related_parent():
             "collaboration_auth": True,
             "descendants": True,
             "cors_proxy": True,
+            "content": True,
             "destroy": access.role == "owner",
             "duplicate": True,
             "favorite": True,
diff --git a/src/backend/core/tests/documents/test_api_documents_trashbin.py b/src/backend/core/tests/documents/test_api_documents_trashbin.py
index 9e80539777..66a023fdbe 100644
--- a/src/backend/core/tests/documents/test_api_documents_trashbin.py
+++ b/src/backend/core/tests/documents/test_api_documents_trashbin.py
@@ -81,6 +81,7 @@ def test_api_documents_trashbin_format():
             "collaboration_auth": True,
             "descendants": True,
             "cors_proxy": True,
+            "content": True,
             "destroy": True,
             "duplicate": True,
             "favorite": True,
diff --git a/src/backend/core/tests/test_models_documents.py b/src/backend/core/tests/test_models_documents.py
index 57427fb9c8..72d9aa574f 100644
--- a/src/backend/core/tests/test_models_documents.py
+++ b/src/backend/core/tests/test_models_documents.py
@@ -161,6 +161,7 @@ def test_models_documents_get_abilities_forbidden(
         "collaboration_auth": False,
         "descendants": False,
         "cors_proxy": False,
+        "content": False,
         "destroy": False,
         "duplicate": False,
         "favorite": False,
@@ -223,6 +224,7 @@ def test_models_documents_get_abilities_reader(
         "collaboration_auth": True,
         "descendants": True,
         "cors_proxy": True,
+        "content": True,
         "destroy": False,
         "duplicate": is_authenticated,
         "favorite": is_authenticated,
@@ -287,6 +289,7 @@ def test_models_documents_get_abilities_editor(
         "collaboration_auth": True,
         "descendants": True,
         "cors_proxy": True,
+        "content": True,
         "destroy": False,
         "duplicate": is_authenticated,
         "favorite": is_authenticated,
@@ -340,6 +343,7 @@ def test_models_documents_get_abilities_owner(django_assert_num_queries):
         "collaboration_auth": True,
         "descendants": True,
         "cors_proxy": True,
+        "content": True,
         "destroy": True,
         "duplicate": True,
         "favorite": True,
@@ -390,6 +394,7 @@ def test_models_documents_get_abilities_administrator(django_assert_num_queries)
         "collaboration_auth": True,
         "descendants": True,
         "cors_proxy": True,
+        "content": True,
         "destroy": False,
         "duplicate": True,
         "favorite": True,
@@ -443,6 +448,7 @@ def test_models_documents_get_abilities_editor_user(django_assert_num_queries):
         "collaboration_auth": True,
         "descendants": True,
         "cors_proxy": True,
+        "content": True,
         "destroy": False,
         "duplicate": True,
         "favorite": True,
@@ -503,6 +509,7 @@ def test_models_documents_get_abilities_reader_user(
         "collaboration_auth": True,
         "descendants": True,
         "cors_proxy": True,
+        "content": True,
         "destroy": False,
         "duplicate": True,
         "favorite": True,
@@ -561,6 +568,7 @@ def test_models_documents_get_abilities_preset_role(django_assert_num_queries):
         "collaboration_auth": True,
         "descendants": True,
         "cors_proxy": True,
+        "content": True,
         "destroy": False,
         "duplicate": True,
         "favorite": True,
diff --git a/src/backend/core/tests/test_services_converter_services.py b/src/backend/core/tests/test_services_converter_services.py
index 01773f8570..086d132b35 100644
--- a/src/backend/core/tests/test_services_converter_services.py
+++ b/src/backend/core/tests/test_services_converter_services.py
@@ -1,4 +1,4 @@
-"""Test converter services."""
+"""Test y-provider services."""
 
 from base64 import b64decode
 from unittest.mock import MagicMock, patch
@@ -84,6 +84,42 @@ def test_convert_full_integration(mock_post, settings):
         headers={
             "Authorization": "Bearer test-key",
             "Content-Type": "text/markdown",
+            "Accept": "application/vnd.yjs.doc",
+        },
+        timeout=5,
+        verify=False,
+    )
+
+
+@patch("requests.post")
+def test_convert_full_integration_with_specific_headers(mock_post, settings):
+    """Test successful conversion with specific content type and accept headers."""
+    settings.Y_PROVIDER_API_BASE_URL = "http://test.com/"
+    settings.Y_PROVIDER_API_KEY = "test-key"
+    settings.CONVERSION_API_ENDPOINT = "conversion-endpoint"
+    settings.CONVERSION_API_TIMEOUT = 5
+    settings.CONVERSION_API_SECURE = False
+
+    converter = YdocConverter()
+
+    expected_response = "# Test Document\n\nThis is test content."
+    mock_response = MagicMock()
+    mock_response.text = expected_response
+    mock_response.raise_for_status.return_value = None
+    mock_post.return_value = mock_response
+
+    result = converter.convert(
+        b"test_content", "application/vnd.yjs.doc", "text/markdown"
+    )
+
+    assert result == expected_response
+    mock_post.assert_called_once_with(
+        "http://test.com/conversion-endpoint/",
+        data=b"test_content",
+        headers={
+            "Authorization": "Bearer test-key",
+            "Content-Type": "application/vnd.yjs.doc",
+            "Accept": "text/markdown",
         },
         timeout=5,
         verify=False,
diff --git a/src/frontend/servers/y-provider/__tests__/convert.test.ts b/src/frontend/servers/y-provider/__tests__/convert.test.ts
index 67de07cf1f..44c21c2870 100644
--- a/src/frontend/servers/y-provider/__tests__/convert.test.ts
+++ b/src/frontend/servers/y-provider/__tests__/convert.test.ts
@@ -18,6 +18,9 @@ import {
   COLLABORATION_SERVER_ORIGIN as origin,
 } from '../src/env';
 
+const expectedMarkdown = '# Example document\n\nLorem ipsum dolor sit amet.';
+const expectedHTML =
+  '<h1>Example document</h1><p>Lorem ipsum dolor sit amet.</p>';
 const expectedBlocks = [
   {
     children: [],
@@ -121,23 +124,43 @@ describe('Server Tests', () => {
     });
   });
 
+  test('POST /api/convert with unsupported Content-Type returns 415', async () => {
+    const app = initApp();
+    const response = await request(app)
+      .post('/api/convert')
+      .set('origin', origin)
+      .set('authorization', apiKey)
+      .set('content-type', 'image/png')
+      .send('randomdata');
+    expect(response.status).toBe(415);
+    expect(response.body).toStrictEqual({ error: 'Unsupported Content-Type' });
+  });
+
+  test('POST /api/convert with unsupported Accept returns 406', async () => {
+    const app = initApp();
+    const response = await request(app)
+      .post('/api/convert')
+      .set('origin', origin)
+      .set('authorization', apiKey)
+      .set('content-type', 'text/markdown')
+      .set('accept', 'image/png')
+      .send('# Header');
+    expect(response.status).toBe(406);
+    expect(response.body).toStrictEqual({ error: 'Unsupported format' });
+  });
+
   test.each([[apiKey], [`Bearer ${apiKey}`]])(
     'POST /api/convert with correct content with Authorization: %s',
     async (authHeader) => {
       const app = initApp();
 
-      const document = [
-        '# Example document',
-        '',
-        'Lorem ipsum dolor sit amet.',
-        '',
-      ].join('\n');
-
       const response = await request(app)
         .post('/api/convert')
         .set('Origin', origin)
         .set('Authorization', authHeader)
-        .send(document);
+        .set('content-type', 'text/markdown')
+        .set('accept', 'application/vnd.yjs.doc')
+        .send(expectedMarkdown);
 
       expect(response.status).toBe(200);
       expect(response.body).toBeInstanceOf(Buffer);
@@ -150,4 +173,95 @@ describe('Server Tests', () => {
       expect(blocks).toStrictEqual(expectedBlocks);
     },
   );
+
+  test('POST /api/convert Yjs to HTML', async () => {
+    const app = initApp();
+    const editor = ServerBlockNoteEditor.create();
+    const blocks = await editor.tryParseMarkdownToBlocks(expectedMarkdown);
+    const yDocument = editor.blocksToYDoc(blocks, 'document-store');
+    const yjsUpdate = Y.encodeStateAsUpdate(yDocument);
+    const response = await request(app)
+      .post('/api/convert')
+      .set('origin', origin)
+      .set('authorization', apiKey)
+      .set('content-type', 'application/vnd.yjs.doc')
+      .set('accept', 'text/html')
+      .send(Buffer.from(yjsUpdate));
+    expect(response.status).toBe(200);
+    expect(response.header['content-type']).toBe('text/html; charset=utf-8');
+    expect(typeof response.text).toBe('string');
+    expect(response.text).toBe(expectedHTML);
+  });
+
+  test('POST /api/convert Yjs to Markdown', async () => {
+    const app = initApp();
+    const editor = ServerBlockNoteEditor.create();
+    const blocks = await editor.tryParseMarkdownToBlocks(expectedMarkdown);
+    const yDocument = editor.blocksToYDoc(blocks, 'document-store');
+    const yjsUpdate = Y.encodeStateAsUpdate(yDocument);
+    const response = await request(app)
+      .post('/api/convert')
+      .set('origin', origin)
+      .set('authorization', apiKey)
+      .set('content-type', 'application/vnd.yjs.doc')
+      .set('accept', 'text/markdown')
+      .send(Buffer.from(yjsUpdate));
+    expect(response.status).toBe(200);
+    expect(response.header['content-type']).toBe(
+      'text/markdown; charset=utf-8',
+    );
+    expect(typeof response.text).toBe('string');
+    expect(response.text.trim()).toBe(expectedMarkdown);
+  });
+
+  test('POST /api/convert Yjs to JSON', async () => {
+    const app = initApp();
+    const editor = ServerBlockNoteEditor.create();
+    const blocks = await editor.tryParseMarkdownToBlocks(expectedMarkdown);
+    const yDocument = editor.blocksToYDoc(blocks, 'document-store');
+    const yjsUpdate = Y.encodeStateAsUpdate(yDocument);
+    const response = await request(app)
+      .post('/api/convert')
+      .set('origin', origin)
+      .set('authorization', apiKey)
+      .set('content-type', 'application/vnd.yjs.doc')
+      .set('accept', 'application/json')
+      .send(Buffer.from(yjsUpdate));
+    expect(response.status).toBe(200);
+    expect(response.header['content-type']).toBe(
+      'application/json; charset=utf-8',
+    );
+    expect(Array.isArray(response.body)).toBe(true);
+    expect(response.body).toStrictEqual(expectedBlocks);
+  });
+
+  test('POST /api/convert Markdown to JSON', async () => {
+    const app = initApp();
+    const response = await request(app)
+      .post('/api/convert')
+      .set('origin', origin)
+      .set('authorization', apiKey)
+      .set('content-type', 'text/markdown')
+      .set('accept', 'application/json')
+      .send(expectedMarkdown);
+    expect(response.status).toBe(200);
+    expect(response.header['content-type']).toBe(
+      'application/json; charset=utf-8',
+    );
+    expect(Array.isArray(response.body)).toBe(true);
+    expect(response.body).toStrictEqual(expectedBlocks);
+  });
+
+  test('POST /api/convert with invalid Yjs content returns 400', async () => {
+    const app = initApp();
+    const response = await request(app)
+      .post('/api/convert')
+      .set('origin', origin)
+      .set('authorization', apiKey)
+      .set('content-type', 'application/vnd.yjs.doc')
+      .set('accept', 'application/json')
+      .send(Buffer.from('notvalidyjs'));
+    expect(response.status).toBe(400);
+    expect(response.body).toStrictEqual({ error: 'Invalid Yjs content' });
+  });
 });
diff --git a/src/frontend/servers/y-provider/package.json b/src/frontend/servers/y-provider/package.json
index 7364781bfc..6a89231815 100644
--- a/src/frontend/servers/y-provider/package.json
+++ b/src/frontend/servers/y-provider/package.json
@@ -10,7 +10,7 @@
     "dev": "cross-env COLLABORATION_LOGGING=true && nodemon --config nodemon.json",
     "start": "node ./dist/start-server.js",
     "lint": "eslint . --ext .ts",
-    "test": "vitest --run"
+    "test": "vitest --run --disable-console-intercept"
   },
   "engines": {
     "node": ">=22"
diff --git a/src/frontend/servers/y-provider/src/handlers/convertHandler.ts b/src/frontend/servers/y-provider/src/handlers/convertHandler.ts
index 15bab784d5..9d8cd237c8 100644
--- a/src/frontend/servers/y-provider/src/handlers/convertHandler.ts
+++ b/src/frontend/servers/y-provider/src/handlers/convertHandler.ts
@@ -1,3 +1,4 @@
+import { PartialBlock } from '@blocknote/core';
 import { ServerBlockNoteEditor } from '@blocknote/server-util';
 import { Request, Response } from 'express';
 import * as Y from 'yjs';
@@ -12,29 +13,79 @@ const editor = ServerBlockNoteEditor.create();
 
 export const convertHandler = async (
   req: Request<object, Uint8Array | ErrorResponse, Buffer, object>,
-  res: Response<Uint8Array | ErrorResponse>,
+  res: Response<Uint8Array | string | object | ErrorResponse>,
 ) => {
   if (!req.body || req.body.length === 0) {
     res.status(400).json({ error: 'Invalid request: missing content' });
     return;
   }
 
-  try {
-    // Perform the conversion from markdown to Blocknote.js blocks
-    const blocks = await editor.tryParseMarkdownToBlocks(req.body.toString());
+  const contentType = (req.header('content-type') || 'text/markdown').split(
+    ';',
+  )[0];
+  const accept = (req.header('accept') || 'application/vnd.yjs.doc').split(
+    ';',
+  )[0];
 
+  let blocks: PartialBlock[] | null = null;
+  try {
+    // First, convert from the input format to blocks
+    // application/x-www-form-urlencoded is interpreted as Markdown for backward compatibility
+    if (
+      contentType === 'text/markdown' ||
+      contentType === 'application/x-www-form-urlencoded'
+    ) {
+      blocks = await editor.tryParseMarkdownToBlocks(req.body.toString());
+    } else if (
+      contentType === 'application/vnd.yjs.doc' ||
+      contentType === 'application/octet-stream'
+    ) {
+      try {
+        const ydoc = new Y.Doc();
+        Y.applyUpdate(ydoc, req.body);
+        blocks = editor.yDocToBlocks(ydoc, 'document-store') as PartialBlock[];
+      } catch (e) {
+        logger('Invalid Yjs content:', e);
+        res.status(400).json({ error: 'Invalid Yjs content' });
+        return;
+      }
+    } else {
+      res.status(415).json({ error: 'Unsupported Content-Type' });
+      return;
+    }
     if (!blocks || blocks.length === 0) {
       res.status(500).json({ error: 'No valid blocks were generated' });
       return;
     }
 
-    // Create a Yjs Document from blocks
-    const yDocument = editor.blocksToYDoc(blocks, 'document-store');
+    // Then, convert from blocks to the output format
+    if (accept === 'application/json') {
+      res.status(200).json(blocks);
+    } else {
+      const yDocument = editor.blocksToYDoc(blocks, 'document-store');
 
-    res
-      .status(200)
-      .setHeader('content-type', 'application/octet-stream')
-      .send(Y.encodeStateAsUpdate(yDocument));
+      if (
+        accept === 'application/vnd.yjs.doc' ||
+        accept === 'application/octet-stream'
+      ) {
+        res
+          .status(200)
+          .setHeader('content-type', 'application/octet-stream')
+          .send(Y.encodeStateAsUpdate(yDocument));
+      } else if (accept === 'text/markdown') {
+        res
+          .status(200)
+          .setHeader('content-type', 'text/markdown')
+          .send(await editor.blocksToMarkdownLossy(blocks));
+      } else if (accept === 'text/html') {
+        res
+          .status(200)
+          .setHeader('content-type', 'text/html')
+          .send(await editor.blocksToHTMLLossy(blocks));
+      } else {
+        res.status(406).json({ error: 'Unsupported format' });
+      }
+    }
   } catch (e) {
     logger('conversion failed:', e);
     res.status(500).json({ error: 'An error occurred' });
diff --git a/src/frontend/servers/y-provider/src/servers/appServer.ts b/src/frontend/servers/y-provider/src/servers/appServer.ts
index 0c355fee8e..c9807bf783 100644
--- a/src/frontend/servers/y-provider/src/servers/appServer.ts
+++ b/src/frontend/servers/y-provider/src/servers/appServer.ts
@@ -49,7 +49,7 @@ export const initApp = () => {
   );
 
   /**
-   * Route to convert Markdown or BlockNote blocks
+   * Route to convert Markdown or BlockNote blocks and Yjs content
    */
   app.post(
     routes.CONVERT,