add offset param (#9977)

server.py

@@ -645,7 +645,14 @@ class PromptServer():
             max_items = request.rel_url.query.get("max_items", None)
             if max_items is not None:
                 max_items = int(max_items)
-            return web.json_response(self.prompt_queue.get_history(max_items=max_items))
+
+            offset = request.rel_url.query.get("offset", None)
+            if offset is not None:
+                offset = int(offset)
+            else:
+                offset = -1
+
+            return web.json_response(self.prompt_queue.get_history(max_items=max_items, offset=offset))
 
         @routes.get("/history/{prompt_id}")
         async def get_history_prompt_id(request):

tests/execution/test_execution.py

@@ -84,6 +84,21 @@ class ComfyClient:
         with urllib.request.urlopen("http://{}/history/{}".format(self.server_address, prompt_id)) as response:
             return json.loads(response.read())
 
+    def get_all_history(self, max_items=None, offset=None):
+        url = "http://{}/history".format(self.server_address)
+        params = {}
+        if max_items is not None:
+            params["max_items"] = max_items
+        if offset is not None:
+            params["offset"] = offset
+
+        if params:
+            url_values = urllib.parse.urlencode(params)
+            url = "{}?{}".format(url, url_values)
+
+        with urllib.request.urlopen(url) as response:
+            return json.loads(response.read())
+
     def set_test_name(self, name):
         self.test_name = name
 
@@ -498,7 +513,6 @@ class TestExecution:
         assert len(images1) == 1, "Should have 1 image"
         assert len(images2) == 1, "Should have 1 image"
 
-
     # This tests that only constant outputs are used in the call to `IS_CHANGED`
     def test_is_changed_with_outputs(self, client: ComfyClient, builder: GraphBuilder):
         g = builder
@@ -762,3 +776,92 @@ class TestExecution:
         except urllib.error.HTTPError:
             pass  # Expected behavior
 
+    def _create_history_item(self, client, builder):
+        g = GraphBuilder(prefix="offset_test")
+        input_node = g.node(
+            "StubImage", content="BLACK", height=32, width=32, batch_size=1
+        )
+        g.node("SaveImage", images=input_node.out(0))
+        return client.run(g)
+
+    def test_offset_returns_different_items_than_beginning_of_history(
+        self, client: ComfyClient, builder: GraphBuilder
+    ):
+        """Test that offset skips items at the beginning"""
+        for _ in range(5):
+            self._create_history_item(client, builder)
+
+        first_two = client.get_all_history(max_items=2, offset=0)
+        next_two = client.get_all_history(max_items=2, offset=2)
+
+        assert set(first_two.keys()).isdisjoint(
+            set(next_two.keys())
+        ), "Offset should skip initial items"
+
+    def test_offset_beyond_history_length_returns_empty(
+        self, client: ComfyClient, builder: GraphBuilder
+    ):
+        """Test offset larger than total history returns empty result"""
+        self._create_history_item(client, builder)
+
+        result = client.get_all_history(offset=100)
+        assert len(result) == 0, "Large offset should return no items"
+
+    def test_offset_at_exact_history_length_returns_empty(
+        self, client: ComfyClient, builder: GraphBuilder
+    ):
+        """Test offset equal to history length returns empty"""
+        for _ in range(3):
+            self._create_history_item(client, builder)
+
+        all_history = client.get_all_history()
+        result = client.get_all_history(offset=len(all_history))
+        assert len(result) == 0, "Offset at history length should return empty"
+
+    def test_offset_zero_equals_no_offset_parameter(
+        self, client: ComfyClient, builder: GraphBuilder
+    ):
+        """Test offset=0 behaves same as omitting offset"""
+        self._create_history_item(client, builder)
+
+        with_zero = client.get_all_history(offset=0)
+        without_offset = client.get_all_history()
+
+        assert with_zero == without_offset, "offset=0 should equal no offset"
+
+    def test_offset_without_max_items_skips_from_beginning(
+        self, client: ComfyClient, builder: GraphBuilder
+    ):
+        """Test offset alone (no max_items) returns remaining items"""
+        for _ in range(4):
+            self._create_history_item(client, builder)
+
+        all_items = client.get_all_history()
+        offset_items = client.get_all_history(offset=2)
+
+        assert (
+            len(offset_items) == len(all_items) - 2
+        ), "Offset should skip specified number of items"
+
+    def test_offset_with_max_items_returns_correct_window(
+        self, client: ComfyClient, builder: GraphBuilder
+    ):
+        """Test offset + max_items returns correct slice of history"""
+        for _ in range(6):
+            self._create_history_item(client, builder)
+
+        window = client.get_all_history(max_items=2, offset=1)
+        assert len(window) <= 2, "Should respect max_items limit"
+
+    def test_offset_near_end_returns_remaining_items_only(
+        self, client: ComfyClient, builder: GraphBuilder
+    ):
+        """Test offset near end of history returns only remaining items"""
+        for _ in range(3):
+            self._create_history_item(client, builder)
+
+        all_history = client.get_all_history()
+        # Offset to near the end
+        result = client.get_all_history(max_items=5, offset=len(all_history) - 1)
+
+        assert len(result) <= 1, "Should return at most 1 item when offset is near end"