invoke-ai/InvokeAI · error · InvalidEdgeError

One or both nodes don't exist ({edge})

Error message

One or both nodes don't exist ({edge})

What it means

InvalidEdgeError raised by _get_edge_nodes() when either the source or destination node of an edge cannot be found (NodeNotFoundError). It converts the low-level lookup failure into an edge-level validation error naming the edge. Called by edge validators that need both endpoint nodes.

Source

Thrown at invokeai/app/services/shared/graph.py:1917

            InvalidEdgeError,
        ):
            return False
        except Exception as e:
            raise UnknownGraphValidationError(f"Problem validating graph {e}") from e

    def _is_destination_field_Any(self, edge: Edge) -> bool:
        """Checks if the destination field for an edge is of type typing.Any"""
        return get_input_field_type(self.get_node(edge.destination.node_id), edge.destination.field) == Any

    def _is_destination_field_list_of_Any(self, edge: Edge) -> bool:
        """Checks if the destination field for an edge is of type typing.Any"""
        return get_input_field_type(self.get_node(edge.destination.node_id), edge.destination.field) == list[Any]

    def _get_edge_nodes(self, edge: Edge) -> tuple[BaseInvocation, BaseInvocation]:
        try:
            return self.get_node(edge.source.node_id), self.get_node(edge.destination.node_id)
        except NodeNotFoundError:
            raise InvalidEdgeError(f"One or both nodes don't exist ({edge})")

    def _validate_edge_destination_uniqueness(self, edge: Edge, destination_node: BaseInvocation) -> None:
        input_edges = self._get_input_edges(edge.destination.node_id, edge.destination.field)
        if len(input_edges) > 0 and (
            not isinstance(destination_node, CollectInvocation) or edge.destination.field != ITEM_FIELD
        ):
            raise InvalidEdgeError(f"Edge already exists ({edge})")

    def _validate_edge_would_not_create_cycle(self, edge: Edge) -> None:
        graph = self.nx_graph_flat()
        graph.add_edge(edge.source.node_id, edge.destination.node_id)
        if not nx.is_directed_acyclic_graph(graph):
            raise InvalidEdgeError(f"Edge creates a cycle in the graph ({edge})")

    def _validate_edge_field_compatibility(
        self, edge: Edge, source_node: BaseInvocation, destination_node: BaseInvocation
    ) -> None:
        if isinstance(destination_node, CallSavedWorkflowInvocation) and is_call_saved_workflow_dynamic_input(

View on GitHub (pinned to 0b6a024f2f)

Solutions

1. Add the missing node to the graph before creating the edge
2. Delete dangling edges referencing the removed node
3. Verify node id strings match exactly (they are case/whitespace sensitive)
4. Run validate_self() on deserialized workflows to surface dangling edges early

Example fix

// before
g.add_edge("res_1", "image", "save_1", "image")  # save_1 not added
// after
g.add_node(save_image_node)  # id "save_1"
g.add_edge("res_1", "image", "save_1", "image")

def edge_nodes_exist(graph, edge) -> bool:
    return (
        edge.source.node_id in graph.nodes
        and edge.destination.node_id in graph.nodes
    )

assert all(edge_nodes_exist(g, e) for e in g.edges), "dangling edges present"

def is_connectable(graph, source_id: str, dest_id: str) -> bool:
    return source_id in graph.nodes and dest_id in graph.nodes

from invokeai.app.services.shared.graph import InvalidEdgeError

try:
    g.add_edge(src, "image", dst, "image")
except InvalidEdgeError as e:
    if "don't exist" in str(e):
        add_missing_nodes_and_retry()
    raise

When it happens

Trigger: Adding or validating an edge whose edge.source.node_id or edge.destination.node_id is not present in graph.nodes — e.g. g.add_edge(a, "image", b, "image") where b was never added, or after removing a node while its edges remain.

Common situations: Hand-built graphs where a node was forgotten, deleting nodes without deleting their edges (hand-edited JSON), wrong node id strings, subgraphs referenced with mismatched ids.

Related errors

• The selected saved workflow must contain exactly one workflo
• Edge source and target types do not match ({edge})
• Edge already exists ({edge})
• Edge creates a cycle in the graph ({edge})
• Field types are incompatible ({edge})

AI-assisted analysis of invoke-ai/InvokeAI@0b6a024f2f (2026-08-29). Data as JSON: /api/errors/2630bd566b039cb3. Report an issue: GitHub.