OpenBMB/ChatDev · error · ValueError

Node {node.id} missing passthrough configuration

Error message

Node {node.id} missing passthrough configuration

What it means

A passthrough node must carry a PassthroughConfig; as_config returned None so the executor can't read its (optional) behavior settings and treats the node as misconfigured.

Source

Thrown at runtime/node/executor/passthrough_executor.py:20

from typing import List

from entity.configs import Node
from entity.configs.node.passthrough import PassthroughConfig
from entity.messages import Message, MessageRole
from runtime.node.executor.base import NodeExecutor


class PassthroughNodeExecutor(NodeExecutor):
    """Forward input messages without modifications."""

    def execute(self, node: Node, inputs: List[Message]) -> List[Message]:
        if node.node_type != "passthrough":
            raise ValueError(f"Node {node.id} is not a passthrough node")

        config = node.as_config(PassthroughConfig)
        if config is None:
            raise ValueError(f"Node {node.id} missing passthrough configuration")

        if not inputs:
            warning_msg = f"Passthrough node '{node.id}' triggered without inputs"
            self.log_manager.warning(warning_msg, node_id=node.id, details={"input_count": 0})
            return [Message(content="", role=MessageRole.USER)]

        if config.only_last_message:
            if len(inputs) > 1:
                self.log_manager.debug(
                    f"Passthrough node '{node.id}' received {len(inputs)} inputs; forwarding the latest entry",
                    node_id=node.id,
                    details={"input_count": len(inputs)},
                )
            return [inputs[-1].clone()]
        else:
            return [msg.clone() for msg in inputs]

View on GitHub (pinned to 4fb2db0ea9)

Solutions

1. Include a PassthroughConfig (even an empty/default one) on the node
2. Validate node configs before execution
3. Regenerate workflows with the current builder so defaults are materialized

Example fix

# before
Node(id='p1', node_type='passthrough')

# after
Node(id='p1', node_type='passthrough', config={})  # or PassthroughConfig()

assert node.as_config(PassthroughConfig) is not None

When it happens

Trigger: Executing a 'passthrough' node with no config payload at all.

Common situations: Workflow builders that create passthrough nodes as bare edges; schema drift; hand-edited workflow JSON dropping empty config objects.

Related errors

• Node {node.id} has no human configuration
• Node {node.id} missing literal configuration
• Node {node.id} missing loop_counter configuration
• Node {node.id} missing loop_timer configuration
• Node {node.id} is not a passthrough node

AI-assisted analysis of OpenBMB/ChatDev@4fb2db0ea9 (2026-08-27). Data as JSON: /api/errors/54caf8471f2c71a3. Report an issue: GitHub.