OpenBMB/ChatDev · error · DesignError

No node types registered; cannot validate workflow

Error message

No node types registered; cannot validate workflow

What it means

Raised by the POST /api/tools/local endpoint when the request body's filename field is empty or only whitespace after stripping. It is a 400 Bad Request from FastAPI's HTTPException, meaning the client omitted the required filename for creating a local function-calling tool file.

Source

Thrown at check/check.py:26

from check.check_workflow import check_workflow_structure
from entity.config_loader import prepare_design_mapping
from entity.configs import DesignConfig, ConfigError
from schema_registry import iter_node_schemas
from utils.io_utils import read_yaml


ensure_schema_registry_populated()


class DesignError(RuntimeError):
    """Raised when a workflow design cannot be loaded or validated."""



def _allowed_node_types() -> set[str]:
    names = set(iter_node_schemas().keys())
    if not names:
        raise DesignError("No node types registered; cannot validate workflow")
    return names


def _ensure_supported(graph: Dict[str, Any]) -> None:
    """Ensure the MVP constraints are satisfied for the provided graph."""
    for node in graph.get("nodes", []) or []:
        nid = node.get("id")
        ntype = node.get("type")
        allowed = _allowed_node_types()
        if ntype not in allowed:
            raise DesignError(
                f"Unsupported node type '{ntype}' for node '{nid}'. Only {allowed} nodes are supported."
            )
        if ntype == "agent":
            agent_cfg = node.get("config") or {}
            if not isinstance(agent_cfg, dict):
                raise DesignError(f"Agent node '{nid}' config must be an object")
            for legacy_key in ["memory"]:

View on GitHub (pinned to 4fb2db0ea9)

Solutions

  1. Supply a non-empty filename in the JSON body, e.g. {"filename": "my_tool"}.
  2. Trim client-side and disable the submit button until the name field is filled.
  3. If the field is optional in your flow, generate a default name like f"tool_{uuid4().hex[:8]}".

Example fix

// before
fetch('/api/tools/local', {method:'POST', body: JSON.stringify({filename: nameInput.value})})
// after
const name = nameInput.value.trim();
if (!name) throw new Error('filename required');
fetch('/api/tools/local', {method:'POST', body: JSON.stringify({filename: name, content: code})})
Defensive patterns

Strategy: validation

Validate before calling

const name = (req.body.filename ?? '').trim();
if (!name) return res.status(400).send('filename required');

Try / catch

catch (e) { if (e.status === 400 && e.detail === 'filename is required') { /* prompt user for name */ } }

Prevention

When it happens

Trigger: POST /api/tools/local with {"filename": ""} or {"filename": " "} (whitespace only) or omitting the field entirely if the Pydantic model defaults it to an empty string.

Common situations: Frontend forms submitting before the user typed a name; scripts that build the payload from an empty variable; JSON typos like "file_name" causing the default empty value to be used.

Related errors

AI-assisted analysis of OpenBMB/ChatDev@4fb2db0ea9 (2026-08-27). Data as JSON: /api/errors/b5ed6e3607b43724. Report an issue: GitHub.