OpenBB-finance/OpenBB · error · OpenBBError

Invalid JSON format for 'filters_dict': {e}

Error message

Invalid JSON format for 'filters_dict': {e}

What it means

Raised when the `filters_dict` parameter is passed as a string but json.loads fails with JSONDecodeError. The query model accepts either a dict or a serialized JSON string; if a string, it must be parseable JSON. Common JSON syntax faults (trailing commas, single quotes, unquoted keys) trigger this.

Source

Thrown at openbb_platform/providers/finviz/openbb_finviz/models/equity_screener.py:166

        """Check to reject running template file."""
        if v is not None and v == "screener_template":
            raise OpenBBError(
                f"Invalid preset '{v}'. Please rename the file to use as a preset."
            )
        return v if v else None

    @field_validator("filters_dict", mode="before", check_fields=False)
    @classmethod
    def validate_filters_dict(cls, v):
        """Validate the filters_dict."""
        if isinstance(v, str):
            # pylint: disable=import-outside-toplevel
            import json

            try:
                v = json.loads(v)
            except json.JSONDecodeError as e:
                raise OpenBBError(f"Invalid JSON format for 'filters_dict': {e}") from e
        if v is not None and not isinstance(v, dict):
            raise OpenBBError(
                "Invalid 'filters_dict' format. Must be a dictionary or serialized JSON string."
            )

        return v


class FinvizEquityScreenerData(EquityScreenerData):
    """Finviz Equity Screener Data. Actual returned data varies by the 'metric' parameter."""

    __alias_dict__ = {
        "symbol": "Ticker",
        "name": "Company",
        "earnings_date": "Earnings",
        "sector": "Sector",
        "industry": "Industry",
        "country": "Country",

View on GitHub (pinned to 3e071fcc2c)

Solutions

  1. Pass a real dict instead of a string when using the Python API
  2. If a string is required (CLI), produce it with json.dumps, not str()
  3. Validate the string parses with json.loads before sending

Example fix

# before
q = FinvizEquityScreenerQueryParams(filters_dict="{'Debt/Equity': 'Over 0.5'}")  # single quotes

# after
import json
q = FinvizEquityScreenerQueryParams(filters_dict={"Debt/Equity": "Over 0.5"})
# or on the CLI: --filters_dict '{"Debt/Equity": "Over 0.5"}'
Defensive patterns

Strategy: validation

Validate before calling

import json

if isinstance(filters_dict, str):
    json.loads(filters_dict)  # raises early with a clear JSONDecodeError if malformed
# better: pass a dict and let json.dumps handle serialization when needed

Type guard

def is_valid_filters_json(v) -> bool:
    if isinstance(v, dict):
        return True
    if isinstance(v, str):
        try:
            return isinstance(json.loads(v), dict)
        except json.JSONDecodeError:
            return False
    return False

Try / catch

import json
from openbb_core.app.model.obb_error import OpenBBError

try:
    q = FinvizEquityScreenerQueryParams(filters_dict=filters_dict)
except OpenBBError as e:
    if "Invalid JSON" in str(e):
        filters_dict = json.dumps(dict_from_elsewhere)  # rebuild correctly
        q = FinvizEquityScreenerQueryParams(filters_dict=filters_dict)
    else:
        raise

Prevention

When it happens

Trigger: Passing filters_dict="{'Debt/Equity': 'Over 0.5'}" (Python repr, single quotes); trailing commas; unquoted keys; a truncated string from shell escaping issues on the CLI.

Common situations: Building the JSON via f-strings or str(dict) instead of json.dumps; shell quoting on the CLI that eats inner double quotes; LLM- or template-generated filter strings.

Understand the failure class

Related errors

AI-assisted analysis of OpenBB-finance/OpenBB@3e071fcc2c (2026-08-14). Data as JSON: /api/errors/7c7d5d18a64b46df. Report an issue: GitHub.