HKUDS/Vibe-Trading · error · Trading212APIError

Trading 212 API returned invalid JSON.

Error message

Trading 212 API returned invalid JSON.

What it means

Raised by _request when the HTTP response has content but response.json() raises ValueError, i.e. the server returned a 2xx body that is not valid JSON. The chained exception holds the parser detail.

Source

Thrown at agent/src/trading/connectors/trading212/sdk.py:438

            url,
            headers=headers,
            auth=auth,
            params=dict(params or {}),
            timeout=config.timeout,
        )
    except requests.RequestException as exc:
        raise Trading212APIError(f"Trading 212 request failed: {exc}") from exc

    if response.status_code in (401, 403):
        raise Trading212APIError("Trading 212 API authentication failed: check api_key/api_secret.")
    if response.status_code >= 400:
        raise Trading212APIError(f"Trading 212 API returned HTTP {response.status_code}: {_error_message(response)}")
    if not response.content:
        return None
    try:
        return response.json()
    except ValueError as exc:
        raise Trading212APIError("Trading 212 API returned invalid JSON.") from exc


def _error_message(response: requests.Response) -> str:
    try:
        payload = response.json()
    except ValueError:
        return response.text.strip() or response.reason or "request failed"
    if isinstance(payload, Mapping):
        for key in ("message", "error", "detail", "title"):
            value = payload.get(key)
            if value:
                return str(value)
    return str(payload)


def _missing_fields(config: Trading212Config) -> list[str]:
    missing = []
    if not config.api_key:

View on GitHub (pinned to 80ffdda44c)

Solutions

1. Retry the request — truncated/garbled responses are often transient
2. Log response headers and a body snippet to identify what non-JSON payload came back (proxy page vs API body)
3. If a proxy/WAF is intercepting, bypass or configure it for the Trading 212 host
4. Report/check the Trading 212 status page if it persists account-wide

try:
    data = get_account_metadata(config)
except Trading212APIError as exc:
    if "invalid JSON" in str(exc):
        data = get_account_metadata(config)  # one retry; often transient truncation
    else:
        raise

When it happens

Trigger: Any _get call where the API (or an intermediary proxy) returns 200 with an HTML error page, plain-text body, truncated JSON, or a gateway interstitial instead of JSON.

Common situations: Captive portal / proxy injecting an HTML page; CDN or WAF challenge page; truncated response on flaky connections; API incident returning non-JSON payloads.

Understand the failure class

Background: "Invalid JSON response" and "Failed to parse response" errors: when an API answers 200 but the body isn't the JSON your library expected — this error's family across 28 libraries.

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• invalid JSON response: {exc}
• invalid Trading 212 config at {path}: {exc}
• Trading 212 request failed: {exc}
• Trading 212 API returned HTTP {response.status_code}: {_erro
• Feishu QR login requires a JSON agent config; use ~/.vibe-tr

AI-assisted analysis of HKUDS/Vibe-Trading@80ffdda44c (2026-08-28). Data as JSON: /api/errors/152423ce2860dd9d. Report an issue: GitHub.