HKUDS/Vibe-Trading · error · UsdMObservationError

Binance USD-M margin mode is missing

Error message

Binance USD-M margin mode is missing

What it means

The account row's isolated field must be a real boolean (true/false). If it is missing, None, or arrives as the string "true"/"false" or "isolated"/"cross", isinstance(isolated, bool) fails and this error is raised.

Source

Thrown at agent/src/trading/connectors/binance/usdm.py:199

            ),
        )
        if any(open_order_margins):
            raise UsdMObservationError("Binance USD-M Shadow Account requires zero open-order margin")
        for account_field, risk_field in (
            ("positionInitialMargin", "positionInitialMargin"),
            ("maintMargin", "maintMargin"),
            ("unrealizedProfit", "unRealizedProfit"),
        ):
            if not close_enough(
                _number(account_row.get(account_field), account_field),
                _number(risk_row.get(risk_field), risk_field),
            ):
                raise UsdMObservationError("Binance USD-M position reads are incoherent")
        if str(risk_row.get("marginAsset") or "").upper() != "USDT":
            raise UsdMObservationError("Binance USD-M Shadow Account supports USDT collateral only")
        isolated = account_row.get("isolated")
        if not isinstance(isolated, bool):
            raise UsdMObservationError("Binance USD-M margin mode is missing")
        isolated_margin = _number(
            risk_row.get("isolatedMargin"),
            "isolatedMargin",
            non_negative=True,
        )
        if isolated and isolated_margin == 0:
            raise UsdMObservationError("Binance USD-M isolated position requires positive isolated margin")
        if not isolated and isolated_margin != 0:
            raise UsdMObservationError("Binance USD-M cross position must report zero isolated margin")
        result.append(
            {
                "symbol": _canonical_symbol(raw_symbol),
                "quantity": quantity,
                "entry_price": entry_price,
                "leverage": _number(account_row.get("leverage"), "leverage", positive=True),
                "margin_mode": "isolated" if isolated else "cross",
                "isolated_margin": isolated_margin if isolated else None,
                "unrealized_pnl": _number(risk_row.get("unRealizedProfit"), "unRealizedProfit"),

View on GitHub (pinned to 80ffdda44c)

Solutions

  1. Log the raw account row to see what type isolated actually is
  2. If a proxy/transform layer converts booleans, fix it to preserve native JSON types
  3. Update the library if Binance changed the field format
  4. In tests/fixtures, use real booleans for isolated

Example fix

# before (fixture)
{"symbol": "BTCUSDT", "isolated": "true", ...}
# after
{"symbol": "BTCUSDT", "isolated": true, ...}
Defensive patterns

Strategy: validation

Validate before calling

acct = await client.futures_account()
for p in acct['positions']:
    if not isinstance(p.get('isolated'), bool):
        raise RuntimeError(f"isolated field not boolean for {p['symbol']}: {p.get('isolated')!r}")

Type guard

def has_boolean_isolated(row: dict) -> bool:
    return isinstance(row.get('isolated'), bool)

Try / catch

try:
    obs = await connector.read_account_observation()
except UsdMObservationError as e:
    if "margin mode is missing" in str(e):
        logger.error("response middleware likely mangled booleans: %r", e)
    raise

Prevention

When it happens

Trigger: Binance changing the field's JSON type (e.g. serializing it as a string), a middleware/proxy mangling the response, or a mocked/test payload using strings instead of booleans.

Common situations: Version drift after a Binance API change; response post-processing (custom JSON normalization) converting booleans to strings; incomplete test fixtures.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

AI-assisted analysis of HKUDS/Vibe-Trading@80ffdda44c (2026-08-28). Data as JSON: /api/errors/32dbde17dd0186d4. Report an issue: GitHub.