BerriAI/litellm · warning · HTTPException

Fixed margin amount for {provider} must be a number

Error message

Fixed margin amount for {provider} must be a number

What it means

Validation error (HTTP 400) from PATCH /config/cost_margin_config in the complex dict format: the optional 'fixed_amount' field is present but is not an int/float. fixed_amount is an absolute dollar surcharge added per request, so it must be a bare number.

Source

Thrown at litellm/proxy/management_endpoints/cost_tracking_settings.py:390

                )
        elif isinstance(margin_value, dict):
            # Complex format: {"percentage": 0.08, "fixed_amount": 0.0005}
            if "percentage" in margin_value:
                percentage = margin_value["percentage"]
                if not isinstance(percentage, (int, float)):
                    raise HTTPException(
                        status_code=400,
                        detail=f"Margin percentage for {provider} must be a number",
                    )
                if not (0 <= percentage <= 10):
                    raise HTTPException(
                        status_code=400,
                        detail=f"Margin percentage for {provider} must be between 0 and 10 (0% to 1000%)",
                    )
            if "fixed_amount" in margin_value:
                fixed_amount = margin_value["fixed_amount"]
                if not isinstance(fixed_amount, (int, float)):
                    raise HTTPException(
                        status_code=400,
                        detail=f"Fixed margin amount for {provider} must be a number",
                    )
                if fixed_amount < 0:
                    raise HTTPException(
                        status_code=400,
                        detail=f"Fixed margin amount for {provider} must be non-negative",
                    )
            if not margin_value:  # Empty dict
                raise HTTPException(
                    status_code=400,
                    detail=f"Margin config for {provider} cannot be empty. Must include 'percentage' and/or 'fixed_amount'",
                )
        else:
            raise HTTPException(
                status_code=400,
                detail=f"Margin for {provider} must be a number (percentage) or dict with 'percentage' and/or 'fixed_amount'",
            )

View on GitHub (pinned to 77b7c6c40c)

Solutions

1. Send fixed_amount as a bare number: {"fixed_amount": 0.001}.
2. Cast with float() when constructing payloads from string sources.
3. Omit the key if you don't want a fixed component.

Example fix

# before
{"openai": {"fixed_amount": "0.001"}}

# after
{"openai": {"fixed_amount": 0.001}}

for provider, margin in cost_margin_config.items():
    if isinstance(margin, dict) and "fixed_amount" in margin:
        fa = margin["fixed_amount"]
        if isinstance(fa, str):
            margin["fixed_amount"] = fa = float(fa)
        assert isinstance(fa, (int, float)) and not isinstance(fa, bool), f"{provider}.fixed_amount must be numeric"

def is_valid_fixed_amount(m: dict) -> bool:
    return "fixed_amount" not in m or (
        isinstance(m["fixed_amount"], (int, float))
        and not isinstance(m["fixed_amount"], bool)
        and m["fixed_amount"] >= 0
    )

When it happens

Trigger: Sending {"fixed_amount": "0.001"} (string), null, or a list; template/env-driven values that arrive as strings.

Common situations: Currency values pasted as strings from billing configs; JSON built via string templates where every value is quoted.

Related errors

• Discount for {provider} must be a number
• Margin percentage for {provider} must be a number
• Margin for {provider} must be a number (percentage) or dict
• Invalid provider(s): {', '.join(invalid_providers)}. Must be
• Discount for {provider} must be between 0 and 1 (0% to 100%)

AI-assisted analysis of BerriAI/litellm@77b7c6c40c (2026-08-18). Data as JSON: /api/errors/df3a6824c591e96a. Report an issue: GitHub.