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MarketInputs is the frozen dataclass you pass to every OIPD fitting method. It captures the risk-free rate, valuation date, and optional market data such as the underlying price. When you fetch an option chain with sources.fetch_chain, the returned VendorSnapshot carries the vendor’s price data and download timestamp — you can use it to populate MarketInputs with minimal boilerplate. 
from oipd import MarketInputs

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MarketInputs

MarketInputs is a frozen dataclass. All fields are set at construction and cannot be modified afterward. The valuation_date field is normalized to a pd.Timestamp with intraday precision when the object is created. 
from oipd import MarketInputs

market = MarketInputs(
    risk_free_rate=0.053,
    valuation_date="2025-04-01",
    underlying_price=512.40,
)

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Fields

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risk_free_rate
float
required
The risk-free interest rate used for option pricing and forward price calculation. Interpretation depends on risk_free_rate_mode. For "annualized" mode, provide the simple annualized nominal rate (e.g., 0.053 for 5.3%). For "continuous" mode, provide the continuously compounded rate.
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valuation_date
DateTimeLike
required
The pricing date. Accepts str (ISO format, e.g., "2025-04-01"), Python date, Python datetime, or pd.Timestamp. The value is normalized to a timezone-naive pd.Timestamp on construction.
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risk_free_rate_mode
Literal['annualized', 'continuous']
default:"\"annualized\""
Specifies how risk_free_rate is quoted. "annualized" treats the rate as a simple annualized nominal rate on an ACT/365 basis. "continuous" treats it as a continuously compounded rate.
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underlying_price
float | None
default:"None"
Current price of the instrument the options are written on. For equity or ETF spot options (Black-Scholes), this is the cash spot price S. For options on futures (Black-76), this is the current futures price F of the relevant contract. Required when calling VolCurve.fit, VolSurface.fit, or any probability method.
By default, you do not need to enter dividends. OIPD infers the forward price from put-call parity and uses Black-76 for IV inversion. The fitted forward already reflects the market’s expected carry, including dividends.

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VendorSnapshot

VendorSnapshot is a frozen dataclass returned by sources.fetch_chain. It records the point-in-time market data retrieved from the vendor, including the underlying price and the time of download. 
from oipd import VendorSnapshot

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Fields

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asof
datetime
required
Timestamp of when the data was downloaded from the vendor.
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vendor
str
required
Vendor name string. For the default integration, this is "yfinance".
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underlying_price
float | None
default:"None"
Underlying asset price reported by the vendor at the time of download.

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Examples

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Manual

Use MarketInputs directly when you have your own market data. 
from oipd import MarketInputs

market = MarketInputs(
    risk_free_rate=0.053,
    valuation_date="2025-04-01",
    underlying_price=512.40,
)

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Vendor snapshot

When you use sources.fetch_chain, the returned VendorSnapshot provides the data you need to build MarketInputs with one step. 
from oipd import MarketInputs, sources

chain, snapshot = sources.fetch_chain("SPY", horizon="3m")

market = MarketInputs(
    risk_free_rate=0.053,
    valuation_date=snapshot.asof,            # datetime from vendor
    underlying_price=snapshot.underlying_price,
)

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Rate convention

from oipd import MarketInputs

market = MarketInputs(
    risk_free_rate=0.0516,
    valuation_date="2025-04-01",
    risk_free_rate_mode="continuous",
    underlying_price=512.40,
)
MarketInputs is frozen. Once created, none of its fields can be modified. To change any parameter, create a new instance.