Options Greeks API MCP: One Live Greek Feed for Excel and Your AI Assistant (2026)

Options Greeks API MCP is the piece most options workflows are missing right now. If you have ever asked an AI assistant for an option's Delta in one window, then opened Excel to roll that Delta up across a whole book in another, you already know the friction: two surfaces, two data pulls, and a quiet worry that the Greeks do not agree. This guide closes that gap. It shows how to point both your AI agent, through the Model Context Protocol (MCP), and your Excel workbook at one licensed feed of Delta, Gamma, Theta, Vega, and Rho through MarketXLS, so a Greek you read in a chat answer is calculated once and read everywhere. It also ships two ready-to-use Excel templates that turn a list of positions into a net Greek profile and a full stress test.

This is an educational walkthrough, not investment advice. The tickers below are examples of how the data and formulas behave, not recommendations. Options carry substantial risk and are not suitable for every investor.

Options Greeks API MCP at a Glance

Here is the core idea in one table. Each Greek can be requested by an AI agent through MCP or written as an Excel formula. Both routes call the identical MarketXLS function against one licensed feed, so the numbers match to the decimal.

The value is not any single number. It is that the assistant and the spreadsheet share one source, calculated one way, so nothing has to be reconciled by hand.

Why the Greeks, Specifically

Prices tell you where an option is. The Greeks tell you how it will move. For anyone holding more than one contract, the Greeks are the real position, and they are what an API and an MCP server should hand you first.

• Delta is directional exposure: how much the option value changes for a $1 move in the underlying. Sum it across a book and you get share-equivalent exposure.
• Gamma is the rate of change of Delta. High net Gamma means your directional exposure shifts quickly, so a hedge needs frequent adjustment.
• Theta is daily time decay. Net Theta is the profit or loss the book earns or pays each day from the passage of time alone.
• Vega is sensitivity to implied volatility. Net Vega is your exposure to a volatility repricing, the thing that moves hardest around earnings and macro events.
• Rho is sensitivity to the risk-free rate. It is usually the smallest Greek for short-dated equity options, but it matters for LEAPS and in a moving-rate environment.

A single Greek on a single contract is easy to eyeball. The hard part, and the part that benefits most from an API plus a spreadsheet, is rolling five Greeks up across many legs and then stressing the total. That is exactly what the templates in this post do.

What the MCP Path Does Well

The Model Context Protocol is how an AI assistant such as Claude or an OpenAI agent calls external tools. When MarketXLS runs as an MCP server, the assistant can request the same licensed options data that powers the Excel functions. That has three honest strengths.

1. Speed of question. Natural language is faster than typing a symbol string. "What is the net Delta if I add ten more of the Aug 230 calls?" is a sentence, not a spreadsheet edit.
2. Exploration. An assistant is good at scanning a chain, surfacing the highest-Gamma strikes, or explaining why Theta accelerates near expiration.
3. One feed. Because the assistant calls the same functions the workbook uses, the Delta it quotes is the Delta your sheet will show. No second data provider, no reconciliation.

Where the MCP path is weaker is structure and auditability. A chat answer is a snapshot in a conversation. It does not persist as a model you can version, hand to a colleague, or stress across a grid of scenarios. That is where Excel earns its place.

Where Excel Takes a Different Path

Excel is not competing with the assistant. It is the durable, auditable surface for the same data. A workbook holds your actual positions, recalculates every Greek on open, rolls them into a net book profile, and lets you stress the total across spot, volatility, and time. It is the difference between asking about a Greek and owning a living model of your Greeks.

The bridge between the two is that both read one feed. The next sections show the exact formulas, then the templates that assemble them.

The MarketXLS Greek Formulas, Verified

Every formula below is a real, current MarketXLS function. The five per-contract Greeks share one signature:

=opt_Delta(CurrentStockPrice, MarketOptionPrice, ExpiryDate, OptionType, StrikePrice, [RiskFreeRate], [ImpliedVolatility])
=opt_Gamma(CurrentStockPrice, MarketOptionPrice, ExpiryDate, OptionType, StrikePrice, ...)
=opt_Theta(CurrentStockPrice, MarketOptionPrice, ExpiryDate, OptionType, StrikePrice, ...)
=opt_Vega(CurrentStockPrice, MarketOptionPrice, ExpiryDate, OptionType, StrikePrice, ...)
=opt_Rho(CurrentStockPrice, MarketOptionPrice, ExpiryDate, OptionType, StrikePrice, ...)

To feed them, you need the underlying price and the contract's market price. MarketXLS gives you both, plus a helper that builds the QuoteMedia option symbol every contract-level function expects:

=QM_Last("AAPL")
=OptionSymbol("AAPL", DATE(2026,8,21), "Call", 230)   ' -> @AAPL  260821C00230000
=QM_Last(OptionSymbol("AAPL", DATE(2026,8,21), "Call", 230))

Put them together and one cell returns a live Delta for a specific contract:

=opt_Delta(QM_Last("AAPL"), QM_Last(OptionSymbol("AAPL",DATE(2026,8,21),"Call",230)), DATE(2026,8,21), "Call", 230)

If you would rather pull the whole chain with every Greek in a single spill, use the array function that anchors the AI-assistant answer too:

=QM_GetOptionQuotesAndGreeks("AAPL")

That one call returns bid, ask, last, volume, open interest, implied volatility, and all five Greeks for the chain. A few more that the templates lean on:

None of these are invented. Each maps to a MarketXLS function you can verify in the MarketXLS function docs, and each is a primitive the MCP server can expose to an assistant.

Building the Net Portfolio Greek Roll-Up

A single contract's Greeks are only step one. The exposure that matters is the book. Standard US equity options represent 100 shares, so the position-level math is straightforward:

Position Delta = per-contract Delta x contracts x 100
Net Delta      = sum of every leg's position Delta

The same pattern rolls up Gamma, Theta, Vega, and Rho. In Excel, once each leg has its per-contract Greek in a column, the net book Greek is one formula:

=SUMPRODUCT(DeltaRange, ContractsRange) * 100

A worked example makes it concrete. Suppose the book is long 10 AAPL Aug 230 calls and short 8 AAPL Aug 210 puts. The calls carry positive Delta; the short puts also carry positive Delta (a short put is a bullish position), so the net Delta is clearly long. But the short puts add negative Gamma and positive Theta, while the long calls add positive Gamma and negative Theta. Only the roll-up tells you which way the totals land. That is the number a hedger acts on, and it is the same number whether you asked your assistant or read your sheet.

The Template: Two Files, One Feed

This post ships two Excel files. Both carry MarketXLS branding, a "MarketXLS Functions Used" box on every sheet, and links back to the site.

Download the templates:

• - pre-filled with a data-date snapshot so you can see the layout and the formula behind each cell
• - every data cell is a live MarketXLS formula that updates on open

Both workbooks share seven sheets:

The Inputs sheet

Everything you edit lives here, in yellow cells with a gold border. Set the focus ticker, the expiry, the risk-free rate, and the implied-volatility shock the scenario sheet uses. Below the settings, the Positions table is your book: one row per leg, with ticker, Call or Put, strike, and contract count. A negative contract count marks a short leg. A covered call, a put spread, a collar, or a mixed multi-name book all fit the same table.

The Portfolio Greeks sheet

This is the heart of the workbook and the reason the Greeks belong in an API and a spreadsheet, not just a chat window. Six KPI tiles report the net Delta, Gamma, Theta, Vega, and Rho of the whole book, plus the net premium paid or collected. Below them, a table shows each leg with its per-contract Greeks and its position-weighted contribution, so you can see at a glance which leg drives your directional, convexity, decay, or volatility exposure. In the template file each cell is a live formula such as:

=opt_Vega(QM_Last("NVDA"), QM_Last(OptionSymbol("NVDA",DATE(2026,8,21),"Call",160)), DATE(2026,8,21), "Call", 160)

The net row uses SUMPRODUCT to weight each Greek by its contract count, then multiplies by the 100-share multiplier.

The Greeks Option Chain sheet

For the focus ticker, this sheet builds an at-the-money ladder and shows Delta, Gamma, Theta, Vega, and Rho at each strike for both calls and puts, with implied volatility alongside. It is the single-name view you use to pick a strike before you add it to the book. Every cell is an opt_ formula built on OptionSymbol(), and a note points you to QM_GetOptionQuotesAndGreeks() when you want the entire chain in one spill.

The Greek Scenario sheet

Greeks are abstract until you price them. This sheet re-prices the whole book across underlying moves from -15 percent to +15 percent, then shows how a volatility shock and the passage of time reshape the same totals. You see the dollar impact of a gap, a volatility spike, or a week of decay before it happens. A P/L curve chart plots the book across the move so the shape of the exposure, not just the numbers, is obvious. The model is an educational Black-Scholes approximation; a live book will differ because each contract sits on its own point of the volatility surface.

How the AI Assistant and the Workbook Stay in Sync

The reason the two surfaces agree is simple: they call the same functions. When the MarketXLS MCP server is connected, an assistant that answers "the AAPL Aug 230 call has a Delta of 0.42" is calling the same licensed Greek calculation that fills cell for cell in your workbook. Change the underlying price and both update from the same feed. There is no second data vendor to reconcile and no copy-paste step where a number can drift.

A practical workflow looks like this:

1. Ask the assistant to scan a name and surface the strikes with the Greeks you want.
2. Drop those legs into the Inputs sheet of the template.
3. Read the net book Greeks on the Portfolio Greeks sheet.
4. Stress the total on the Greek Scenario sheet before you act.

The assistant is the fast front door; the workbook is the durable model. One feed underneath keeps them honest.

Common Mistakes This Setup Avoids

• Mixing data sources. Pulling Greeks from one provider for the assistant and another for Excel guarantees mismatches. One feed removes the problem.
• Reading Greeks one contract at a time. The exposure that matters is the net book. A roll-up is not optional for multi-leg positions.
• Ignoring the sign on short legs. A short put is long Delta and short Gamma. The template handles the sign through the contract count so you do not have to flip it in your head.
• Treating a scenario as a prediction. The Greek Scenario sheet is analysis, not a forecast. It shows what would happen under an assumption, not what will happen.

Frequently Asked Questions

What is an options Greeks API MCP?

It is the combination of an options data API that returns the Greeks (Delta, Gamma, Theta, Vega, Rho) and a Model Context Protocol server that exposes those same calls to an AI assistant. With MarketXLS, the API powers Excel functions and the MCP server powers the assistant, both reading one licensed feed, so the Greeks match across both surfaces.

Which Greeks does MarketXLS return?

All five. opt_Delta, opt_Gamma, opt_Theta, opt_Vega, and opt_Rho each return a single Greek for a single contract, while QM_GetOptionQuotesAndGreeks returns the full chain with all five Greeks, plus bid, ask, last, volume, open interest, and implied volatility.

How do I build the option symbol the Greek functions need?

Use OptionSymbol(Ticker, ExpiryDate, "Call" or "Put", Strike). For example, =OptionSymbol("AAPL", DATE(2026,8,21), "Call", 230) returns the QuoteMedia symbol @AAPL 260821C00230000, which you then pass to QM_Last or any Greek function.

Can I roll the Greeks up across a whole portfolio?

Yes, and that is what the Portfolio Greeks sheet does. Each leg's per-contract Greek is multiplied by its contract count and the 100-share multiplier, then summed with SUMPRODUCT to give net Delta, Gamma, Theta, Vega, and Rho for the book.

Are the Greeks live or static?

Both files are available. The template version uses live MarketXLS formulas that recalculate on open. The sample version holds a data-date snapshot so you can study the layout and see the formula behind every value.

Do the assistant and the spreadsheet ever disagree?

Not on the data, because they call the same licensed functions. Small display differences can appear from rounding or from a contract with little time value where a Greek rounds to zero, but the underlying calculation is identical.

The Bottom Line

Options Greeks API MCP is not about a flashier chat answer or a prettier spreadsheet. It is about one licensed feed of Delta, Gamma, Theta, Vega, and Rho serving two surfaces, so the Greek your assistant quotes is the Greek your workbook rolls up, and the net book exposure you stress is built on the same numbers. Ask fast in natural language, model durably in Excel, and never reconcile two providers again. Download the two templates above, drop in your positions, and read your net Greeks in one view.

To see the full library of options and Greek functions, or to connect the MCP server to your AI assistant, visit MarketXLS or book a demo.