Best GEX API 2026: FlashAlpha vs SpotGamma vs Unusual Whales

TL;DR: Best GEX API 2026 at a Glance

Verdict: if you are a developer, quant, or AI agent that wants gamma exposure as JSON over HTTP, the FlashAlpha GEX API is the only one of these four with a public, documented REST endpoint, broad ticker coverage, and a free tier. SpotGamma is a dashboard with the strongest discretionary-trader brand. Unusual Whales is a flow platform that ships GEX as a secondary product. SqueezeMetrics is the SPX research benchmark.

Pricing for all four vendors changes. The numbers above are accurate as of publication and reflect each vendor's public pricing pages. Always check the live page before committing.

What Is a GEX API and What Should It Return

Gamma exposure (GEX) is the dollar amount that dealers must buy or sell for every 1% move in the underlying, given the open interest they are short to retail. It is the single most-watched options-market-structure number on the desk. The full primer is in the what is gamma exposure article.

A GEX API is a programmatic interface that returns this number, plus the per-strike breakdown that produced it, plus the levels traders actually act on. A dashboard with no documented endpoint is not a GEX API. A CSV download with no live refresh is not a GEX API. A vendor that requires a sales call before you can read the spec is not, in practical terms, a GEX API for developers.

The minimum capability set for a real GEX API:

• Per-strike GEX for the requested symbol, calls and puts separated, with open interest and volume per strike.
• Net GEX for the symbol, expressed in dollars per 1% underlying move.
• Key levels derived from the gamma profile: gamma flip, call wall, put wall, highest-OI strike, 0DTE magnet.
• Regime label (positive vs negative gamma) so you can branch trading logic without writing your own threshold.
• Public REST endpoint with a documented response shape and a rate-limit policy you can program against.
• Authentication by API key, not OAuth, not session cookie, not a scraped HTML page.
• Historical replay with point-in-time semantics, so the same code that runs live also runs against any past minute without lookahead.
• SDK or at least curl-friendly examples so a developer can go from sign-up to first call in under five minutes.

Most GEX vendors meet some of these. Only one in this list meets all of them. That gap is the whole reason this article exists.

If you only care about a snapshot for a single symbol on a single day, any of the four products in this comparison can produce a number. If you care about programmatic access, broad ticker coverage, point-in-time backtesting, and a price tier that does not require a sales call, the field narrows fast.

FlashAlpha GEX API

The FlashAlpha GEX API is the developer-first answer to gamma exposure data. Single endpoint, documented JSON response, free tier with no credit card, official SDKs in five languages, and an MCP server that lets AI assistants query GEX directly.

Endpoint and Companion Endpoints

The FlashAlpha GEX API surface is built around a small number of orthogonal endpoints, all under https://lab.flashalpha.com:

• GET /v1/exposure/gex/{symbol} - per-strike gamma exposure, net GEX, regime, by-strike call and put OI
• GET /v1/exposure/levels/{symbol} - gamma flip, call wall, put wall, highest OI strike, 0DTE magnet
• GET /v1/exposure/dex/{symbol} - delta exposure by strike
• GET /v1/exposure/vex/{symbol} - vanna exposure by strike
• GET /v1/exposure/chex/{symbol} - charm exposure by strike
• GET /v1/exposure/summary/{symbol} - net GEX/DEX/VEX/CHEX, regime, and dealer hedging estimates for plus/minus 1% moves
• GET /v1/exposure/zero-dte/{symbol} - same-day-expiry pin risk, expected move, gamma acceleration
• GET /v1/maxpain/{symbol} - max pain analysis with dealer alignment overlay

Historical replay of every endpoint is available at https://historical.flashalpha.com/v1/exposure/gex/{symbol}?at=YYYY-MM-DDTHH:mm:ss on the Alpha tier, with point-in-time semantics for any minute since 2017-01-03 (Alpha-tier coverage; check /v1/tickers for the current backfilled list).

Sample FlashAlpha GEX API Response

GET https://lab.flashalpha.com/v1/exposure/gex/SPY
X-Api-Key: YOUR_API_KEY

{
  "symbol": "SPY",
  "spot_price": 583.42,
  "as_of": "2026-05-09T20:00:00Z",
  "net_gex": 1847293000,
  "net_gex_label": "positive",
  "gamma_flip": 578.50,
  "call_wall": 595.00,
  "put_wall": 570.00,
  "regime": "positive_gamma",
  "strikes": [
    {"strike": 575.0, "gex": -185000000, "call_oi": 42100, "put_oi": 78400, "volume": 21850},
    {"strike": 580.0, "gex":  245000000, "call_oi": 88200, "put_oi": 51100, "volume": 33420},
    {"strike": 585.0, "gex":  312000000, "call_oi": 102400, "put_oi": 38900, "volume": 41250},
    {"strike": 590.0, "gex":  198000000, "call_oi": 76300, "put_oi": 22100, "volume": 18900},
    {"strike": 595.0, "gex":  421000000, "call_oi": 134800, "put_oi": 12500, "volume": 28100}
  ]
}

One call, one symbol, the entire dealer-positioning picture. No options-chain ingestion, no Greeks engine, no dealer-positioning model, no aggregation logic on your side. The GEX trading guide walks through what to do with this response in a strategy.

Strengths

• Public REST API with free tier. Sign up, get an API key in seconds, make five calls a day forever with no credit card. The only vendor in this list that lets you go from "what is gamma exposure" to a working integration without spending money.
• Broad coverage. 6,000+ US equities and ETFs across the platform; 250 names with sub-10-second refresh on the screener tier.
• SDKs in five languages. Python (pip install flashalpha), JavaScript, C#, Go, Java, all with typed responses.
• MCP server for AI agents. Claude, Cursor, and Windsurf can query the FlashAlpha GEX API natively over Model Context Protocol; the only options-analytics platform with first-class AI agent support.
• Historical replay with leak-free semantics. Same response shapes live and historical; ?at= on every endpoint; identical SDK code runs against both.
• Beyond GEX. DEX, VEX, CHEX, SVI vol surfaces, VRP analytics, max pain, and a real-time multi-factor screener are part of the same API.

Weaknesses

• Streaming is commercial-only. Standard FlashAlpha plans are REST polling, with cache TTLs of seconds to a minute depending on tier; WebSocket streaming of computed metrics is a commercial tier (from $4,500/mo, see flashalpha.com/streaming). Raw sub-second tick feeds are not offered.
• US equity options only. No futures options, no FX options, no foreign listings.
• Pre-2017 historical data not available. The minute-resolution backfill starts 2017-01-03.

The full FlashAlpha vs Polygon comparison covers the build-vs-buy tradeoff for developers who are choosing between raw chains and computed analytics.

SpotGamma

SpotGamma is the institutional-flavour brand of the gamma exposure world. Twice-daily Founder's Notes, a polished web dashboard, the HIRO real-time hedging-impact indicator, and a TRACE heatmap that has become the visual shorthand for SPX dealer positioning on FinTwit.

Strengths

• Brand. When mainstream finance media writes about "gamma walls" on SPX, they usually cite SpotGamma. That brand is real and reflects genuine product depth on indices.
• Discretionary-trader UX. The dashboard and Equity Hub are designed for screen-time. Most users come in for the daily SPY/SPX levels and the morning note, not for an API.
• HIRO indicator. Real-time options hedging-impact oscillator is a unique signal. There is nothing else like it in the retail space.
• Coverage on Equity Hub. 3,500+ stocks and ETFs at the Pro tier, which is broader than most discretionary traders need.
• Platform integrations. Key levels are available inside TrendSpider, Bookmap, NinjaTrader, Sierra Chart, TradingView, and ThinkorSwim, which is a real distribution moat.

Weaknesses

• No public REST API for retail or developer tiers. SpotGamma's product is the dashboard. There are partner integrations and an institutional dashboard, but for a developer who wants a documented public REST endpoint they can hit with curl, this is not it.
• No raw SVI parameters or surface arbitrage detection in the dashboard. The discretionary trader does not need them; the quant does.
• Index-tilted. The Essential tier is largely SPX/SPY/QQQ/IWM with the Equity Hub gated to higher tiers.
• Subscription model is per-seat, not per-call. Fine for one trader, awkward for a team that wants to embed the data into a research pipeline.

SpotGamma's strength is exactly the thing that makes it not a GEX API: it is a polished, opinionated discretionary product. If you want the morning narrative, you want SpotGamma. If you want JSON, you want a different vendor.

Unusual Whales

Unusual Whales is the flow platform. It made its name on options order flow, dark pool data, and the politician-trading tracker. Gamma exposure is on the platform, but it is a secondary product layered on top of the flow-and-darkpool DNA.

Strengths

• Real flow + GEX bundle. If your edge involves cross-referencing block trades with dealer positioning, no other product packages both in one subscription.
• Broad equity coverage. Per-stock greek-exposure pages exist for thousands of US tickers, including a public read-only page for SPY and a sample FREE page so non-subscribers can see what the data looks like.
• API access exists. api.unusualwhales.com with OpenAPI spec, including a per-strike spot exposure endpoint at /api/stock/{ticker}/spot-exposures/strike. Auth is bearer-token over HTTPS.
• Affordable retail entry. Lower retail tiers are accessible to individual traders; the platform's marketing leans on retail accessibility.
• Dark pool data. Unique to the platform; not part of any GEX-only vendor's offering.

Weaknesses

• API access is gated to the upper tier. The API is real, but it is reserved for the higher-priced subscription. The low-priced retail entry is dashboard-only.
• GEX is a secondary product. The platform was built around flow and dark pools. The GEX page is good, but it is not the marketing centrepiece, and the team's investment is visibly weighted toward flow features.
• No SVI surfaces, no VRP analytics, no historical-replay-with-leak-free-percentiles. The depth that quant work needs beyond per-strike GEX is not the focus.
• Pricing changes. Tier names and prices have shifted multiple times; verify on the live pricing page.

Unusual Whales is the right answer for traders whose primary signal is flow and who want GEX as confirmation. It is not the right answer for a quant who wants gamma exposure as the primary signal and the supporting analytics depth that goes with it. The deeper SpotGamma vs Unusual Whales comparison goes into the discretionary side-by-side.

SqueezeMetrics

SqueezeMetrics is the original GEX research source. The 2017 white paper and the public DIX (Dark Index) page on sqzme.co are why a generation of options traders even know what gamma exposure is. The methodology has been cited in academic and practitioner work for nearly a decade.

Strengths

• Research depth on SPX. The white paper is still the best free introduction to the structural argument for why dealer gamma matters.
• Free historical CSV downloads. SqueezeMetrics releases historical GEX and DIX data publicly, which is unusual generosity for a paid signal vendor.
• Pure-research positioning. No flow scanner, no Discord, no dashboard fluff. The product is the number.
• Component GEX aggregate. The aggregate gamma of SPX components, which is a different methodology from index-options GEX and useful as a sanity check.

Weaknesses

• SPX-only. The paid signal is structured around SPX and SPX-component aggregates. There is no per-stock real-time GEX feed for individual equities.
• No public REST API. Subscribers receive the signal via the SqueezeMetrics monitor and CSV; there is no documented programmatic endpoint that a developer can hit with curl.
• Subscription pricing is opaque. Public references suggest the signal is in the $200 to $1,000/mo range, but pricing is not as transparent as competitor public pages.
• No live replay with point-in-time semantics. CSV files are flat snapshots. Building a backtesting harness that respects the no-lookahead constraint is on you.

SqueezeMetrics is the academic benchmark. It is not, in 2026, a developer API for gamma exposure on the broad market. If you only care about SPX dealer gamma at a research level, it remains a credible source. If you want a per-stock GEX feed for 6,000 names with a documented endpoint, it is not the tool.

Decision Rule: When to Use Which

• If you need a REST API with broad ticker coverage and a free tier: the FlashAlpha GEX API. This is the only one in the list that meets all three.
• If you only trade SPX/SPY and want institutional commentary plus a real-time HIRO indicator: SpotGamma. Their dashboard product is best in class for the discretionary index trader.
• If your primary signal is options flow and dark pools, with GEX as confirmation: Unusual Whales. The flow + GEX bundle is unique.
• If you are doing academic research on SPX dealer gamma and want historical CSV at zero cost: SqueezeMetrics. The white paper and free historical data are still the canonical reference.

For most developer use cases (trading bots, dashboards, AI agents, research pipelines, SaaS products that overlay GEX on charts), the FlashAlpha GEX API is the only option in this comparison that matches the question. The other three are excellent products, but they are answering different questions.

Full Feature Comparison

The pattern is clear: FlashAlpha optimises for breadth of computed analytics and developer access. SpotGamma and Unusual Whales optimise for discretionary trader experience, with API access as a secondary or upper-tier feature. SqueezeMetrics optimises for SPX-research depth.

Pricing Comparison

Pricing changes. The numbers below are accurate as of publication. For commitments, always verify on each vendor's live pricing page before subscribing.

FlashAlpha (annual / monthly)

• Free ($0): 5 req/day, no card, single-expiry GEX, key levels, BSM Greeks, IV solver, vol surface. Live host only.
• Basic ($63/mo annual, $79/mo monthly): 250 req/day. Adds ETFs and index symbols (SPY, QQQ, SPX, VIX), DEX/VEX/CHEX, max pain.
• Growth ($239/mo annual, $299/mo monthly): 2,500 req/day. Adds option quotes, full-chain GEX, 0DTE analytics, volatility analytics, narrative, Kelly sizing, screener.
• Alpha ($1,199/mo annual, $1,499/mo monthly): Unlimited req/day. Adds advanced volatility (SVI parameters, variance surfaces, arb detection, greeks surfaces), VRP analytics, near-real-time ~1 s snapshots, and the full Historical API at historical.flashalpha.com with point-in-time replay on 51 analytics routes.
• Commercial tiers (Professional, Streaming, custom Enterprise): Professional from $2,500/mo is a dedicated options-analytics node for a hedge fund or prop desk's own internal research and trading; Streaming from $4,500/mo adds real-time WebSocket push of 500+ metrics (bundled dedicated node + streaming compute); Enterprise is custom. All are internal use only, with no redistribution.

See the FlashAlpha pricing page for current tiers and upgrade triggers.

SpotGamma (per public pricing pages)

SpotGamma's published consumer tiers, on annual billing, are roughly Essential ($74/mo), Pro ($97/mo), and Alpha ($224/mo). Monthly billing is higher. The Alpha tier adds the HIRO real-time indicator and the TRACE heatmap. Institutional pricing is sales-quoted and not publicly listed. Verify on spotgamma.com/subscribe-to-spotgamma.

Unusual Whales (per public pricing pages)

Unusual Whales runs a tiered retail subscription, with the entry tier in the $50/mo range and the upper tier (which includes API access) priced higher. Specific tier names and prices have shifted across the platform's history; verify on unusualwhales.com/pricing. API access is gated to the upper tier.

SqueezeMetrics

SqueezeMetrics's paid signal is positioned in the institutional-research range, public references put it between roughly $200 and $1,000/mo depending on the package. Historical CSV data is available free at squeezemetrics.com/monitor.

The cost-per-API-call comparison is the relevant frame for developers. FlashAlpha is the only vendor in this list that exposes a documented per-call price tier with a free entry; the others sell a subscription bundle where the API (where it exists at all) is one feature among many.

FAQ

What is the best GEX API in 2026?

For developers, quants, and AI agents that want gamma exposure as JSON over HTTP, the FlashAlpha GEX API at https://lab.flashalpha.com/v1/exposure/gex/{symbol} is the only option in the comparison set with a public, documented REST endpoint, broad ticker coverage (6,000+ US equities and ETFs), a free tier, and historical replay with point-in-time semantics. SpotGamma is the strongest discretionary-trader brand but has no public REST API for retail; Unusual Whales has an API but it is gated to the upper tier and GEX is a secondary product; SqueezeMetrics is an SPX-only research signal without a developer API.

Is there a free GEX API?

Yes. The FlashAlpha GEX API has a permanent free tier (5 requests per day, no credit card, no time limit) that returns single-expiry GEX, key levels (gamma flip, call wall, put wall), and BSM Greeks. It is the only vendor in this comparison with a free programmatic tier. SqueezeMetrics releases historical CSV files for free, but there is no live free API. SpotGamma and Unusual Whales do not offer a free programmatic tier.

What is the best SpotGamma alternative for developers?

For developers specifically, the FlashAlpha GEX API is the SpotGamma alternative that matches the question. SpotGamma is a polished discretionary-trader dashboard; FlashAlpha is a developer-first REST API. They overlap on the underlying analytics (gamma flip, call wall, put wall, regime label) but the delivery model is different. If your goal is to integrate GEX into a Python script, a trading bot, an AI agent, a research pipeline, or a SaaS product, the FlashAlpha GEX API is the more natural fit. If your goal is to read a daily morning note and watch a real-time hedging-impact indicator on a screen, SpotGamma's dashboard is purpose-built for that.

Does Unusual Whales have a GEX API?

Yes. Unusual Whales exposes api.unusualwhales.com with an OpenAPI spec; the per-strike spot exposure endpoint at /api/stock/{ticker}/spot-exposures/strike returns gamma, delta, vanna, and charm exposure per strike. Authentication is bearer-token over HTTPS. The catch is that API access is gated to the upper retail tier, and GEX is a secondary product to the platform's flow-and-dark-pool focus. If you are already a flow trader and want GEX as confirmation, the bundle works. If you are a quant whose primary signal is gamma exposure, FlashAlpha's GEX API is the more focused tool.

Can I get GEX for any stock?

For broad single-stock coverage, yes. The FlashAlpha GEX API covers 6,000+ US equities and ETFs and returns per-strike gamma exposure for any of them via GET /v1/exposure/gex/{symbol}. SpotGamma's Equity Hub covers around 3,500 stocks and ETFs at the Pro tier. Unusual Whales covers a broad set of US equities. SqueezeMetrics is SPX-only at the signal level. For any single ticker outside SPX, FlashAlpha's coverage is the broadest in the comparison set.

Is there an MCP server for GEX data?

Yes, FlashAlpha provides an MCP (Model Context Protocol) server at https://lab.flashalpha.com/mcp with 73 native tools: 56 live tools including GEX, DEX, VEX, CHEX, key levels, exposure summary, narrative, 0DTE, max pain, flow analytics, screener, vol surface, and VRP, plus 17 historical-replay tools. Claude, Cursor, and Windsurf can query the FlashAlpha GEX API directly through this server with no glue code. As of publication, FlashAlpha is the only options-analytics platform with first-class AI agent support over MCP. Setup is one command: claude mcp add flashalpha --transport http https://lab.flashalpha.com/mcp.

How does FlashAlpha compare to SpotGamma?

SpotGamma is a discretionary-trader dashboard with strong brand recognition, a polished morning note, the HIRO real-time hedging-impact indicator, and integrations into chart platforms like TrendSpider and Bookmap. FlashAlpha is a developer-first REST API that returns the same underlying analytics (gamma flip, call wall, put wall, per-strike GEX, regime label) as structured JSON, with broader ticker coverage (6,000+ vs 3,500), a free tier, SDKs in five languages, an MCP server for AI agents, and historical replay with point-in-time semantics. Use SpotGamma if you want a dashboard to look at; use FlashAlpha if you want JSON in your code. Many developers use SpotGamma for the morning narrative and the FlashAlpha GEX API for the systematic layer.

Do I need GEX data for retail options trading?

Not strictly, but it materially improves the quality of decisions. Gamma exposure tells you whether dealers are positioned to suppress moves (positive gamma, range-bound) or amplify them (negative gamma, trending). That information changes which options structures make sense: short premium in positive gamma, long premium or stay flat in negative gamma. Retail traders who incorporate GEX levels into their range estimates and structure choice tend to outperform retail traders who do not, which is why dashboards like SpotGamma and APIs like the FlashAlpha GEX API exist as products. The barrier is access cost; FlashAlpha's free tier makes the data available to retail at zero spend.

Where can I backtest a GEX strategy without lookahead bias?

The FlashAlpha Historical API at https://historical.flashalpha.com/v1/exposure/gex/{symbol}?at=YYYY-MM-DDTHH:mm:ss replays the GEX response for any minute since 2017-01-03 with leak-free percentiles, identical response shape to the live endpoint, and the same SDK. It is the only vendor in this comparison with point-in-time minute-resolution gamma exposure replay. The historical GEX API article walks through the backtest cookbook.

Which GEX API supports AI coding agents?

The FlashAlpha GEX API is the only one in this comparison that ships an MCP server. Claude, Cursor, Windsurf, and any other MCP-aware AI assistant can call FlashAlpha's GEX, DEX, VEX, CHEX, levels, summary, narrative, 0DTE, max pain, VRP, vol surface, and historical-replay tools directly as native MCP functions. SpotGamma, Unusual Whales, and SqueezeMetrics do not, as of publication, expose MCP servers.

How to Evaluate a GEX API for Your Use Case

Five questions, in order:

1. Is there a documented public REST endpoint? If the answer is "you have to talk to sales", it is not a developer API. Cross it off the list unless you have institutional procurement willing to do the call.
2. Is there a free or near-free tier you can build a proof of concept against? Subscriptions in the high-three-digit per-month range are reasonable for production use; they are not reasonable for evaluation. Evaluate on the free tier, then upgrade.
3. Does the coverage include the symbols you actually trade? SPX-only is fine if you are an SPX trader; useless if you are a single-stock trader. Check the vendor's symbol list before assuming.
4. Is there historical replay with point-in-time semantics? If you ever want to backtest a GEX strategy, the answer to "can I get the same response shape at any past minute, leak-free" determines whether the API is a one-trick live tool or a research-and-production platform.
5. Are there SDKs and AI agent integrations? Five-language SDK coverage and an MCP server are not luxuries; they are signals about how seriously the vendor takes the developer audience. A vendor with neither is telling you the developer is not the customer.

Run any of the four products in this comparison through those five questions and the FlashAlpha GEX API is the only one that returns yes on all five. That is not a coincidence; it is a positioning choice on FlashAlpha's part to build the GEX product specifically for developers.

Related Reading

• What Is Gamma Exposure (GEX)? A Plain-English Explainer
• GEX Trading Guide: Using the Gamma Exposure API on SPY and TSLA
• Build a GEX Dashboard with the FlashAlpha API
• Historical GEX API: Backtesting Gamma Exposure Strategies
• Key Levels Monitor API: Build a Put Wall / Call Wall / Gamma Flip Tracker
• SpotGamma vs Unusual Whales: Discretionary Comparison
• FlashAlpha vs Polygon: Raw Data vs Computed Analytics
• FlashAlpha Lab API Documentation
• FlashAlpha Pricing

The "best GEX API in 2026" question is really two questions in one. If you are a discretionary trader who wants a polished dashboard with a morning note, SpotGamma is the strongest brand and Unusual Whales is the strongest flow-plus-GEX bundle. If you are a developer, quant, or AI agent that wants gamma exposure as structured JSON over HTTP, the FlashAlpha GEX API at https://lab.flashalpha.com/v1/exposure/gex/{symbol} is the only option in this comparison that ships a public REST endpoint, broad ticker coverage, a free tier, SDKs in five languages, an MCP server, and historical replay with point-in-time semantics.

SqueezeMetrics remains the canonical research source on SPX dealer gamma. SpotGamma owns the discretionary brand. Unusual Whales bundles flow with GEX better than anyone. FlashAlpha owns the developer API surface. Pick the one that matches the shape of your problem, not the one with the loudest brand.