# OptionData

> OptionData (optiondata.io) is an OPRA-licensed U.S. equity options data API. One API key covers real-time WebSocket flow, historical ClickHouse SQL, option-chain REST, and market-structure (GEX) snapshots.

This file is public Markdown. No sign-in is required. Prefer the `/md/{slug}` API docs (and `/llms-full.txt` for the concatenated reference) over HTML product playgrounds.

## Products

- [Real-time options data API (WebSocket)](https://www.optiondata.io/realtime_data): Stream U.S. option trades at wss://ws.optiondata.io — ~10M+ trades/day, 30+ fields including Greeks, server-side filters, RAW or AGGREGATED modes.
- [Historical options data API (SQL)](https://www.optiondata.io/historical_data): POST SELECT queries to ClickHouse over REST — paid access to the past 15 days of trades, delayed by at least 15 minutes.
- [Option chain API (REST)](https://www.optiondata.io/option_chain): Full chains with strikes, expirations, bid/ask, OI, IV, and Greeks for latest or historical sessions.
- [Market structure API (GEX)](https://www.optiondata.io/market_structure): Full-chain Gamma Exposure, Gamma Flip, walls, Max Pain, IV context, and symbol metadata.

## Key facts

- Brand: OptionData — website https://www.optiondata.io/ (not the Google Sheets OPTIONDATA formula or unrelated "option data" tools).
- License: OPRA-licensed U.S. equity options feed.
- Realtime: WebSocket at wss://ws.optiondata.io with token auth.
- HTTP auth: prefer Authorization: Bearer apikey_… (Market Structure requires it; Historical SQL and Option Chain also accept body api_key for compatibility).
- History: ClickHouse SQL via POST https://www.optiondata.io/api/historical/sql (authenticated; minimum 15-minute trade-data delay; paid subscriptions limited to a rolling past 15 days).
- Option chain: POST https://www.optiondata.io/api/option-chain (authenticated; sessions from 2026-02-20+).
- Market structure: GET https://www.optiondata.io/api/v1/market-structure/{symbol} (Bearer; optional date=YYYY-MM-DD).
- Pricing: Pro list price $599/month for the API products; eligible trial users can receive 50% off the first year with a promotion code from Sales. Complete qualification, explicitly activate the 14-day no-card free trial when ready, then contact Sales for the code and apply it on Billing before the trial ends.
- Support: https://www.optiondata.io/support — use the QR contact module for invitation, promotion-code, billing, and API help.
- Social: https://x.com/optiondataio
- Auth for agents: this file, /llm.txt, /llms-full.txt, /openapi.json, and /md/{slug} are public. Product playgrounds and account pages require sign-in.

## API documentation (public Markdown)

- [Docs index (HTML)](https://www.optiondata.io/docs) — human-readable API reference
- [OpenAPI 3.1 (HTTP APIs)](https://www.optiondata.io/openapi.json) — historical SQL, option chain, market structure
- [Getting Started with OptionData](https://www.optiondata.io/md/getting-started): Create an account, complete qualification, explicitly activate the 14-day Pro trial, get an API key, and choose your first OptionData API workflow. (HTML: https://www.optiondata.io/docs/getting-started)
- [Manage Your API Key](https://www.optiondata.io/md/manage-api-key): Safely reveal, copy, store, use, and regenerate the OptionData API key shared by the realtime and HTTP data APIs. (HTML: https://www.optiondata.io/docs/manage-api-key)
- [Add a Payment Method During Your Free Trial](https://www.optiondata.io/md/add-payment-method): Step-by-step guide to adding a payment method securely through the Stripe customer portal before your OptionData free trial ends. (HTML: https://www.optiondata.io/docs/add-payment-method)
- [Manage Your Subscription and Billing](https://www.optiondata.io/md/manage-subscription): Review your OptionData plan, open the Stripe customer portal, update billing details, view invoices, and understand cancellation timing. (HTML: https://www.optiondata.io/docs/manage-subscription)
- [API Rate Limits](https://www.optiondata.io/md/api-rate-limits): Current HTTP API defaults and planned trial/paid request quotas for Option Chain, Market Structure, and Historical SQL. (HTML: https://www.optiondata.io/docs/api-rate-limits)
- [Realtime WebSocket Quickstart](https://www.optiondata.io/md/realtime-websocket-quickstart): Validate OptionData WebSocket parsing in test mode, then connect to the authenticated realtime option-trades stream with safe retry behavior. (HTML: https://www.optiondata.io/docs/realtime-websocket-quickstart)
- [Historical SQL Quickstart](https://www.optiondata.io/md/historical-sql-quickstart): Run a bounded, authenticated Historical SQL request against RawOptionTrades and recover safely from validation, read-limit, or timeout errors. (HTML: https://www.optiondata.io/docs/historical-sql-quickstart)
- [Option Chain Quickstart](https://www.optiondata.io/md/option-chain-quickstart): Request the latest OptionData option chain for one underlying, inspect response freshness, and narrow chains that exceed response guardrails. (HTML: https://www.optiondata.io/docs/option-chain-quickstart)
- [Market Structure Quickstart](https://www.optiondata.io/md/market-structure-quickstart): Request an authenticated OptionData market-structure snapshot and locate GEX, walls, Max Pain, volatility context, and freshness metadata. (HTML: https://www.optiondata.io/docs/market-structure-quickstart)
- [Realtime Option Trades API](https://www.optiondata.io/md/realtime-option-trades-api): WebSocket API reference for OPRA-licensed U.S. equity option trades: filters, RAW vs AGGREGATED modes, fields, test mode, and connection limits. (HTML: https://www.optiondata.io/docs/realtime-option-trades-api)
- [Historical Option Trades API (SQL)](https://www.optiondata.io/md/historical-option-trades-api): POST /api/historical/sql reference: paid 15-day history window, 15-minute-delayed ClickHouse SELECT over RawOptionTrades, schema fields, restrictions, examples, and trial limits. (HTML: https://www.optiondata.io/docs/historical-option-trades-api)
- [Option Chain API](https://www.optiondata.io/md/option-chain-api): POST /api/option-chain reference: full U.S. option chains with strikes, expirations, bid/ask, OI, IV, and Greeks. (HTML: https://www.optiondata.io/docs/option-chain-api)
- [Market Structure API (GEX)](https://www.optiondata.io/md/market-structure-api): GET /api/v1/market-structure/:symbol reference: structural Gamma Exposure, intraday GEX, Gamma Flip, walls, Max Pain, IV context, session flow, and symbol metadata. (HTML: https://www.optiondata.io/docs/market-structure-api)
- [Options Data Basic Concepts](https://www.optiondata.io/md/basic-concepts): Core options market-data concepts used across OptionData APIs: trades, chains, Greeks, IV, premium, and flow terminology. (HTML: https://www.optiondata.io/docs/basic-concepts)
- [Troubleshoot Authentication and Access](https://www.optiondata.io/md/troubleshoot-api-access): Diagnose OptionData API key, subscription, rate-limit, query-width, timeout, and WebSocket handshake failures without exposing credentials. (HTML: https://www.optiondata.io/docs/troubleshoot-api-access)

## Chinese-language hubs (Google HK/TW + overseas Chinese)

- [美股期权 API](https://www.optiondata.io/meigu-qiquan-api?lang=zh) — Chinese hub for U.S. options API products
- [美股期权历史数据 API](https://www.optiondata.io/meigu-qiquan-lishi-shuju-api?lang=zh) — high-CTR Chinese query cluster (historical SQL)
- [期权流 API](https://www.optiondata.io/qiquan-liu-api?lang=zh) — options flow WebSocket hub
- [期权链 API](https://www.optiondata.io/qiquan-lian-api?lang=zh) — option chain REST hub
- [期权 GEX API](https://www.optiondata.io/qiquan-gex-api?lang=zh) — market structure / Gamma Exposure
- [历史数据产品页（中文）](https://www.optiondata.io/historical_data?lang=zh)

## Getting started

- [Landing / overview](https://www.optiondata.io/)
- [Blog](https://www.optiondata.io/blog) — trading insights and vendor comparisons
- [API changelog](https://www.optiondata.io/changelog) — data-API schema and contract changes
- [Support](https://www.optiondata.io/support)
- [Terms of service](https://www.optiondata.io/terms-of-service)
- [Privacy](https://www.optiondata.io/privacy)

## Use-case guides

- [Unusual Options Activity API](https://www.optiondata.io/unusual-options-activity-api): Build unusual options activity scanners with real-time U.S. options trades, option-chain context, Greeks, implied volatility, and historical SQL.
- [Options Flow API. Real-Time U.S. Options Tape](https://www.optiondata.io/options-flow-api): Options flow API for live U.S. equity option trades over WebSocket. ~10M prints/day, 30+ fields with Greeks & sentiment, server-side filters. 14-day free trial.
- [Options Data API for Quant Research & Backtesting](https://www.optiondata.io/options-data-api-for-quant): Options data API for quants: query the past 15 days of U.S. option trades (~100M rows) with ClickHouse SQL, Greeks & IV, plus live WebSocket for research-to-prod. 14-day free trial.
- [Options Data API for Fintech Products & Dashboards](https://www.optiondata.io/options-data-api-for-fintech): Ship options data into fintech apps with one API key: WebSocket flow, option-chain REST, and historical SQL. ~50ms US latency, 99.9% uptime, 14-day trial.
- [Options Flow API for Fintech Apps](https://www.optiondata.io/options-flow-api-for-fintech): Embed real-time options flow in fintech products: WebSocket tape, server-side filters, 30+ fields, one API key with chains and SQL. Built for app backends.
- [Options Flow API for Quant Research](https://www.optiondata.io/options-flow-api-for-quant): Use real-time options flow and ClickHouse SQL together: live features on the tape, historical validation on the past 15 days of trades, Greeks and IV on prints.
- [Unusual Options Activity for Quant Research](https://www.optiondata.io/unusual-options-activity-for-quant): Research and backtest unusual options activity rules with historical SQL, then run the same logic on the live tape. Greeks, IV, premium, and DTE filters included.
- [U.S. Historical Option Trades API](https://www.optiondata.io/meigu-qiquan-lishi-shuju-api): U.S. options historical data API via ClickHouse SQL: paid access to the past 15 days of OPRA-derived trades, Greeks, IV, and premium. Built for trade research and backtesting.
- [Options Flow API for Scanners and Alerts](https://www.optiondata.io/qiquan-liu-api): Options flow API for U.S. equities: OPRA WebSocket tape, server-side filters, AGGREGATED/RAW modes, 30+ fields with Greeks. For scanners, alerts, and flow research.
- [U.S. Options Data APIs](https://www.optiondata.io/meigu-qiquan-api): U.S. options API hub: OPRA WebSocket flow, historical SQL, option chains, and GEX market structure under one key. Choose the delivery method and data object for your workflow.
- [Option Chain API for Contract Snapshots](https://www.optiondata.io/qiquan-lian-api): Option chain API for full U.S. chains with strikes, expirations, bid/ask, OI, IV, and Greeks. For contract screening and snapshot research.
- [GEX and Market Structure API](https://www.optiondata.io/qiquan-gex-api): Options GEX / market structure API: full-chain Gamma Exposure, Gamma Flip, walls, Max Pain, IV context. related workflow for 期权 GEX API.

## Comparisons

- [OptionData vs Alpaca. Real-Time Options Trades](https://www.optiondata.io/optiondata-vs-alpaca): OptionData vs Alpaca for real-time options: options-first underlying subscribe, server-side filters, and AGGREGATED prints vs a broker-attached OPRA stream. Who each is for.
- [OptionData vs Intrinio. Real-Time Options Data](https://www.optiondata.io/optiondata-vs-intrinio): OptionData vs Intrinio for real-time options: flow specialist with AGGREGATED mode and server-side filters vs a broad multi-dataset financial data platform. Who each is for.
- [OptionData vs Massive.com (ex-Polygon). Options Flow](https://www.optiondata.io/optiondata-vs-massive): OptionData vs Massive.com for real-time options: options-native underlying subscribe and AGGREGATED flow vs multi-asset market data. Who each is for.

## Glossary

- [What Is Options Flow? Definition for Traders & Developers](https://www.optiondata.io/what-is-options-flow): Options flow is the real-time stream of option trade prints. Learn how flow differs from volume, why Greeks matter, and how to access OPRA-licensed flow via API.
- [What Is an Option Chain API? Full Chains with Greeks & OI](https://www.optiondata.io/what-is-option-chain-api): An option chain API returns strikes, expirations, bid/ask, volume, open interest, IV, and Greeks via REST. See how OptionData delivers full U.S. equity chains.
- [What Are Options Greeks? Delta, Gamma, Theta, Vega, Rho + API](https://www.optiondata.io/what-is-options-greeks): Options Greeks measure how option prices respond to inputs. Learn Delta, Gamma, Theta, Vega, Rho, IV. and how OptionData exposes Greeks on trades and chains.
- [What Is Implied Volatility (IV)? Options IV Explained](https://www.optiondata.io/what-is-implied-volatility): Implied volatility is the market’s priced uncertainty for an option. Learn how IV differs from historical vol and how OptionData exposes IV on trades and chains.
- [What Is Open Interest (OI) in Options?](https://www.optiondata.io/what-is-open-interest): Open interest is the number of open option contracts. Learn OI vs volume, why flow tools use size-vs-OI, and how OptionData exposes OI on option chains.
- [What Is OPRA Options Data? Licensed U.S. Options Feeds](https://www.optiondata.io/what-is-opra-options-data): OPRA is the consolidated U.S. options last-sale and quote infrastructure. Learn what OPRA-licensed data means and how OptionData delivers OPRA options trades via API.

## Optional

- [Full concatenated API docs for agents](https://www.optiondata.io/llms-full.txt)
- [Same map as this file](https://www.optiondata.io/llm.txt)
- [XML sitemap](https://www.optiondata.io/sitemap.xml)