# 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 — 2.8B+ stored trades from Feb 2025+, 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; trade history from 2025-02-18).
- 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; first-year promotional pricing may apply with a coupon; 14-day free trial.
- Support: support@optiondata.io · Discord https://discord.com/invite/mE5pEDMdWs
- 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, start 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/)
- [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: 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/) — 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/) — high-CTR Chinese query cluster (historical SQL)
- [期权流 API](https://www.optiondata.io/qiquan-liu-api/) — options flow WebSocket hub
- [期权链 API](https://www.optiondata.io/qiquan-lian-api/) — option chain REST hub
- [期权 GEX API](https://www.optiondata.io/qiquan-gex-api/) — 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 2.8B+ U.S. option trades with ClickHouse SQL, full 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 2.8B+ 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. Options Historical Data API (Chinese demand hub)](https://www.optiondata.io/meigu-qiquan-lishi-shuju-api/): U.S. options historical data API via ClickHouse SQL: 2.8B+ OPRA-derived trades, Greeks, IV, and premium. Built for backtests and the 美股期权历史数据 query cluster.
- [Options Flow API (Chinese: 期权流 API)](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. Chinese hub for 期权流 API.
- [U.S. Options API Hub (美股期权 API)](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. Chinese hub for 美股期权 API / 美股期权数据.
- [Option Chain API (Chinese: 期权链 API)](https://www.optiondata.io/qiquan-lian-api/): Option chain API for full U.S. chains with strikes, expirations, bid/ask, OI, IV, and Greeks. Chinese hub for 期权链 API.
- [Options GEX API (Chinese: 期权 GEX API)](https://www.optiondata.io/qiquan-gex-api/): Options GEX / market structure API: full-chain Gamma Exposure, Gamma Flip, walls, Max Pain, IV context. Chinese hub 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)