# CS2Cap > One free REST API for real-time CS2 skin prices, buy orders, sales history, items, and analytics across 40+ marketplaces. Built for developers, trading tools, and data teams. ## Docs - [Account API: View and Rotate Your CS2Cap API Key](https://docs.cs2cap.com/api-reference/account.md): Retrieve metadata for your active CS2Cap API key, check effective rate limits and quota, and reissue the key to rotate credentials and revoke child keys. - [Alerts API: CS2Cap Price and Spread Notifications](https://docs.cs2cap.com/api-reference/alerts.md): Create price-below, price-above, and spread-exceeds alerts for CS2 items, manage them in bulk, and retrieve triggered event history with delivery status. - [Bids API: Buy Orders Across CS2 Marketplaces](https://docs.cs2cap.com/api-reference/bids.md): Query the highest active buy orders across CS2 marketplaces, stream the full live bids catalog as NDJSON, or batch-lookup up to 100 items at once. - [Catalog API: Items, Providers, and FX Rates](https://docs.cs2cap.com/api-reference/catalog.md): Search the CS2 item catalog, load provider metadata and health status, and fetch live FX rates for currency conversion across 200+ currencies (fiat & crypto). - [Steam Inventory API: Fetch Your CS2 Items](https://docs.cs2cap.com/api-reference/inventory.md): Fetch your linked Steam CS2 inventory or look up any player's public inventory by Steam64ID or vanity URL. Data is fetched live and never stored. - [Market Analytics API: Arbitrage and Indicators](https://docs.cs2cap.com/api-reference/market-analytics.md): Query cross-market arbitrage opportunities, category indexes, technical indicators, and per-item market analytics snapshots across all CS2 providers. - [CS2Cap API: Base URL, Auth, and Rate Limits](https://docs.cs2cap.com/api-reference/overview.md): Base URL, Bearer authentication, per-tier rate limits, response envelope conventions, and error handling for the CS2Cap market-data API. - [Portfolio API: Track and Value Your CS2 Items](https://docs.cs2cap.com/api-reference/portfolio.md): Create saved portfolios, record buy/sell transactions, import Steam inventory, and value holdings statlessly or against stored portfolios across providers. - [Prices API: Current Asks, History, and Candles](https://docs.cs2cap.com/api-reference/prices.md): Fetch current lowest asks, stream full price snapshots, batch-query up to 100 items, retrieve OHLCV candles, and page through raw price history. - [Sales API: Recent CS2 Sales with Float and Stickers](https://docs.cs2cap.com/api-reference/sales.md): Retrieve recent CS2 sale records across marketplaces, including float, paint seed, stickers, charms, and inspect links where available. - [Sub-Keys API: Create Child API Keys (Quant)](https://docs.cs2cap.com/api-reference/sub-keys.md): Create and manage up to 25 child API keys under your Quant root key, each with optional per-key quota and rate limit overrides for access delegation. - [Webhooks API: Real-Time Event Delivery (Quant)](https://docs.cs2cap.com/api-reference/webhooks.md): Register HTTPS endpoints to receive CS2Cap alert events in real time, rotate signing secrets, and inspect delivery history and retry attempts. - [Authentication: API Keys and Bearer Tokens](https://docs.cs2cap.com/authentication.md): CS2Cap uses API key authentication via the Authorization header. Learn how to get your key, use it in requests, and handle auth errors. - [Changelog: Releases and Breaking Changes](https://docs.cs2cap.com/changelog.md): Public-facing API, documentation, and platform changes to CS2Cap that affect integrators. Breaking changes, new endpoints, and deprecations listed here. - [Core Concepts: Data Model and Terminology](https://docs.cs2cap.com/core-concepts.md): Understand the CS2Cap data model: quotes, providers, minor units, item identity, data availability, and common integration pitfalls to avoid. - [Liquidity Score: Inputs and Formula Calculation](https://docs.cs2cap.com/guides/liquidity-score.md): How CS2Cap calculates the 0-100 item liquidity score from market depth, bid/ask quality, churn, price stability, and external confirmation signals. - [Building Portfolio Valuation and P&L Workflows](https://docs.cs2cap.com/guides/portfolio.md): Use CS2Cap to value customer inventories, maintain saved CS2 portfolios, track buy and sell transactions, and build daily portfolio performance reporting. - [Pricing: Compare Free, Starter, Pro, and Quant Plans](https://docs.cs2cap.com/guides/pricing-plans.md): Compare CS2Cap's 4 API tiers — Free, Starter, Pro, and Quant — by monthly request quota, rate limits, endpoint access, and feature availability. - [Rate Limits: Per-Minute and Monthly Quotas](https://docs.cs2cap.com/guides/rate-limits.md): Understand CS2Cap's per-minute and monthly request limits, how to read rate-limit headers, and best practices for staying within your quota. - [Using CS2Cap Webhooks as an Alerting Backend](https://docs.cs2cap.com/guides/webhooks-alerts.md): Use CS2Cap for market monitoring and alert detection, then receive alert events in your own service or supported delivery platform. - [CS2Cap: Unified CS2 Market Data API Documentation](https://docs.cs2cap.com/index.md): CS2Cap aggregates prices, buy orders, sales, and analytics from 41 CS2 marketplaces into one unified API. Start querying in minutes. - [CS2Cap API: Build on Normalized CS2 Market Data](https://docs.cs2cap.com/introduction.md): CS2Cap aggregates normalized prices, buy orders, sales, analytics, and portfolio data from 41 CS2 marketplaces into one unified REST API. - [Quickstart: Make Your First CS2Cap API Call](https://docs.cs2cap.com/quickstart.md): Learn how to make your first CS2Cap API request using cURL, Python, or JavaScript. Goes from zero to a live price response in 5 steps. - [Error Codes and HTTP Status Reference](https://docs.cs2cap.com/reference/error-codes.md): Reference for every HTTP status code and machine-readable error code returned by the CS2Cap API, with descriptions and retry guidance. - [Field Reference: All Response Fields](https://docs.cs2cap.com/reference/field-reference.md): Complete definitions for every field returned by the CS2Cap API, including price fields, pagination, the response envelope, and item catalog metadata. - [Supported Marketplaces and Providers](https://docs.cs2cap.com/reference/providers.md): Complete list of all 40 active CS2Cap provider keys with market types, fee data, health fields, and usage examples for the providers request parameter. ## OpenAPI Specs - [openapi](https://docs.cs2cap.com/openapi.json)