# Market Data

**Canonical:** https://apis.io/providers/marketdata-app/  
**Website:** https://www.marketdata.app  
**APIs profiled:** 4

Market Data (marketdata.app) is a financial market data provider offering a REST API for real-time and historical U.S. stock, options, and index data. The API (base https://api.marketdata.app/v1, Bearer-token authenticated) covers stock candles and quotes - single and bulk - plus earnings and news; full options chains with per-contract quotes, expirations, strikes, and OCC symbol lookup; index candles and quotes; and market open/closed status. Responses are JSON or CSV and are billed on a daily API-credit model, where multi-symbol responses (bulk quotes, options chains) consume one credit per symbol. A 30-day trial, a Free Forever tier, and paid Starter, Trader, and Prime plans are available. Note that the API may return HTTP 203 from its caching tier and clients must treat it as success.

## Kin Score — 63.3 / 100 (strong)

Scored 2026-08-17 under rubric 0.11.0. Trend: flat (+0.0 from 63.3).

| Facet | Score |
|---|---|
| Discoverability | 81.5 |
| Contract Quality | 60.4 |
| Governance | 11.5 |
| Operational Transparency | 73.7 |
| Developer Ergonomics | 71.2 |
| Commercial Clarity | 84.2 |

Regulatory layer — **Securities & Market Data**: 51.7 (matched via tags).

## Agent readiness — 38.1 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| MCP Server | derived |
| Auth Clarity | yes |
| Idempotency | no |
| Error Semantics | documented |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | derived |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Freemium (free trial) · Open access — onboarding: open, pricing: freemium, trial: yes (confidence: high).

## APIs (4)

- **Market Data Indices API** — Real-time and historical index candles and quotes.
- **Market Data Markets API** — Reference and status data about the markets covered by Market Data.
- **Market Data Options API** — Options chains, per-contract quotes, expirations, strikes, and OCC symbol lookup.
- **Market Data Stocks API** — Real-time and historical stock candles, quotes, bulk data, prices, earnings, and news.

## MCP servers (1)

- **marketdata-app-mcp.yml**

## Agentic access (1)

- **Marketdata App Agentic Access** — 14 operations

## Security (2)

- **Marketdata App Authentication** — http/apiKey · 2 schemes
- **Marketdata App Domain Security** — TLSv1.3 · HSTS · DMARC

## Plans (1)

- **Marketdata App Plans Pricing**

## Tags

Market Data, Financial Data, Stocks, Options, Indices, Real-Time Data, Historical Data, Quotes

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/marketdata-app/). Scores are computed from the provider's own public artifacts under a published rubric.