Market Data

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.

Market Data publishes 4 APIs on the APIs.io network, including Indices API, Markets API, Options API, and 1 more. Tagged areas include Market Data, Financial Data, Stocks, Options, and Indices.

Market Data’s developer surface includes authentication, changelog, sandbox, documentation, API reference, getting-started guide, support, and 29 more developer resources.

🌐 Visit website 📡 Source on GitHub

65.6/100 strong ▬ flat Agent 76/100 agent native Full breakdown ↓
scored 2026-07-27 · rubric v0.5

AccessFreemiumOpenFree trial⚡ Free to try

4 APIs 1 MCP Servers

Market DataFinancial DataStocksOptionsIndicesReal-Time DataHistorical DataQuotes

Kin Score

Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5

Composite quality — 65.6/100 · strong

Contract Quality 14.6 / 25

Developer Ergonomics 16.5 / 20

Commercial Clarity 16.8 / 20

Operational Transparency 9.6 / 13

Governance 0.0 / 12

Discoverability 10.0 / 10

Agent readiness — 76/100 · agent native

Machine-Readable Contract 18 / 18

Agentic Access Contract 15 / 15

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 4 / 4

Consent & Bot Identity 0 / 3

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/marketdata-app: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 4

Individual APIs this provider publishes, each with its own machine-readable definition.

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Rate Limits 1

Documented rate limits and quota policies.

Marketdata App Rate Limits

7 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

AGENTIC

Resources

Get Started 4

Portal, sign-up, and the first successful call

Sandbox

DeveloperPortal

GettingStarted

SignUp

Documentation 3

Reference material describing how the API behaves

OpenAPI

OpenAPI

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 5

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

WellKnown

MCPServer

LLMsTxt

AgentSkill

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Conformance

ErrorCatalog

Lifecycle

Conventions

Components

DataModel

Build 4

SDKs, sample code, and the tooling you integrate with

Packages

Packages

SDKs

SDKs

Postman

Postman

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 5

Status, limits, changes, and where to get help

StatusPage

ChangeLog

Roadmap

Support

RateLimits

Commercial 5

Pricing, plans, and the legal terms of use

TermsOfService

PrivacyPolicy

Plans

FinOps

Pricing

Company 2

The organization behind the API

LinkedIn

Website

Website

Source (apis.yml)

aid: marketdata-app
url: https://raw.githubusercontent.com/api-evangelist/marketdata-app/refs/heads/main/apis.yml
name: Market Data
kind: company
description: 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.
accessModel:
  pricing: freemium
  onboarding: open
  trial: true
  try_now: true
  public: true
  label: Freemium (free trial) · Open access
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/marketdata-app.png
tags:
- Market Data
- Financial Data
- Stocks
- Options
- Indices
- Real-Time Data
- Historical Data
- Quotes
created: '2026-07-11'
modified: '2026-07-22'
specificationVersion: '0.19'
apis:
- aid: marketdata-app:marketdata-app-indices-api
  name: Market Data Indices API
  description: Real-time and historical index candles and quotes.
  humanURL: https://www.marketdata.app/docs/api/
  baseURL: https://api.marketdata.app/v1
  tags:
  - Indices
  properties:
  - type: OpenAPI
    url: openapi/marketdata-app-indices-api-openapi.yml
  - type: Overlay
    url: overlays/marketdata-app-indices-api-overlay.yaml
  - type: Documentation
    url: https://www.marketdata.app/docs/api/
  - type: PostmanCollection
    url: collections/marketdata-app.postman_collection.json
  - type: OpenCollection
    url: collections/marketdata-app.opencollection.json
- aid: marketdata-app:marketdata-app-markets-api
  name: Market Data Markets API
  description: Reference and status data about the markets covered by Market Data.
  humanURL: https://www.marketdata.app/docs/api/markets/status/
  baseURL: https://api.marketdata.app/v1/markets
  tags:
  - Markets
  properties:
  - type: OpenAPI
    url: openapi/marketdata-app-markets-api-openapi.yml
  - type: Overlay
    url: overlays/marketdata-app-markets-api-overlay.yaml
  - type: Documentation
    url: https://www.marketdata.app/docs/api/markets/status/
  - type: APIReference
    url: https://www.marketdata.app/docs/api/markets/status/
  - type: PostmanCollection
    url: collections/marketdata-app.postman_collection.json
  - type: OpenCollection
    url: collections/marketdata-app.opencollection.json
- aid: marketdata-app:marketdata-app-options-api
  name: Market Data Options API
  description: Options chains, per-contract quotes, expirations, strikes, and OCC symbol lookup.
  humanURL: https://www.marketdata.app/docs/api/options/
  baseURL: https://api.marketdata.app/v1/options
  tags:
  - Options
  properties:
  - type: OpenAPI
    url: openapi/marketdata-app-options-api-openapi.yml
  - type: Overlay
    url: overlays/marketdata-app-options-api-overlay.yaml
  - type: Documentation
    url: https://www.marketdata.app/docs/api/options/
  - type: APIReference
    url: https://www.marketdata.app/docs/api/options/chain/
  - type: PostmanCollection
    url: collections/marketdata-app.postman_collection.json
  - type: OpenCollection
    url: collections/marketdata-app.opencollection.json
- aid: marketdata-app:marketdata-app-stocks-api
  name: Market Data Stocks API
  description: Real-time and historical stock candles, quotes, bulk data, prices, earnings, and news.
  humanURL: https://www.marketdata.app/docs/api/stocks/
  baseURL: https://api.marketdata.app/v1/stocks
  tags:
  - Stocks
  properties:
  - type: OpenAPI
    url: openapi/marketdata-app-stocks-api-openapi.yml
  - type: Overlay
    url: overlays/marketdata-app-stocks-api-overlay.yaml
  - type: Documentation
    url: https://www.marketdata.app/docs/api/stocks/
  - type: APIReference
    url: https://www.marketdata.app/docs/api/stocks/candles/
  - type: PostmanCollection
    url: collections/marketdata-app.postman_collection.json
  - type: OpenCollection
    url: collections/marketdata-app.opencollection.json
common:
- type: OpenAPI
  url: openapi/marketdata-app-openapi-original.yml
- type: DomainSecurity
  url: security/marketdata-app-domain-security.yml
- type: AgenticAccess
  url: agentic-access/marketdata-app-agentic-access.yml
- type: Authentication
  url: authentication/marketdata-app-authentication.yml
- type: Packages
  url: packages/marketdata-app-packages.yml
- type: SDKs
  url: packages/marketdata-app-packages.yml
- type: WellKnown
  url: well-known/marketdata-app-well-known.yml
- type: MCPServer
  url: mcp/marketdata-app-mcp.yml
- type: LLMsTxt
  url: llms/marketdata-app-llms.txt
- type: Conformance
  url: conformance/marketdata-app-conformance.yml
- type: ErrorCatalog
  url: errors/marketdata-app-problem-types.yml
- type: Lifecycle
  url: lifecycle/marketdata-app-lifecycle.yml
- type: StatusPage
  url: https://status.marketdata.app/
- type: ChangeLog
  url: changelog/marketdata-app-changelog.yml
- type: Roadmap
  url: https://roadmap.marketdata.app/
- type: Sandbox
  url: sandbox/marketdata-app-sandbox.yml
- type: Conventions
  url: conventions/marketdata-app-conventions.yml
- type: Components
  url: components/marketdata-app-components.yml
- type: DataModel
  url: data-model/marketdata-app-data-model.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Postman
  url: https://app.getpostman.com/run-collection/27146376-b1331cd2-4749-4708-96fe-2f1708b02854?action=collection%2Ffork&source=rip_markdown&collection-url=entityId%3D27146376-b1331cd2-4749-4708-96fe-2f1708b02854%26entityType%3Dcollection%26workspaceId%3Dbd65af1d-3c36-4e62-ae64-f71008c154b4
- type: GitHubOrganization
  url: https://github.com/MarketDataApp
- type: LinkedIn
  url: https://www.linkedin.com/company/marketdataapp
- type: Website
  url: https://www.marketdata.app
- type: DeveloperPortal
  url: https://www.marketdata.app/dashboard/
- type: Documentation
  url: https://www.marketdata.app/docs/api/
- type: APIReference
  url: https://www.marketdata.app/docs/api/
- type: GettingStarted
  url: https://www.marketdata.app/docs/api/
- type: Support
  url: https://www.marketdata.app/helpdesk/
- type: SignUp
  url: https://www.marketdata.app/signup/
- type: TermsOfService
  url: https://www.marketdata.app/terms/
- type: PrivacyPolicy
  url: https://www.marketdata.app/privacy/
- type: Plans
  url: plans/marketdata-app-plans-pricing.yml
- type: RateLimits
  url: rate-limits/marketdata-app-rate-limits.yml
- type: FinOps
  url: finops/marketdata-app-finops.yml
- type: Pricing
  url: https://www.marketdata.app/pricing/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Market Data

Kin Score

APIs 4

Market Data Indices API

Market Data Markets API

Market Data Options API

Market Data Stocks API

Open Collections 1

Market Data API

MCP Servers 1

marketdata-app-mcp.yml

Pricing Plans 1

Marketdata App Plans Pricing