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 API contracts indexed 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.

The Market Data catalog on APIs.io includes 1 Spectral governance ruleset.

Market Data’s developer surface includes authentication, changelog, sandbox, documentation, API reference, getting-started guide, support, and 30 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

60.7/100 strong ▬ flat Agent 30/100 agent ready Front door AI 1/6 silent Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

2 published contracts 3 Agent Skills

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

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 60.7/100 · strong

Contract Quality 10.1 / 21

Developer Ergonomics 12.9 / 17

Access Clarity 14.3 / 17

Operational Transparency 5.2 / 11

Contract Governance 1.9 / 10

Discoverability 6.2 / 9

Regulatory Posture 4.3 / 15

Agent readiness — 30/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 4 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Securities & Market Data regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks
Protected Resource Metadata +5 pts — a served /.well-known/oauth-protected-resource carrying `resource` (documented), and naming its authorization_servers (verified)

3 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 47.4 — up to +13.2 composite points
Contract Governance scores 18.2 — up to +9.8 composite points
Operational Transparency scores 47.4 — up to +6.8 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/marketdata-app/apis.yml: open an issue on github.com/api-evangelist/marketdata-app to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Private Markets and Fund Administration (ILPA, broker-dealer registration, options market-data vendors)	builds-on	34.5	-	-
Official SDKs on Packagist, pub.dev and Hex	builds-on	34.5	-	-

AGENT SKILL

Analyze an options chain without exhausting credits

AGENT SKILL

Fetch stock quotes and historical candles

AGENT SKILL

Market Data API pricing

Prices published by Market Data, read 2026-10-28 from www.marketdata.app/pricing/.

Plan	Price
Free Forever	$0 Includes: 100 Sheets Formulas, 100 Daily API Credits, Standard API Endpoints, 1 Year Historical Data, 24h Dela
Starter	$12/ month Includes: 10,000 Sheets Formulas, 10,000 Daily API Credits, Premium API Endpoints, 5 Years Historical Data; an
Trader	$30/ month Includes: 100,000 Sheets Formulas, 100,000 Daily API Credits, Premium API Endpoints, No Limit On Historical Da
Quant	$125/ month Includes: Unlimited Sheets Formulas, 10,000 API Credits Per Minute, Premium API Endpoints, Internal Use
Prime	$250/ month Includes: Unlimited Sheets Formulas, 100,000 API Credits Per Minute, Premium API Endpoints, Internal Use
Commercial	$333/ month billed quarterly Includes: Real-time stock & options prices, WebSocket streaming & REST, tick-level & historical data, commerci
Custom plan	Contact Sales Includes: Custom endpoint development and onboarding

Plan details, limits and sources →

Rate limits

Free Forever Daily Requests: 100 per day requests
Starter Daily Credits: 10000 per day credits
Trader Daily Credits: 100000 per day credits

Compiled by API Evangelist, not yet checked against Market Data's documentation. All 7 limits →

Billed by: subscription · FinOps profile →

Pricing Plans 2

Published pricing tiers and plan structures.

Marketdata App Plans Pricing

7 plans

PLANS

Marketdata App Price Estimates

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Marketdata App Rate Limits

7 limits

RATE LIMITS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

Market Data

SLA

FinOps 1

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

Marketdata App Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Market Data API Rules

54 rules · 47 errors 6 warnings 1 info

SPECTRAL

OpenAPI Overlays 4

Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.

Marketdata App Indices Api Overlay

2 actions · update · marketdata-app-indices-api-openapi.yml

DERIVED

Marketdata App Markets Api Overlay

2 actions · update · marketdata-app-markets-api-openapi.yml

DERIVED

Marketdata App Options Api Overlay

2 actions · update · marketdata-app-options-api-openapi.yml

DERIVED

Marketdata App Stocks Api Overlay

2 actions · update · marketdata-app-stocks-api-openapi.yml

DERIVED

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Marketdata App Authentication

http/apiKey · 2 schemes

SECURITY

Marketdata App Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Marketdata App Agentic Access

29 operations

29 operations · 0 acting

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

AgenticAccess

WellKnown

WellKnown

X-MCPServerCandidate

X-MCPServerCandidate

LLMsTxt

LLMsTxt

AgentSkill

AgentSkill

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Conformance

ErrorCatalog

Lifecycle

Conventions

Components

DataModel

Build 5

SDKs, sample code, and the tooling you integrate with

PostmanWorkspace

Packages

SDKs

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.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  - security
  - sandbox
  generated: '2026-11-06'
  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: '2026-09-16'
specificationVersion: '0.23'
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: PostmanWorkspace
  url: https://www.postman.com/kinlaneapi/market-data/overview
- type: OpenAPI
  url: openapi/_original/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: X-MCPServerCandidate
  url: mcp/marketdata-app-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- 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 API — frequently asked questions

Does Market Data have an API?

Yes. APIs.io lists 4 APIs from Market Data, including Market Data Indices API, Market Data Markets API and Market Data Options API, and 1 more.

Is there an OpenAPI specification for the Market Data API?

Yes. APIs.io indexes 4 OpenAPI specifications for Market Data, each linked for download from this page.

How do I authenticate with the Market Data API?

Market Data uses bearer-token authentication (http/apiKey · 2 schemes). The details are profiled on APIs.io as Marketdata App Authentication.

How much does the Market Data API cost?

Market Data publishes its prices; its Free Forever plan is $0 as of 2026-10-28. APIs.io lists 7 pricing plans for Market Data, with each plan's price, limits and inclusions under Pricing on this page.

Is the Market Data API ready for AI agents?

Market Data has a Kin Score of 60.7 out of 100 (strong) and an Agent Readiness score of 29.8 (agent-ready), scored by API Evangelist on 2026-11-06.

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