Public

Public (Public Holdings, Inc.) is a multi-asset investing platform where people can trade stocks, ETFs, options, index options, crypto, bonds, and treasuries, and hold IRAs, direct indexing, high-yield cash, and margin in one account. Public positions itself as an "agentic brokerage" and ships a public Trading API (api.public.com) that lets developers programmatically manage accounts, pull market data, and place equity, crypto, and options orders with commission-free execution and options rebates. It also operates a hosted, OAuth-secured MCP server (mcp.public.com) so AI assistants like Claude and ChatGPT can query portfolios and trade on a user's behalf, alongside an official Python SDK, command-line interface, and Postman collection. Backed by Accel.

Public is listed with 1 API on the APIs.io network. Tagged areas include Company, Consumer, Investing, Brokerage, and Trading.

Public’s developer surface includes documentation, getting-started guide, changelog, signup flow, pricing, support, engineering blog, and 23 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

37.9/100 thin ▬ flat Agent 27/100 agent aware Front door AI 6/6 dominant Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →

1 API 1 MCP Servers

Company Consumer Investing Brokerage Trading Fintech Stocks Options Cryptocurrency Market Data AI Agents MCP Financial Services

Kin Score

Kin Score How this is scored →
scored 2026-11-13 · rubric v0.28.0

Composite quality — 37.9/100 · thin

Contract Quality 0.0 / 21

Developer Ergonomics 11.7 / 17

Access Clarity 8.7 / 17

Operational Transparency 2.1 / 11

Contract Governance 1.9 / 10

Discoverability 6.4 / 9

Regulatory Posture 4.9 / 15

Agent readiness — 27/100 · agent aware

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 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 could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

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):

Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document Ask about this →
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author Ask about this →
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented) Ask about this →
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes Ask about this →
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0 Ask about this →
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented) Ask about this →

8 more unmet checks in the Agent Readiness table above.

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

Contract Quality scores 0.0 — up to +25.0 composite points Ask about this →
Operational Transparency scores 19.0 — up to +10.5 composite points Ask about this →
Contract Governance scores 18.2 — up to +9.8 composite points Ask about this →

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.

Not sure how this applies to your stack? Ask about any one item. Kin Lane reads every question, looks at your profile and your situation, and replies with what a fix would take — scoped to that one area, priced up front, yours whether you ship it or not. Ask a question →

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/public/apis.yml: open an issue on github.com/api-evangelist/public 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)	regulated	47.9	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 3

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

Model Context Protocol (MCP)

measured — observed by APIs.io (verified)

OAuth 2.0 Protected Resource Metadata

measured — observed by APIs.io (verified)

Dynamic Client Registration

measured — observed by APIs.io (published)

APIs 1

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

Public Trading API

REST API for programmatic trading on Public — manage brokerage accounts, pull portfolio and transaction history, retrieve market data (quotes, bars, option chains, greeks), and ...

MCP Servers 1

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

Public MCP Server

Public's hosted, remote MCP server — described by Public as part of "the world's first agentic brokerage." Lets AI assistants query portfolios and place trades on a connected Pu...

MCP SERVER

Terms of Service 1

What its API terms permit and prohibit, quoted from its own page.

Public

6 quoted statements, read from Public's own page on 2026-11-10.

TERMS

Privacy & Data 1

Its role, the data it processes, retention and transfers, quoted from its own privacy page.

Public

23 quoted statements, read from Public's own page on 2026-11-10.

PRIVACY

Eligibility 1

Who may sign up and where, quoted from its own terms.

Public

4 quoted statements, read from Public's own page on 2026-11-10.

ELIGIBILITY

AI Preferences 1

Its stance on AI training, inference and agents, quoted from its own pages.

Public

1 quoted statement, read from Public's own page on 2026-11-10.

AI PREFS

Data License 1

How its data and outputs may be reused, quoted from its own terms.

Public

2 quoted statements, read from Public's own page on 2026-11-10.

LICENSE

Security Posture 2

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

Public Authentication

http/oauth2 · 2 schemes

SECURITY

Public Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Public Scopes

4 scopes

SCOPES

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

SignUp

SignUp

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

AIPreferences

AIPreferences

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

MCPServer

MCPServer

WellKnown

WellKnown

LLMsTxt

LLMsTxt

Design & Contract 3

Pagination, idempotency, versioning, errors, and events

Conventions

Conventions

Conformance

Conformance

Lifecycle

Lifecycle

Build 5

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

Packages

SDKs

CLI

Postman

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

OAuthScopes

OAuthScopes

Operate 2

Status, limits, changes, and where to get help

ChangeLog

ChangeLog

Support

Support

Commercial 5

Pricing, plans, and the legal terms of use

Pricing

TermsOfService

PrivacyPolicy

UsageTerms

DataLicense

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 2

Properties that don't map to a standard resource type

DataProcessing

DataProcessing

Eligibility

Eligibility

Source (apis.yml)

x-enrichment:
  date: '2026-07-20'
  status: enriched
  artifacts_added: 12
  pass: local-v1
aid: public
name: Public
description: Public (Public Holdings, Inc.) is a multi-asset investing platform where people can trade stocks, ETFs, options,
  index options, crypto, bonds, and treasuries, and hold IRAs, direct indexing, high-yield cash, and margin in one account.
  Public positions itself as an "agentic brokerage" and ships a public Trading API (api.public.com) that lets developers programmatically
  manage accounts, pull market data, and place equity, crypto, and options orders with commission-free execution and options
  rebates. It also operates a hosted, OAuth-secured MCP server (mcp.public.com) so AI assistants like Claude and ChatGPT can
  query portfolios and trade on a user's behalf, alongside an official Python SDK, command-line interface, and Postman collection.
  Backed by Accel.
url: https://raw.githubusercontent.com/api-evangelist/public/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- accel
x-tier: stub
x-tier-reason: portfolio-lead
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - scopes
  - security
  generated: '2026-11-13'
  method: derived
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Company
- Consumer
- Investing
- Brokerage
- Trading
- Fintech
- Stocks
- Options
- Cryptocurrency
- Market Data
- AI Agents
- MCP
- Financial Services
tags_raw:
- Company
- Consumer
- Investing
- Brokerage
- Trading
- Fintech
- Stocks
- Options
- Crypto
- Market Data
- Agentic
- MCP
- Financial Services
image: https://public.com/favicon.ico
apis:
- name: Public Trading API
  description: REST API for programmatic trading on Public — manage brokerage accounts, pull portfolio and transaction history,
    retrieve market data (quotes, bars, option chains, greeks), and place, replace, and cancel equity, crypto, and multi-leg
    options orders. Authentication exchanges a long-lived secret key for a short-lived bearer JWT access token.
  humanURL: https://public.com/api/docs
  baseURL: https://api.public.com
  tags:
  - Trading
  - Market Data
  - Brokerage
  - Options
  - Cryptocurrency
  tags_raw:
  - Trading
  - Market Data
  - Brokerage
  - Options
  - Crypto
  properties:
  - type: Documentation
    url: https://public.com/api/docs
  - type: Quickstart
    url: https://public.com/api/docs/quickstart
  - type: Authentication
    url: authentication/public-authentication.yml
  - type: OAuthScopes
    url: scopes/public-scopes.yml
  - type: ChangeLog
    url: https://public.com/api/docs/changelog
  - type: SDKs
    url: packages/public-packages.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/public-domain-security.yml
- type: Website
  url: https://public.com
- type: DeveloperPortal
  url: https://public.com/api
- type: Documentation
  url: https://public.com/api/docs
- type: GettingStarted
  url: https://public.com/api/docs/quickstart
- type: ChangeLog
  url: changelog/public-changelog.yml
- type: SignUp
  url: https://public.com/signup
- type: Pricing
  url: https://public.com/disclosures/fee-schedule
- type: TermsOfService
  url: https://public.com/terms-of-service
- type: PrivacyPolicy
  url: https://public.com/privacy-policy
- type: Support
  url: https://help.public.com
- type: Blog
  url: https://public.com/learn
- type: GitHubOrganization
  url: https://github.com/PublicDotCom
- type: Packages
  url: packages/public-packages.yml
- type: SDKs
  url: packages/public-packages.yml
- type: CLI
  url: cli/public-cli.yml
- type: MCPServer
  url: mcp/public-mcp.yml
- type: WellKnown
  url: well-known/public-well-known.yml
- type: LLMsTxt
  url: llms/public-llms.txt
- type: Authentication
  url: authentication/public-authentication.yml
- type: OAuthScopes
  url: scopes/public-scopes.yml
- type: Conventions
  url: conventions/public-conventions.yml
- type: Conformance
  url: conformance/public-conformance.yml
- type: Lifecycle
  url: lifecycle/public-lifecycle.yml
- type: Postman
  url: https://github.com/PublicDotCom/postman-collection
- type: UsageTerms
  url: terms/public-terms-of-service.yml
- type: DataProcessing
  url: privacy/public-privacy-policy.yml
- type: Eligibility
  url: eligibility/public-eligibility.yml
- type: AIPreferences
  url: ai-preferences/public-ai-preferences.yml
- type: DataLicense
  url: data-license/public-data-license.yml

Public API — frequently asked questions

Does Public have an API?

Yes. APIs.io lists 1 API from Public, including Public Trading API.

How do I authenticate with the Public API?

Public documents its authentication (http/oauth2 · 2 schemes). The details are profiled on APIs.io as Public Authentication.

Does Public have an MCP server?

Yes. APIs.io lists 1 MCP server for Public: Public's hosted, remote MCP server — described by Public as part of "the world's first agentic brokerage." Lets AI assistants query portfolios and place trades on a connected Public account across sto

Is the Public API ready for AI agents?

Public has a Kin Score of 37.9 out of 100 (thin) and an Agent Readiness score of 27.3 (agent-aware), scored by API Evangelist on 2026-11-13.

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

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