Carta

Carta is an equity management platform offering a REST API for cap table management, 409A valuations, fund administration, employee equity plans, and investor portfolio management. Carta's Developer Platform exposes four API suites — Launch, Investor, Issuer, and Portfolio — authenticated via OAuth 2.0 (Authorization Code and Client Credentials flows). Partner access is invite-only and requires SOC 2 Type 2 certification; Carta customers may request access to their own data on demand. A mock API environment at mock-api.carta.com is provided for sandbox development.

Carta is listed with 6 APIs on the APIs.io network. Tagged areas include Equity Management, Cap Table, 409A Valuations, Fund Administration, and Employee Equity.

The Carta catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Carta’s developer surface includes sandbox, authentication, API reference, getting-started guide, support, documentation, engineering blog, and 34 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

40.8/100 developing ▼ -8.4 Agent 50/100 agent ready Front door AI 5/6 prominent Heartbeat 50/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreeSelf serve⚡ Free to try

6 APIs 1 MCP Servers 2 Agent Skills

Equity Management Cap Table409A ValuationsFund AdministrationEmployee EquityInvestor PortfolioPrivate Markets Fintech Startups

Kin Score

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

Composite quality — 40.8/100 · developing

Contract Quality 4.4 / 19

Developer Ergonomics 6.0 / 15

Access Clarity 7.1 / 15

Operational Transparency 4.6 / 10

Contract Governance 2.0 / 9

Discoverability 6.1 / 8

Regulatory Posture 3.5 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 50/100 · agent ready

Machine-Readable Contract 18 / 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 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

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 Horizontal (data, software, accessibility, platform) 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 applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% 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):

Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
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)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too

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 23.7 — up to +19.1 composite points
Developer Ergonomics scores 39.9 — up to +12.0 composite points
Access Clarity scores 47.4 — up to +10.5 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/carta/apis.yml: open an issue on github.com/api-evangelist/carta 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)	standard	51.7	-	-
Zoom App Marketplace and Partner Ecosystem (builders and partners on Zoom)	standard	51.7	-	-

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 6

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

Carta Launch API

Enables incorporation partners and law firms to programmatically onboard new companies onto the Carta platform, streamlining the company formation and cap table initialisation w...

Carta Investor API

Permits fund operators to retrieve cap table summaries and portfolio position data for their holdings, enabling downstream analytics, reporting, and portfolio management workflows.

Carta Issuer API

Allows law firms and technology partners to retrieve cap table data on behalf of companies, supporting legal workflows, equity issuance, and 409A valuation processes.

Carta Portfolio API

Enables personal finance and wealth management platforms to aggregate equity holdings data for individuals, supporting estate planning, tax preparation, option financing, and un...

Carta CRM API

Facilitates deal and fundraising relationship management across investment processes for fund operators, providing structured access to CRM data within the Carta platform.

Carta API

Carta API as documented publicly: 40 operations. Contract generated from the documentation by API Evangelist (2026-10-20); not the provider's own document.

MCP Servers 1

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

Carta MCP Server

Remote MCP server at mcp.app.carta.com over HTTP.

MCP SERVER

Agent Skills 2

Packaged agent skills for driving this provider's APIs from an AI assistant.

carta-book-capital-call

AGENT SKILL

carta-list-fund-investments

AGENT SKILL

Carta API pricing

Not yet checked against Carta's own pricing page. Compiled by API Evangelist; confirm before you rely on a figure.

Plan	Price
Customer Self-Service	—
Partner Program (Invite-Only)	—
Playground / Sandbox	—

Plan details, limits and sources →

Rate limits

per-second: Up to 10 requests/second
per-minute: Up to 300 requests/minute

Rate-limit details →

Pricing Plans 1

Published pricing tiers and plan structures.

Carta Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Carta Rate Limits

2 limits

RATE LIMITS

FinOps 1

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

Carta Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Carta Context

10 classes · 0 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Carta API Rules

10 rules · 8 errors 1 warnings 1 info

SPECTRAL

JSON Schema 6

Standalone JSON Schema definitions for this provider's data models.

GetV1Alpha1IssuersIssueridTransactionsResponse

1 properties

JSON SCHEMA

PostV1Alpha1InvestorsFirmsFirmidFundsFundidCapitalcallsReque

4 properties

JSON SCHEMA

PostV1Alpha1InvestorsFirmsFirmidFundsFundidCapitalcallsRespo

2 properties

JSON SCHEMA

PostV1Alpha1InvestorsFirmsFirmidFundsFundidManagementfeesReq

4 properties

JSON SCHEMA

PostV1Alpha1InvestorsFirmsFirmidFundsFundidManagementfeesRes

1 properties

JSON SCHEMA

PostV1Alpha1IssuersIssueridSecuritiesStocksplitchangesRespon

3 properties

JSON SCHEMA

Security Posture 3

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

Carta Authentication

2 schemes

SECURITY

Carta Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Carta Trust Center

SOC 2, ISO 27001, GDPR

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

Sandbox

Sandbox

GettingStarted

GettingStarted

Login

Documentation 2

Reference material describing how the API behaves

APIReference

APIReference

Documentation

Documentation

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgentSkill

LLMsTxt

MCPServer

WellKnown

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

Conventions

ErrorCatalog

Conformance

Scroll for all 7

Build 3

SDKs, sample code, and the tooling you integrate with

ToolCrosswalk

ToolCrosswalk

IntegrationEdges

IntegrationEdges

GitHubOrg

GitHubOrg

Access & Security 6

Authentication, authorization, and security posture

Compliance

Authentication

SecurityTxt

Security

TrustCenter

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

Support

Support

StatusPage

StatusPage

RateLimits

RateLimits

Commercial 5

Pricing, plans, and the legal terms of use

TermsOfService

PrivacyPolicy

Pricing

Plans

FinOps

Company 4

The organization behind the API

Newsroom

Newsroom

Website

Website

LinkedIn

Blog

Blog

Other 4

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Leadership

Leadership

Source (apis.yml)

aid: carta
name: Carta
description: Carta is an equity management platform offering a REST API for cap table management, 409A valuations, fund administration,
  employee equity plans, and investor portfolio management. Carta's Developer Platform exposes four API suites — Launch, Investor,
  Issuer, and Portfolio — authenticated via OAuth 2.0 (Authorization Code and Client Credentials flows). Partner access is
  invite-only and requires SOC 2 Type 2 certification; Carta customers may request access to their own data on demand. A mock
  API environment at mock-api.carta.com is provided for sandbox development.
type: Index
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: free
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Free · Self-serve signup
  confidence: high
  probe_state: covered
  source:
  - plans
  - authentication
  - rate-limits
  - security
  - sandbox
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/carta.png
url: https://raw.githubusercontent.com/api-evangelist/carta/refs/heads/main/apis.yml
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.23'
x-docs-platform: docusaurus
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-09-21
tags:
- Equity Management
- Cap Table
- 409A Valuations
- Fund Administration
- Employee Equity
- Investor Portfolio
- Private Markets
- Fintech
- Startups
tags_raw:
- Equity Management
- Cap Table
- 409A Valuations
- Fund Administration
- Employee Equity
- Investor Portfolio
- Private Markets
- FinTech
- Startups
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
common:
- type: AgentSkill
  url: skills/_index.yml
- type: Spectral
  url: rules/carta-rules.yml
- type: JSONLD
  url: json-ld/carta-context.jsonld
- type: Vocabulary
  url: vocabulary/carta-vocabulary.yml
- type: DataModel
  url: data-model/carta-data-model.yml
- type: Conventions
  url: conventions/carta-conventions.yml
- type: Sandbox
  url: sandbox/carta-sandbox.yml
- type: Compliance
  url: https://trust.carta.com/
- type: Authentication
  url: authentication/carta-authentication.yml
- type: ErrorCatalog
  url: errors/carta-problem-types.yml
- type: Conformance
  url: conformance/carta-conformance.yml
- type: LLMsTxt
  url: llms/carta-llms.txt
- type: ToolCrosswalk
  url: mcp/carta-tool-crosswalk.yml
- type: MCPServer
  url: mcp/carta-mcp.yml
- type: SecurityTxt
  url: well-known/carta-status-security.txt
- type: WellKnown
  url: well-known/carta-well-known.yml
- type: Hosts
  url: hosts/carta-hosts.yml
- type: IntegrationEdges
  url: integrations/carta-integration-edges.yml
- type: Vendors
  url: vendors/carta-vendors.yml
- type: TermsOfService
  url: https://carta.com/terms-of-service/
- type: Security
  url: https://carta.com/security/generative-ai-at-carta/
- type: PrivacyPolicy
  url: https://carta.com/privacy/
- type: Newsroom
  url: https://carta.com/press/
- type: Leadership
  url: https://carta.com/learn/private-funds/management/
- type: APIReference
  url: https://docs.carta.com/api-platform/reference/v-1-alpha-1-draft-issuers-create-draft-issuer
- type: GettingStarted
  url: https://docs.carta.com/api-platform/guides/getting-started/quickstart-guide
- type: Login
  url: https://login.app.carta.com/credentials/login/
- type: Support
  url: https://docs.carta.com/api-platform/guides/references/faq-and-support
- type: TrustCenter
  url: security/carta-trust-center.yml
- type: DomainSecurity
  url: security/carta-domain-security.yml
- type: Website
  url: https://carta.com
- type: Documentation
  url: https://docs.carta.com/api-platform/guides/getting-started/introduction
- type: GitHubOrg
  url: https://github.com/carta
- type: LinkedIn
  url: https://www.linkedin.com/company/carta--
- type: Blog
  url: https://carta.com/blog/
- type: Pricing
  url: https://carta.com/plans/pricing-for-investors/
- type: StatusPage
  url: https://status.carta.com
- type: X
  url: https://x.com/cartainc
- type: Plans
  url: plans/carta-plans-pricing.yml
- type: RateLimits
  url: rate-limits/carta-rate-limits.yml
- type: FinOps
  url: finops/carta-finops.yml
apis:
- aid: carta:launch-api
  name: Carta Launch API
  description: Enables incorporation partners and law firms to programmatically onboard new companies onto the Carta platform,
    streamlining the company formation and cap table initialisation workflow.
  humanURL: https://docs.carta.com/api-platform/guides/getting-started/introduction
  baseURL: https://api.carta.com
  tags:
  - Incorporation
  - Company Onboarding
  - Cap Table
  properties:
  - type: Documentation
    url: https://docs.carta.com/api-platform/guides/getting-started/introduction
- aid: carta:investor-api
  name: Carta Investor API
  description: Permits fund operators to retrieve cap table summaries and portfolio position data for their holdings, enabling
    downstream analytics, reporting, and portfolio management workflows.
  humanURL: https://docs.carta.com/api-platform/guides/getting-started/introduction
  baseURL: https://api.carta.com
  tags:
  - Investor
  - Portfolio
  - Cap Table
  - Fund Management
  properties:
  - type: Documentation
    url: https://docs.carta.com/api-platform/guides/getting-started/introduction
- aid: carta:issuer-api
  name: Carta Issuer API
  description: Allows law firms and technology partners to retrieve cap table data on behalf of companies, supporting legal
    workflows, equity issuance, and 409A valuation processes.
  humanURL: https://docs.carta.com/api-platform/guides/getting-started/introduction
  baseURL: https://api.carta.com
  tags:
  - Issuer
  - Cap Table
  - 409A
  - Legal
  properties:
  - type: Documentation
    url: https://docs.carta.com/api-platform/guides/getting-started/introduction
- aid: carta:portfolio-api
  name: Carta Portfolio API
  description: Enables personal finance and wealth management platforms to aggregate equity holdings data for individuals,
    supporting estate planning, tax preparation, option financing, and underwriting use cases.
  humanURL: https://docs.carta.com/api-platform/guides/getting-started/introduction
  baseURL: https://api.carta.com
  tags:
  - Portfolio
  - Personal Finance
  - Wealth Management
  - Equity Holdings
  properties:
  - type: Documentation
    url: https://docs.carta.com/api-platform/guides/getting-started/introduction
- aid: carta:crm-api
  name: Carta CRM API
  description: Facilitates deal and fundraising relationship management across investment processes for fund operators, providing
    structured access to CRM data within the Carta platform.
  humanURL: https://docs.carta.com/api-platform/guides/getting-started/introduction
  baseURL: https://api.carta.com
  tags:
  - CRM
  - Fundraising
  - Deal Management
  - Fund
  properties:
  - type: Documentation
    url: https://docs.carta.com/api-platform/guides/getting-started/introduction
- aid: carta:carta-api
  name: Carta API
  description: 'Carta API as documented publicly: 40 operations. Contract generated from the documentation by API Evangelist
    (2026-10-20); not

    the provider''s own document.'
  humanURL: https://docs.carta.com/api-platform/reference/v-1-alpha-1-files-upload-file
  baseURL: https://api.carta.com
  properties:
  - type: OpenAPI
    url: openapi/_ae-authored/carta-openapi-generated.yml
    x-provenance: generated
  - type: JSONSchema
    url: json-schema/carta-post-v1-alpha1-investors-firms-firmid-funds-fundid-capitalcalls-reque-schema.json
  - type: JSONSchema
    url: json-schema/carta-post-v1-alpha1-investors-firms-firmid-funds-fundid-managementfees-req-schema.json
  - type: JSONSchema
    url: json-schema/carta-post-v1-alpha1-investors-firms-firmid-funds-fundid-capitalcalls-respo-schema.json
  - type: JSONSchema
    url: json-schema/carta-post-v1-alpha1-issuers-issuerid-securities-stocksplitchanges-respon-schema.json
  - type: JSONSchema
    url: json-schema/carta-get-v1-alpha1-issuers-issuerid-transactions-response-schema.json
  - type: JSONSchema
    url: json-schema/carta-post-v1-alpha1-investors-firms-firmid-funds-fundid-managementfees-res-schema.json
x-coverage:
  state: covered
  reason: covered
  checked: '2026-10-20'
  detail: API Platform reference read and a 40-operation contract generated from docs; CRM MCP tool list documented.
  evidence:
  - url: https://docs.carta.com/api-platform/reference/v-1-alpha-1-investors-list-firms
    status: 200
x-enrichment:
  date: '2026-10-20'
  status: enriched
  artifacts_added: 9
  pass: local-v5

Carta API — frequently asked questions

Does Carta have an API?

Yes. APIs.io lists 6 APIs from Carta, including Carta Launch API, Carta Investor API and Carta Issuer API, and 3 more.

Is there an OpenAPI specification for the Carta API?

Yes. APIs.io indexes 1 OpenAPI specification for Carta, each linked for download from this page.

How do I authenticate with the Carta API?

Carta documents its authentication (2 schemes). The details are profiled on APIs.io as Carta Authentication.

How much does the Carta API cost?

APIs.io lists 3 pricing plans for Carta, with each plan's price, limits and inclusions under Pricing on this page.

Does Carta have an MCP server?

Yes. APIs.io lists 1 MCP server for Carta: Remote MCP server at mcp.app.carta.com over HTTP.

Is the Carta API ready for AI agents?

Carta has a Kin Score of 40.8 out of 100 (developing) and an Agent Readiness score of 49.5 (agent-ready), scored by API Evangelist on 2026-11-06.

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