Developer Platform | API

Build with equity, together

Carta’s API platform unlocks equity data across private markets—empowering customers and partners with their ownership.

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Streamlined onboarding and consolidated resources

Self-service test access

Leverage Carta test data during implementation easily through our developer portal.

Developer support

Access documentation, guidance, and resources to help you every step of the way.

Reference guides

Get onboarding tips, common integration use cases, and implementation patterns based on your needs.

Designed to support your team’s unique use cases

In the last year, Carta debuted four API suites for ecosystem partners:

Issuer API

Embed company data into platforms such as HRIS, law firm portals, and financial services.

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Investor API

Retrieve cap table and holdings data to monitor and report on investments.

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Portfolio API

Use data for personal wealth management, estate planning, and other financial needs.

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Launch API

Seamlessly create and set up new Carta accounts.

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See how others have built with our platform

Automating Carta cap table setup

Stripe Atlas uses the Launch API to automate Carta cap table onboarding post-incorporation.

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Rippling Simplifying compensation management

Rippling uses the Issuer API to consolidate compensation data for efficient HRIS reporting and planning.

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Simplifying client management and cap table creation with Cooley

Cooley uses the Issuer API and Launch API to streamline cap table creation and client management.

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Improving users’ wealth management experience

Compound uses the Portfolio API to help clients make the best possible decisions concerning their financial well-being.

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Providing compensation transparency with ChartHop

ChartHop uses the Issuer API to empower HR admin in compensation decisions and provide employee visibility.

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Working with Carta's APIs has enabled us to give our joint customers a 360-degree view of employee compensation.

Brad Armstrong, SVP of Business Development

We're excited to deepen our partnership with Carta – the Launch API helps founders get started as fast as possible.

Jeff Weinstein, Product Lead

Thanks to the Investor API we now have real-time cap table updates of our portfolio companies in our Salesforce.

Jean-Luc Vanhulst, Venture Partner

Carta’s API has enabled Assemble to deliver a rich, integrated experience for equity compensation workflows.

Lisa Wallace, Co-founder and CEO

Carta’s API creates a seamless flow for clients, who rely on our platform and team to manage their wealth holistically.

Jordan Gonen, CEO

The Investor API lets Foresight customers add real-time ownership data to analysis of their portfolio companies or fund.

Jason Miller, Founder and CEO

We look forward to leveraging Carta’s new API integrations for the benefit of our company clients.

Peter Werner, Co-chair of Global ECVC Practice

With Carta APIs, we’re empowering users to access equity data in ChartHop, creating more visibility around total comp.

Justin Garrity, VP of Product

Carta’s Issuer API has helped streamline our client workflows, which ensure global equity compliance with local laws.

Valentin Haarscher, Co-founder and CEO

Carta's APIs greatly enhanced our customer experience! Implementation was smooth and their team was always ready to help.

Max Bruner, CEO

Customers used to input equity data manually, but the Issuer API allows them to focus solely on global employment needs.

Michael McCormick, SVP of Product and Engineering

Great experience launching Carta’s API. Their team was responsive & collaborative and the resources were very helpful.

Amrita Banerjee, Head of Product

We were excited to work with Carta – the Launch API sets up a founder for success right out the gate post-incorporation.

Mark Milastsivy, Founder and CEO

Partnering with Carta was a no brainer – setup for the Portfolio API was quick, and it’s been a time saver for our users.

Dave Thornton, Co-founder and CEO

The Portfolio API has made it easy for our customers to auto-populate their private equity in their trust.

Alessandro Chesser, Co-founder and CEO

The Portfolio API has made it easy for our customers to auto-populate their private equity in their trust.

David J LaPlaca, Founder and CEO

Getting started

What is the timing for getting API access?

Access to our playground environment is self service using the Quickstart documentation here. Production access requires Carta approval but will be automatic for Carta customers starting Q3 2026.

Where can I find API information to learn more?

Check out our API Documentation to explore Carta’s developer platform more in-depth. The API Reference, Quickstart Guide, and Playground Environment are great starting points.

Can I interact with sample data prior to getting playground access?

Yes, Carta offers a mocking service. We invite you to experiment with our mocking service while waiting for broader API access in 2024. It doesn’t require genuine credentials and always returns static but valid responses to your requests.

Build with equity, together

Build your business with Carta’s API platform to better support your team’s unique use cases.