Juniper Square vs Carta: API, MCP and investor access compared
Both are US LP portals that also run a fund administration service on the same platform, and both give investors one login across every fund they hold there. This page sets the two registry entries side by side: how investors log in, whether an API or MCP server exists and for whom, what files can be exported, and what the terms say about automation.
Side by side
| Field |  Juniper Square Investor Portal |  Carta LP Portal |
|---|---|---|
| Vendor | Juniper SquareCountry: US Vendor site | CartaCountry: US Vendor site |
| Category | LP portal | LP portal |
| Regions | North America | North America, Europe, Global |
| Asset classes | Private equity, Venture capital, Real estate, Private credit | Venture capital, Private equity |
| Web and SSO | AvailableSSO: SAML and Microsoft | AvailableSSO: not recorded |
| API | Partner onlyStyle: REST Audience: GP, fund administrator and partner Docs: not public | Partner onlyStyle: REST Auth: OAuth 2 authorization code and OAuth 2 client credentials Audience: GP and partner Sandbox: yes API docs |
| Investor-side API | Not offeredFrom the registry assessment | UnknownFrom the registry assessment |
| MCP | BetaMaintainer: vendor Endpoint: not published MCP docs | AvailableMaintainer: vendor Endpoint: https://mcp.app.carta.com/mcpTransport: Streamable HTTP Auth: OAuth 2 MCP docs |
| SFTP | Partner only | Partner only |
| Webhooks | Partner only | Unknown |
| Email notifications | Unknown | Available |
| Export formats | ||
| Capabilities | Documents, Tax documents, Subscriptions, Capital calls, Distributions, Capital account statements, Performance, KYC | Documents, Capital calls, Distributions, Capital account statements, Tax documents, Fund reports, Subscriptions, KYC, Performance |
| Standards | ILPA capital call template, OpenAPI, SAML SSO | OAuth 2 |
| Difficulty | 4 / 5Web login only, exports possible | 3 / 5Exports, SFTP or email feeds, no investor-side API |
| Automation policy and terms | ProhibitedTerms | UnknownTerms URL not recorded |
| Known deployments | 1Funds administered by Juniper Square | 1Funds administered by Carta |
| Verification | UnverifiedUpdated 2026-11-07 | UnverifiedUpdated 2026-11-07 |
"Not documented" and "Unknown" mean the researchers found no public statement either way, not that the feature is missing.
Key differences
- API. Juniper Square: partner only (REST, for GP, fund administrator and partner users). Carta: partner only (REST, OAuth 2 authorization code and OAuth 2 client credentials, for GP and partner users, public docs, sandbox).
- MCP server. Juniper Square: in beta (vendor-maintained). Carta: available (vendor-maintained, endpoint published, Streamable HTTP, OAuth 2).
- Webhooks. Juniper Square: partner only. Carta: not documented.
- Email notifications. Juniper Square: not documented. Carta: available.
- Investor-side API. The assessment records access for the investor as not offered for Juniper Square and unknown for Carta.
- Difficulty. The registry rates Juniper Square 4 of 5 (web login only, exports possible) and Carta 3 of 5 (exports, SFTP or email feeds, no investor-side API). The rating describes how hard programmatic access is for an investor, not product quality.
- Capabilities. Listed for Carta only: Fund reports.
- Regions. Listed for Carta only: Europe and Global.
- Asset classes. Listed for Juniper Square only: Real estate and Private credit.
- Standards. Listed for Juniper Square only: ILPA capital call template, OpenAPI and SAML SSO; listed for Carta only: OAuth 2.
- Web SSO. Juniper Square lists: SAML and Microsoft; none recorded for Carta.
- Automation in the terms. Recorded as prohibited for Juniper Square and unknown for Carta.
What the entries have in common
- SFTP: both are recorded as partner only.
- Export formats: both list PDF.
- Known deployments: 1 each in the registry.
Which fits which need
Neither product is right for every team. The statements below are conditional and come straight from the registry fields above.
For investors and LP operations teams
- If your investors or your operations team need documents and data through an API, the registry records the API as partner only (aimed at GP, fund administrator and partner users) for Juniper Square and partner only (aimed at GP and partner users) for Carta. Access for the investor itself is recorded as not offered for Juniper Square and unknown for Carta.
- If you want to reach the data from an AI assistant, the MCP server is in beta for Juniper Square and available for Carta. A vendor MCP server can still be limited to the vendor's direct customers, so read the research notes below for who may sign in.
- If you process capital call and distribution notices from your inbox, email notifications are not documented for Juniper Square and available for Carta.
- If you load files into your own systems, the registry lists PDF for both.
- If you plan to automate your own login, automation in the terms is prohibited for Juniper Square and unknown for Carta. Where it is prohibited or unknown, ask the GP or the vendor for a sanctioned channel first.
For GPs, fund administrators and buyers
- If you need to connect the product to your back office, Juniper Square records API partner only, webhooks partner only and SFTP partner only; Carta records API partner only, webhooks not documented and SFTP partner only.
- If the product must carry the core LP reporting items (capital calls, distributions, capital account statements and tax documents), the structured capabilities cover all four for both.
- If your investors are concentrated in particular markets, the regions recorded are North America for Juniper Square and North America, Europe and Global for Carta.
- If you manage a specific strategy, the asset classes recorded are private equity, venture capital, real estate and private credit for Juniper Square and venture capital and private equity for Carta.
- If you want to see who already runs each product, the registry documents 1 known deployment for each. The portal pages name the operators.
- If your investors will want programmatic access later, the difficulty rating is 4 of 5 for Juniper Square and 3 of 5 for Carta, where 1 is a documented self-serve API an investor can use and 5 is web login only with MFA.
For a structured shortlist beyond these two products, see the guide how to choose an investor portal.
What the research says
Juniper Square Investor Portal
Assessment. LP side is web login with 2FA only. GP-side REST API, webhooks, SFTP and a read-only MCP server exist but are not offered to investors. Terms prohibit automated queries without written permission.
Research notes. High confidence (vendor pages 2026-11-07): GP-side REST API, webhooks, inbound SFTP and a read-only MCP server exist, all sales-led and not offered to investors. Also sold as a fund administration service on the same platform. LP access is the web portal with 2FA. Unknown: LP email notification behaviour, MCP endpoint and auth.
- Web: One Juniper Square login reused across every sponsor portal (700k+ investors). 2FA available to investors, methods not stated. SSO (Okta, Microsoft Entra ID) for enterprise GP users.
- API: GP-side REST API and webhooks aligned with OpenAPI, sales-led, no public reference docs. No LP-facing API. A headless LP portal is on the vendor roadmap.
- MCP: Headless GPX MCP server, live with select customers since June 2026, read-only tools (contacts, accounts, positions, documents, transactions). GP-side only. Endpoint and auth not published. Not in the official MCP registry.
- SFTP: Inbound only, for administrators and GPs posting statements into Juniper Square.
- Webhooks: GP-side only.
- Terms: End User Terms and Website Terms prohibit scraping, robots and other automated queries without prior written permission, and sharing passwords with advisers.
Sources: www.junipersquare.com/platform/investor-portal · www.junipersquare.com/gpx/apis-and-integrations · www.junipersquare.com/gpx/headless · www.junipersquare.com/terms-and-policies/end-user-terms-of-use
Carta LP Portal
Assessment. Publicly documented OAuth API with sandbox and a vendor MCP server, both oriented to fund managers and partners. LP access to own commitments via API or MCP unconfirmed. Email notices give a machine-readable trigger.
Research notes. High confidence: public API docs with sandbox, production gated; vendor MCP server with OAuth sign-in. Carta also runs a fund administration service on this platform. Unknown: whether an LP can use the MCP server or an API scope for their own commitments; terms on automation.
- Web: Single LP login across all funds administered on Carta. 2FA set up at registration; methods not confirmed. Multi-select download of K-1s, capital notices and annual reports.
- API: Public docs and a mock server; production access requires Carta approval. Suites: Launch, Investor (portfolio cap-table data for fund operators), Issuer, Portfolio, CRM. No LP self-serve path for fund-account data found.
- MCP: Vendor remote MCP server, Anthropic-verified connector since May 2026. Tools include discover, fetch, list_accounts, cap_table_chart. Fund performance and accounting data for investors are mentioned; documents and capital calls are not. LP coverage unconfirmed.
- SFTP: Only for the separate Carta LP Portfolio Analytics product (formerly Accelex).
- Email: Capital call notices emailed from investor-notices@carta.com with a link into the portal.
- Terms: Terms page returned HTTP 403 to the researcher.
Sources: docs.carta.com/api-platform/guides/getting-started/introduction/ · claude.com/connectors/carta · support.carta.com/kb/en/limited-partners-425509
Frequently asked questions
Does Juniper Square or Carta have an API investors can use?
Juniper Square: API partner only (REST, for GP, fund administrator and partner users), investor-side access not offered. Carta: API partner only (REST, OAuth 2 authorization code and OAuth 2 client credentials, for GP and partner users, public docs, sandbox), investor-side access unknown. These are registry records from public sources, so confirm current terms with the vendor.
Do Juniper Square and Carta offer an MCP server?
Juniper Square: in beta (vendor-maintained). Carta: available (vendor-maintained, endpoint https://mcp.app.carta.com/mcp, Streamable HTTP, OAuth 2). Vendor MCP servers often serve the vendor's direct customers first, such as GP teams, rather than every investor.
How hard is it to get data out of Juniper Square and Carta automatically?
The registry rates Juniper Square 4 of 5 (web login only, exports possible) and Carta 3 of 5 (exports, SFTP or email feeds, no investor-side API). The scale runs from 1, a documented self-serve API an investor can use, to 5, web login only with MFA.
May I automate my login to Juniper Square or Carta?
Juniper Square's terms prohibit automated access, so use an API, export or delegated user the vendor offers. Carta's position on automated access is not recorded; check the terms before automating.
Is this comparison affiliated with Juniper Square or Carta?
No. OpenInvestorPortal is independent community research built from an open registry. It is not affiliated with, sponsored by or reviewed by Juniper Square or Carta. Both entries were last updated on 2026-11-07, and corrections are welcome by pull request or email to hello@openinvestorportal.com.