# Mastercard Open Finance US (Finicity) API: access, auth, sandbox and MCP

> Mastercard Open Finance US, provided by Finicity, is a REST API with a self-serve Sandbox project and a published OpenAPI 3.0.3 spec. Investment account data comes through the general account and transaction APIs, and Production access requires a contract with Mastercard.

- Vendor: Mastercard (Finicity) (Finicity)
- Website: https://www.finicity.com/
- Category: Account aggregation (adjacent)
- API access: Open: self-serve docs and keys
- Last checked: 2026-10-17
- Id: `finicity` · JSON: https://wealthtech.dev/products/finicity.json

## Developer surface

| Field | Value | Source and quote | Checked |
|---|---|---|---|
| API access | Open: self-serve docs and keys | Checked on the source's own page. [developer.mastercard.com](https://developer.mastercard.com/open-finance-us/documentation/onboarding/) "Open Finance provides Sandbox and Production environments." | 2026-10-17 |
| Developer docs | https://developer.mastercard.com/open-finance-us/documentation/ | Checked on the source's own page. [developer.mastercard.com](https://developer.mastercard.com/open-finance-us/documentation/) "Mastercard Open Finance US enables simple and secure financial data sharing for consumer and small business applications." | 2026-10-17 |
| API style | REST | Checked on the source's own page. [developer.mastercard.com](https://developer.mastercard.com/open-finance-us/documentation/onboarding/) "To use the Open Finance REST APIs, you will need the following:" | 2026-10-17 |
| Authentication | Partner credentials | Checked on the source's own page. [developer.mastercard.com](https://developer.mastercard.com/open-finance-us/documentation/onboarding/) "To create a token, you are required to provide the PartnerID along with the corresponding secret and appKey." | 2026-10-17 |
| How to get access | Create a Sandbox project in the developer dashboard to get a Partner ID, secret and app key; request Production access from the project Summary page, which needs an executed contract with Mastercard. | Checked on the source's own page. [developer.mastercard.com](https://developer.mastercard.com/open-finance-us/documentation/onboarding/) "To request Production access, click the Request Production access button on the Summary page." | 2026-10-17 |
| Sandbox | Yes, self-serve | Checked on the source's own page. [developer.mastercard.com](https://developer.mastercard.com/open-finance-us/documentation/onboarding/) "A Sandbox project gives you access to the Open Finance Test Drive plan. Test Drive is a non-billable, unlimited plan that provides access to all Open Finance API endpoints." | 2026-10-17 |
| Rate limits | Not found | Not found. No numeric rate limits found on the overview, API basics (onboarding), quick start, webhooks or release history pages. The onboarding page says the App Key controls the rate limit and that invalid keys have a rate limit of 0. No numeric rate limits found on the overview, API basics (onboarding), quick start, webhooks or release history pages. The onboarding page says the App Key controls the rate limit and that invalid keys have a rate limit of 0. | 2026-10-17 |
| Webhooks | Yes | Checked on the source's own page. [developer.mastercard.com](https://developer.mastercard.com/open-finance-us/documentation/) "Webhooks deliver real-time event notifications for Data Connect, TxPUSH and report generation." | 2026-10-17 |
| SDKs | Data Connect SDKs (Web, iOS, Android, React Native), client libraries generatable from the OpenAPI spec (Java, C#, JavaScript, Python and more) | Checked on the source's own page. [developer.mastercard.com](https://developer.mastercard.com/open-finance-us/documentation/quick-start-guide/) "Generate type-safe client libraries from the API specification for Java, C#, JavaScript, Python, and more" | 2026-10-17 |
| OpenAPI spec | Published | Checked on the source's own page. [static.developer.mastercard.com](https://static.developer.mastercard.com/content/open-finance-us/swagger/openbanking-us.yaml) "OpenAPI specification for Finicity APIs." | 2026-10-17 |
| Partner program | Partner Linked Access and Partner Direct Model participant models documented | Checked on the source's own page. [developer.mastercard.com](https://developer.mastercard.com/open-finance-us/documentation/participant-model/partner-linked/client/client-steps/) "This page is intended for clients (application developers) who wish to obtain and share an access token (consent receipt) to allow their customers to consent to allow a third party processor to access some of their details" | 2026-10-17 |
| Public integration list | Not found | Not found. No public list of integrations found on the documentation pages read. No public list of integrations found on the documentation pages read. | 2026-10-17 |
| Ways to connect | Native API | Checked on the source's own page. [developer.mastercard.com](https://developer.mastercard.com/open-finance-us/documentation/usecases/investment-data/) "Eligible investment accounts are returned through the regular Account Aggregation and Transaction Data APIs with no need for any additional API calls." | 2026-10-17 |

## MCP servers and AI connectors

- [Mastercard Developers Agent Toolkit (MCP)](https://wealthtech.dev/mcp/finicity-agent-toolkit): Developer-tooling MCP server, Live

## What the docs don't say

- No numeric rate limits are published on the pages read.
- The Investment Data use case page describes accounts, holdings and related activity but names no separate investments product; investment accounts come through the general account and transaction APIs.
- Production access depends on an executed contract with Mastercard, and the pages read state no pricing.

## Changes

No changes recorded since this record was first published.
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Source: https://wealthtech.dev/products/finicity · Facts licensed CC BY 4.0 (attribution "wealthtech.dev"). Every fact states where it was checked and when; check the source before relying on it.