Consult this site first to locate comprehensive documentation when developing apps to interact with Prosper services.

Investor API Support

If you run into problems using the Investor platform APIs, you can send questions to investorapi@prosper.com. When contacting us, please briefly explain the API call you’re trying to make, and any errors you may have received in response to your call.

If you’d like the ability to purchase whole loans instead of Borrower Payment Dependent Notes (“Notes”), or if you would like to onboard as a third party agent (e.g. you are a broker dealer or Registered Investment Advisor, and you wish to provide investment services for other Prosper investors) please contact the Prosper Capital Markets Team at investorteam@prosper.com.


Borrower Services Support

Prosper Borrower Services include the offers API, Mobile SDK for iOS, and Mobile SDK for Android. Before you can integrate Prosper Borrower Services into your website or mobile experience, you will need to engage the Prosper Business Development team. Send inquiries to the team at bizdev@prosper.com.

If you run into problems using Prosper Borrower Services, reach out to your Partnership Manager directly or send questions to bizdev@prosper.com. When contacting us, please briefly explain the service you’re using (SDK on iOS, SDK on Android, or offers API), the API call you’re trying to make, and any errors you may have received in response to your call.

Investor API FAQs

Q: Why are the Investor APIs changing?

The new Investor APIs are built on a more modern architecture. They run queries faster than before. We also want to move on to the industry-standard security protocol which is OAuth 2.0. Prosper is also able to provide more granular level of data.

Q: When did you release this new platform? When did the old platform cease to exist?

Prosper switched to a new Java framework on December 10, 2015. The old OData API endpoints reached end-of-life status on March 10, 2016.

Q: What is the <base_prosper_address> mentioned in your Investor API reference documentation?

The <base_prosper_address> is the base URI for making API calls. You can find the value for <base_prosper_address> in the Investor API Overview

Q: What security standard do you use?

We use the industry-standard OAuth 2.0 security protocol for authentication. OAuth allows Prosper account holders to grant access to your app to make investments on their behalf without having to provide login information to you directly.

Q: What is an authorization key? How is it different from an authorization code?

In an authorization flow, your client receives an authorization key after a user grants your app authorization to act on their behalf.

An authorization key is a Prosper extension of the standard OAuth 2.0 code. OAuth codes are one-time use codes for a client session.

The authorization key is an authorization code that does not expire. Once an authorization key is generated by the grant, you do not have to regenerate an authorization key.

Q: Why are there two authentication flows? Which one should I use?

If you want to view and/or make investments programmatically for yourself, whether you are an institutional or individual investor, please use the password flow.

If you are a third party agent and want to view/or make investments on someone else’s behalf, please use the authorization grant flow.

Q: What’s a refresh token? How do I use it?

You get a refresh token when you receive an access token. Once the access token expires, you can use the refresh token to receive a new access token.

Q: How long are the tokens valid for?

The access token is valid for 1 hour. The refresh token is valid for 10 hours.

Q: Can I buy whole loans using the Investor APIs?

Only qualified institutional investors can purchase whole loans. To onboard, please get in touch with our investor services team: investorteam@prosper.com

Q: What return formats do your APIs support?

Results are returned in JSON format only. We do not support XML as a return format.

Q: Is there an API throttling limit?

We restrict our API volume to 20 requests per second across all investors, per Client ID + user combination.

Q: Where did ListingsFull and LoansFull go?

Please access them from the following location:
https://www.prosper.com/investor/marketplace#/download

Q: Where is the ListingsWhole API?

We have consolidated listings to a single API: please use the listings API. If you want to see whole loans (and have the permissions) you may use the whole_loan filter.

Q: Where is the Invest API?

The invest API has been renamed orders API.

Q: Where is the Investments API?

We used to provide historical listings through a public endpoint, which we have discontinued. Please retrieve historical listings by downloading the CSV files at the following location:
https://www.prosper.com/investor/marketplace#/download

Q: The Loans API looks different. What’s being returned?

The Loans API will only return loans corresponding to Notes you own. This is different from our previous API standard.

Q: I don’t see a field I expect to see in the result. What happened?

If the result is null, the field will not be returned.

Q: What if I want to create more than one app?

You’ll need to create a separate Prosper account to get a separate client ID.

Q: How do I become an institutional investor?

Please get in touch with Prosper’s Capital Markets Team at investorteam@prosper.com.

Q: I am a Registered Investment Advisor (RIA). How do I get started?

Please get in touch with Prosper’s Capital Markets team at investorteam@prosper.com.

Q: How can I get in touch with you?

If you run into problems using the Investor platform APIs, you can send questions to investorapi@prosper.com. When contacting us, please briefly explain the API call you’re trying to make, any request parameters sent (if applicable), the request body sent (if required for the call), and any errors you may have received in response to your call.