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Prosper

Prosper Marketplace operates one of the largest peer-to-peer (marketplace) lending platforms in the United States, matching individual and institutional investors with consumers seeking personal loans, and also offering a HELOC and a credit-card product. For investors, Prosper publishes a RESTful Investor API that lets individual, institutional, and third-party agents connect directly to the platform to view account balances, search active loan listings, place orders (bids) to purchase Notes, and track owned Notes, loans, and payments. The API uses OAuth 2.0 over SSL with comprehensive filtering and sorting, and offers a sandbox environment for integration testing. This profile was surfaced as a portfolio company of Emergence Capital, IVP, and QED Investors and enriched from Prosper's public developer documentation.

agent aware

Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.

Kin Score

API Evangelist profiles Prosper the way a machine reads it — 4 machine-readable artifacts across 1 API, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.

Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Prosper scores 31.2/100 (thin), with a separate agent-readiness read of 18/100 (agent aware). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.

Kin Score

This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 31.2/100 · thin
Contract Quality 0.0 / 25
Developer Ergonomics 13.0 / 20
Commercial Clarity 8.9 / 20
Operational Transparency 0.0 / 13
Governance 0.0 / 12
Discoverability 9.3 / 10
Agent readiness — 18/100 · agent aware
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 15
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 4 / 4
Consent & Bot Identity 0 / 3

How we profile Prosper

Each block below is one kind of artifact we hold for Prosper. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.

APIs 1

Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.

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

Prosper Investor API

RESTful API for Prosper investors and third-party agents to view account information, search active loan listings, place orders to purchase Notes, and retrieve owned Notes, inve...

MCP Servers 1

Model Context Protocol servers expose these APIs directly to AI agents. We profile them because agent-native access is the fastest-growing way this provider's capabilities actually get used.

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

prosper-mcp.yml

MCP SERVER

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.

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

Prosper Authentication

oauth2 · 3 schemes

SECURITY

Prosper Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Every other property we hold for Prosper — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

Build 1

SDKs, sample code, and the tooling you integrate with

Access & Security 3

Authentication, authorization, and security posture

Operate 2

Status, limits, changes, and where to get help

Commercial 3

Pricing, plans, and the legal terms of use

Company 2

The organization behind the API

← All providers · Data indexed from github.com/api-evangelist/prosper · machine-readable index on apis.io