> ## Documentation Index
> Fetch the complete documentation index at: https://blackswan-23965643.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# BlackSwan: On-Chain Credit Infrastructure for Web3

> BlackSwan is decentralized credit infrastructure that exposes wallet reputation, trust scores, APR, and lending history through REST APIs and SDKs.

BlackSwan is decentralized credit infrastructure built for the next generation of Web3 lending. It transforms raw on-chain activity into actionable credit intelligence — exposing wallet reputation scores, trust ratios, APR recommendations, and full loan history through a suite of REST APIs and developer SDKs. Whether you're building a lending protocol, a DeFi dashboard, or an underwriting engine, BlackSwan gives you the credit primitives you need without requiring centralized intermediaries.

<CardGroup cols={2}>
  <Card title="Quickstart" icon="bolt" href="/getting-started/quickstart">
    Get your first credit score in under 2 minutes.
  </Card>

  <Card title="Credit API Reference" icon="code" href="/api/credit">
    Explore every endpoint in the BlackSwan REST API.
  </Card>

  <Card title="JavaScript SDK" icon="js" href="/sdks/javascript/installation">
    Install and initialize the BlackSwan JS SDK.
  </Card>

  <Card title="Python SDK" icon="python" href="/sdks/python/installation">
    Install and initialize the BlackSwan Python SDK.
  </Card>
</CardGroup>

## What is BlackSwan?

BlackSwan is a protocol-agnostic credit layer for Web3. It reads on-chain data — borrow events, repayments, defaults, wallet age, and activity patterns — and converts that data into standardized credit signals that your application can consume directly.

Instead of rebuilding credit scoring logic from scratch, developers integrate BlackSwan once and immediately gain access to:

* **Structured credit tiers** (A through F) derived from real lending behavior
* **Dynamic APR recommendations** calibrated to a wallet's risk profile
* **Full loan histories** including borrowed amounts, repaid amounts, and default counts
* **Soulbound token (SBT) metadata** that anchors reputation on-chain

BlackSwan is designed for teams building decentralized lending apps, credit marketplaces, risk dashboards, and any protocol where trust and borrower history matter. The API is stateless and requires no authentication on testnet — you can start fetching credit data with a single `curl` command.

## Key Features

<CardGroup cols={2}>
  <Card title="Wallet Reputation" icon="shield-check">
    Aggregate on-chain signals into a single, normalized reputation score for any wallet address.
  </Card>

  <Card title="Credit Scores" icon="chart-bar">
    Tiered credit scores (A–F) derived from real borrowing and repayment history across supported networks.
  </Card>

  <Card title="Trust Ratio" icon="scale-balanced">
    A numeric trust ratio that quantifies creditworthiness on a standardized scale for easy comparison and filtering.
  </Card>

  <Card title="APR Calculation" icon="percent">
    Risk-adjusted APR recommendations calculated per wallet, ready to plug directly into your lending logic.
  </Card>

  <Card title="Loan History" icon="clock-rotate-left">
    Complete borrow, repayment, and default records for any wallet, queryable by address and network.
  </Card>

  <Card title="Soulbound Token" icon="hexagon-check">
    On-chain SBT metadata that permanently anchors a wallet's credit identity to its address.
  </Card>

  <Card title="REST API" icon="plug">
    Simple, stateless HTTP endpoints that work with any language or framework — no SDK required.
  </Card>

  <Card title="JS & Python SDKs" icon="code">
    First-class SDKs for JavaScript/TypeScript and Python with full type support and async-ready interfaces.
  </Card>
</CardGroup>

<Note>
  Testnet access on **Amoy** and **Sepolia** requires no API key. Send requests directly to the API without any authentication headers.
</Note>