> ## Documentation Index
> Fetch the complete documentation index at: https://docs.0xtrustline.online/llms.txt
> Use this file to discover all available pages before exploring further.

# Getting started

> Revenue-underwritten, uncollateralized USDC credit for AI agents on Stellar.

**TrustLine is a revenue-underwritten, uncollateralized USDC credit protocol for AI agents on Stellar.** An agent proves what it actually earns — on-chain x402 revenue, optionally backed by a zkTLS-verified off-chain figure — and gets a credit line sized and priced against that proof. It draws and repays autonomously. No collateral, no human in the loop, no wallet-age heuristics.

<Note>
  **Status:** live, working prototype on Stellar **testnet**. The core loop (earn → prove → underwrite → borrow → repay → lender yield) runs end-to-end on real testnet infrastructure. Not yet on mainnet — see [Roadmap](/roadmap) for what that requires.
</Note>

## The five-second mental model

<Steps>
  <Step title="Earn">
    An agent earns real USDC revenue (x402 payments, optionally + a zkTLS-proven off-chain figure).
  </Step>

  <Step title="Prove independence">
    TrustLine's underwriting engine checks that revenue is genuinely **independent** (not the agent quietly paying itself), scores it, and publishes the score on-chain.
  </Step>

  <Step title="Price">
    An on-chain `credit_line` contract derives a credit limit and APR from that score.
  </Step>

  <Step title="Fund">
    Lenders deposit USDC into the agent's **isolated vault** — exposed only to that one agent's default risk, never pooled across agents.
  </Step>

  <Step title="Borrow & repay">
    The agent borrows against its line and repays as it earns. On-time repayment ramps the limit up over time; a default collapses it and socializes the loss to that vault's lenders via a first-loss reserve.
  </Step>
</Steps>

## What do you want to do?

<CardGroup cols={2}>
  <Card title="What & why" icon="lightbulb" href="/what-and-why">
    Understand *why* this exists and the core thesis.
  </Card>

  <Card title="Architecture" icon="diagram-project" href="/architecture">
    See how the pieces fit together — contracts, backend, SDK.
  </Card>

  <Card title="How the credit engine works" icon="gears" href="/credit-engine">
    Understand exactly how revenue is judged and scored.
  </Card>

  <Card title="Onboarding kit" icon="rocket" href="/onboarding-kit">
    Build an AI agent that earns credit on TrustLine.
  </Card>

  <Card title="SDK reference" icon="code" href="/sdk-reference">
    The full agent-facing API — JavaScript/TypeScript and Python.
  </Card>

  <Card title="Contract addresses" icon="file-contract" href="/contracts">
    Look up a deployed contract ID.
  </Card>
</CardGroup>

## Quick links

<CardGroup cols={2}>
  <Card title="Live app" icon="globe" href="https://0xtrustline.online">
    0xtrustline.online
  </Card>

  <Card title="Live underwriter" icon="magnifying-glass-chart" href="https://0xtrustline.online/underwrite">
    Paste any address, watch a live verdict.
  </Card>

  <Card title="GitHub" icon="github" href="https://github.com/TechnicallyKiller/TrustLine">
    TechnicallyKiller/TrustLine
  </Card>

  <Card title="Roadmap" icon="road" href="/roadmap">
    See what's shipped vs. planned.
  </Card>
</CardGroup>

The backend API is at `https://trustline-rpxt.onrender.com`.

## Honest status, up front

<Warning>
  This is a genuine, adversarially-tested testnet prototype — **not** a production lending product. The credit-risk engine, anti-Sybil independence model, and safety rails are real and tested (fuzzed contracts, a live on-chain default run, a synthetic + live attacker catalog). What's explicitly **not** yet true: nothing has touched real money or a real adversary, the score-signing key is a single trusted signer (not yet decentralized), and external adoption is still near zero. See [Roadmap](/roadmap) for the plan to close each of these.
</Warning>