# Aegis KYT — x402 API

> Pay-per-call AML / KYT screening for AI agents. No account, no API key:
> call an endpoint, get HTTP 402 with payment requirements, pay in USDC on
> Base, retry with the payment header. Same engine and prices as the
> key-based V2 API.

## Endpoints

- `GET https://x402.aegis-kyt.com/screen/{chain}/{address}` — labels + consensus risk, no graph traversal — $0.10
- `GET https://x402.aegis-kyt.com/check-address/{chain}/{address}` — full 4-tier verdict (sanctions, label consensus, 1-hop inheritance, BFS exposure) — $1.00
- `GET https://x402.aegis-kyt.com/check-transfer/{chain}/{tx_hash}` — Transaction Check (KYT): decodes the tx, analyses every sender, applies the Aegis Standard policy. Waits up to 30 s, otherwise 202 with a free retry URL — $1.00
- `GET https://x402.aegis-kyt.com/check-transfer-result/{check_id}` — free retry for a paid check-transfer
- `GET https://x402.aegis-kyt.com/health` — liveness, free

EVM addresses are case-insensitive; TRON, BTC and SOL addresses are
case-sensitive base58 — send them exactly as they appear on-chain.
Results are risk scores and exposure evidence, not accusations.

## Machine-readable

- [x402 discovery](https://x402.aegis-kyt.com/.well-known/x402.json): paid endpoints, prices, settlement network
- [OpenAPI 3.1](https://x402.aegis-kyt.com/openapi.json): paid operations with `x-payment-info` (price, protocol)
- [OpenAPI reference](https://docs.aegis-kyt.com/openapi.json): full reference copy in the docs
- [Resource list](https://x402.aegis-kyt.com/.well-known/x402): `{version, resources[]}` for catalogs
- [API catalog](https://aegis-kyt.com/.well-known/api-catalog): RFC 9727 linkset of all Aegis APIs
- [Aegis llms.txt](https://aegis-kyt.com/llms.txt): both APIs, which one to use

## Docs

- [x402 protocol](https://docs.aegis-kyt.com/authentication/x402.md): the 402 → pay → retry flow on the wire
- [Quickstart](https://docs.aegis-kyt.com/quickstart.md)
- [Networks](https://docs.aegis-kyt.com/reference/networks.md)
- [Error codes](https://docs.aegis-kyt.com/reference/error-codes.md)