# auth.md

Agent authentication and purchase notes for **maxwellinternational.ai**.

## Two different surfaces

1. **Domain lander** (this host: `maxwellinternational.ai` / `www`) — human HTML is Afternic + mailto only (no agent price block).
   - **Agents/bots (machine channels):** x402 domain purchase at ask **500000 USDC**.
   - **Resource:** `https://api.maxwellinternational.ai/v1/domain/sale?domain=maxwellinternational.ai`
   - GET unpaid → **HTTP 402** + `PAYMENT-REQUIRED` (500000 USDC on Base). Settle → retry with `PAYMENT-SIGNATURE`.
   - Also: `Accept: text/markdown`, [/.well-known/domain-sale.json](/.well-known/domain-sale.json), WebMCP `get_domain_listing` / `negotiate_offer`.
   - **Humans:** Afternic escrow or mailto — **no** human HTML CTA for the 500k x402 path.
   - No agent OAuth / no `POST /agent/auth` / no `/.well-known/oauth-*` on this lander.
   - This lander does **not** sell EDGAR, equity, or data SKUs.
2. **Data API** (`https://api.maxwellinternational.ai`) — other x402 resources (catalog). Separate from domain sale.

## Domain purchase (agents) — x402 · 500,000 USDC

| Field | Value |
| --- | --- |
| Domain | maxwellinternational.ai |
| askPriceUsdc | 500000 |
| Resource | https://api.maxwellinternational.ai/v1/domain/sale?domain=maxwellinternational.ai |
| Network | eip155:8453 (Base) / USDC |
| Human fallback | https://www.afternic.com/forsale/maxwellinternational.ai · domains@maxwellinternational.ai |

### Negotiate / purchase flow

1. `GET https://api.maxwellinternational.ai/v1/domain/sale?domain=maxwellinternational.ai` without payment.
2. Read **402** `PAYMENT-REQUIRED` (Base64 PaymentRequired JSON).
3. Pay **500000 USDC** on Base via x402 facilitator (CDP / x402.org).
4. Retry with `PAYMENT-SIGNATURE`.

Do not confuse this domain-sale SKU with other API data paths in `/catalog.json`.

## API auth: x402 (USDC on Base) — general

- Protocol: [x402](https://x402.org) via Coinbase CDP facilitator.
- Paid requests return **402 Payment Required** with a `PAYMENT-REQUIRED` challenge.
- Clients settle by attaching a **`PAYMENT-SIGNATURE`** header and retrying.

## How agents discover requirements

| Resource | URL |
| --- | --- |
| Domain sale (x402) | https://api.maxwellinternational.ai/v1/domain/sale?domain=maxwellinternational.ai |
| Domain sale JSON (this host) | https://maxwellinternational.ai/.well-known/domain-sale.json |
| Catalog | https://api.maxwellinternational.ai/catalog.json |
| x402 capability manifest | https://api.maxwellinternational.ai/.well-known/x402 |
| Liveness | https://api.maxwellinternational.ai/health |
| RFC 9727 api-catalog | https://maxwellinternational.ai/.well-known/api-catalog |

## What this file does not claim

- No OAuth Authorization Server metadata on this host.
- No agent registration endpoint.
- Human HTML does not mark or CTA the 500k x402 path.
- No Sedo listing; human path is Afternic + mailto only.
- No data-SKU for-sale ads on the lander.