---
title: "Paid: Pay-as-you-learn tutor (one charge per answer)"
method: POST
path: "/api/x402/tutor"
---

# Paid: Pay-as-you-learn tutor (one charge per answer)

`POST /api/x402/tutor`

## Request

- Base URL: `https://three.ws`
- URL: `https://three.ws/api/x402/tutor`
- Auth: none required

Pay $0.01 USDC per answered question. Returns a leveled explanation, key points, a worked example, and a follow-up, plus a running session tab so the UI can render a live itemized invoice. Pass a sessionId to accumulate a tab across questions.

## Request body

- object
  - `sessionId` string: Stable session identifier to accumulate a running tab. Omit to start a new session.
  - `question` string, required: The question to be explained.
  - `context` string: Optional code or context to ground the explanation.
  - `level` 'beginner' | 'intermediate' | 'expert': Target expertise level — controls depth and assumed background.

## Response `200`

Answer JSON with running session tab

## Other responses

- `400`: Missing or invalid question
- `402`: Payment Required (x402)

---

[API](https://skmtc.dev/three/apis/three-ws-api.md) · [All operations](https://skmtc.dev/three/apis/three-ws-api/llms.txt) · [OpenAPI document](https://skmtc.dev/three/apis/three-ws-api/revisions/dbc5e3a81b79?raw)