# WHYLY — Market Reasoning Protocol
> Structured explanations of why the crypto market moved.

WHYLY is a market reasoning protocol that answers one question:
**Why did the price move?**

Every response includes a confidence score, weighted drivers with
cited sources, and a human-readable summary.

## Quick Start
No signup required. Use the public API key to try instantly:

```
curl -H "X-API-Key: sk8f3kx9m2v7nq4w1jabc" https://api.whyly.app/v1/explain
```

## Base URL
https://api.whyly.app

## Authentication
Pass your API key via the `X-API-Key` header.
Public key (free tier): sk8f3kx9m2v7nq4w1jabc

## Free Tier Limits
- MARKET asset only
- 2 drivers per response
- English only (lang parameter requires pro)
- 1,000 requests/day

## Endpoints

### GET /v1/explain
Returns a structured explanation of why a given asset moved.
Parameters: asset (default MARKET), window (default 24h), lang (default en, pro+ only), rescan (default false, pro+ only)
Requires: API key

### GET /v1/assets
Lists all supported assets and time windows. No auth required.

### GET /v1/plans
Lists plans with rate limits and pricing. No auth required.

### GET /v1/subscribe
Returns subscription plans and payment instructions. No auth required.

### GET /v1/health
Health check. No auth required.

## OpenAPI
Full spec: https://api.whyly.app/v1/openapi.json
Interactive docs: https://api.whyly.app/v1/docs