# Wintergreen x402 Failure Patterns Knowledge Endpoint

> Wintergreen x402 Failure Patterns Knowledge Endpoint is a paid API for AI agents from x402.wintergreen.uk, paid per call via x402, $0.01/call, status down (last checked 2026-09-16).

Returns payment-gated knowledge content about trading strategy failure patterns and kill battery rules for crypto quant systems, delivered via x402 micropayment on Base.

## Facts

- Endpoint: GET https://x402.wintergreen.uk/api/v1/knowledge/failure-patterns
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/wintergreen-x402-failure-patterns-knowledge-endpoint-8a90304f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_G_ff6melL-InpL6as4I2R

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability wintergreen-x402-failure-patterns-knowledge-endpoint-8a90304f
```

Example prompt: Pull the failure patterns guide from Wintergreen — I need to understand the kill battery rules and what signals indicate a crypto trading strategy has broken down and should be shut off.

## When to prefer this

Choose this endpoint when an AI agent or quant developer needs authoritative, curated documentation on crypto trading strategy failure patterns and kill battery rules, and is willing to pay $1 USDC per retrieval via the x402 micropayment protocol on Base. Prefer this over free web search when you need structured, practitioner-grade quant methodology content rather than generic articles.

## Known failure modes

- HTTP 402 returned if no valid X-PAYMENT header is provided — agent must sign EIP-712 TransferWithAuthorization and retry
- Invalid or expired payment signature results in rejected payment and no content
- Incorrect file_slug or route_slug returns empty or mismatched content
- Network errors on Base chain may delay payment confirmation
- Content may be unavailable if the specific slug does not exist on the broker

## How this service works

Payment-gated crypto trading intelligence for AI agents.
    
## Categories
- **Hyperliquid Signals**: Real-time funding divergence, lead-lag correlation, liquidation clusters, session volume area levels
- **Quant Methodology**: Backtesting walk-forward validation, strategy generation with kill battery (19 rules), risk management with Kelly sizing, regime detection, execution frameworks, agent orchestration
- **Market Insights**: 22 crypto microstructure observations — funding, liquidation, orderbook, regime, flow, anomaly
- **Power Markets**: ERCOT field guide, merit-order model, duck curve analysis
- **Career Guides**: Firefighter oral board prep, medical coding, ATSA, contractor estimating
- **Trust Scoring**: x402 endpoint verification, P2D badges

## Payment
All paid endpoints return HTTP 402 with USDC on Base (eip155:8453). 
Sign EIP-712 TransferWithAuthorization and retry with X-PAYMENT header.
PayTo: 0xAe9834d71F1Bd989A0dc17593451af823E31CeeD

## Output

A knowledge document covering trading strategy failure patterns, including the kill battery (19 rules for strategy termination), walk-forward validation failure modes, and risk management guidelines for crypto quant systems. Returned as structured content after successful $1 USDC micropayment on Base.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "_file_slug": {
   "type": "string"
  },
  "_route_slug": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/wintergreen-x402-failure-patterns-knowledge-endpoint-8a90304f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.wintergreen.uk](https://www.zero.xyz/host/x402.wintergreen.uk/llms.txt)