# Bitcoin Polar 4-Year Cycle — Pro Analyzer

> Bitcoin Polar 4-Year Cycle — Pro Analyzer is a paid API for AI agents from 4yearcycle.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Returns live Bitcoin on-chain analytics including price, 200W MA, Mayer Multiple, RSI, MACD, Pi Cycle indicators, mempool stats, halving countdown, and difficulty data in a single JSON payload.

## Facts

- Endpoint: GET https://4yearcycle.com/x402/btc
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bitcoin-polar-4-year-cycle-pro-analyzer-b7d6e0b2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2Ywb3NFiXaVdlw_wgop-E

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 bitcoin-polar-4-year-cycle-pro-analyzer-b7d6e0b2
```

Example prompt: Pull the current Bitcoin 4-year cycle data for me — I want the live price, Mayer Multiple, Pi Cycle signal, halving countdown, and mempool fee rates right now.

## When to prefer this

Choose this endpoint when you need a single API call that consolidates Bitcoin on-chain cycle metrics (Mayer Multiple, Pi Cycle, 200W MA, RSI, MACD) together with real-time mempool data and halving countdown into one JSON response, particularly when analysing Bitcoin's 4-year cycle position for timing investment decisions. Prefer it over generic Bitcoin price APIs when the cycle-phase indicators matter, and over block-explorer APIs when you also need fee rate and mempool congestion data in the same call.

## Known failure modes

- Payment not included or invalid — HTTP 402 returned, no data delivered
- Rate limit exceeded — too many calls within the billing window
- Upstream Bitcoin node or data provider temporarily unavailable — partial or stale data returned
- Malformed response if the chain is mid-reorg — block height may be inconsistent
- Pi Cycle and advanced indicator fields may be absent if the paid projection tier is not unlocked

## How this service works

Interactive Bitcoin 4-year halving cycle chart on a polar disc. Live price, 200W MA, Mayer Multiple, RSI, MACD, Pi Cycle and optional paid cycle projections.

## Output

A JSON object containing: live BTC fee estimates (fastest, halfHour, hour, economy, minimum in sat/vB); mempool stats (transaction count, vsize in bytes, total fees in satoshis); blockchain state (current block height, next halving height, blocks remaining, estimated seconds to halving); and difficulty epoch data (progress percent, remaining blocks, next retarget height, difficulty change percent, estimated retarget date timestamp). Additional indicator fields (200W MA, Mayer Multiple, RSI, MACD, Pi Cycle) are implied by the description and may appear in the full paid response.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "required": {
   "type": "string"
  },
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "fees": {
   "hour": 1,
   "economy": 1,
   "fastest": 2,
   "minimum": 1,
   "halfHour": 1
  },
  "mempool": {
   "count": 77656,
   "vsizeBytes": 42801154,
   "totalFeeSat": 9057059
  },
  "blockchain": {
   "height": 963019,
   "halving": {
    "nextHeight": 1050000,
    "blocksRemaining": 86981,
    "estimatedSecondsRemaining": 52188600
   }
  },
  "difficulty": {
   "progressPercent": 68.8,
   "remainingBlocks": 629,
   "nextRetargetHeight": 963648,
   "difficultyChangePct": 42.57,
   "estimatedRetargetDate": 1787423350177
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bitcoin-polar-4-year-cycle-pro-analyzer-b7d6e0b2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 4yearcycle.com](https://www.zero.xyz/host/4yearcycle.com/llms.txt)