# SiteCheck Crypto Fear & Greed Index

> SiteCheck Crypto Fear & Greed Index is a paid API for AI agents from api.sitecheck-api.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-15).

Retrieves the current and historical Crypto Fear & Greed Index values with sentiment classification (Fear, Greed, etc.) for up to 30 days.

## Facts

- Endpoint: GET https://api.sitecheck-api.workers.dev/api/crypto/fear-greed?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-crypto-fear-greed-index-5a3f45fa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_i9N-ecP5qLTM8ny8aGsVJ

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 sitecheck-crypto-fear-greed-index-5a3f45fa
```

Example prompt: What's the crypto fear and greed index today, and can you show me how it's trended over the last 7 days?

## When to prefer this

Choose this endpoint when you need a quick, low-cost sentiment gauge for the overall crypto market without requiring exchange-specific data. Ideal for agents that need to contextualize crypto decisions with market mood, generate sentiment reports, or monitor fear/greed trends over time. The historical range (up to 30 days) makes it useful for trend analysis as well as spot checks.

## Known failure modes

- Invalid 'days' parameter outside 1-30 range may return an error or default to 1 day
- Upstream alternative.me API downtime may cause failed or stale responses
- No authentication errors expected as this is a pay-per-call endpoint handled via x402 payment

## How this service works

The Crypto Fear & Greed Index today and for the previous days (up to 30), with its classification (extreme fear to extreme greed). Attribution: alternative.me. Information only, not financial advice.

## Output

Returns today's Fear & Greed Index value (0-100) with a classification label (e.g. 'Greed', 'Fear', 'Extreme Fear', 'Extreme Greed'), plus an array of historical daily values for the requested number of days, each with date, numeric value, and classification. Also includes source attribution and a disclaimer.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "days": {
       "type": "string",
       "description": "1 to 30 days (default 1)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "today": {
   "date": "2026-10-14",
   "value": 62,
   "classification": "Greed"
  },
  "source": "https://api.alternative.me/fng/",
  "history": [
   {
    "date": "2026-10-13",
    "value": 57,
    "classification": "Greed"
   },
   {
    "date": "2026-10-12",
    "value": 69,
    "classification": "Greed"
   }
  ],
  "checkedAt": "2026-10-14T07:00:24.033Z",
  "disclaimer": "Information only, not financial advice.",
  "attribution": "alternative.me"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-crypto-fear-greed-index-5a3f45fa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.sitecheck-api.workers.dev](https://www.zero.xyz/host/api.sitecheck-api.workers.dev/llms.txt)