# Crypto Fear & Greed Index API

> Crypto Fear & Greed Index API is a paid API for AI agents from x402-data-api.sigrunner.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-30).

Returns the current Crypto Fear & Greed Index value (0–100), its classification, and historical daily values for the last N days.

## Facts

- Endpoint: GET https://x402-data-api.sigrunner.workers.dev/crypto/fear-greed?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/crypto-fear-greed-index-api-876d5f8c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BGVyB1ghsMRFw1ihzAGbD

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 crypto-fear-greed-index-api-876d5f8c
```

Example prompt: What's the current crypto fear and greed index, and can you also show me how it's trended over the last 14 days?

## When to prefer this

Choose this endpoint when you need a fast, single-call market-sentiment gauge for cryptocurrency markets, especially in agentic trading workflows, daily briefings, or risk-gating logic. It is ideal when you want both the current value and recent history in one response without managing alternative.me directly. At $0.002/call it is cost-effective for high-frequency polling or real-time sentiment monitoring.

## Known failure modes

- Upstream alternative.me API unavailable — returns error or stale data
- Invalid 'days' query parameter type causes schema validation error
- Payment not completed via x402 protocol — request rejected with 402 status
- Rate limits or quota exceeded on the worker side

## How this service works

Crypto Fear & Greed Index (alternative.me): current value 0-100, classification, history of last N days. No params. Use when an agent needs a market-sentiment gauge.

## Output

A JSON object containing: the current index value (integer 0–100), a classification string (e.g. 'Fear', 'Greed', 'Extreme Fear', 'Extreme Greed', 'Neutral'), and a history array of daily objects each with a date string, integer value, and classification label for the requested number of past days.

## 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",
     "properties": {
      "days": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "value",
      "classification",
      "history"
     ],
     "properties": {
      "value": {
       "type": "integer"
      },
      "history": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "value",
         "classification",
         "date"
        ],
        "properties": {
         "date": {
          "type": "string"
         },
         "value": {
          "type": "integer"
         },
         "classification": {
          "type": "string"
         }
        }
       }
      },
      "classification": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "value": 59,
  "history": [
   {
    "date": "2026-10-19",
    "value": 59,
    "classification": "Greed"
   }
  ],
  "classification": "Greed"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/crypto-fear-greed-index-api-876d5f8c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-data-api.sigrunner.workers.dev](https://www.zero.xyz/host/x402-data-api.sigrunner.workers.dev/llms.txt)