# Crypto Fear & Greed Index

> Crypto Fear & Greed Index is a paid API for AI agents from api.chainmarket-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-24).

Returns the current and historical Crypto Fear & Greed Index values with momentum indicators and short-term change metrics

## Facts

- Endpoint: GET https://api.chainmarket-api.workers.dev/api/crypto/fear-greed-index?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-24
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/crypto-fear-greed-index-3af41c18
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_z9po0equ4Wm-w7TjB9mWh

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-3af41c18
```

Example prompt: What's the current crypto fear and greed index, and has sentiment been rising or falling over the past two weeks? Give me the 14-day history.

## When to prefer this

Choose this endpoint when you need a quick, no-signup sentiment gauge for the broader crypto market with built-in trend analysis (7-day average, momentum, delta). It is ideal for agents that need a single structured response combining current state and recent history without querying multiple endpoints. Prefer over raw blockchain data sources when the question is about collective market mood rather than specific token prices or on-chain metrics.

## Known failure modes

- Invalid 'days' parameter (outside 8–30 range) may return an error or default behavior
- Upstream Alternative.me API downtime could cause stale or missing data
- Payment failure over x402 protocol results in no charge and no data returned
- Requesting fewer than 8 days may produce unreliable 7-day change figures per schema notes

## How this service works

Crypto Fear & Greed Index (0-100) from alternative.me: today's value and label, change vs yesterday and vs 7 days ago, 7-day average, and a sentiment momentum label (rising, falling, flat). Daily; the source updates once a day. Attribution to alternative.me is requested by the source.

## Output

Returns a JSON object with: current index value (0–100) and sentiment label (e.g. 'Neutral', 'Greed', 'Fear'), 7-day average score, 1-day and 7-day point changes, a momentum indicator ('rising' or 'falling'), an array of daily historical entries (date, value, label), and the timestamp of when data was fetched. Source is Alternative.me.

## 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": "How many daily values to read, 8 to 30 (default 30; needs at least 8 for the 7-day figures)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "avg7d": 57.57,
  "source": "https://api.alternative.me/fng/",
  "current": {
   "date": "2026-10-23",
   "label": "Neutral",
   "value": 50
  },
  "history": [
   {
    "date": "2026-10-23",
    "label": "Neutral",
    "value": 50
   },
   {
    "date": "2026-10-22",
    "label": "Greed",
    "value": 68
   }
  ],
  "change1d": -18,
  "change7d": -13,
  "momentum": "falling",
  "checkedAt": "2026-10-23T09:35:56.333Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/crypto-fear-greed-index-3af41c18/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.chainmarket-api.workers.dev](https://www.zero.xyz/host/api.chainmarket-api.workers.dev/llms.txt)