# greeneris-data Crypto Fear & Greed Index

> greeneris-data Crypto Fear & Greed Index is a paid API for AI agents from data.greeneris.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns the current Crypto Fear & Greed Index value with classification and 7-day delta, optionally for up to 90 daily data points

## Facts

- Endpoint: GET https://data.greeneris.io/v1/crypto/fng
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/greeneris-data-crypto-fear-greed-index-4d3a4af4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_k-GEoHbAQPnPaojCjxUTT

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 greeneris-data-crypto-fear-greed-index-4d3a4af4
```

Example prompt: What's the current crypto fear and greed index? Show me today's value and the last 7 days of data so I can see how sentiment has trended.

## When to prefer this

Use this endpoint when you need a pay-per-call, no-account sentiment gauge for the crypto market based on the widely-recognized alternative.me Fear & Greed Index. Prefer it over self-hosted alternatives when operating in an x402-compatible agent environment and you want a single commodity-priced call without subscription overhead.

## Known failure modes

- HTTP 402 returned with machine-readable payment quote if USDC payment via x402 has not been made
- Invalid days parameter (outside 1-90 range) returns validation error
- Upstream alternative.me data unavailable causes service failure
- No charge occurs for empty or failed responses

## How this service works

**European business verification for AI agents** - check that a company exists (official French SIREN registry), screen insolvency records (BODACC), validate EU VAT numbers before invoicing (VIES), verify SIRET/IBAN/LEI, addresses and email deliverability, find EU public tenders. Plus 70+ supporting pay-per-call data endpoints (FX, macro, energy, weather, crypto) at commodity prices.

**No account, no API key**: every paid endpoint answers HTTP 402 with a machine-readable quote; pay in USDC on Base via the x402 protocol and retry. AI agents can also use the MCP server (`/mcp`, streamable HTTP, x402-paid tools) or read `/llms.txt` for the full plain-text catalog. Official data sources (INSEE, European Commission, DILA, GLEIF, ECB); no personal data served; buyers are never charged for empty or failed answers.

## Output

Returns a JSON object with the Fear & Greed index value (0-100), classification label (e.g. 'Fear', 'Greed', 'Extreme Fear'), 7-day delta, Unix timestamp, and source attribution from alternative.me. When multiple days are requested, returns an array of daily data points.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "days": {
       "type": "integer",
       "default": 1,
       "maximum": 90,
       "minimum": 1,
       "description": "Number of daily data points to return"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "value": 28,
  "source": "Crypto Fear & Greed Index by alternative.me",
  "delta_7d": -5,
  "timestamp": 1783900800,
  "classification": "Fear"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/greeneris-data-crypto-fear-greed-index-4d3a4af4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from data.greeneris.io](https://www.zero.xyz/host/data.greeneris.io/llms.txt)