# SperaxOS DeFi Fear & Greed Index API

> SperaxOS DeFi Fear & Greed Index API is a paid API for AI agents from chat.sperax.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-20).

Returns the current crypto Fear & Greed Index score and sentiment label for DeFi market intelligence

## Facts

- Endpoint: POST https://chat.sperax.io/api/x402/tools/defi-analytics/getFearGreedIndex?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/speraxos-defi-fear-greed-index-api-f4ef0a3f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UafSXvAvVHc2CY_zBPfLI

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 speraxos-defi-fear-greed-index-api-f4ef0a3f -d '<json body>'
```

Example prompt: What is the current crypto Fear and Greed Index? I want to know if DeFi markets are in fear or greed territory right now.

## When to prefer this

Choose this endpoint when you need a quick, real-time crypto market sentiment pulse without setting up an API key — especially when operating in a pay-per-use agent context using x402/USDC on Base. Ideal for DeFi-native workflows where wallet-based micropayments are already in use and you want AI-augmented market intelligence without a subscription.

## Known failure modes

- Payment failure if USDC balance is insufficient or x402 payment not completed
- HTTP 402 returned if payment is not attached to the request
- Empty or malformed response body if the upstream data source is unavailable
- Rate limiting or timeout if the SperaxOS backend is overloaded
- Stale data if the index has not been recently updated by the underlying data provider

## How this service works

AI-powered DeFi intelligence APIs payable via the x402 HTTP payment protocol. No API key required — pay per request with USDC on Base. Identity-only (SIWX) endpoints are free for wallets with an agentcash identity.

## Output

Returns the current Fear & Greed Index value (typically 0–100) and a corresponding sentiment classification such as 'Extreme Fear', 'Fear', 'Neutral', 'Greed', or 'Extreme Greed', providing a snapshot of current DeFi/crypto market sentiment.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [],
     "properties": {},
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/speraxos-defi-fear-greed-index-api-f4ef0a3f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from chat.sperax.io](https://www.zero.xyz/host/chat.sperax.io/llms.txt)