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SperaxOS Fear & Greed Index API
x402
SperaxOS 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 2026-09-14).
Returns the current and historical Crypto Fear & Greed Index value and classification, payable per-request with USDC via x402.
Price / call$0.001
Success—
StatusUnknown
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 a JSON array of data points each containing a numeric index value (0-100), a human-readable classification string (e.g. 'Extreme Fear', 'Fear', 'Neutral', 'Greed', 'Extreme Greed'), and a Unix timestamp. Also returns the index name and any error metadata.
Example use cases
Daily crypto sentiment check
“What's the crypto fear and greed index right now — is the market in fear or greed territory today?”
Historical sentiment trend review
“Pull the last 30 days of the crypto fear and greed index so I can see how market sentiment has trended over the past month.”
Automated DeFi strategy signal
“Check the current fear and greed index value and tell me if it's in Extreme Fear, Fear, Neutral, Greed, or Extreme Greed — I want to use it to decide whether to rebalance my DeFi portfolio.”
Technical details
Endpoint
GEThttps://chat.sperax.io/api/x402/fear-greedWhen to prefer
Choose this endpoint when you need real-time or recent historical Crypto Fear & Greed Index data without managing API keys, and you are already operating in an x402 USDC payment-capable environment on Base. Ideal for DeFi agents, trading bots, or portfolio management tools that need a quick sentiment signal payable programmatically per call.
Side effects
- Payment not included or insufficient USDC — returns 402 Payment Required
- limit parameter exceeds maximum of 30 — may return error or truncated data
- Network or upstream data source unavailable — metadata.error field will be populated
- Invalid limit type (non-integer) — request may be rejected with a 400 error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| limit | integer | Number of historical data points (default: 1, max: 30) |
Output
Schema · Response
| Field | Type | Description |
|---|---|---|
| data | array | |
| name | string | |
| metadata | object |
Tags
x402
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