Historical crypto Fear & Greed Index data via x402 micropayment
What it does
This endpoint provides historical Fear & Greed Index data for the cryptocurrency market, accessible via the x402 payment protocol. It is operated by Erudite Intelligence LLC through their EruditePay Bridge infrastructure. The endpoint accepts a POST request with a JSON body containing a `token` field (token address or symbol) and returns JSON with a `success` boolean and a `data` object.
Payment is required per-call at $0.01 (10,000 base units of USDC on Base, or 10,000 base units of USDT on Tron). The x402 challenge was successfully captured, confirming the endpoint is live. Two payment rails are supported: USDC on Base (eip155:8453) via the Coinbase CDP facilitator, and USDT on Tron (tron:728126428).
Documentation is sparse — the endpoint description in the x402 challenge is simply "Crypto data intelligence," and the output example is a generic `{"success": true, "data": {}}` stub. The exact shape of the returned historical data (time range, granularity, fields) is not documented. The `token` input parameter's role is also unclear for a market-wide sentiment index. Users should expect to experiment with the request body to understand the full response structure.
Capabilities
Use cases
- —Retrieve historical Fear & Greed Index values for backtesting crypto trading strategies
- —Feed market sentiment data into AI agents that make portfolio allocation decisions
- —Build dashboards showing crypto market sentiment over time
- —Correlate Fear & Greed Index trends with token price movements
Fit
Best for
- —AI agents needing on-demand crypto sentiment data with micropayment access
- —Quantitative traders backtesting sentiment-based strategies
- —Developers building crypto market analytics dashboards
Not for
- —Users needing real-time streaming sentiment data (this is a request-response endpoint)
- —Non-crypto market sentiment analysis
- —Users who need detailed documentation before integrating — response schema is undocumented
Quick start
curl -X POST https://bridge.eruditepay.com/v1/market/fear-greed-history \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_header>" \
-d '{"token": "0x0000000000000000000000000000000000000000"}'Example
Request
{
"token": "0x0000000000000000000000000000000000000000"
}Response
{
"data": {},
"success": true
}Endpoint
Quality
The endpoint is live (402 challenge captured) with clear pricing ($0.01 per call), but documentation is minimal. The output example is a stub with an empty data object, the role of the token parameter for a market-wide index is unclear, and no external docs were found (all doc paths returned 404). The response schema is entirely unknown.
Warnings
- —Output schema is undocumented — the example response contains only an empty data object
- —The role of the 'token' parameter is unclear for a market-wide Fear & Greed Index
- —No external documentation found — /docs, /api, /pricing, /README all return endpoint_not_found
- —Response data structure (fields, time range, granularity) must be discovered experimentally
Citations
- —Endpoint returns x402 v2 challenge with price of 10000 base units USDC on Base or USDT on Tronhttps://bridge.eruditepay.com/v1/market/fear-greed-history
- —Provider is Erudite Intelligence LLC, FinCEN MSB registeredhttps://bridge.eruditepay.com
- —USDC on Base uses 6 decimals, so 10000 base units = $0.01https://bridge.eruditepay.com
- —Facilitator is Coinbase CDP for Base chain paymentshttps://bridge.eruditepay.com