Crypto Fear & Greed index via x402 micropayment on Base (USDC) or Tron (USDT)
What it does
The Fear & Greed endpoint at bridge.eruditepay.com returns crypto market sentiment data (a fear-and-greed index) for a given token. It is an x402-protocol paid endpoint operated by Erudite Intelligence LLC. Callers POST a JSON body containing a token address or symbol and receive a JSON response with sentiment data.
The endpoint accepts payment via two rails: USDC on Base (eip155:8453) at 10,000 base units ($0.01 per call) or USDT on Tron at 10,000 base units ($0.01 per call). Payment is facilitated through the EruditePay x402 Bridge, which supports the x402 v2 protocol. The facilitator for the Base rail is Coinbase CDP.
Documentation is sparse — the provider's /docs path returns a 404, and the Bazaar schema embedded in the 402 challenge provides only a minimal example (an empty data object). The input schema indicates a POST with a JSON body containing a "token" field (a token address or symbol such as the zero address). The output is typed as JSON with a success boolean and a data object, but the structure of the data object is not documented. The provider is a FinCEN-registered MSB (BSA ID 31000324258137) and operates non-custodially.
Capabilities
Use cases
- —Querying real-time crypto fear-and-greed sentiment for a specific token
- —Integrating market sentiment signals into automated trading bots
- —Displaying fear/greed indicators in crypto portfolio dashboards
- —Feeding sentiment data into AI agents that make on-chain decisions
Fit
Best for
- —AI agents or bots that need on-demand crypto sentiment data via micropayment
- —Developers building x402-native applications with per-call pricing
- —Low-cost market sentiment lookups at $0.01 per request
Not for
- —Users who need free or bulk-discounted sentiment data
- —Applications requiring detailed historical fear-and-greed time series (output schema is undocumented)
- —Non-crypto market sentiment analysis
Quick start
curl -X POST https://bridge.eruditepay.com/v1/market/fear-greed \
-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 and a minimal input schema, but the output data structure is entirely undocumented (example shows an empty object), /docs returns 404, and there are no usage examples or detailed field descriptions.
Warnings
- —Output schema is effectively empty — the example data object contains no fields, so the actual response structure is unknown.
- —Provider documentation at /docs returns 404; no OpenAPI spec is available.
- —The Bazaar schema example output is just {"success": true, "data": {}} which provides no insight into actual response fields.
Citations
- —Endpoint returns x402 v2 challenge with USDC on Base (10000 base units) and USDT on Tron (10000 base units)https://bridge.eruditepay.com/v1/market/fear-greed
- —Provider is Erudite Intelligence LLC, FinCEN MSB registered with BSA ID 31000324258137https://bridge.eruditepay.com
- —USDC on Base uses 6 decimals, so 10000 base units = $0.01https://bridge.eruditepay.com
- —Facilitator for Base rail is Coinbase CDPhttps://bridge.eruditepay.com/v1/market/fear-greed
- —Input body accepts a 'token' field described as 'Token address or symbol'https://bridge.eruditepay.com/v1/market/fear-greed