# BaseBuilder Sentiment Fear & Greed Index

> BaseBuilder Sentiment Fear & Greed Index is a paid API for AI agents from bbx-sentiment.vercel.app, paid per call via x402, $0.161038/call, status unknown (last checked 2026-10-30).

Returns a fear and greed sentiment score for crypto/financial markets using the Fear-Greed index methodology

## Facts

- Endpoint: POST https://bbx-sentiment.vercel.app/api/sentiment/fear-greed?utm_source=zero.xyz
- Price: $0.161038/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/basebuilder-sentiment-fear-greed-index-f3fda5de
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tiNztR9K5i8___GggAGWF

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 basebuilder-sentiment-fear-greed-index-f3fda5de -d '<json body>'
```

Example prompt: What's the current fear and greed index reading for the crypto market — is sentiment leaning fearful or greedy right now?

## When to prefer this

Choose this endpoint when you need a structured, scored fear-greed sentiment reading for crypto markets via a pay-per-call micropayment model (x402/USDC). Prefer it over free alternatives when operating in an agent pipeline that already handles x402 payments, or when you need a reliable, hosted API without managing API keys. Best for agents doing periodic market sentiment checks or trading strategy inputs.

## Known failure modes

- Missing or malformed POST body returns 400 error
- Payment not included or insufficient USDC balance triggers 402 Payment Required
- Service temporarily unavailable returns 500 or 503
- Rate limiting may occur under high request volume
- Stale data if underlying market data feed is delayed

## How this service works

BaseBuilder Sentiment API hub - 14 paid endpoints

## Output

Returns a numerical fear-greed index score and a categorical sentiment label (e.g. Extreme Fear, Fear, Neutral, Greed, Extreme Greed) reflecting current market sentiment, computed from market signals.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/basebuilder-sentiment-fear-greed-index-f3fda5de/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bbx-sentiment.vercel.app](https://www.zero.xyz/host/bbx-sentiment.vercel.app/llms.txt)