# BaseBuilder Sentiment API

> BaseBuilder Sentiment API is a paid API for AI agents from bb-sentiment.vercel.app, paid per call via x402, $0.142876/call, status unknown (last checked 2026-09-15).

Analyzes and classifies the sentiment of input text, returning sentiment scores and labels

## Facts

- Endpoint: POST https://bb-sentiment.vercel.app/api/sentiment
- Price: $0.142876/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/basebuilder-sentiment-api-0ca58927
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ji0f62yTkh4bxgzKA9F5E

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-api-0ca58927 -d '<json body>'
```

Example prompt: Can you analyze the sentiment of this customer review and tell me if it's positive, negative, or neutral along with a confidence score: 'The product arrived on time and works perfectly, but the packaging was a bit damaged'?

## When to prefer this

Choose this endpoint when you need a paid, production-grade sentiment classification for arbitrary text, particularly when working in an x402-compatible payment flow on Base. Suitable for processing reviews, social posts, or customer feedback where a numeric confidence score alongside a categorical label is needed.

## Known failure modes

- Empty or missing text input returns a 400 error
- Text exceeding maximum length limit may be rejected
- Payment of 0.142876 USDC not provided returns a 402 error
- Unsupported language or encoding may produce inaccurate results
- Ambiguous or very short text may yield low confidence scores

## How this service works

BaseBuilder Sentiment API hub - 14 paid endpoints

## Output

A sentiment classification (positive, negative, or neutral), a numerical sentiment score, and a confidence level indicating how strongly the text aligns with the detected sentiment category.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/basebuilder-sentiment-api-0ca58927/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bb-sentiment.vercel.app](https://www.zero.xyz/host/bb-sentiment.vercel.app/llms.txt)