# Sentiment Analyzer API

[![MCP Server](https://img.shields.io/badge/MCP-server-blue)](https://sentiment-analyzer.api.klymax402.com/mcp)
[![x402](https://img.shields.io/badge/payments-x402-6E56CF)](https://x402.org)
[![License: MIT](https://img.shields.io/badge/license-MIT-green)](LICENSE)

Sentiment analysis with emotion detection, confidence scores, and key phrase extraction. Single or batch mode. Pay-per-call via [x402](https://x402.org) (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the [klymax402](https://klymax402.com) marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

## Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

```json
{
  "mcpServers": {
    "sentiment-analyzer": {
      "url": "https://sentiment-analyzer.api.klymax402.com/mcp"
    }
  }
}
```

## Quickstart -- HTTP (x402)

```bash
curl -X POST "https://sentiment-analyzer.api.klymax402.com/api/analyze" \
  -H "Content-Type: application/json" \
  -d '{"text":"..."}'
# -> 402 Payment Required, with an x402 payment challenge in the response body
```

Any x402-aware client ([`@x402/fetch`](https://www.npmjs.com/package/@x402/fetch), [`x402-agent-tools`](https://www.npmjs.com/package/x402-agent-tools), ATXP) handles the 402 -> sign -> retry cycle automatically.

## Tools

| Tool | Method | Path | Price | Description |
|---|---|---|---|---|
| `text_analyze_sentiment` | POST | `/api/analyze` | $0.015 | Analyze sentiment of a single text |
| `text_analyze_sentiment_batch` | POST | `/api/analyze/batch` | $0.10 | Analyze sentiment of up to 20 texts in batch |

### `text_analyze_sentiment`

Use this when you need to determine the emotional tone and sentiment of text. Returns structured sentiment analysis with emotion breakdown and key drivers.

**Parameters**

| Name | Type | Required | Description |
|---|---|---|---|
| `text` | string | yes | The text to analyze for sentiment |

**Returns**

- `sentiment` -- overall sentiment label (positive, negative, neutral)
- `confidence` -- confidence score 0-100
- `emotions` -- detected emotions with scores (joy, anger, fear, surprise, sadness)
- `keyPhrases` -- array of phrases driving the sentiment
- `score` -- numeric sentiment score from -1.0 (negative) to 1.0 (positive)

Example response:

```json
{"sentiment":"positive","confidence":87,"score":0.73,"emotions":{"joy":0.82,"surprise":0.15,"anger":0.01,"fear":0.01,"sadness":0.01},"keyPhrases":["excellent results","exceeded expectations"]}
```

**When to use**: responding to customer feedback, reviews, or social media mentions. Essential for brand monitoring, support ticket triage, and content tone analysis.

### `text_analyze_sentiment_batch`

Use this when you need to analyze sentiment of multiple texts at once (up to 20). Returns an array of individual sentiment results in one call.

**Parameters**

| Name | Type | Required | Description |
|---|---|---|---|
| `texts` | array | yes | Array of texts to analyze (max 20) |

**Returns**

- `results` -- array of sentiment objects, one per input text
- `averageSentiment` -- overall average sentiment score across all texts
- `distribution` -- count of positive/negative/neutral texts

Example response:

```json
{"results":[{"sentiment":"positive","confidence":91,"score":0.8},{"sentiment":"negative","confidence":74,"score":-0.6}],"averageSentiment":0.1,"distribution":{"positive":1,"negative":1,"neutral":0}}
```

**When to use**: bulk analysis of reviews, survey responses, or social media feeds. Essential when comparing sentiment across multiple data points.

## Example agent prompts

- "Determine the emotional tone and sentiment of text"
- "Analyze sentiment of multiple texts at once (up to 20)"

## Payment

- Protocol: [x402](https://x402.org) -- HTTP-native pay-per-call, no signup, no API key
- Network: Base L2 (`eip155:8453`)
- Asset: USDC
- Facilitator: Coinbase CDP (primary), PayAI (fallback)
- Also reachable via [ATXP](https://atxp.ai) (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

## Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

- Catalog: https://klymax402.com/llms.txt
- Full API reference: https://klymax402.com/llms-full.txt
- Live stats: https://klymax402.com/stats

## License

MIT