# HARS-Zero Signal API — Text Summarization

> HARS-Zero Signal API — Text Summarization is a paid API for AI agents from hars.cryptotavern.xyz, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Summarizes input text into 1–5 bullet points with named-entity extraction and a model-confidence score, paid per call in USDC via x402

## Facts

- Endpoint: GET https://hars.cryptotavern.xyz/paid/summarize
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hars-zero-signal-api-text-summarization-a4243264
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_H3pJBJP9jzTgRDA8ejpfd

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 hars-zero-signal-api-text-summarization-a4243264
```

Example prompt: Summarize this article into bullet points and tell me which people, organizations, and places are mentioned, along with how confident you are: [paste article text here]

## When to prefer this

Choose this endpoint when you need a fast, cheap, pay-per-call text summarization with structured entity extraction and no API key setup — especially in high-volume agent loops where sub-cent pricing matters. Prefer it over subscription NLP APIs when you want to avoid monthly commitments and pay only for what you use in USDC on Base or Solana. It is particularly well-suited for pipelines that also use other HARS utility endpoints (URL fetch, FX rates, geocoding) since all share the same x402 payment flow.

## Known failure modes

- Payment not received or insufficient USDC — 402 response requiring x402 payment header
- Empty or missing text input — validation error returned
- Text too short or malformed — low confidence score or minimal summary bullets
- Network timeout on upstream model call — may return partial or no summary
- Schema validation failure if required fields (as_of, summary, entities, confidence) cannot be populated

## How this service works

Utility API for AI agents — fetch URLs, extract structured HTML,
summarize text, get live FX rates, and geocode addresses. Pay per call
in USDC on Base or Solana via x402. No API keys, no subscriptions.
Sub-cent pricing optimized for high-volume agent loops.

## Output

Returns a JSON object containing: an array of 1–5 summary bullet strings, an array of named entities each tagged as person/org/place/date/money/other, a confidence float (0–1), an RFC3339 timestamp, and optional metadata including word count, sentence count, compression ratio, product label, risks array, evidence URLs, Polymarket market IDs, and a next-best-action suggestion pointing to related endpoints.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "as_of",
  "summary",
  "entities",
  "confidence"
 ],
 "properties": {
  "as_of": {
   "type": "string",
   "format": "date-time",
   "description": "RFC3339 timestamp"
  },
  "risks": {
   "type": "array",
   "items": {
    "type": "string"
   }
  },
  "product": {
   "type": "string"
  },
  "summary": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "maxItems": 5,
   "minItems": 1
  },
  "entities": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "text",
     "type"
    ],
    "properties": {
     "text": {
      "type": "string"
     },
     "type": {
      "enum": [
       "person",
       "org",
       "place",
       "date",
       "money",
       "other"
      ],
      "type": "string"
     }
    }
   }
  },
  "evidence": {
   "type": "array",
   "items": {
    "type": "string",
    "format": "uri"
   },
   "description": "Polymarket order book / event / reference URLs"
  },
  "confidence": {
   "type": "number",
   "maximum": 1,
   "minimum": 0,
   "description": "Model confidence 0.0-1.0"
  },
  "market_ids": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "description": "Polymarket slugs or ids referenced in this response"
  },
  "word_count": {
   "type": "integer"
  },
  "sentence_count": {
   "type": "integer"
  },
  "next_best_action": {
   "type": "object",
   "properties": {
    "why": {
     "type": "string"
    },
    "endpoint": {
     "type": "string"
    },
    "price_usd": {
     "type": "number"
    },
    "product_id": {
     "type": "string"
    }
   }
  },
  "compression_ratio": {
   "type": "number"
  }
 },
 "description": "Text -> 3-bullet summary + key entities + confidence."
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "as_of",
  "summary",
  "entities",
  "confidence"
 ],
 "properties": {
  "as_of": {
   "type": "string",
   "format": "date-time",
   "description": "RFC3339 timestamp"
  },
  "risks": {
   "type": "array",
   "items": {
    "type": "string"
   }
  },
  "product": {
   "type": "string"
  },
  "summary": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "maxItems": 5,
   "minItems": 1
  },
  "entities": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "text",
     "type"
    ],
    "properties": {
     "text": {
      "type": "string"
     },
     "type": {
      "enum": [
       "person",
       "org",
       "place",
       "date",
       "money",
       "other"
      ],
      "type": "string"
     }
    }
   }
  },
  "evidence": {
   "type": "array",
   "items": {
    "type": "string",
    "format": "uri"
   },
   "description": "Polymarket order book / event / reference URLs"
  },
  "confidence": {
   "type": "number",
   "maximum": 1,
   "minimum": 0,
   "description": "Model confidence 0.0-1.0"
  },
  "market_ids": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "description": "Polymarket slugs or ids referenced in this response"
  },
  "word_count": {
   "type": "integer"
  },
  "sentence_count": {
   "type": "integer"
  },
  "next_best_action": {
   "type": "object",
   "properties": {
    "why": {
     "type": "string"
    },
    "endpoint": {
     "type": "string"
    },
    "price_usd": {
     "type": "number"
    },
    "product_id": {
     "type": "string"
    }
   }
  },
  "compression_ratio": {
   "type": "number"
  }
 },
 "description": "Text -> 3-bullet summary + key entities + confidence."
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hars-zero-signal-api-text-summarization-a4243264/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from hars.cryptotavern.xyz](https://www.zero.xyz/host/hars.cryptotavern.xyz/llms.txt)