# HN Pulse

> HN Pulse is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns top Hacker News stories for a given topic, ranked by points and comments.

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/hn-pulse
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hn-pulse-f2238713
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_i-4JMMFFpQRWdRm3qE4hW

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 hn-pulse-f2238713
```

Example prompt: Can you pull the top Hacker News stories about large language models right now, ranked by points and comments?

## When to prefer this

Use this endpoint when you need a quick, ranked snapshot of what the Hacker News developer community is currently discussing about a specific technology, company, or topic. It is preferable over raw HN API queries when you want pre-ranked, summarized results with sentiment signals rather than raw story data. Best for trend discovery, research validation, and newsletter curation in tech-savvy domains.

## Known failure modes

- Missing or empty sector parameter returns no results
- Topic too broad or misspelled may yield irrelevant stories
- Payment failure (402) if USDC balance is insufficient
- Rate limiting or service unavailability from upstream HN data source
- No stories found for niche or very new topics

## How this service works

Top Hacker News stories for a topic, ranked by points and comments.

## Output

Returns a ranked list of top Hacker News stories matching the given topic, including scores, comment counts, a summary of community sentiment, confidence rating, strengths, evidence details, and risk factors. Response also includes metadata about the service and payment confirmation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "meta": {
       "enum": [
        "0",
        "1"
       ],
       "type": "string",
       "description": "Set to 1 for free metadata JSON (no payment required)"
      },
      "sector": {
       "type": "string",
       "description": "Composite input parameter"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "HN Pulse paid response",
     "$schema": "https://json-schema.org/draft/2020-12/schema",
     "required": [
      "ok",
      "paid",
      "service",
      "provider",
      "result"
     ],
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "paid": {
       "type": "boolean"
      },
      "result": {
       "type": "object",
       "required": [
        "ok",
        "service"
       ],
       "properties": {
        "ok": {
         "type": "boolean",
         "description": "Handler success"
        },
        "score": {
         "type": "number"
        },
        "service": {
         "type": "string",
         "description": "Service slug"
        },
        "summary": {
         "type": "string"
        },
        "evidence": {
         "type": "object"
        },
        "strengths": {
         "type": "array",
         "items": {
          "type": "string"
         }
        },
        "confidence": {
         "type": "string"
        },
        "generatedAt": {
         "type": "string",
         "description": "ISO-8601 timestamp"
        },
        "riskFactors": {
         "type": "array",
         "items": {
          "type": "string"
         }
        }
       }
      },
      "payment": {
       "type": "object",
       "properties": {
        "code": {
         "type": "string"
        },
        "payer": {
         "type": "string"
        },
        "detail": {
         "type": "string"
        },
        "selfPay": {
         "type": "bo
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "paid": true,
  "result": {
   "ok": true,
   "service": "hn-pulse"
  },
  "service": "hn-pulse",
  "provider": "K-2SO"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hn-pulse-f2238713/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from k2so.wrong.systems](https://www.zero.xyz/host/k2so.wrong.systems/llms.txt)