# Hacker News Keyword Discussion Velocity

> Hacker News Keyword Discussion Velocity is a paid API for AI agents from api.fadeandco.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-29).

Returns 24h and 7-day story counts, velocity ratio, and top stories for a keyword on Hacker News via Algolia HN Search

## Facts

- Endpoint: GET https://api.fadeandco.workers.dev/api/agent-intel/social-signal-aggregator?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hacker-news-keyword-discussion-velocity-8467684f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_G0_cIU-PzvSMww2y2dSAC

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 hacker-news-keyword-discussion-velocity-8467684f
```

Example prompt: What's the Hacker News discussion velocity for 'WebAssembly' right now — how many stories have come up in the last 24 hours versus the 7-day daily average, and what are the top posts?

## When to prefer this

Choose this endpoint when you need quantitative Hacker News discussion momentum for a specific keyword — particularly useful for tech launches, developer-focused products, or open-source projects where HN is a primary community signal. Unlike generic social listening tools, this gives a structured velocity ratio (24h vs 7-day average) purpose-built for trend detection, not just raw counts. Note it is HN-only; if Reddit or Bluesky coverage is needed, a different service is required.

## Known failure modes

- Missing or empty keyword returns validation error
- Keyword shorter than 2 or longer than 80 characters rejected
- No stories found returns zero counts and empty topStories24h array
- Algolia HN Search API upstream downtime causes failure
- Rate limiting or payment failure returns 402 response before data is returned

## How this service works

Keyword discussion velocity on Hacker News (Algolia HN Search, public): stories in the last 24 hours, stories in the last 7 days, velocity (24h count vs. 7-day daily average) and the top 24h stories with points and comments. Only Hacker News: Reddit and Bluesky blocked automated requests in testing, and no sentiment score is given.

## Output

A JSON object containing: last24h story count, last7d story count and daily average, a velocity ratio (24h count vs 7-day daily average), the timestamp of the check, the Algolia source URL, and an array of top 24h stories each with title, HN URL, external URL, points, comment count, and creation time.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "keyword"
     ],
     "properties": {
      "keyword": {
       "type": "string",
       "description": "Keyword or short phrase, 2 to 80 characters"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "last7d": {
   "stories": 6,
   "dailyAverage": 0.86
  },
  "source": "https://hn.algolia.com/api/v1/search_by_date",
  "keyword": "bitcoin",
  "last24h": {
   "stories": 1
  },
  "velocity": 1.17,
  "checkedAt": "2026-10-23T09:35:16.781Z",
  "topStories24h": [
   {
    "url": "https://www.ft.com/content/bb564eb1-79d4-4694-aa24-1155202a9abc",
    "hnUrl": "https://news.ycombinator.com/item?id=50202402",
    "title": "OpenAI trims valuation target after pitching higher price",
    "points": 6,
    "comments": 1,
    "createdAt": "2026-10-22T23:15:44Z"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hacker-news-keyword-discussion-velocity-8467684f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.fadeandco.workers.dev](https://www.zero.xyz/host/api.fadeandco.workers.dev/llms.txt)