# AgentDiet Hacker News Velocity Radar

> AgentDiet Hacker News Velocity Radar is a paid API for AI agents from rag-diet.agentdiet.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-22).

Fetches and distills a velocity/momentum radar of trending Hacker News stories, compressed for minimal token usage in AI agent context windows.

## Facts

- Endpoint: GET https://rag-diet.agentdiet.dev/v1/hackernews-velocity-radar?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentdiet-hacker-news-velocity-radar-2ebf713a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mliQ0ktSfK6G63bRaq_1W

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 agentdiet-hacker-news-velocity-radar-2ebf713a
```

Example prompt: What's surging on Hacker News right now? Give me a velocity radar — the stories gaining the most momentum — and keep it token-efficient so it fits cleanly in my context.

## When to prefer this

Choose this endpoint when you need a token-efficient, pre-distilled view of Hacker News momentum (velocity) rather than raw top stories, especially inside agent pipelines where context window size matters. Ideal for agents that need to monitor tech community sentiment or breakout topics without burning large token budgets on raw HN feeds. The built-in ~91% compression ratio makes it uniquely suited for A2A and MCP contexts where bandwidth and tokens are constrained.

## Known failure modes

- Invalid query parameter format returns an error response
- Payment not settled in USDC on Base results in 402 Payment Required
- Hacker News upstream unavailability may return empty or stale data
- Rate limiting if payment not included per call
- Malformed input schema (missing required 'type' or 'method' fields) returns validation error

## How this service works

Deterministic B2A/A2A/MCP/x402/MPP/L402 execution and intelligence node at https://rag-diet.agentdiet.dev settling in USDC on Base.

## Output

Returns a JSON object with status 'ok', a data payload containing compressed Hacker News velocity/momentum rankings (stories ranked by rate of acceleration rather than raw score), and an roi_proof field showing the compression ratio achieved (e.g. 91.4% compression), allowing agents to ingest trending HN data with minimal token consumption.

## 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",
      "POST"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "query": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {},
  "status": "ok",
  "roi_proof": {
   "compression_ratio_pct": 91.4
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentdiet-hacker-news-velocity-radar-2ebf713a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from rag-diet.agentdiet.dev](https://www.zero.xyz/host/rag-diet.agentdiet.dev/llms.txt)