# Zhuanqian Research Digest API (Paid)

> Zhuanqian Research Digest API (Paid) is a paid API for AI agents from research-api-production-d642.up.railway.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-29).

Returns a research digest aggregating recent discussions and papers from Hacker News, GitHub, and arXiv for a given topic over a configurable time window, paid via x402 USDC on Base.

## Facts

- Endpoint: GET https://research-api-production-d642.up.railway.app/paid/digest?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/zhuanqian-research-digest-api-paid-a9305e85
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_r14w8PLgy4_KVevXBxaKQ

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 zhuanqian-research-digest-api-paid-a9305e85
```

Example prompt: Pull me a research digest on 'AI agents' covering the last 30 days from Hacker News, GitHub, and arXiv — I want to see what's been trending across all three sources.

## When to prefer this

Choose this endpoint when you need a multi-source research digest combining community discussion (Hacker News), open-source activity (GitHub), and academic papers (arXiv) in a single call. It is well-suited for agents that need to brief users on emerging tech topics, monitor discourse across dev communities, or bootstrap domain knowledge. Prefer this over single-source scrapers when breadth across community, code, and academic dimensions matters. The $0.01/call x402 pricing makes it suitable for automated pipelines with moderate call frequency.

## Known failure modes

- Missing required 'topic' query parameter returns a 400 or validation error
- Payment not provided or insufficient USDC triggers a 402 Payment Required response
- Topic string exceeding 200 characters is rejected
- Days value outside 1–365 range is rejected
- Source names not in the accepted set (hn, github, arxiv) may be ignored or error
- External source APIs (HN, GitHub, arXiv) being unavailable may result in partial or empty results for that source
- Rate limiting on the underlying source scrapers may return fewer results than expected

## How this service works

Research digest (HN/GitHub/arXiv) and web page → markdown extractor. Paid x402 (USDC on Base) routes under /paid/*; free rate-limited demo under /v1/*.

## Output

A JSON object containing the original topic query, per-source result counts, a list of extracted themes, and per-source arrays of results — each result including a URL, publication date, score, title, and short summary — enabling an agent to surface the most relevant and highly-scored recent content across the selected sources.

## 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": [
      "topic"
     ],
     "properties": {
      "days": {
       "type": "integer",
       "default": 30,
       "maximum": 365,
       "minimum": 1
      },
      "topic": {
       "type": "string",
       "maxLength": 200
      },
      "sources": {
       "type": "string",
       "default": "hn,github,arxiv"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "query": "ai agents",
  "topic": "ai agents",
  "counts": {
   "hn": 8
  },
  "themes": [
   "agents"
  ],
  "results": {
   "hn": [
    {
     "url": "https://...",
     "date": "2026-10-20",
     "score": 120,
     "title": "...",
     "summary": "..."
    }
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/zhuanqian-research-digest-api-paid-a9305e85/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from research-api-production-d642.up.railway.app](https://www.zero.xyz/host/research-api-production-d642.up.railway.app/llms.txt)