# Quant Agent Shop – Research Answer with Citations

> Quant Agent Shop – Research Answer with Citations is a paid API for AI agents from quantagentshop.com, paid per call via x402, $0.009/call, status unknown (last checked 2026-10-23).

Answers a single plain-language question with a 120–300 word sourced response including numbered inline citations and the URLs read, retrieved via web search or from specified URLs.

## Facts

- Endpoint: POST https://quantagentshop.com/v1/research-answer?utm_source=zero.xyz
- Price: $0.009/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quant-agent-shop-research-answer-with-citations-469f07cf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JWLh13fARcxUykiqYuT1X

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 quant-agent-shop-research-answer-with-citations-469f07cf -d '<json body>'
```

Example prompt: Can you research what the current corporate tax rate in Germany is and give me a cited answer with up to 5 sources I can reference?

## When to prefer this

Choose this endpoint when an AI agent needs a human-readable, citable answer to a specific factual question — especially when the response must be shown to a person and include verifiable source links. It is better than raw search endpoints when you want synthesis rather than a list of links, and better than general LLM answers when grounded citations are required. Prefer it over document-extraction endpoints when you want the agent to autonomously find and read the most relevant pages. Not suitable when you need raw HTML, paginated results, or must access login-gated content.

## Known failure modes

- Question too short (under 10 chars) or too long (over 500 chars) returns a validation error
- URLs provided are behind logins or paywalls — content cannot be retrieved
- Web search returns no relevant results for the question — answer may be empty or low quality
- More than 8 URLs provided in the urls array — schema validation error
- Network timeout if sources are slow — typical response is 5–12 seconds, may exceed limits
- Non-public or localhost URLs in the urls array are rejected

## How this service works

Cited research answer. Send one question; returns a 120 to 300 word answer with numbered [n] citations and the source URLs read, each with the time it was read. Searches the web, or reads only the urls you pass. Suited to an agent that needs a sourced answer it can show a person. Not for raw result lists or pages behind logins. Typical response 5 to 12 s. Failed calls are not charged.

## Output

A JSON object containing a concise 120–300 word answer with numbered inline citations (e.g. [1], [2]), and an array of source objects each including the citation number, URL, article title, whether it was cited in the answer, and the ISO 8601 timestamp when it was read. The original question is echoed back in the response.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "question"
     ],
     "properties": {
      "urls": {
       "anyOf": [
        {
         "type": "array",
         "items": {
          "type": "string",
          "format": "uri",
          "maxLength": 2083,
          "minLength": 1
         },
         "maxItems": 8
        },
        {
         "type": "null"
        }
       ],
       "title": "Urls",
       "default": null,
       "description": "Optional pages to answer from instead of searching."
      },
      "question": {
       "type": "string",
       "title": "Question",
       "maxLength": 500,
       "minLength": 10,
       "description": "One question in plain language."
      },
      "max_sources": {
       "type": "integer",
       "title": "Max Sources",
       "default": 3,
       "maximum": 8,
       "minimum": 1,
       "description": "How many sources to read, 1 to 8."
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "answer": "The first 1,000 payments a month are free, then each costs $0.001 [1].",
  "sources": [
   {
    "n": 1,
    "url": "https://docs.cdp.coinbase.com/x402/welcome",
    "cited": true,
    "title": "x402",
    "read_at": "2026-10-22T09:00:00+00:00"
   }
  ],
  "question": "What fee does the Coinbase CDP facilitator charge per x402 payment?"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/quant-agent-shop-research-answer-with-citations-469f07cf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from quantagentshop.com](https://www.zero.xyz/host/quantagentshop.com/llms.txt)