# David Agent Services — Research Brief

> David Agent Services — Research Brief is a paid API for AI agents from david-agent-services.david-works.workers.dev, paid per call via x402, $0.1/call, status unknown (last checked 2026-10-29).

Generates a cited, structured research brief on any topic using AI summarization, Wikipedia, and Hacker News sources

## Facts

- Endpoint: POST https://david-agent-services.david-works.workers.dev/research-brief?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/david-agent-services-research-brief-c5fa9140
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CtIpRNidkDs7d13b0hHK7

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 david-agent-services-research-brief-c5fa9140 -d '<json body>'
```

Example prompt: Give me a standard-depth research brief on transformer neural networks — I need key facts and cited sources.

## When to prefer this

Choose this endpoint when you need a concise, citation-backed research brief on a specific topic without maintaining an account or API key — ideal for agent pipelines that need sourced summaries on demand. Prefer it over generic LLM completions when citations and traceable sources are required, and over full web search when a structured, synthesized brief is more useful than raw results.

## Known failure modes

- Topic too short or too long (violates minLength 2 / maxLength 200 constraint)
- Payment not completed — 402 response returned before content is delivered
- Topic too vague or unsupported may produce low-quality or empty keyFacts
- Network or Workers AI backend failure resulting in 5xx error
- Invalid depth enum value causes schema validation rejection

## How this service works

Pay-per-call summarization, cited research briefs, and code review for AI agents. x402 v2, USDC on Base. No account or API key.

## Output

A JSON object containing a structured brief text, a list of keyFacts each tagged with numbered citations, an array of sources with URLs and titles, the original topic, the engine used (workers-ai+wikipedia+hn), and a retrievedAt timestamp.

## 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": [
      "topic"
     ],
     "properties": {
      "depth": {
       "enum": [
        "quick",
        "standard"
       ],
       "type": "string",
       "default": "standard"
      },
      "topic": {
       "type": "string",
       "maxLength": 200,
       "minLength": 2
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "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": {
  "brief": "OVERVIEW … KEY FACTS … [1]",
  "topic": "…",
  "engine": "workers-ai+wikipedia+hn",
  "sources": [
   {
    "n": 1,
    "url": "https://en.wikipedia.org/wiki/…",
    "title": "…"
   }
  ],
  "keyFacts": [
   "… [1]"
  ],
  "retrievedAt": "2026-01-01T00:00:00.000Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/david-agent-services-research-brief-c5fa9140/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from david-agent-services.david-works.workers.dev](https://www.zero.xyz/host/david-agent-services.david-works.workers.dev/llms.txt)