# Paul Graham Researcher — Semantic Retrieval Endpoint

> Paul Graham Researcher — Semantic Retrieval Endpoint is a paid API for AI agents from paulgraham.researcher.now, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).

Searches Paul Graham's complete corpus (essays, talks, interviews, X posts) by semantic + lexical query and returns grounded claim/quote/evidence packets with citations

## Facts

- Endpoint: POST https://paulgraham.researcher.now/v1/x402/entities/paul-graham/retrieve
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/paul-graham-researcher-semantic-retrieval-endpoint-e48698cb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rto0rCMqo7w3BhrqOeUmj

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 paul-graham-researcher-semantic-retrieval-endpoint-e48698cb -d '<json body>'
```

Example prompt: Search Paul Graham's complete corpus — his essays, talks, and posts — for what he says about founder burnout and give me up to 10 grounded claim or quote packets with their source citations.

## When to prefer this

Use this endpoint when you need source-grounded, citable evidence from Paul Graham's actual writings rather than a generative summary. It is the right choice when accuracy and citation provenance matter — e.g. fact-checking, research, journalism, or building applications that must attribute claims to specific Paul Graham works. Prefer it over asking a general LLM, which may hallucinate quotes or misattribute sources.

## Known failure modes

- Empty results if the query is too narrow or uses terms not present in the corpus
- Limit parameter exceeding 100 returns a validation error
- Missing required 'query' field returns a 400-level schema validation error
- Payment failure or insufficient USDC balance blocks the request via x402 protocol
- packetTypes filter with unrecognized type strings may return zero matching packets

## How this service works

Search Paul Graham's source corpus — a source-grounded persona of the Y Combinator co-founder and essayist, built from 13,000+ cited sources: his complete essays, talks, interviews, and X posts — by semantic + lexical query and retrieve grounded packets (graded claims, quotes, evidence with citations). POST a JSON body { query, limit? (<=100), packetTypes? }. Flat micro-price per query.

## Output

Returns an array of grounded evidence packets, each containing a typed item (claim, quote, or fact), the verbatim or paraphrased text grounded to Paul Graham's corpus, and citation metadata pointing to the specific source (essay title, talk, interview, or X post). Up to 100 packets per call, defaulting to 20.

## 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": [
      "query"
     ],
     "properties": {
      "limit": {
       "type": "integer",
       "maximum": 100,
       "minimum": 1,
       "description": "Maximum packets to return (default 20, matching the route default)."
      },
      "query": {
       "type": "string",
       "maxLength": 1000,
       "minLength": 1,
       "description": "Semantic + lexical search query over Paul Graham's source corpus."
      },
      "packetTypes": {
       "type": "array",
       "items": {
        "type": "string",
        "maxLength": 80
       },
       "maxItems": 20,
       "description": "Optional filter by packet type, e.g. claim, quote, fact."
      }
     }
    },
    "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"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/paul-graham-researcher-semantic-retrieval-endpoint-e48698cb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from paulgraham.researcher.now](https://www.zero.xyz/host/paulgraham.researcher.now/llms.txt)