# Arch Tools Semantic Search

> Arch Tools Semantic Search is a paid API for AI agents from archtools.dev, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-15).

Performs semantic (vector/meaning-based) web search given a natural language query, returning ranked results with optional full page text

## Facts

- Endpoint: POST https://archtools.dev/v1/tools/semantic-search
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/arch-tools-semantic-search-7c8fa611
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VLEWMUsf1seGTaecI7KrB

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 arch-tools-semantic-search-7c8fa611 -d '<json body>'
```

Example prompt: Search the web for 'open source LLM fine-tuning techniques for small datasets' and give me the top 5 results with their full page text included.

## When to prefer this

Choose this endpoint when you need meaning-based (semantic) web search rather than keyword matching — ideal for research, discovery, and retrieval tasks where exact keyword overlap is insufficient. Prefer this over traditional search APIs when the query is conceptual or phrased in natural language. The optional full-text inclusion makes it especially useful when downstream NLP tasks (summarization, entity extraction, sentiment analysis) will consume the results.

## Known failure modes

- Query string missing — returns 400 validation error
- num_results set to 0 or negative — may return empty results or error
- Network timeout if underlying search index is slow
- Payment not sent or insufficient USDC — returns 402 Payment Required
- Query too long or malformed — may return empty results or truncation error

## How this service works

Arch Tools — semantic-search

## Output

A JSON object containing a ranked list of search results, each with page URL, title, relevance score, and optionally the full extracted text of the page. Default returns up to 10 results.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "query": {
   "type": "string",
   "description": "Natural language search query"
  },
  "num_results": {
   "type": "integer",
   "default": 10,
   "description": "Number of results to return"
  },
  "include_text": {
   "type": "boolean",
   "default": true,
   "description": "Include full page text in results"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/arch-tools-semantic-search-7c8fa611/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from archtools.dev](https://www.zero.xyz/host/archtools.dev/llms.txt)