# Web URL & HTML Prompt Compressor with BM25 Budget Control

> Web URL & HTML Prompt Compressor with BM25 Budget Control is a paid API for AI agents from preflight.agentdiet.dev, paid per call via MPP, $0.001/call, status unknown (last checked 2026-10-21).

Fetches a URL or raw HTML and distills it into compact, agent-ready tokens using markdown, structured, skeleton, or BM25-focused budget modes

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/prompt-compress?utm_source=zero.xyz
- Price: $0.001/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: preflight.agentdiet.dev
- Website: https://preflight.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/preflight-agentdiet-dev-web-url-html-prompt-compressor-with-bm25-c7250e13
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xKyujjt5u--mxw2U14-HC

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 preflight-agentdiet-dev-web-url-html-prompt-compressor-with-bm25-c7250e13
```

Example prompt: Grab the Stripe documentation page at https://stripe.com/docs/payments and distill it into markdown, keeping it under 800 tokens focused on the query 'payment intents'.

## When to prefer this

Choose this endpoint when an AI agent needs to fetch and condense web content to fit within a strict LLM context window, especially when you need BM25-relevance filtering to surface only query-relevant passages. Prefer it over generic scrapers when token economy matters — the built-in ROI proof lets agents verify compression gains. Use mode=budget when you have a hard token ceiling, mode=structured for tabular/metadata extraction, mode=skeleton for outline navigation, and mode=markdown for general clean text distillation.

## Known failure modes

- URL is unreachable or returns a non-200 response — endpoint may return an error status
- Token budget too low (max_tokens < 20) — rejected by schema validation
- BM25 query provided without mode=budget — query parameter silently ignored
- Raw HTML is empty or malformed — may produce minimal or empty distillation output
- Rate limit or payment failure via x402 — billing error returned instead of data

## How this service works

Distill a URL or raw HTML payload with BM25 budget control (Live x402 v2, IETF MPP & MCP endpoint at https://preflight.agentdiet.dev/v1/prompt-compress)

## Output

Returns a distilled 'data' object containing the page content in the requested format (markdown text, structured JSON tables/metadata, skeleton outline, or BM25-ranked excerpt), plus an ROI proof block showing raw token count, distilled token count, tokens saved, compression ratio percentage, and estimated LLM cost saved in USD. Also includes cache status (HIT/MISS) and billing details.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "url"
 ],
 "properties": {
  "url": {
   "type": "string",
   "minLength": 1,
   "description": "Target webpage URL to fetch and distill (or builtin://stripe-docs)"
  },
  "html": {
   "type": "string",
   "description": "Optional raw HTML string to distill directly without fetching"
  },
  "mode": {
   "enum": [
    "markdown",
    "structured",
    "skeleton",
    "budget"
   ],
   "type": "string",
   "default": "markdown",
   "description": "Distillation mode"
  },
  "query": {
   "type": "string",
   "description": "BM25 focus query when mode=budget"
  },
  "max_tokens": {
   "type": "integer",
   "minimum": 20,
   "description": "Strict token budget ceiling when mode=budget"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "status",
  "roi_proof",
  "data"
 ],
 "properties": {
  "data": {
   "type": "object",
   "description": "Distilled Markdown, structured JSON tables/metadata, skeleton outline, or BM25 budget excerpt."
  },
  "cache": {
   "type": "object",
   "properties": {
    "status": {
     "enum": [
      "HIT",
      "MISS"
     ],
     "type": "string"
    },
    "cache_key": {
     "type": "string"
    },
    "latency_ms": {
     "type": "number"
    }
   }
  },
  "status": {
   "type": "string",
   "description": "Execution status ('ok')"
  },
  "billing": {
   "type": "object",
   "properties": {
    "agent_id": {
     "type": "string"
    },
    "payment_method": {
     "type": "string"
    },
    "fee_charged_usd": {
     "type": "number"
    }
   }
  },
  "roi_proof": {
   "type": "object",
   "properties": {
    "raw_tokens": {
     "type": "integer"
    },
    "tokens_saved": {
     "type": "integer"
    },
    "roi_multiplier": {
     "type": "number"
    },
    "distilled_tokens": {
     "type": "integer"
    },
    "llm_cost_saved_usd": {
     "type": "number"
    },
    "compression_ratio_pct": {
     "type": "number"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/preflight-agentdiet-dev-web-url-html-prompt-compressor-with-bm25-c7250e13/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from preflight.agentdiet.dev](https://www.zero.xyz/host/preflight.agentdiet.dev/llms.txt)