# Web URL Context Trimmer with BM25 Budget Control

> Web URL Context Trimmer 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 configurable modes (markdown, structured, skeleton, or BM25 budget) with a strict token ceiling

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/context-trimmer?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-context-trimmer-with-bm25-budget-55120452
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_78DO-eFciCvo5-4tEi66E

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-context-trimmer-with-bm25-budget-55120452
```

Example prompt: Can you distill https://stripe.com/docs/payments into compact markdown, keeping it under 2000 tokens using budget mode focused on 'payment intents'?

## When to prefer this

Choose this endpoint when an AI agent needs to read web content but must stay within a token budget or minimize LLM costs. It is especially useful when passing full web pages to an LLM is impractical due to context window limits. Prefer it over generic scrapers when you need structured output modes (markdown, skeleton, structured tables) or BM25-focused excerpts. The built-in ROI proof makes it easy to justify the compression step in agent pipelines. Use it over browser automation tools when raw content retrieval and compression are sufficient — no JavaScript rendering required.

## Known failure modes

- URL unreachable or returns non-200 — endpoint may return an error status
- HTML too large or malformed — distillation may fail or return partial content
- max_tokens too low (below 20) — rejected by schema validation
- BM25 query missing when mode=budget — may fall back to default or return error
- Payment not completed via x402 — 402 response blocking access
- Invalid mode enum value — request rejected

## 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/context-trimmer)

## Output

Returns a 'data' object containing the distilled content (markdown text, structured JSON tables/metadata, skeleton outline, or BM25-ranked excerpt depending on mode), plus an 'roi_proof' object showing raw token count, distilled token count, tokens saved, compression ratio percentage, ROI multiplier, and estimated LLM cost saved in USD. Also includes optional billing details and a cache hit/miss indicator with latency.

## 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-context-trimmer-with-bm25-budget-55120452/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)