# know.fast URL Knowledge Extraction

> know.fast URL Knowledge Extraction is a paid API for AI agents from know.fast, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Converts any URL (article, video, podcast, paper, PDF, GitHub repo) into a cited knowledge page and token-efficient markdown packet for agent use, at $0.01 per link.

## Facts

- Endpoint: POST https://know.fast/v1/x402/know
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/know-fast-url-knowledge-extraction-bce7489d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ftBXh-Rbzn0U0r305Kqc0

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 know-fast-url-knowledge-extraction-bce7489d -d '<json body>'
```

Example prompt: Can you process this link for me and turn it into a clean, cited knowledge summary I can use — https://www.example.com/some-article? It should come back as a markdown packet so you can relay it efficiently.

## When to prefer this

Choose this endpoint when an agent needs to ingest and understand arbitrary URLs — articles, videos, podcasts, PDFs, or repos — as structured, cited knowledge in a single flat-rate call. Ideal when you want token-efficient markdown output ready for LLM relay, benefit from a shared global cache (previously seen links return instantly), and want transcription costs (e.g. long podcasts) absorbed by the provider rather than billed separately.

## Known failure modes

- URL is inaccessible or returns an error (404, 403, paywall)
- URL points to unsupported content type or malformed page
- Transcription or extraction fails for certain media formats
- Payment of $0.01 USDC not completed or rejected via x402
- Rate limiting or service unavailability

## How this service works

Send a link, know it: any URL — article, YouTube video, X post, podcast episode, paper, PDF, GitHub repo — becomes a durable, cited knowledge page plus a token-efficient markdown packet built for agent relay. Flat $0.01 per link. Links are unique: anything any agent has ever known answers instantly from the shared knowledge base; first-ever links are processed once, for everyone (we absorb transcription costs — a 2-hour podcast is still one cent).

## Output

A durable cited knowledge page and a token-efficient markdown packet containing the extracted, structured content of the submitted URL, ready for agent relay and downstream use. For previously processed URLs, results are returned instantly from a shared knowledge base without reprocessing.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/know-fast-url-knowledge-extraction-bce7489d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from know.fast](https://www.zero.xyz/host/know.fast/llms.txt)