# SourceLens: Website to Markdown & JSON (`onsq/sourcelens`) Actor

Turn any public webpage into clean, LLM-ready Markdown or structured JSON with CSS selectors. Optional same-site crawling, robots.txt aware, pay only for pages that succeed.

- **URL**: https://apify.com/onsq/sourcelens.md
- **Developed by:** [Owen Eskew](https://apify.com/onsq) (community)
- **Categories:** AI, Developer tools
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $1.00 / 1,000 markdown pages

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## SourceLens: Website to Markdown & JSON for AI

Turn any public webpage into **clean, LLM-ready Markdown** or **structured JSON** in seconds. SourceLens strips menus, footers, cookie banners and scripts, keeps the content that matters, and hands it back in a format your AI agent, RAG pipeline or spreadsheet can use straight away.

**You only pay for pages that succeed.** Failed, blocked or empty pages are returned as free error rows, so you can see exactly what happened without paying for it.

Built and maintained by **ONSQ Enterprises**.

> 🤖 **Want specific fields without writing CSS selectors?** Try **[SourceLens AI](https://apify.com/onsq/sourcelens-ai)**. Describe what you want in plain English, bring your own OpenAI or Claude key, and get JSON where every value is backed by a quote from the page.

### What can SourceLens do?

- 📝 **Clean Markdown.** It finds the main content of each page and converts headings, lists, tables and links into tidy Markdown. Navigation, footers, forms and scripts are removed.
- 🎯 **Structured JSON with CSS selectors.** Name the fields you want, point each one at a CSS selector, and get one JSON record per page. Each value comes with the matching page text as evidence.
- 🕸️ **Same-site crawling.** Start from a homepage or a docs index and follow internal links up to the depth and page count you choose. Filter links with include and exclude patterns.
- 🧠 **Extra metadata for free.** Every page includes its title, meta description, language, canonical URL, word count and any JSON-LD structured data the site publishes, such as products, articles and organizations.
- 🛡️ **Polite and safe.** It respects robots.txt by default, retries temporary errors once, and never visits private or local network addresses.
- ⚡ **Fast and cheap.** Plain HTTP requests with no browser, so runs finish quickly and stay inexpensive.

### Who is it for?

- **AI and LLM developers** feeding websites into RAG, vector databases, fine-tuning sets or chatbots.
- **AI agents** that need to read a webpage and get clean text back through the Apify API or MCP.
- **Marketers and analysts** pulling prices, headlines, product names or links from many pages into a spreadsheet.
- **Researchers** archiving articles and documentation as Markdown.

### How to use it

1. Click **Try for free**.
2. Paste one or more URLs. You can leave off `https://`.
3. Choose **Clean Markdown** or **Structured JSON from CSS selectors**.
4. Optionally set a **Crawl depth** to follow links on the same website.
5. Click **Start**, then download your results as JSON, CSV, Excel or HTML, or read them through the API.

### Input examples

**Markdown for a list of pages**

```json
{
  "urls": ["https://www.python.org/about/", "en.wikipedia.org/wiki/Web_scraping"],
  "mode": "markdown"
}
```

**Crawl a documentation site**

```json
{
  "urls": ["https://docs.example.com/"],
  "mode": "markdown",
  "maxCrawlDepth": 2,
  "maxCrawlPages": 200,
  "includeUrlPattern": "/docs/",
  "excludeUrlPattern": "/(changelog|tags)/"
}
```

**Structured JSON with CSS selectors**

```json
{
  "urls": ["https://news.ycombinator.com/"],
  "mode": "selectors",
  "fields": [
    { "name": "stories", "selector": ".titleline > a", "multiple": true },
    { "name": "storyLinks", "selector": ".titleline > a", "attribute": "href", "multiple": true }
  ]
}
```

Each field takes a `name`, a CSS `selector`, an optional `attribute` and an optional `multiple`. The attribute is `text` by default. You can also use `html`, `href`, `src` or any other attribute name. Set `multiple` to `true` to get every match as a list.

| Setting | What it does | Default |
| --- | --- | --- |
| `urls` | Pages to extract, up to 1,000 per run | required |
| `mode` | `markdown` or `selectors` | `markdown` |
| `fields` | Fields to extract in selectors mode | none |
| `maxCrawlDepth` | How many link levels to follow on the same site. 0 means no crawling | 0 |
| `maxCrawlPages` | Most extra pages crawling may add | 100 |
| `includeUrlPattern` | Only follow links matching this regular expression | none |
| `excludeUrlPattern` | Never follow links matching this regular expression | none |
| `maxChars` | Most Markdown characters kept per page | 100,000 |
| `concurrency` | Pages fetched at the same time | 5 |
| `timeoutSeconds` | Time limit per page | 30 |
| `respectRobotsTxt` | Skip pages that robots.txt disallows | true |

### Output

You get one dataset row per page. A Markdown result looks like this:

```json
{
  "url": "https://www.python.org/about/",
  "status": "ok",
  "mode": "markdown",
  "title": "About Python™ | Python.org",
  "description": "The official home of the Python Programming Language",
  "language": "en",
  "wordCount": 331,
  "markdown": "## Getting Started\n\nPython can be easy to pick up whether you're a first time programmer or you're experienced with other languages...\n\n- [Beginner's Guide, Programmers](https://wiki.python.org/moin/BeginnersGuide/Programmers)\n...",
  "jsonLd": [{ "@context": "https://schema.org", "@type": "WebSite", "url": "https://www.python.org/" }],
  "truncated": false,
  "depth": 0,
  "statusCode": 200,
  "billed": true
}
```

A selectors result has a `data` object with your fields and an `evidence` object showing the page text each value came from. Pages that fail have `"status": "error"`, an `error` message and `"billed": false`.

A run summary with counts of successful, failed and skipped pages is saved in the key-value store as `SUMMARY`.

### How much does it cost?

You pay a small fee for each page that is extracted successfully. Markdown pages and selector pages have separate prices, which are shown on the **Pricing** tab. There are no proxy or browser costs.

- **Failed pages are free.** That includes pages that time out, are blocked, are disallowed by robots.txt, are empty, or match none of your selectors.
- **Your spending limit is respected.** If you set a maximum cost per run, SourceLens stops cleanly when it is reached and keeps everything extracted so far.

### Use it from code or an AI agent

Call SourceLens through the [Apify API](https://docs.apify.com/api/v2) from any language, or use the Apify Python and JavaScript clients:

```python
from apify_client import ApifyClient

client = ApifyClient("<YOUR_APIFY_TOKEN>")
run = client.actor("onsq/sourcelens").call(run_input={"urls": ["https://www.python.org/about/"]})
for page in client.dataset(run["defaultDatasetId"]).iterate_items():
    print(page["title"], page["wordCount"])
```

AI agents can also call SourceLens through the [Apify MCP server](https://docs.apify.com/platform/integrations/mcp). It works with Make, Zapier, n8n, LangChain, LlamaIndex and Google Sheets through Apify integrations.

### Limits and good to know

- SourceLens reads the HTML a server returns. It does not run JavaScript, so pages that only build their content in the browser may come back nearly empty.
- Sites with strong bot protection, such as some large news sites, may refuse the request. Those pages come back as free error rows.
- It does not log in, solve CAPTCHAs or read PDFs and images.
- Crawling always stays on the same website as the start URL. `www.` and non-`www.` count as the same site.

### FAQ

**Is it legal to scrape websites?**
SourceLens only fetches public pages and respects robots.txt by default. Results can still contain personal or copyrighted data. Make sure you have a legitimate reason to collect it, follow each website's terms, and consult a lawyer if you are unsure.

**Why did a page return an error?**
The `error` field explains it. Common reasons are `HTTP 403` (the site blocks bots), `Disallowed by robots.txt`, or a timeout. You are not charged for these pages.

**Can I crawl a whole website?**
Yes, within limits. Set a crawl depth and a page limit of up to 5,000 extra pages per run.

**Can it pull specific facts without selectors?**
Yes, with **[SourceLens AI](https://apify.com/onsq/sourcelens-ai)**. You list the fields in plain English, it uses your own OpenAI or Claude key, and it checks every value against a quote from the page. It can also turn a product grid or job board into one row per item.

**Something is broken or missing.**
Open an issue on the **Issues** tab. Feature requests are welcome too.

# Actor input Schema

## `urls` (type: `array`):

Public webpages to extract, up to 1,000 per run. Missing https:// is added for you and #anchors are ignored.

## `mode` (type: `string`):

Markdown returns the main content of each page as clean Markdown. CSS selectors return only the fields you define below.

## `fields` (type: `array`):

Each field needs a name and a CSS selector. Optional: attribute (text by default, html, href, src or any attribute name) and multiple (true returns every match as a list).

## `maxCrawlDepth` (type: `integer`):

0 extracts only the URLs above. 1 also follows links found on those pages, 2 follows links on those pages too, and so on. Crawling stays on the same website.

## `maxCrawlPages` (type: `integer`):

Upper limit on extra pages added by crawling, on top of your start URLs. Only used when crawl depth is above 0.

## `includeUrlPattern` (type: `string`):

Optional regular expression. Example: /blog/ follows only blog pages.

## `excludeUrlPattern` (type: `string`):

Optional regular expression. Example: /(login|cart|tag)/

## `maxChars` (type: `integer`):

Longer pages are cut off and marked truncated.

## `concurrency` (type: `integer`):

How many pages to fetch at the same time.

## `timeoutSeconds` (type: `integer`):

Give up on a page after this many seconds. One automatic retry is made for timeouts and temporary server errors.

## `respectRobotsTxt` (type: `boolean`):

Skip pages that the website's robots.txt asks crawlers not to visit.

## Actor input object example

```json
{
  "urls": [
    "https://www.python.org/about/"
  ],
  "mode": "markdown",
  "fields": [
    {
      "name": "heading",
      "selector": "h1"
    },
    {
      "name": "links",
      "selector": "main a",
      "attribute": "href",
      "multiple": true
    }
  ],
  "maxCrawlDepth": 0,
  "maxCrawlPages": 100,
  "maxChars": 100000,
  "concurrency": 5,
  "timeoutSeconds": 30,
  "respectRobotsTxt": true
}
```

# Actor output Schema

## `results` (type: `string`):

No description

## `summary` (type: `string`):

No description

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "urls": [
        "https://www.python.org/about/"
    ],
    "fields": [
        {
            "name": "heading",
            "selector": "h1"
        },
        {
            "name": "links",
            "selector": "main a",
            "attribute": "href",
            "multiple": true
        }
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("onsq/sourcelens").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = {
    "urls": ["https://www.python.org/about/"],
    "fields": [
        {
            "name": "heading",
            "selector": "h1",
        },
        {
            "name": "links",
            "selector": "main a",
            "attribute": "href",
            "multiple": True,
        },
    ],
}

# Run the Actor and wait for it to finish
run = client.actor("onsq/sourcelens").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "urls": [
    "https://www.python.org/about/"
  ],
  "fields": [
    {
      "name": "heading",
      "selector": "h1"
    },
    {
      "name": "links",
      "selector": "main a",
      "attribute": "href",
      "multiple": true
    }
  ]
}' |
apify call onsq/sourcelens --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,onsq/sourcelens"
        }
    }
}
```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/6VdC40cJjb0Aw5wqZ/builds/kWh9H7VrCnC4cYdxJ/openapi.json