Data Scraping Guide

Data Scraping Guide

For large datasets (followers, posts, search results), intercept and replay network requests rather than scrolling and parsing the DOM. This is faster, more reliable, and handles pagination automatically.

Why Not Scroll?

Scrolling is slow, unreliable, and wastes time. APIs return structured data with pagination built in. Always prefer API replay.

Start Small, Then Scale

Don't try to automate everything at once. Work incrementally:

1. Capture one request - verify you're intercepting the right endpoint
2. Inspect one response - understand the schema before writing extraction code
3. Extract a few items - make sure your parsing logic works
4. Then scale up - add pagination loop only after the basics work

This prevents wasting time debugging a complex script when the issue is a simple path like data.user.timeline vs data.user.result.timeline.

Step-by-Step Workflow

1. Capture Request Details

First, intercept a request to understand URL structure and required headers:

import { connect, waitForPageLoad } from "@/client.js";
import * as fs from "node:fs";

const client = await connect();
const page = await client.page("site");

let capturedRequest = null;
page.on("request", (request) => {
  const url = request.url();
  // Look for API endpoints (adjust pattern for your target site)
  if (url.includes("/api/") || url.includes("/graphql/")) {
    capturedRequest = {
      url: url,
      headers: request.headers(),
      method: request.method(),
    };
    fs.writeFileSync("tmp/request-details.json", JSON.stringify(capturedRequest, null, 2));
    console.log("Captured request:", url.substring(0, 80) + "...");
  }
});

await page.goto("https://example.com/profile");
await waitForPageLoad(page);
await page.waitForTimeout(3000);

await client.disconnect();

2. Capture Response to Understand Schema

Save a raw response to inspect the data structure:

page.on("response", async (response) => {
  const url = response.url();
  if (url.includes("UserTweets") || url.includes("/api/data")) {
    const json = await response.json();
    fs.writeFileSync("tmp/api-response.json", JSON.stringify(json, null, 2));
    console.log("Captured response");
  }
});

Then analyze the structure to find:

• Where the data array lives (e.g., data.user.result.timeline.instructions[].entries)
• Where pagination cursors are (e.g., cursor-bottom entries)
• What fields you need to extract

3. Replay API with Pagination

Once you understand the schema, replay requests directly:

import { connect } from "@/client.js";
import * as fs from "node:fs";

const client = await connect();
const page = await client.page("site");

const results = new Map(); // Use Map for deduplication
const headers = JSON.parse(fs.readFileSync("tmp/request-details.json", "utf8")).headers;
const baseUrl = "https://example.com/api/data";

let cursor = null;
let hasMore = true;

while (hasMore) {
  // Build URL with pagination cursor
  const params = { count: 20 };
  if (cursor) params.cursor = cursor;
  const url = `${baseUrl}?params=${encodeURIComponent(JSON.stringify(params))}`;

  // Execute fetch in browser context (has auth cookies/headers)
  const response = await page.evaluate(
    async ({ url, headers }) => {
      const res = await fetch(url, { headers });
      return res.json();
    },
    { url, headers }
  );

  // Extract data and cursor (adjust paths for your API)
  const entries = response?.data?.entries || [];
  for (const entry of entries) {
    if (entry.type === "cursor-bottom") {
      cursor = entry.value;
    } else if (entry.id && !results.has(entry.id)) {
      results.set(entry.id, {
        id: entry.id,
        text: entry.content,
        timestamp: entry.created_at,
      });
    }
  }

  console.log(`Fetched page, total: ${results.size}`);

  // Check stop conditions
  if (!cursor || entries.length === 0) hasMore = false;

  // Rate limiting - be respectful
  await new Promise((r) => setTimeout(r, 500));
}

// Export results
const data = Array.from(results.values());
fs.writeFileSync("tmp/results.json", JSON.stringify(data, null, 2));
console.log(`Saved ${data.length} items`);

await client.disconnect();

Key Patterns

Tips

• Extension mode: page.context().cookies() doesn't work - capture auth headers from intercepted requests instead
• Rate limiting: Add 500ms+ delays between requests to avoid blocks
• Stop conditions: Check for empty results, missing cursor, or reaching a date/ID threshold
• GraphQL APIs: URL params often include variables and features JSON objects - capture and reuse them