How to Integrate Lovable with Redfin

Firecrawl is one of Lovable's 17 native shared connectors. Before creating the Edge Function, connect Firecrawl at the workspace level. Navigate to Settings → Connectors and find Firecrawl in the list. Click 'Connect' and enter your Firecrawl API key from your account at firecrawl.dev. If you don't have a Firecrawl account, sign up at firecrawl.dev. The free tier provides 500 pages/month — sufficient for development and low-traffic production use. Paid plans start at $19/month for 3,000 pages/month. For a home value lookup feature where each user lookup scrapes one Redfin page, 500 pages translates to 500 property lookups per month on the free tier. After connecting in Settings → Connectors, also add your Firecrawl API key to Cloud Secrets as FIRECRAWL_API_KEY. Although the connector gives Lovable's AI context about Firecrawl, the Edge Function needs the key directly via Deno.env.get() for server-side API calls. Both steps are needed: the connector for AI context, and the Cloud Secret for the Edge Function runtime.

Redfin property URLs follow a pattern based on the property address. A typical Redfin property URL looks like: https://www.redfin.com/CA/San-Francisco/123-Main-St-94102/home/1234567. The path structure is: /STATE/City-Name/Street-Number-Street-Name-ZipCode/home/PropertyId. Constructing this URL from a user-entered address requires some text formatting: the state uses the two-letter code, city and street names use hyphens instead of spaces, and the zip code is appended to the street. However, you cannot reliably construct the exact Redfin URL from an address without knowing the numeric property ID that Redfin assigns internally. A more reliable approach is to use Firecrawl to search Redfin's search results page first, extract the property URL from the results, then scrape that URL for the estimate data. Alternatively, use Redfin's search URL pattern: https://www.redfin.com/zipcode/94102 and scrape the first matching result for the entered address. Ask Lovable to build a two-step approach: first search Redfin with the address to find the property URL, then scrape that URL for estimate data. This is more reliable than URL construction and handles addresses that do not perfectly match Redfin's URL format.

Build the Edge Function that orchestrates the two Firecrawl calls — search for the property URL, then scrape the estimate data. The Firecrawl API endpoint for scraping is https://api.firecrawl.dev/v1/scrape, and for search it is https://api.firecrawl.dev/v1/search. The Firecrawl scrape endpoint accepts: url (the page to scrape), formats (['extract'] for AI-powered extraction), and extractorOptions.extractionPrompt (natural language description of what to extract). The response includes extract.data with the extracted fields as a JSON object. For Redfin property pages, an effective extraction prompt is: 'Extract from this Redfin property page: the current Redfin Estimate value (in dollars), the estimate high and low range, the last sold date, the last sold price, the number of bedrooms, number of bathrooms, total square footage, year built, and whether the property is currently for sale. Return null for any field not found on the page.' Firecrawl's AI extraction is generally reliable for structured data on consistent page layouts. However, Redfin may periodically update its page structure, which can affect extraction accuracy. Add validation in your Edge Function to detect when the extraction returns unexpected null values and return a graceful error to the frontend.

1// supabase/functions/redfin-estimate/index.ts
2import { serve } from "https://deno.land/std@0.168.0/http/server.ts";
3
4const corsHeaders = {
5  "Access-Control-Allow-Origin": "*",
6  "Access-Control-Allow-Headers": "authorization, x-client-info, apikey, content-type",
7  "Access-Control-Allow-Methods": "POST, OPTIONS",
8};
9
10serve(async (req: Request) => {
11  if (req.method === "OPTIONS") {
12    return new Response("ok", { headers: corsHeaders });
13  }
14
15  try {
16    const { address, city, state, zipCode } = await req.json();
17    const apiKey = Deno.env.get("FIRECRAWL_API_KEY");
18
19    // Step 1: Find the Redfin property URL
20    const searchResponse = await fetch("https://api.firecrawl.dev/v1/search", {
21      method: "POST",
22      headers: { "Authorization": `Bearer ${apiKey}`, "Content-Type": "application/json" },
23      body: JSON.stringify({
24        query: `${address} ${city} ${state} ${zipCode} site:redfin.com`,
25        limit: 3,
26      }),
27    });
28    const searchData = await searchResponse.json();
29    const redfinUrl = searchData.data?.[0]?.url;
30
31    if (!redfinUrl || !redfinUrl.includes("redfin.com")) {
32      return new Response(JSON.stringify({ error: "Property not found on Redfin", redfinUrl: null }), {
33        status: 404, headers: { ...corsHeaders, "Content-Type": "application/json" },
34      });
35    }
36
37    // Step 2: Scrape the Redfin property page for estimate data
38    const scrapeResponse = await fetch("https://api.firecrawl.dev/v1/scrape", {
39      method: "POST",
40      headers: { "Authorization": `Bearer ${apiKey}`, "Content-Type": "application/json" },
41      body: JSON.stringify({
42        url: redfinUrl,
43        formats: ["extract"],
44        extract: {
45          prompt: "Extract: currentEstimate (number in dollars), estimateLow (number), estimateHigh (number), lastSoldDate (string YYYY-MM-DD), lastSoldPrice (number), bedrooms (number), bathrooms (number), squareFeet (number), yearBuilt (number), currentlyListed (boolean), listPrice (number or null), daysOnMarket (number or null). Return null for missing fields.",
46          schema: { type: "object" },
47        },
48      }),
49    });
50    const scrapeData = await scrapeResponse.json();
51    const estimate = scrapeData.extract;
52
53    return new Response(JSON.stringify({ ...estimate, redfinUrl, scrapedAt: new Date().toISOString() }), {
54      status: 200, headers: { ...corsHeaders, "Content-Type": "application/json" },
55    });
56  } catch (error) {
57    return new Response(JSON.stringify({ error: error.message }), {
58      status: 500, headers: { ...corsHeaders, "Content-Type": "application/json" },
59    });
60  }
61});

With the Edge Function deployed, open the Lovable chat and describe the home value estimator component. This is typically a prominent feature in financial apps — a card or widget where users enter their address and see their current estimated home value within seconds. The UI should handle loading states (Firecrawl scraping takes 3-8 seconds), success states (showing the estimate and details), not-found states (properties with no Redfin Estimate), and error states (scraping failures). A loading skeleton matches the final card layout to reduce perceived wait time. Displaying the estimate range (low to high) alongside the point estimate helps users understand that automated valuations have uncertainty. A simple visual like a range bar or confidence interval helps convey this. Include the scrape date ('Redfin Estimate as of March 30, 2026') so users know the data freshness. For apps where users enter their address during onboarding or sign-up, consider triggering the Redfin lookup automatically rather than requiring an explicit button press — this creates a more seamless 'wow' moment when the home value appears without user effort.

Web scraping is inherently less reliable than a first-party API. Redfin may update its page structure, rate-limit scraping requests, or return partial data. Building robust caching and graceful degradation makes the feature reliable enough for production. Cache successful Redfin lookups in Supabase with a 24-hour TTL. Store: address (as a normalized key), all extracted fields, redfinUrl, and scrapedAt. Before calling the Edge Function, check Supabase for a recent cached result. Return the cached result if it is less than 24 hours old, with a 'Cached result' indicator showing the original scrape date. For error resilience, the UI should: never show a raw error message to users, always offer an alternative path (manual value entry), log errors to Cloud → Logs for monitoring, and include a 'Retry' option for transient failures. A common failure mode is the Firecrawl search returning a non-property Redfin URL (like a neighborhood page) — validate that the scraped URL contains /home/ before proceeding to the estimate scrape. For applications requiring highly reliable real-time home valuations where Redfin scraping is insufficient, RapidDev's team can help evaluate alternative data sources including direct data licensing options.