Bolt.new AI and CoStar integration: Step-by-Step Guide 2025

To integrate Bolt.new with CoStar, you cannot connect directly to “CoStar” because CoStar does not provide an open public API. What you can integrate with is CoStar’s LoopNet / Apartments.com / Homes.com data services, but only if you have a paid enterprise contract with CoStar that explicitly grants API access. Integration is done the standard way inside Bolt.new: store API keys in environment variables, call their REST endpoints from server-side routes, and never let the key leak to the client.

 

The Direct Answer

 

You integrate Bolt.new with CoStar by using CoStar’s private enterprise APIs (only available under contract); storing the API credentials in Bolt.new environment variables; calling their REST endpoints from a Bolt.new server route; and returning only safe, filtered data to the frontend. Without a CoStar API contract, there is no legitimate integration path because CoStar does not offer public, open, or free APIs.

 

What This Really Means (Explained Simply)

 

Bolt.new is just a coding environment in your browser where you write backend code (Node/Express), frontend code, and call external APIs. Bolt never “auto-connects” to CoStar itself. You integrate the same way you integrate any enterprise data source: get API access from CoStar, store your API keys securely, write server-side API calls, test them, and then expose the data to your frontend app.

CoStar is extremely strict about their data. Their raw data is NOT public. They only allow API access to customers with signed contracts. If you are not one of those customers, the integration cannot be built.

 

How to Integrate (Step-by-Step)

 

Below is the real-world sequence a senior engineer follows. This is exactly how you’d build this in Bolt.new.

• Get API access from CoStar: Your CoStar account manager must activate your API product. You receive: base API URL, client ID, client secret, and documentation.
• Add your credentials to Bolt.new environment variables: Bolt.new provides a sidebar for ENV variables like COSTAR_CLIENT_ID, COSTAR_SECRET, COSTAR_BASE\_URL.
• Create a server route in Bolt.new that makes authenticated requests to CoStar’s endpoints.
• Call the server route from your frontend instead of calling CoStar directly. This avoids exposing secrets.
• Parse and sanitize the response because CoStar contracts usually enforce display rules.

 

Example Server Route in Bolt.new (Node/Express)

 

// server/routes/costar.js
import express from "express";
import fetch from "node-fetch";

const router = express.Router();

// Example: Fetch listings from a fictional CoStar endpoint
// NOTE: Replace URL + fields with real endpoints from your CoStar contract!

router.get("/costar/listings", async (req, res) => {
  try {
    const tokenResponse = await fetch(process.env.COSTAR_BASE_URL + "/oauth/token", {
      method: "POST",
      headers: {
        "Content-Type": "application/json"
      },
      body: JSON.stringify({
        client_id: process.env.COSTAR_CLIENT_ID,     // stored in Bolt env
        client_secret: process.env.COSTAR_SECRET,    // stored in Bolt env
        grant_type: "client_credentials"
      })
    });

    const tokenData = await tokenResponse.json();

    const apiResponse = await fetch(process.env.COSTAR_BASE_URL + "/listings/search", {
      method: "GET",
      headers: {
        Authorization: "Bearer " + tokenData.access_token
      }
    });

    const data = await apiResponse.json();

    res.json({ listings: data });
  } catch (err) {
    res.status(500).json({ error: "CoStar API call failed", details: err.message });
  }
});

export default router;

 

Frontend Example (Safe)

 

// client/src/api/getListings.js
export async function getListings() {
  const res = await fetch("/costar/listings");  // hits your server, NOT CoStar directly
  return res.json();
}

 

Important Constraints You Must Understand

 

• You cannot integrate unless CoStar grants API access. This is the biggest blocker for almost everyone.
• The API endpoints are not publicly documented. They are only provided to enterprise customers.
• Do not call CoStar from the browser. Their terms prohibit exposing keys or allowing client-side access.
• Bolt.new environment variables are safe for server-side code, but you should not store secrets in client code.
• Expect CoStar to enforce branding and data usage rules.

 

Summary

 

You integrate Bolt.new with CoStar exactly the same way you would integrate any private enterprise REST API: obtain credentials under a contract, store them in Bolt.new env vars, build server-side API routes that authenticate to CoStar, and expose sanitized responses to the frontend. There is no public or free CoStar API and therefore no integration path without an enterprise agreement.