# Buildium

- Tool: FlutterFlow
- Difficulty: Intermediate
- Time required: 1-2 hours
- Last updated: July 2026

## TL;DR

Connect FlutterFlow to Buildium using a FlutterFlow API Call pointed at a Firebase or Supabase proxy that sets the x-buildium-client-id and x-buildium-client-secret headers. Buildium's auth is the simplest of any accounting tool — just an API key and secret — but those two credentials grant full access to a property portfolio and all tenant PII, so they must never appear in a FlutterFlow API Call header or compiled app bundle.

## Simple Auth, Powerful Access — Why the Proxy Still Matters

Buildium's API uses the simplest authentication of any finance tool in this category: two request headers — x-buildium-client-id and x-buildium-client-secret — generated in the Buildium settings interface. There is no OAuth flow, no token expiry, no refresh dance. This simplicity is appealing. But it is also the primary risk: those two headers grant unrestricted access to your entire property portfolio — every tenant record, every lease, every rent payment, every piece of tenant PII. If they appear in a FlutterFlow API Call header or Dart constant, they compile into the app binary. Anyone who decompiles the APK or IPA gets full access to your property management data. The proxy is just as mandatory here as it is for OAuth-based tools.

Buildium is built for property managers and landlords — tracking units, tenants, leases, rent payments, work orders, and financials. The FlutterFlow build is a landlord mobile app: a property owner checking which units have outstanding rent, which maintenance tickets are open, and what recent bank transactions look like — all without opening a browser. The Buildium API covers all of this through straightforward REST endpoints at https://api.buildium.com/api/v1.

Critical prerequisite: API access is not available on all Buildium plans and is off by default. It requires a paid subscription (Essential, Growth, or Premium — verify the current tier requirements) and must be explicitly enabled under Settings → API Configuration in Buildium. Until you do this, no API key or secret exists. Readers on a free trial have no path to the API — establish this early so they do not spend an hour on proxy setup before discovering the blocker.

## Before you start

- A paid Buildium account at the Essential, Growth, or Premium tier (verify which tier provides API access — it is not available on free trials)
- API access enabled in Buildium under Settings → API Configuration (it is off by default and must be manually activated)
- A Firebase project with Cloud Functions on Blaze plan OR a Supabase project with Edge Functions
- A FlutterFlow project on a paid plan (Starter or above for API Calls)
- Basic understanding of deploying serverless functions (Node.js for Firebase or Deno for Supabase)

## Step-by-step guide

### 1. Step 1: Enable API access in Buildium and generate your API key and secret

Log into your Buildium account and navigate to Settings in the left navigation. Look for the API Configuration section (sometimes under Account Settings or Administration). If you do not see API Configuration, your account plan does not include API access — contact Buildium support to confirm which plan tier enables it, or upgrade to a tier that does. API access is not available on free trials.

In API Configuration, toggle API access to Enabled. Once enabled, a form appears to create a new API key. Fill in a label (e.g., 'FlutterFlow App') and click Create. Buildium generates two values: the Client ID (this is your x-buildium-client-id header value) and the Client Secret (your x-buildium-client-secret header value). Copy both values to a secure location immediately — the Client Secret may only be displayed once.

These two values are the only credentials you need to authenticate with the Buildium API. There is no token exchange, no OAuth flow, no expiry by default. Every HTTP request to https://api.buildium.com/api/v1/... must include these two headers. The base URL for all Buildium REST calls is https://api.buildium.com/api/v1. Endpoints follow a predictable structure: /rentals for properties, /rentals/leases for lease records, /leases/{id}/outstandingitems for outstanding charges, /maintenance/requests for work orders.

**Expected result:** API access is enabled in Buildium. You have a Client ID (x-buildium-client-id) and Client Secret (x-buildium-client-secret) copied to a secure location. Buildium's Settings page shows the key as Active.

### 2. Step 2: Deploy a Firebase Cloud Function proxy that sets the auth headers

Create a Firebase Cloud Function that accepts requests from your FlutterFlow app and forwards them to the Buildium API with the authentication headers set server-side. Store your Client ID and Client Secret in Firebase Functions config — not in the function code file: run firebase functions:config:set buildium.client_id='YOUR_ID' buildium.client_secret='YOUR_SECRET' from your local terminal.

The proxy function receives a request specifying which Buildium resource to fetch (e.g., leases, maintenance requests, transactions). It reads the client ID and secret from Firebase config, adds them as headers to an outbound request to https://api.buildium.com/api/v1/..., and returns the Buildium response to the FlutterFlow app. Keep the proxy thin: let FlutterFlow pass a resource type and optional filter parameters; the proxy constructs the Buildium URL and headers.

For pagination, Buildium REST endpoints typically accept offset and limit query parameters and return a total count in the response. Have the proxy accept an offset parameter from FlutterFlow and forward it. For most landlord dashboard use cases — one portfolio of properties with tens to hundreds of units — returning 100 records per call covers the full dataset in one or two calls. Add a cache layer: store the response in a Firestore document with a timestamp, and serve the cached version for the next 3-5 minutes before re-fetching from Buildium. This reduces API calls and speeds up the app.

```
// Firebase Cloud Function proxy — index.js
const functions = require('firebase-functions');
const admin = require('firebase-admin');
const axios = require('axios');
admin.initializeApp();

const BUILDIUM_BASE = 'https://api.buildium.com/api/v1';
const CACHE_TTL_MS = 4 * 60 * 1000; // 4-minute cache

// Generic proxy function for Buildium endpoints
exports.buildiumProxy = functions.https.onCall(async (data, context) => {
  const cfg = functions.config().buildium;
  // data.resource = 'rentals/leases' | 'maintenance/requests' | 'leases/{id}/outstandingitems' etc.
  const { resource, params = {}, offset = 0, limit = 100 } = data;

  // Check Firestore cache
  const cacheKey = `${resource}_${JSON.stringify(params)}_${offset}`;
  const cacheDoc = await admin.firestore().doc(`buildium_cache/${Buffer.from(cacheKey).toString('hex')}`).get();
  if (cacheDoc.exists) {
    const { responseData, cached_at } = cacheDoc.data();
    if (Date.now() - cached_at < CACHE_TTL_MS) {
      return { data: responseData, fromCache: true };
    }
  }

  // Call Buildium API with credentials in headers (never in the client)
  const queryParams = new URLSearchParams({ ...params, offset, limit }).toString();
  const url = `${BUILDIUM_BASE}/${resource}${queryParams ? '?' + queryParams : ''}`;
  const resp = await axios.get(url, {
    headers: {
      'x-buildium-client-id': cfg.client_id,
      'x-buildium-client-secret': cfg.client_secret,
      'Content-Type': 'application/json',
    },
  });

  // Write to cache
  await admin.firestore().doc(`buildium_cache/${Buffer.from(cacheKey).toString('hex')}`).set({
    responseData: resp.data,
    cached_at: Date.now(),
  });

  return { data: resp.data, fromCache: false };
});
```

**Expected result:** The buildiumProxy Cloud Function is deployed. A test call with resource='rentals/leases' returns lease data from Buildium. A second call within 4 minutes returns the same data from the Firestore cache.

### 3. Step 3: Create a FlutterFlow API Group pointing to your proxy

Open your FlutterFlow project. Click API Calls in the left navigation panel, then click + Add → Create API Group. Name the group BuildiumProxy. Set the Base URL to your Firebase Functions URL: https://us-central1-YOUR-PROJECT-ID.cloudfunctions.net.

Add the first API Call: click + Add API Call. Name it GetLeases. Set the method to POST (Firebase callable functions require POST) and the path to /buildiumProxy. In the Body tab, add a JSON body that passes the resource to the proxy: {"resource": "rentals/leases", "limit": 100}. FlutterFlow will POST this body to your proxy function, which reads the resource field and calls the corresponding Buildium endpoint.

For endpoints that need dynamic parameters — like fetching outstanding items for a specific lease — add Variables in the Variables tab. Create a variable leaseId (String). In the Body, reference it as: {"resource": "leases/{{leaseId}}/outstandingitems"}. The variable becomes available in FlutterFlow's UI so you can pass the lease ID when the user taps into a lease detail screen.

In the Response & Test tab, paste a sample Buildium leases response (see the code block below) and click Generate JSON Paths. Create a Data Type called BuildiumLease with fields: id (Integer), tenantNames (String), unitAddress (String), monthlyRent (Double), leaseEndDate (String), status (String). Map the JSON paths to this Data Type. Repeat the process to add GetMaintenanceRequests and GetTransactions API Calls for the other screens your app needs.

```
// Paste as sample in FlutterFlow Response & Test for GetLeases
{
  "data": [
    {
      "Id": 10042,
      "StartDate": "2024-01-01",
      "EndDate": "2025-12-31",
      "Rent": 1850.00,
      "Status": "Active",
      "Tenants": [
        { "Id": 2201, "FirstName": "Jordan", "LastName": "Smith" }
      ],
      "Unit": {
        "Id": 305,
        "Address": {
          "AddressLine1": "12 Maple Street",
          "Unit": "3B",
          "City": "Portland",
          "State": "OR"
        }
      }
    }
  ]
}
```

**Expected result:** The BuildiumProxy API Group is configured in FlutterFlow with a GetLeases call. Clicking Test API Call returns a 200 response with lease data from Buildium through the proxy. JSON paths are generated and mapped to the BuildiumLease Data Type.

### 4. Step 4: Build a rental dashboard screen and bind data to widgets

Add a new Screen called Rentals. Add a ListView widget. Set its Backend Query to BuildiumProxy → GetLeases. Set the list type to BuildiumLease. FlutterFlow calls the proxy on screen load and populates the list.

Inside the ListView item template, add a Container with a card style (border radius 10, drop shadow, white background). Inside, add a Column with: a Text widget for the unit address (bound to BuildiumLease.unitAddress), a Text widget for the tenant names (bound to BuildiumLease.tenantNames), a Row with the monthly rent amount (BuildiumLease.monthlyRent formatted as currency) and the lease end date (BuildiumLease.leaseEndDate), and a status Badge widget showing Active or Expired based on BuildiumLease.status.

Above the ListView, add summary cards: a Container Row with three cards showing total active leases (count of BuildiumLease items with status=Active), total monthly rent (sum of BuildiumLease.monthlyRent), and leases expiring within 90 days (filter on leaseEndDate within 90 days). These computed values use FlutterFlow's List Aggregation and Filter functions without requiring additional API calls.

Add a pull-to-refresh gesture by wrapping the ListView in a RefreshIndicator. Bind the refresh action to the GetLeases API Call. Because the proxy caches results for 4 minutes, rapid pull-to-refresh requests will return the cached data — this is acceptable behaviour; users can wait for the cache to expire for truly fresh data.

**Expected result:** The Rentals screen displays lease cards with unit address, tenant name, monthly rent, and lease end date. Summary cards show totals at the top. The status badge is colour-coded green for Active and red for Expired.

### 5. Step 5: Add a maintenance requests screen and navigate between screens

Add a second Screen called Maintenance. Add a ListView widget bound to BuildiumProxy → GetMaintenanceRequests. The request body to the proxy should be {"resource": "maintenance/requests", "params": {"Status": "New,InProgress"}}. This filters to only open and in-progress requests.

Create a Data Type called MaintenanceRequest with fields: id (Integer), title (String), description (String), status (String), priority (String), unitAddress (String), submittedDate (String). Map JSON paths from a sample maintenance request response. Inside the ListView item, show the issue title, unit address, status, and a priority colour indicator (red for Urgent, amber for Normal, green for Low).

For navigation: on the Rentals screen, make each lease card tappable. In the Action Flow Editor for the card's on-tap action, add a Navigate action to a Lease Detail screen. Pass the leaseId as a page parameter. On the Lease Detail screen, make a GetOutstandingItems API Call using the passed leaseId as a variable: Body = {"resource": "leases/{{leaseId}}/outstandingitems"}. This shows rent due, fees, and other charges for the specific lease.

At the bottom of the Lease Detail screen, add a separate section for recent transactions for that lease, bound to another API Call: {"resource": "leases/{{leaseId}}/transactions", "params": {"limit": 20}}. This gives a complete financial picture for that lease without the user leaving the app.

**Expected result:** The Maintenance screen shows open work orders with priority indicators. Tapping a lease on the Rentals screen navigates to a Lease Detail screen showing outstanding charges and recent transactions for that specific lease.

### 6. Step 6: Handle pagination for large portfolios and add error states

For property managers with large portfolios — hundreds of units — a single API call returning 100 records may not be sufficient. Buildium's API supports pagination via offset and limit parameters. In FlutterFlow, add a Load More button at the bottom of the ListView. Bind it to an App State variable called currentOffset (Integer, starts at 0). When the user taps Load More, trigger a GetLeases API Call with the body {"resource": "rentals/leases", "offset": currentOffset + 100, "limit": 100}, then append the new results to your existing lease list in App State, and increment currentOffset by 100.

For error states, add a Conditional widget to the Rentals screen that shows a different layout when the GetLeases API Call returns an error. A simple column with an icon, 'Could not load rental data', and a Retry button (which re-triggers the GetLeases call) handles this gracefully. Also add a check for the case where the proxy returns an empty data array: show a 'No active leases found' empty state instead of a blank screen.

For the API key itself: if the key is ever compromised, regenerate it in Buildium's Settings → API Configuration and update the Firebase Functions config (firebase functions:config:set buildium.client_id='NEW_ID' buildium.client_secret='NEW_SECRET'), then redeploy. The FlutterFlow side needs no changes because it talks to your proxy URL, not directly to Buildium. If you would rather have a team set up the proxy, configure the caching, and handle ongoing maintenance for your property management app, RapidDev builds FlutterFlow integrations like this regularly — free scoping call at rapidevelopers.com/contact.

**Expected result:** Large portfolios load in paginated batches. The Load More button appends additional leases to the list. Error states show a user-friendly message and retry option. An empty state shows when no active leases are returned.

## Best practices

- Never put the x-buildium-client-id or x-buildium-client-secret in FlutterFlow API Call headers, App Values, or Dart code — keep them exclusively in Firebase Functions config or Supabase Edge Function environment variables.
- Verify that API access is enabled in Buildium's Settings → API Configuration before spending time on proxy setup — it is off by default and plan-gated.
- Cache Buildium API responses in Firestore for 3-5 minutes in the proxy to reduce call volume on large portfolios and protect against per-account throttling.
- Flatten nested Buildium objects (Tenants array, Unit.Address) in the proxy before returning them to FlutterFlow — simpler JSON means simpler widget bindings and fewer JSON path errors.
- Paginate all list requests using offset and limit: request 100 records at a time and use a Load More pattern for large portfolios.
- Generate one API key per integration and label it clearly in Buildium — this lets you revoke access for a specific app without affecting other integrations.
- If the API key is ever exposed, immediately regenerate it in Buildium's Settings → API Configuration and update the Firebase Functions config — the FlutterFlow app talks to your proxy URL and needs no changes.
- Show a clear empty state when no active leases are returned rather than a blank screen — the first time a new user connects, the list may be empty while Buildium loads their data.

## Use cases

### Landlord dashboard showing rent status across all units

A landlord with multiple rental properties opens a FlutterFlow app and sees each unit's rent status for the current month: paid, outstanding, or overdue. They can tap a unit to see the tenant name, lease end date, and outstanding balance. The app fetches this data from the Buildium API through a proxy and displays it in a card-based list.

Prompt example:

```
Show a list of rental units with tenant name, monthly rent amount, outstanding balance, and a colour-coded paid or unpaid status badge.
```

### Maintenance request tracker for a property management company

A property management company builds a companion app for their field staff. The app shows open maintenance requests from Buildium: unit, tenant name, issue description, and priority level. Staff can see which tickets are assigned to them and mark progress — with updates synced back to Buildium through the proxy's POST endpoints.

Prompt example:

```
Show open maintenance requests grouped by priority (urgent, normal, low) with the property address, unit number, and issue description. Allow changing status to In Progress.
```

### Financial summary app for a portfolio investor

An investor managing a portfolio of rental properties uses a FlutterFlow app to see a monthly financial snapshot: total rent collected, outstanding balances, and recent expense transactions across all properties. The data comes from Buildium's financial transaction endpoints through the proxy, displayed as summary cards and a transaction list.

Prompt example:

```
Show a financial summary with total rent collected this month, total outstanding balance, and a list of recent transactions with date, description, and amount.
```

## Troubleshooting

### All Buildium API requests return 401 Unauthorized despite using the correct key and secret

Cause: API access is not enabled in Buildium, or the account plan does not include API access. The key and secret exist in Buildium's UI but API calls are blocked at the plan level.

Solution: Log into Buildium and navigate to Settings → API Configuration. Verify that API access is toggled to Enabled. If the setting is not visible, your current Buildium plan does not include API access — contact Buildium to confirm which plan tier enables it and upgrade if necessary. The error is returned even with valid credentials if API access is not activated for the account.

### XMLHttpRequest error when testing from FlutterFlow web preview

Cause: The Firebase Cloud Function does not have CORS headers enabled, and the browser blocks the cross-origin request from FlutterFlow's preview canvas.

Solution: Use Firebase callable functions (onCall) for the proxy — they handle CORS automatically. If you used onRequest, add the cors npm package with origin: true as middleware around your handler function.

### Proxy returns data but tenant names are missing or nested fields are undefined

Cause: Buildium returns nested objects (Tenants is an array; Unit contains nested Address). FlutterFlow's JSON path generation may not have captured deeply nested paths automatically.

Solution: In the FlutterFlow Response & Test tab, verify that paths like $.data[0].Tenants[0].FirstName and $.data[0].Unit.Address.AddressLine1 are listed. If they are missing, manually type the JSON path in the Data Type field binding. Alternatively, flatten nested objects in the proxy before returning them to FlutterFlow: extract the first tenant name and the full address string server-side and return a flat object.

```
// Flatten nested objects in the proxy before returning to FlutterFlow
const flatLeases = resp.data.map(lease => ({
  id: lease.Id,
  tenantName: lease.Tenants?.[0] ? `${lease.Tenants[0].FirstName} ${lease.Tenants[0].LastName}` : 'Vacant',
  unitAddress: `${lease.Unit?.Address?.AddressLine1}, ${lease.Unit?.Address?.Unit || ''} ${lease.Unit?.Address?.City}`.trim(),
  monthlyRent: lease.Rent,
  status: lease.Status,
  leaseEndDate: lease.EndDate,
}));
return { data: flatLeases };
```

### Large portfolio queries are very slow or time out

Cause: Requesting a large number of records (500+) in a single Buildium API call without pagination causes slow response times and may hit Buildium's per-account throttling limits.

Solution: Always paginate: request 100 records at a time using offset and limit parameters. Load the first 100 on screen open. Add a Load More button to fetch the next batch. Use the Firestore cache in your proxy so repeated requests for the same page are served from cache rather than hitting Buildium every time.

## Frequently asked questions

### Why is API Configuration not visible in my Buildium account?

API access is a paid feature in Buildium and is not available on all account tiers or during free trials. If Settings → API Configuration is not visible, your current plan does not include API access. Contact Buildium support to confirm which plan tier enables the API and whether an upgrade is required for your account.

### Can I put the Buildium client ID and secret in a FlutterFlow API Call header directly?

No. FlutterFlow API Call headers are compiled into the app bundle. Anyone who decompiles your APK or IPA can extract hardcoded header values, including your Buildium client ID and secret. Those two values grant unrestricted access to your entire property portfolio and all tenant PII. They must live exclusively in your Firebase Cloud Function or Supabase Edge Function config.

### What Buildium data can I read through the API?

The Buildium API covers rentals (properties and units), tenants, leases, outstanding charges, financial transactions, bank accounts, maintenance requests, tasks, owners, and vendors. Most read operations are GET requests with optional filter parameters. Write operations (creating work orders, logging payments) are available via POST and PUT — add these proxy endpoints when your app needs them.

### How do I handle vacant units in the lease list?

Buildium's /rentals/leases endpoint returns active leases only, which means vacant units with no current lease do not appear in the leases list. To show vacant units, separately call /rentals/units and cross-reference with active leases. Units with no matching lease are vacant. In the proxy, you can merge both lists and mark units without a current lease as Vacant before returning the combined data to FlutterFlow.

### What happens if my Buildium API key is compromised?

Go immediately to Buildium's Settings → API Configuration and delete the compromised key, then create a new one. Update your Firebase Functions config with the new client ID and secret (firebase functions:config:set buildium.client_id='...' buildium.client_secret='...') and redeploy the functions. Your FlutterFlow app talks to your proxy URL and does not need any changes. The key rotation affects only the proxy's Firebase config.

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Source: https://www.rapidevelopers.com/flutterflow-integrations/buildium
© RapidDev — https://www.rapidevelopers.com/flutterflow-integrations/buildium