# Build apps for Lia > Lia's developer docs. Build a web app that runs inside the Lia app, with players signed in, payments in $LIA on Lia's pay sheet, invites, notifications, ads, leaderboards and storage. From the Lia developer docs: https://docs.lialabs.org/
Lia SDK 1.6.0

Build apps for Lia. We bring the people.

Your web app opens inside the Lia app, in front of people who already use it every day. Add one script and every player arrives signed in, in their own language and theme, with $LIA payments, invites and the rest already built.

Start buildingSDK reference
## What a Lia app is A Lia app is a web page you build and host yourself. People open it from the Apps Center in the Lia app, and it runs inside Lia, much like a Telegram mini app. Your page loads the Lia SDK from Lia, and the SDK is how it talks to Lia: who the player is, the pay sheet, the friend picker, notifications, ads, storage and the phone itself. Your app can also have its own server. It calls Lia's server API with your secret key to check what the browser tells it: that a session is real, that a charge was paid, that a video was watched. Nothing important ever trusts the browser. ```html ``` ## Start here
QuickstartA working app in Lia in a few minutes: the script, init and ready. Getting accessHow your app is added to Lia, and how you get your keys today. How apps run in LiaThe frame, the three looks, the header and its menu, and the rules. npm packagesTyped SDK with hooks for React, Vue, Svelte, Solid, Angular and more. Sell an itemLia's pay sheet, then confirm and deliver on your server.
## Everything in the SDK
Players and sessionsEvery player arrives signed in, with a session your server can verify. PaymentsPeople pay in $LIA on Lia's own sheet, at the price in Lia's records. Reward poolsPay players in $LIA from a pool the Lia team funds for your app. InvitesA friend picker and links that open your app in the right room. NotificationsOnly for people who allow them, with limits so nobody is spammed. AdsRewarded and between round videos, played and paced by Lia. Leaderboards and storageBest scores, cloud saves, storage on the phone and in its Keychain. Look and feelLia's theme, 13 languages, safe areas, buttons, haptics and sound. The phoneMotion sensors, Face ID, the QR scanner, the clipboard and links.
## How the pieces fit
  1. The person opens your app in LiaLia opens your page in its frame and signs the person in for you, as a player of your app.
  2. Your page calls the SDKLia.init() gives you the player, a session token, their language and theme. Everything else is a call away.
  3. Lia does the sensitive partsPayments, ads, invites and permissions happen in Lia's own screens over your app, never in your page.
  4. Your server checksWith your secret key, your server verifies sessions, charges and watched videos, and pays rewards from your pool.
## Addresses | What | Where | | --- | --- | | The SDK | `https://api.lialabs.org/sdk/lia-apps-v1.js` | | The server API | `https://api.lialabs.org/api/apps/v1` | | The SDK demo (opens inside Lia) | `https://api.lialabs.org/sdk/demo` | | Invite links | `https://api.lialabs.org/play/` | | These docs as Markdown, for AI tools | [`/llms.txt`](/llms.txt) and [`/llms-full.txt`](/llms-full.txt) | > **Note** In Q1 2027 you'll sign up to the Lia developers dashboard to add your app and get its keys yourself. Until it opens, the Lia team sets your app up and gives you its keys. See [Getting access](/access).