# What is Kora? URL: https://zerodev.ca/blogs/what-is-kora Published: 2026-10-11 Updated: 2026-10-11 > Kora is a self-hosted license server. Issue keys, check them from your products, sync BuiltByBit purchases and let customers manage their own licenses. ## Key Takeaways - Kora issues license keys for the things you sell and answers validation requests from your products. - Validation responses are signed with Ed25519, so a fake server cannot fake a valid answer. - Whitelists limit where a key works, and leak detection flags keys used in too many places. - The BuiltByBit module turns purchases into customers and licenses, and can revoke them on refunds. - Customers sign in with Discord to see their keys and manage their own whitelist entries. ## What Kora Is Kora is a license server you run on your own machine. You create products and customers, Kora issues keys, and your products call Kora to check a key before they run. Everything lives in your own PostgreSQL, MySQL or MariaDB database. There is no third-party service in the middle and no per-key fee. ## Checking a Key Your product sends one request: ```json title="POST /api/v1/licenses/validate" { "license_key": "ABCDE-FGHIJ-KLMNO-PQRST", "product_name": "My Plugin" } ``` Kora answers with `valid` and a `code` that says why, such as `expired`, `wrong_product`, `not_whitelisted` or `leaked`. You can change the message for each code from the dashboard. Every response is signed with an Ed25519 key. Put the public key in your product and check the `x-kora-signature` header, and nobody can point your product at a fake server that always says yes. ## Official SDKs You do not have to write the request yourself. There are SDKs for: * **Node.js and TypeScript**: `@zerodev-ca/kora` * **Java**, for Paper, Spigot, Velocity and Folia: `ca.zerodev:kora-java` * **Python**: `zerodev-kora` * **FiveM and RedM**: `kora-fivem` Each one checks keys, verifies the signature when you give it the public key, and can manage licenses, products and customers with an API token. See the [SDK docs](/docs/kora/developer-documentation/sdks). ## Keeping Keys Where They Belong * **Whitelists** limit where a key works, by IP, a request header or a request body field such as a hardware ID. Customers can add their own entries up to a limit you set. * **Leak detection** flags a key when it is checked from more IPs or devices than you allow in a time window. Kora can return `leaked` and also suspend the license. * **Validation logs** record every request with its key, product, result, IP and device. * **Expiry** is handled for you. A product's duration sets the expiry on new keys, with a grace period you choose. ## BuiltByBit The BuiltByBit module connects Kora to your resources. Paste a BuiltByBit API token and Kora: * Lists your resources and links each one to a Kora product. * Reads every purchase, creates a customer for the buyer and issues their license. * Can revoke a license when its purchase is refunded. * Fills license key placeholders, so buyers get their key in the download. It syncs every five minutes by default, or on demand. ## Discord The Discord module runs a bot in your server. Staff can create and edit licenses, products and customers with slash commands, and customers can run `/mylicenses` to see their keys. Every license check can be posted to a log channel, and the bot's status can show live numbers. ## The Dashboard The dashboard runs inside Kora on port `3000`. Sign in with Discord. It has pages for licenses, products, addons, customers, whitelists and validation logs, plus: * **Integration**, with your request URL, public key, ready-to-paste code and a live tester. * **Team** members and **Roles**, so support staff only see what they need. * **Audit Log** for every change, whether it came from staff, an API token or Kora itself. * **API Tokens** with scopes for the management API. * **Lang**, to edit any text Kora shows, in 16 languages. Customers sign in at the same address and get the client dashboard: their licenses, their keys and the activity on each one. ## Writing Your Own Modules Core, BuiltByBit and Discord are all modules, and you can write your own. A module can add config, lang files, commands, dashboard pages, API routes, events, models and timed jobs. See the [developer docs](/docs/kora/developer-documentation). ## What You Need * A host that runs Node.js 20 or newer, or Bun. * An empty PostgreSQL, MySQL or MariaDB database. * A Discord application for sign-in. * Your Kora license key from the [Zero Development Discord](https://discord.zerodev.ca). The first start opens a setup wizard in your browser. It takes about a minute. ## Questions ### What is Kora? Kora is a self-hosted license server by Zero Development. It issues license keys, answers validation requests from your products and gives you a dashboard for products, customers and keys. ### How does a product check a Kora license? It sends a POST to /api/v1/licenses/validate with the license key and product name. Kora answers with valid and a result code, and signs the response with Ed25519. ### Does Kora work with BuiltByBit? Yes. The BuiltByBit module reads your resources and purchases, creates a customer for each buyer, issues their license and can revoke it on a refund. ### Which languages have a Kora SDK? Node.js and TypeScript, Java (Paper, Spigot, Velocity and Folia), Python, and FiveM and RedM. ### What database does Kora use? Your own PostgreSQL, MySQL or MariaDB database. Kora needs Node.js 20 or newer, or Bun. ### Can customers see their own licenses? Yes. Customers sign in with Discord to the client dashboard to see their keys, manage their whitelist entries and see activity on each key.