# Licensing > Free to build, paid for production, and how the runtime's license key works. This page explains what you can do with Kindgi for free, when you need a license, and how the runtime checks its license key. Kindgi is free to build with. Running it in production needs a commercial license. The license comes as a key, which the runtime checks when it starts. ## Two licenses | Part | License | In short | | ---------------------------------------------------------------------------------- | --------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | The SDKs and the CLI: the `@kindgi/*` npm packages and the `kindgi` Python package | Apache-2.0 | Use, change and ship them, commercially too. | | The runtime: the server that runs your packs, and its container image | Business Source License 1.1 | Free for non-production use, with no time limit. Production use needs a commercial license. Each release becomes Apache-2.0 four years after it's first published. | **Non-production** means building, testing and evaluating software with the runtime, including CI and staging environments that serve no end users and process no live business data. **Production** means using the runtime to serve end users or customers, or to process live business data as part of an organization's operations. That includes internal systems your own employees use. ## Building needs no key `kindgi dev` runs the runtime in development mode, with `KINDGI_DEV=true`. Development mode needs no license key, so everything you build and test on your machine is free. > **Note: Access to the runtime image** > > Sign in at [access.kindgi.com](https://access.kindgi.com/) with GitHub for the runtime image's pull credentials, and log in once with `kindgi auth registry` (see [Install](https://docs.kindgi.com/v0.1.9/start/install.md#access-to-the-runtime-image)). Questions or trouble: . ## Running outside development mode Anywhere else, the runtime needs its key: on a server, in staging, and in CI that runs the runtime itself. It reads the key from the `KINDGI_LICENSE_KEY` environment variable, which you set from your secrets store. A key starts with `kgi_lk_`. When it starts, the runtime checks the key and prints the license under its banner: ```text License: Docs example · non-production · until 2027-10-03 ``` The check is **offline**: the runtime verifies the key's signature against public keys built into the release. It never calls Kindgi, at startup or later. There are two kinds of key: - **A production key** comes with a commercial license, from . - **A non-production key** is free, for staging and CI that run the runtime outside development mode. Get one at [access.kindgi.com](https://access.kindgi.com/), or from . The runtime starts with either and prints which one it has. ## Without a valid key Outside development mode, a runtime with no key doesn't start. It exits with code 2 and says why: ```text KINDGI_LICENSE_KEY is not set. Outside development mode the Kindgi runtime needs a license key: a production key comes with a commercial license, and a free non-production key covers staging and CI. To get one: contact@kindgi.com. Local development needs none: `kindgi dev` runs the runtime with KINDGI_DEV=true. ``` A key that was changed, or that Kindgi didn't issue, is refused the same way, with its own message. ## When a key expires - **From 30 days before** the expiry date, the banner warns that the key expires soon, and says how to renew it. Where the deployment is set up to serve one tenant (without `KINDGI_TENANCY=multi`) and its database holds only that one, that tenant's admins also see a line on every console page. - **After it expires,** the runtime still starts for 14 days, with a warning that says until when. - **After those 14 days,** it refuses to start, naming the date the key expired. ```text KINDGI_LICENSE_KEY expired on 2026-07-31, more than 14 days ago. Renew it: contact@kindgi.com. ``` The key is checked only when the runtime starts, so a running server never stops because of its key. A platform that restarts instances on its own (scaling, a deploy) keeps working through the grace period while you renew. To renew a production key, which goes with your contract, write to . A non-production key from access.kindgi.com renews when you sign in there again. When access.kindgi.com has it turned on, a deployment can also renew its key itself, by hand or on a schedule. See [Renew the license key](https://docs.kindgi.com/v0.1.9/deploy/self-hosted/renew-the-license-key.md). ## Preview releases stop starting after 90 days Until Kindgi 1.0, each runtime release stops starting 90 days after it was released. That holds in every mode, development mode included. A setup that upgrades with each release never meets it. - **From 30 days before,** the startup banner warns, and so does `kindgi dev`. So does the console, for the same tenant admins as a key's expiry ([above](https://docs.kindgi.com/v0.1.9/concepts/licensing.md#when-a-key-expires)). - **From that day on,** the runtime refuses to start, with exit code 2. In development mode it says: ```text This preview build of the Kindgi runtime (0.1.0-preview.3, released 2026-07-01) expired on 2026-09-29: until Kindgi 1.0, a release stops starting 90 days after it was released. Run a newer release. With `kindgi dev`, update the Kindgi CLI (`@kindgi/cli`, or `kindgi-cli` from PyPI): it runs the runtime release the CLI pins. ``` Outside development mode it ends "Run a newer release, or start this one with a production license key: ." - **A running server never stops,** as with a key. But a platform that restarts instances on its own (Cloud Run, Container Apps) doesn't bring one back after that day. **Upgrade at least every 90 days** while Kindgi is in preview. - **A production key exempts** the build. - **`GET /v1/license` reports it** as `preview`: the version, when it was released, the day it stops starting, and the days left. - **For a log alert:** in the JSON log format, the warning is also a record with `"event": "kindgi.preview_expiry"`. It's logged at startup and once a day while the server runs, and once more when the runtime refuses to start. - **From 1.0 on,** releases don't expire.