Jazz uses "lenses" to handle schema migrations — they define how old data gets transformed when you change your data model. I added an animated, interactive diagram to the documentation that visualises how data moves through the lens chain, making the concept much easier to grasp than text alone.
The Jazz Expo integration included three polyfills (bits of code that patch in missing browser features) for standard web networking types — but these were actually harmful. If they ran before React Native had set up its own network globals, they'd overwrite those globals with undefined, breaking third-party libraries like Clerk. I removed the three useless polyfills while keeping the two that do real work.
The jazz-rn library was running database queries by blocking the JavaScript thread, which froze the UI during any database access and could also cause deadlocks when the server needed to respond before a query could complete. I converted the query function to be async, so it runs off the JavaScript thread and returns a Promise, keeping the app responsive while waiting for data.
During Jazz development, whenever you pushed a new schema, you had to manually refresh the browser to pick up the changes. I added a mechanism where the Jazz Webpack/Turbopack plugin writes a small "schema hash" file to a cache directory on every schema push, and the React provider imports this file during development — so the bundler notices the change and automatically reloads the page for you.
The create-jazz tool, which scaffolds new Jazz projects, had a hardcoded reference to the old repo name garden-co/jazz2. After the repo was renamed back to garden-co/jazz, I updated that one-line constant so the scaffolding tool points to the right place.
The chat-react example app had two separate test setups running in parallel — one using Playwright and one using vitest browser mode. I consolidated them by moving the Playwright end-to-end test into the main vitest browser test suite and deleting the now-redundant Playwright config. I also cleaned up some leftover React act() wrapper calls that were printing noisy warnings without actually doing anything useful.
The docs for setting up a Jazz client had Vue and Svelte code examples missing await before createJazzClient, which returns a Promise — so copying the example would store a pending Promise instead of the actual client. I fixed those snippets and added a new section explaining how browsers can silently delete locally-stored data (called "storage eviction") and how to call navigator.storage.persist() to ask the browser to keep your data safe.
Jazz lets users start as anonymous "local-first" users and later upgrade to a full account. On React Native, this upgrade was broken with the error "Sign up requires an active Jazz session" because the identity proof method was trying to use a WebAssembly module — which React Native doesn't support. I overrode the method in the React Native implementation to use the native mintLocalFirstToken function from jazz-rn instead, making the upgrade flow work on iOS and Android.
The create-jazz setup tool got two improvements. The spinner now advances to "Provisioning Jazz Cloud app" before making the network request, so it no longer looks frozen on the previous step. I also added support for loading .env files so CLI commands like deploy can pick up secrets like JAZZ_ADMIN_SECRET from a .env file instead of requiring them to be set as shell environment variables.
When developing with Jazz in watch mode, editing schema.ts now automatically reloads the browser to pick up your changes. Previously you had to manually refresh the page after pushing a schema update to see it take effect. I added a callback that fires after a successful schema push and tells the Vite or SvelteKit dev server to send a full-reload signal to the browser.
On Expo (React Native), Jazz uses a custom fetch wrapper that bridges web-style network calls to the native layer. The web fetch standard allows passing a URL or Request object as input, but the native bridge only accepts plain strings — so libraries like better-auth that use this pattern were crashing. I fixed it by normalising those inputs to a plain string URL plus options before passing them to the native bridge.
When you change your database schema (a "migration"), existing data should stay visible under the new schema. There was a bug where rows that existed before a migration would silently disappear — the resolved table name wasn't being carried through to the query engine, causing a "table not found" error that just dropped the rows silently. I fixed this by making sure the resolved table name is passed all the way through the schema-aware query path.
I added content-based deduplication to the permissions bundle publishing step. When you deploy without changing your schema's access rules, the system now detects that the new bundle is identical to the current one and skips creating a new version — preventing unnecessary version bumps.
I updated Jazz's Svelte query API to accept getter functions — functions that return a query — in addition to plain query objects. This means reactive query updates now flow through automatically, matching what was already possible in the Vue integration.
I updated the Jazz command-line tool to recognise environment variables with framework-specific prefixes — like VITE_, NEXT_PUBLIC_, PUBLIC_, and EXPO_PUBLIC_. Previously, if you set your app ID using your framework's conventional prefix, the CLI wouldn't find it; now it checks all common prefixes automatically.
I extended our automated tests to cover three starter templates that previously had no test coverage. The tests check that the scaffolding tool creates the right files and structure, so we can catch regressions before they reach developers.
I reorganised Jazz's "recipes" (short how-to guides) into clearer sub-folders — access control, auth, and data patterns — so they're easier to find. I also added a new recipe showing how to configure group-level permissions for shared data.
I fixed a race condition in the React chat example where the message input would become usable before the server had confirmed the user was a member of the chat room. I added a readiness check to prevent this, and wrote a Playwright end-to-end test to guard against it happening again.
I fixed a bug where Jazz's SvelteKit plugin didn't apply its configuration correctly the very first time you started the dev server. The plugin now restarts Vite once after allocating the app ID, so SvelteKit's server hooks pick up the config properly.
I fixed broken configuration and authentication in several of Jazz's example applications. The affected apps — including WorkOS auth, Better Auth, Next.js CSR/SSR, Cloudflare Workers, and managed runtime — had issues that stopped developers from using them as working references.