Build an app

A Calimero app is a Rust crate compiled to WASM. You declare its state, built from the SDK’s collection types, and its methods: calls that change the state, and views that read it. You write no storage, sync, encryption or networking code. The cluster runs each call on the instance’s leader, replicates the result, and serves it to signed-in callers over a sealed channel.

1. 01 · cargo mero newScaffoldA crate with SDK pins, the package id and a test.
2. 02 · cargo testTestTestHost runs your logic in-process, no node needed.
3. 03 · cargo mero buildBuildWASM with its ABI embedded.
4. 04 · cargo mero bundleSignA signed .mpk, your release.
5. 05 · cargo mero publishPublishUpload it to the app registry.

The toolchain is cargo mero, which ships in the core repository. Install it with cargo install cargo-mero.

Your first appScaffold, write state and methods, test, build.

What an app seesInit arguments, callers, organizations, events, blobs, upgrades, limits.

Package & publishSign a release and publish it to the registry.

Example appsChat, docs, sheets, forms, games and more, all on the same SDK.

The full SDK reference (every macro, the collection types, storage costs, advanced patterns) is in the core reference’s Build section.