App Directory

The App Directory showcases existing Calimero applications you can deploy, and explains how to publish your own app to the registry.

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In this section

Page	Focus
Registry Overview	Bundle format, validation path, and install-time trust model
Registry API & CLI	Backend endpoints, typed client usage, and local registry workflows
Organizations & Ownership	Shared ownership, signer rotation, and team publishing practices

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Browse the Registry

Browse and install apps from the Calimero App Registry:

👉 Calimero App Registry

To get started with an existing app:

1. Find the app in the registry.
2. Follow its README for build instructions.
3. Install the .mpk bundle onto your node via Calimero Desktop or meroctl.

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Featured Apps

App	Description	Repo
Battleships	Turn-based multiplayer with private boards and Merobox workflows	README
Mero Chat	Rich messaging UI with cross-device workflows	README
KV Store	Minimal read/write example — ideal first integration	README
Demo Blob App	File-style payload handling with frontend wiring	README

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Publishing an App

To publish your Calimero app to the registry you need two tools:

• mero-sign — signs your bundle with Ed25519 (/app-directory/guide)
• calimero-registry CLI — packages and pushes the signed bundle

Step 1 — Install the tools

# Signing tool
cargo install mero-sign

# Registry CLI
npm install -g calimero-registry
# or: pnpm add -g calimero-registry

Step 2 — Build your app

Build your Rust application to WASM and prepare your frontend bundle. Your output directory should contain:

dist/myapp-1.0.0/
├── app.wasm
├── manifest.json
└── frontend/          # optional

Step 3 — Generate a signing key (one-time)

mero-sign generate-key --output my-key.json
echo "my-key.json" >> .gitignore

Keep my-key.json outside your project. Never commit it.

Step 4 — Sign the manifest

mero-sign sign dist/myapp-1.0.0/manifest.json --key my-key.json

Warning Sign before bundling. mero-sign operates on a standalone manifest.json, not on a packed archive.

Step 5 — Create the bundle

calimero-registry bundle create \
  --output myapp-1.0.0.mpk \
  dist/myapp-1.0.0/app.wasm \
  com.yourorg.myapp

This produces a .mpk file containing the signed manifest and WASM binary.

Step 6 — Publish

calimero-registry bundle push myapp-1.0.0.mpk \
  --key my-key.json

The registry validates the Ed25519 signature and, if your email is verified against an org, associates the bundle with that org.

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Publishing Requirements

Requirement	Details
Valid Ed25519 signature	Produced by mero-sign. Any key is accepted; org membership is validated separately via email.
Manifest format	Must include name, version, description, repository, and a signature block.
WASM binary	Must be a valid Calimero WASM application targeting the calimero-sdk runtime.
Semantic versioning	Version strings must follow MAJOR.MINOR.PATCH.

For the full manifest schema and registry API see the App Registry README.

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Signing tool reference

See the full mero-sign guide for key management, team workflows, and how the Ed25519 signing process works end-to-end.