Self-hosted, peer-to-peer applications where the operator can't read your data.
CRDT state sync, local-first governance, WASM execution.
A Calimero app runs on nodes its users control. State is a CRDT set replicated peer-to-peer over libp2p, encrypted so that whoever operates the infrastructure sees metadata and nothing else. Application logic is WASM; membership and permissions are governed by a causal operation log rather than a server.
Practically: shared drives, chat, issue trackers, spreadsheets, design tools — the collaborative SaaS shape, without the vendor holding the plaintext.
brew install calimero-network/tap/merod calimero-network/tap/meroctl
cargo install --git https://github.com/calimero-network/cargo-mero cargo-mero
cargo mero new my-app # scaffold
cargo mero guide # the whole path, start to installable bundlePrefer a GUI? Calimero Desktop runs a node, manages contexts, and installs apps from the registry.
| I want to… | Go to |
|---|---|
| Understand the model | Concepts — contexts, identity, CRDT state, privacy |
| Write an app in Rust | cargo-mero + SDK |
| Write an app in TypeScript | calimero-sdk-js |
| Call a node from my frontend | mero-js · mero-react |
| Run nodes locally / in CI | merobox |
| Operate a node | Operate docs |
| Read the protocol spec | Protocol Reference |
| Propose a protocol change | proposals (CIPs) |
| See it working | Example apps |
| Repo | Description |
|---|---|
| core | Node runtime (merod), operator CLI (meroctl), Rust SDK, CRDT storage engine, libp2p networking, WASM execution. The heart of the stack. |
| app-registry | Registry for signed app bundles (JCS + Ed25519, SemVer-immutable, WASM by IPFS CID). Live at apps.calimero.network. |
| mero-tee | TEE infrastructure — KMS, locked images, attestation. |
| boot-node | Bootstrap/relay node deployment. |
| Repo | Language | Description |
|---|---|---|
| cargo-mero | Rust | cargo mero — scaffold, build to WASM with embedded ABI, node-free tests, signed .mpk bundles. Start here. |
| core/crates/sdk | Rust | Application SDK — proc macros, CRDT collections, events, state helpers. |
| calimero-sdk-js | TypeScript | Write app logic in TS/JS, compiled to WASM via QuickJS. |
| mero-devtools-js | TypeScript | ABI parser and typed-client codegen from Rust app ABIs. |
| mero-mcp | — | MCP server — exposes node admin and every app ABI method as tools for AI agents. |
| calimero-skills | — | Agent skills for Calimero development (SDK, clients, registry, CLI). |
| Repo | Language | Description |
|---|---|---|
| mero-js | TypeScript | Auth, admin API, JSON-RPC, live event streams. Browser, Node, edge; zero dependencies. |
| mero-react | TypeScript | React hooks and provider over mero-js. |
| calimero-client-py | Python | Python client — automation and scripting. |
| swift-sdk | Swift | MeroKit — iOS/macOS, incl. SSO and token refresh. |
| kotlin-sdk | Kotlin | Android — auth, JSON-RPC, Compose login UI. |
| Repo | Description |
|---|---|
| merobox | Docker-based local multi-node networks with declarative workflow files. The standard way to test and run e2e in CI. |
| tauri-app | Calimero Desktop — cross-platform node, context, and app manager. Download. |
| admin-dashboard | Web UI for node administration — contexts, members, apps, metrics. |
| auth-frontend | Login, context selection, and permission-grant UI for apps. |
| homebrew-tap | macOS install for merod, meroctl, cargo-mero, mero-abi, mero-relayer. |
| install-sh | Install scripts for Calimero binaries. |
Real apps, not toy demos — each one is a self-hosted replacement for something you already pay for.
| Repo | Description |
|---|---|
| kv-store | Minimal Rust key-value app. The canonical starter. |
| kv-store-js | Same, in TypeScript, with a React frontend. |
| mero-chat | P2P groups and DMs. |
| mero-meet | Video calling — WASM signaling, WebRTC media, no server. |
| mero-design | Collaborative design tool. |
| mero-pixart | Collaborative image editor — layers, masks, curves. |
| p2p-sheets | Collaborative spreadsheet — CRDT inputs, derive-on-read recalc, live cursors. |
| mero-calendar | Shared team calendars and private events. |
| MeroSign | Privacy-first e-signature and document verification. |
More examples — games, blobs, workshop builds
| Repo | Description |
|---|---|
| battleships | Turn-based game with private hidden boards — encrypted context state + merobox workflows. |
| mero-blocks | Minecraft-style multiplayer voxel sandbox with no game server; the world is a context. |
| merraria | 45 kB Terraria-style 2D multiplayer mining sandbox. |
| demo-blob-app | Blob/binary payload handling with a wired frontend. |
| only-peers-client | Minimal P2P forum client. |
| core/apps | In-repo reference apps: collaborative-editor, private-data, team-metrics, and more. |
| workshop-apps | Apps built live at workshops, one per branch. |
| Repo | Description |
|---|---|
| documentation | docs.calimero.network — concepts, build guides, operations, API reference. Start here for anything conceptual. |
| design-system | Shared UI components and design tokens across Calimero frontends. |
Deep reference for
corelives in-repo and ships to calimero-network.github.io/core — four tracks: Build, Operate, Protocol Reference, Contribute. Same pattern for mero-mcp.
Issues and PRs welcome across every repo. Protocol-level changes go through CIPs. Questions and dev support: Discord.
Licensed MIT OR Apache-2.0.
