Package Map

Crosslink is a monorepo of small packages. Most applications need exactly one or two of them; the rest are layers those two are built on.

Packages you import

Package	Import it when	Entry points
`@crosslink/sdk-node`	You are writing the host — a Node, Electron or Tauri process that owns the data	`createCrosslinkServer`, `composeCrosslinkHost`
`@crosslink/sdk-browser`	You are writing the client — a browser page, PWA or phone UI	`createSecureCrosslinkClient`, `createCrosslinkClient`, `CrosslinkClient`
`@crosslink/react`	Your client UI is React and you want connection state as hooks	React bindings over `sdk-browser`
`@crosslink/sdk`	You want one dependency that resolves to the host entry in Node and the client entry in a browser	Umbrella re-export

@crosslink/sdk-browser also ships testing tools, notably MockSocket — an in-memory WsLike pair that drives a real host pairing manager and acceptor with no network at all. See Testing.

Packages the SDKs are built on

You rarely import these, but reading them is how you answer “what does it actually do”:

Package	Contents
`@crosslink/protocol`	The wire spec: envelopes, framing, canonical JSON, error codes, conformance fixtures. The language-neutral part — a non-JavaScript implementation targets this
`@crosslink/core`	Transport-agnostic engine: identity, CLX1 handshake, sessions, capability registry, RPC router, pairing state machines
`@crosslink/nat-map`	Inbound reachability: PCP, NAT-PMP and UPnP IGD port mapping, plus STUN address discovery. Used by `remote` network mode
`@crosslink/dev-tokens`	Per-machine development tokens, so the default signaling and relay are not open to unauthenticated use
`@crosslink/conformance`	Adapter contract and shared positive/negative wire corpus for non-JavaScript implementations

Import @crosslink/core directly only when you are building a transport, or embedding Crosslink in a runtime that cannot use the sdk-node listener. composeCrosslinkHost(config) (from sdk-node) is the halfway point: it builds the identity, pairing manager, grant store and capability registry and hands them back for you to attach to your own server, without starting one.

Adapters

Package	Contents
`@crosslink/webrtc-adapter`	WebRTC DataChannel transport and SDP exchange over an existing Crosslink session, used to upgrade a relayed connection to a direct one

Services you can host

Package	Role	Default port
`@crosslink/signaling`	Presence directory and pairing-code router. Helps two devices find each other across networks; never sees plaintext	`8081`
`@crosslink/relay`	Stateless encrypted-pipe fallback when no direct route exists. Forwards ciphertext; holds no keys	`8082`

Neither is required for same-network use, and neither is required at all if you use remote mode. Running your own is covered in Self-Hosting.

npm run stack   # signaling :8081 + relay :8082, from the repo root

Apps and examples in the repo

Path	What it demonstrates
`apps/chat`	The full pattern: web host plus installable mobile client on one port, device management, network-mode switching
`apps/demo-pwa`	Reference installable PWA client that uses the canonical mobile bootstrap
`examples/echo-host`	The smallest useful host — one method, ~20 lines
`examples/notes-host`	State sync over RPC and events
`examples/todo-host`	A host that serves its own mobile page through Crosslink’s bootstrap
`examples/webrtc-upgrade`	Relay connection upgraded to direct WebRTC, end to end
`examples/electron-chat`	Sandboxed Electron main/preload/renderer integration and native pairing approval
`examples/react-tsx`, `examples/vanilla`	Minimal client UIs

The protocol baselines under sdks/swift, sdks/kotlin, and sdks/rust are tested against the same canonical JSON/framing behavior. See Native protocol SDKs. Run any of them from the repo root, or use the workspace scripts directly:

cd examples/echo-host && npm run dev
cd examples/notes-host && npm run dev
cd examples/todo-host && npm run dev
npm run dev -w @crosslink/example-electron-chat
npm run dev -w @crosslink/demo-chat
npm run serve -w @crosslink/demo-pwa

The root demo:* scripts are convenience aliases around these workspace entrypoints. The complete list of repo workflows is in Local Development.

GET STARTED

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GUIDES

REFERENCE

RESOURCES

Packages you import

Packages the SDKs are built on

Adapters

Services you can host

Apps and examples in the repo

​Packages you import

​Packages the SDKs are built on

​Adapters

​Services you can host

​Apps and examples in the repo

Packages you import

Packages the SDKs are built on

Adapters

Services you can host

Apps and examples in the repo