Remote

Remote runs a plugin’s code outside the application’s process: in a child process, in a Node worker, or on a runner, a service on another machine that starts plugins for hosts. The application, the host, still sees the plugin’s services, and the plugins that inject them do not change.

	Direct: local, worker	Runner
Where it runs	A child process or a worker on the host	A process the runner starts, usually on another machine
What you install	Nothing beyond the built plugin	The plugin package and graft start runner.yml on the runner
Connection	Private to the host	ws/wss, a Unix socket, or a command such as SSH
Authentication	None	mTLS, a bearer token, a JWT, or the command’s own
Replacing a plugin	Each start is a fresh process	The old process must exit first; each start is a generation

Each loaded remote entry has its own plugin process. Stopping the entry stops it, and restarting the entry replaces it. Moving a plugin has limits:

• It isolates execution, not permissions. A child process runs as your user, a worker shares the host’s process, and a runner starts plugins with its own account’s permissions. For a permission boundary, run the runner in a container or a VM. To limit what plugins see inside one process, use realms.
• Config must encode as JSON. The plugin process decodes it on its own.
• Calls cross a connection. Each call is a message, and a call that fails because the connection broke is not retried.

Move a plugin

A plugin that runs elsewhere is split in two. The contract names the plugin, its config schema and the services that cross the boundary; both sides import it. The implementation is the plugin itself, built to JavaScript; only the plugin process imports it.

src/contract.ts

import { Context, Effect, Schema } from "effect"

import { Contract } from "@graftland/plugin-remote"

export class Greeter extends Context.Service<
  Greeter,
  { readonly greet: (name: string) => Effect.Effect<string> }
>()("app/Greeter") {}

declare const greeter: Contract.Service

export const config = Schema.Struct({ greeting: Schema.String })

export const contract = Contract.make({
  name: "app/greeter",
  config,
  provides: [greeter],
})

src/greeter.ts

import { Effect } from "effect"

import { Graft, Plugin } from "@graftland/graft"

import { config, contract, Greeter } from "./contract.ts"

export default Plugin.make({
  name: "app/greeter",
  config,
  provides: contract.provides,
  apply: ({ greeting }) =>
    Graft.provide(Greeter, {
      greet: (name) => Effect.succeed(`${greeting}, ${name}!`),
    }),
})

graft.yml

- id: greeter
  name: remote
  config:
    contract: ./dist/contract.js
    implementation: ./dist/greeter.js
    connect:
      local: {}
    config:
      greeting: Hello

greeter describes how Greeter crosses the boundary; see Define a contract. Change local: {} to worker: {}, or to a runner’s address, to move the plugin again. The 06 · Remote sample walks through all three.