Plugins

Agent Runtimes is extended — and extends other hosts — through the Datalayer reactor plugin platform, on both tiers. A plugin declares what it contributes; the host discovers it and never names it.

In the browser

The Loop Web workspace is built entirely from reactor plugins: the chat, the editors, the command palette, even the theme arrive as contributions into declared extension points (LoopViewType, LoopEditorView, LoopFrontendTool, LoopCommand, the slots). A host plugin that adds an editor, its agent tools, and a command is ordinary reactor code — the Loop page carries a complete example, and the generic machinery (@datalayer/reactor-shell, @datalayer/reactor-commands, @datalayer/primer-theme) is documented in the reactor's own docs.

In Python

Three hooks, three surfaces:

Hook	Surface	Discovered under
`provide_cli(cli)`	The command line — a Typer application the plugin adds command groups to	`datalayer.cli`, `datalayer.reactor.cli`
`provide_slash_commands(registry)`	The interactive session — the Loop REPL's slash menu	`loop.plugins`
Tool hooks (`before_tool_execute`, …)	The agent's tool lifecycle — see Hooks	agentspec configuration

Agent Runtimes plays both roles. As a host, the REPL discovers slash commands from any distribution advertising under loop.plugins. As an extension, agent_runtimes.reactor_extension packages this package's command groups so the datalayer and reactor CLIs carry them — nothing spawns another executable; the groups register in-process at startup.

# A distribution shipping a /deploy command for the REPL:
[project.entry-points."loop.plugins"]
my-package = "my_package.loop_plugin:plugin"

class MyLoopPlugin:
    def provide_slash_commands(self, registry) -> None:
        registry.try_register(SlashCommandSpec(
            name="deploy",
            description="Ship it",
            handler=deploy,
            source="my-package",
        ))

A plugin that cannot load — a missing optional dependency, a broken hook — costs a warning and is skipped: one bad plugin must never take the host down.

In the browser​

In Python​

In the browser

In Python