Devframe

Devframe is an asset: define your devtool once, serve it anywhere. You describe a single tool — its RPC surface, its data model, its SPA, its CLI shape — and the same definition deploys through any of the runtime adapters: a standalone CLI, a self-contained static report, an embedded SPA, an MCP server, and more. Devframe is framework- and build-tool-agnostic — it has no Vite dependency and no opinion on what UI framework your SPA uses.

Vite DevTools is built on top of devframe. If you need an integrated multi-tool host (docks, command palette, terminals, cross-tool toasts), mount your devframe into Vite DevTools via the vite adapter — or build your own host adapter targeting any environment you like.

Experimental

The Devframe API is still in development and may change between versions. The agent-native surface (agent on defineRpcFunction, ctx.agent, and the MCP adapter) is additionally flagged as experimental.

Design principles

Devframe keeps its surface focused on one tool, so the same definition stays portable across runtimes:

• One tool per definition. A devframe describes a single integration. Deploy it through any adapter; host-level features that only matter when several tools share a UI (palettes, cross-tool toasts, unified terminals) come from whichever host you mount into — Vite DevTools is one example.
• Headless. Hook into onReady, cli.configure, and friends to print your own startup banners and styling — Devframe stays out of the way.
• App-owned file watching. Wire your own watcher (chokidar, fs.watch, …) and signal change via ctx.rpc.sharedState.set(...) or event-typed RPCs.
• Context-aware mount paths. Standalone adapters (cli, spa, build) serve at / by default; hosted adapters (vite, embedded) serve at /.<id>/. Override via DevframeDefinition.basePath.
• SPAs own their base at runtime. Build with relative asset paths (vite.base: './'); connectDevframe discovers the effective base from the executing script's location.
• CLI flags compose. The cac instance is exposed to both the devframe (cli.configure) and the caller of createCli, so capability flags and app flags merge cleanly.

What Devframe provides

Subsystem	What it does
Devframe Definition	One defineDevframe call describes your tool once; the adapters deploy it anywhere.
RPC	Type-safe bidirectional calls built on birpc + valibot. Supports query, static, action, and event types.
Shared State	Observable, patch-synced state that survives reconnects and bridges server ↔ browser.
Diagnostics	Coded warnings/errors via nostics — registered into the host's shared lookup so adapters and consumers share the same surface.
Streaming	One-way (RPC streaming) and two-way (uploads) channel primitives for long-running data.
When Clauses	VS Code-style conditional expressions for docks, commands, and custom UI.
Utilities	Bundled helpers under devframe/utils/* — terminal colors, hashing, editor launch, structured-clone serialization, and more.
Client	Browser-side RPC client (connectDevframe) with auto-auth and WebSocket / static modes.
Agent-Native	Opt-in exposure of your tool's surface to coding agents over MCP.

Install

pnpm add devframe

devframe ships ESM-only and has no Vite dependency. Adapters with optional peers (the MCP adapter needs @modelcontextprotocol/sdk) surface the requirement at import time.

Hello, Devframe

A minimal devframe with a CLI entry point:

import { defineDevframe, defineRpcFunction } from 'devframe'
import { createCli } from 'devframe/adapters/cli'

const devframe = defineDevframe({
  id: 'my-devframe',
  name: 'My Devframe',
  icon: 'ph:gauge-duotone',
  cli: {
    distDir: 'client/dist',
  },
  setup(ctx) {
    ctx.rpc.register(defineRpcFunction({
      name: 'my-devframe:hello',
      type: 'static',
      jsonSerializable: true,
      handler: () => ({ message: 'hello' }),
    }))
  },
})

await createCli(devframe).parse()

The same definition can also be deployed through any of the other adapters — for example, mounted into Vite DevTools via the vite adapter.

Run it:

node ./my-devframe.js        # dev server on http://localhost:9999/
node ./my-devframe.js build  # self-contained static deploy in dist-static/
node ./my-devframe.js mcp    # stdio MCP server (experimental)

The CLI adapter serves the SPA at / by default. When the same devframe is embedded inside a host (vite, embedded), the default becomes /.my-devframe/. Override either side via defineDevframe({ basePath }).

Adapters at a glance

Devframe deploys the same DevframeDefinition through one of these adapters:

Adapter	Entry	Target
cli	createCli(d).parse()	Standalone CLI with dev / build / mcp subcommands
vite	createPluginFromDevframe(d, opts?) (from @vitejs/devtools-kit/node)	Mount the devframe into Vite DevTools (or another compatible host)
build	createBuild(d, opts?)	Self-contained static deploy with baked RPC dumps
embedded	createEmbedded(d, { ctx })	Runtime registration into an existing host
mcp	createMcpServer(d, opts)	Model Context Protocol server

See Adapters for the full reference.

Framework- and build-tool-agnostic

Devframe has zero dependencies on Vite or any @vitejs/* package — the same definition runs in any Node environment, with any UI framework, against any build tool. Vite DevTools is one host built on top of devframe; mount your definition there with the vite adapter, or write adapters for any other host.

What's next

• Devframe Definition — understand defineDevframe and the DevToolsNodeContext
• Adapters — pick the right deployment target for your tool
• RPC — define type-safe server functions your client can call
• Agent-Native — expose your devframe to Claude Desktop, Cursor, or any MCP client