CodeModeKit

Batteries-included server facade for CodeModeKit. TypeScript compilation and QuickJS are configured internally; callers choose MCP sources, application-owned Local Tools, policy, and any overrides.

Create an editable weather server and Agent Plugin with no credentials:

npm create codemodekit@latest weather-code-mode -- --example weather

import {
  allowAllToolCalls,
  mcp,
  serveCodeModeStdio,
} from "codemodekit";

await serveCodeModeStdio({
  name: "my-code-mode",
  version: "0.1.0",
  toolPolicy: allowAllToolCalls(),
  sources: [
    mcp.stdio({
      name: "upstream",
      command: "my-mcp-server",
    }),
  ],
  observer: (event) => console.error(JSON.stringify(event)),
});

Use serveCodeModeHttp for a Streamable HTTP endpoint, or createCodeModeMcp when another host owns the downstream transport. Set healthPath to expose a readiness endpoint that returns 200 after a ready startup and 503 for a degraded catalog. The optional observer receives timing, identity, size, outcome, and stable-error metadata; it never receives authored code, tool payloads, logs, or diagnostic messages, and observer failures cannot affect execution.

configureServer(server, context) can register protocol-native resources or extensions on each fresh downstream server before it connects. These capabilities remain outside the normalized Code Mode tool catalog. The project generator uses this hook when --agent-plugin --experimental-mcp-skills is selected, serving the packaged runtime skill through the experimental SEP-2640 Skills Extension.

The lower-level @codemodekit/core, @codemodekit/mcp, and @codemodekit/sandbox-quickjs packages remain available for expert composition.

Give CodeModeKit to a coding agent with npx skills add stjbrown/codemodekit. The repository exposes build-codemodekit-server and author-codemode-skill; pass --skill <name> to install either independently. Generated projects receive both automatically from the programmatic @codemodekit/skills package.

Local Tools

import { z } from "zod";
import { allowAllToolCalls, defineTool, local, serveCodeModeStdio } from "codemodekit";

const greet = defineTool({
  description: "Greet someone",
  inputSchema: z.object({ name: z.string() }),
  outputSchema: z.object({ greeting: z.string() }),
  execute: ({ name }) => ({ greeting: `Hello, ${name}!` }),
});

await serveCodeModeStdio({
  name: "local-code-mode",
  version: "0.1.0",
  toolPolicy: allowAllToolCalls(),
  sources: [local({ name: "app", tools: { greet } })],
});

Schemas may be plain JSON Schema or a Standard JSON Schema implementation; Zod 4 is covered by the compatibility tests. Execution stays in the trusted host; only validated JSON inputs and outputs cross the QuickJS bridge.