README.md

Optional Send to T3 Code example

This folder is an optional example, not part of the t3code CLI runtime or its required setup. It packages the pattern first built for the Delano viewer: a front-end split button asks a trusted local backend to turn the current task or review context into a fresh T3 Code thread.

Why Delano needed it

Delano is a browser-based project viewer where tasks, workstreams, specifications, and review annotations are already open in the front end. Copying that context by hand into a separate chat was slow and easy to get wrong: the receiving agent also needed the correct repository, source document, intent, and any selected review feedback.

The handover button closes that gap. Delano builds a focused start or review prompt from the current screen, posts it to its trusted local viewer server, and the server invokes t3code. The CLI resolves the repository to its T3 project, creates a fresh thread with the selected model and permissions, submits the prompt, and reveals T3 Code. Copy-command actions remain available as a fallback.

The dropdown shown above is Delano's broader agent handover menu. T3 Code is one destination alongside ChatGPT, Codex, Claude Code, and Claude; the integration example in this repository intentionally demonstrates only the T3 Code path.

The copyable example pieces are:

• react/SendToT3CodeButton.tsx: dependency-light React split button with current-checkout, worktree, and Plan-mode actions.
• react/send-to-t3-code-button.css: neutral styling matching the compact Delano toolbar treatment.
• node/launchT3CodeHandover.mjs: Node bridge that invokes t3code --json handover, passes every option as an argument, and writes the prompt to stdin.

React

Copy the React files into an application, or import them from this repository:

import { SendToT3CodeButton } from "./SendToT3CodeButton";

export function TaskActions({ taskPath }: { taskPath: string }) {
  return (
    <SendToT3CodeButton
      request={{
        prompt: `Implement the task at ${taskPath}. Read AGENTS.md first.`,
      }}
      onSuccess={({ data }) => console.log("Created thread", data.thread.id)}
      onError={(error) => console.error(error)}
    />
  );
}

The browser posts to /api/t3code/handover by default. It cannot and should not launch a local CLI directly.

Node backend

Adapt this route to Express, Fastify, Hono, or the application's existing HTTP server:

import { launchT3CodeHandover } from "./integrations/node/launchT3CodeHandover.mjs";

app.post("/api/t3code/handover", async (request, response) => {
  try {
    const prompt = buildTrustedHandoverPrompt(request.body);
    const result = await launchT3CodeHandover({
      cwd: repositoryRoot, // selected by the server
      prompt,
      checkout: request.body.checkout === "worktree" ? "worktree" : "current",
      mode: request.body.mode === "plan" ? "plan" : "build",
    });
    response.json(result);
  } catch (error) {
    response.status(400).json({
      ok: false,
      error: { message: error instanceof Error ? error.message : String(error) },
    });
  }
});

Keep the repository root server-owned, validate the request, and protect the route like any other local write action. The bridge never concatenates the prompt into a shell command; it sends it to t3code over stdin.

Delano source

The original implementation remains in the Delano repository:

• AgentSplitButton.tsx
• HandoverMenu.tsx
• handover.ts
• server.js (launchT3CodeHandover)

Delano adds annotation bundles, start/review intents, other agent destinations, command-copy fallbacks, and an activity feed. The reusable version here intentionally contains only the T3 Code boundary.