agent-tether-client

Connect any web app to Claude Code running on the user's own machine. Zero dependencies beyond the shared protocol types.

Requires the local daemon: agent-tether.

npm i agent-tether-client

import { createTether } from 'agent-tether-client';

// On a public page, don't go hunting for localhost on load — wait for a user gesture.
const t = await createTether({ app: 'My App', autoConnect: false });

connectButton.onclick = async () => {
  await t.connect();

  for await (const ev of t.prompt('summarize this folder')) {
    if (ev.type === 'text') append(ev.delta);
    if (ev.type === 'tool_start') showChip(ev.name);
  }
};

Permission prompts in your own UI

t.onPermission(async (req) => {
  // req.title is a fully rendered sentence from the daemon — use it as-is
  return (await myDialog(req.title ?? `Run ${req.toolName}?`)) ? 'allow' : 'deny';
});

Expose your app's functions as Claude tools

Instead of pasting screen state into the prompt, let Claude ask for it.

t.tool('get_board', 'Read the notes currently on screen', {}, () => boardRef.current);

t.tool(
  'add_note',
  'Add a note to the board',
  { text: { type: 'string', description: 'Note body' } },
  ({ text }) => {
    setNotes((n) => [...n, { id: uid(), text }]);
    return { ok: true };
  }
);

Status, not exceptions

createTether never throws on connection failure. It reports through status, so you can render an install hint instead of wrapping everything in try/catch.

t.onStatus((s) => {
  // s.phase: idle | discovering | pairing | connected | unavailable
  // s.error: { code, message, hint, install }
});

Browser support

Direct connection needs Chrome or Edge — Safari blocks https → http://localhost. See the repo README for the measured details.

MIT © esc5221