Install & first action

Install the package that matches your runtime.
Terminal window
pnpm add @tesseron/web zod
Terminal window
pnpm add @tesseron/react zod
Terminal window
pnpm add @tesseron/server zod
Terminal window
pnpm add @tesseron/core zod
zod is used in the examples here; swap it for any Standard Schema-compatible validator - Valibot, ArkType, Effect Schema.

Name your app. app.id is what the agent's tool names get prefixed with. It must match /^[a-z][a-z0-9_]*$/.

import { tesseron } from '@tesseron/web';

tesseron.app({
  id: 'notes',
  name: 'My Notes App',
  description: 'Create and organise notes',
});

Declare an action.

import { z } from 'zod';

tesseron
  .action('createNote')
  .describe('Create a new note')
  .input(z.object({ title: z.string().min(1), body: z.string().default('') }))
  .handler(({ title, body }) => {
    const note = { id: crypto.randomUUID(), title, body, createdAt: Date.now() };
    store.add(note);
    return note;
  });

Connect.
```
const welcome = await tesseron.connect();
console.log('claim code:', welcome.claimCode);
```
The MCP gateway prints the claim code to its stderr; you can also surface it in your UI.
Claim from the agent. In Claude Code: "Claim Tesseron session <code>." Once claimed, notes__createNote appears in the tool list.

Typical entry-point layouts

import { tesseron } from '@tesseron/web';
import { z } from 'zod';

tesseron.app({ id: 'notes', name: 'Notes' });

tesseron.action('createNote')
  .input(z.object({ title: z.string(), body: z.string() }))
  .handler(({ title, body }) => notesStore.add({ title, body }));

export const connect = () => tesseron.connect();

import { connect } from './tesseron';
connect();          // fire and forget; retry in UI if you like.

import { useTesseronAction, useTesseronConnection } from '@tesseron/react';
import { z } from 'zod';

export function App() {
  const { claimCode, status } = useTesseronConnection();

  useTesseronAction('createNote', {
    input: z.object({ title: z.string(), body: z.string() }),
    handler: ({ title, body }) => notesStore.add({ title, body }),
  });

  return (
    <div>
      {status === 'open' && claimCode && <ClaimCodeBanner code={claimCode} />}
      <Notes />
    </div>
  );
}

import { tesseron } from '@tesseron/server';
import { z } from 'zod';

tesseron.app({ id: 'notes_api', name: 'Notes API' });

tesseron.action('createNote')
  .input(z.object({ title: z.string(), body: z.string() }))
  .handler(async ({ title, body }) => db.notes.insert({ title, body }));

const welcome = await tesseron.connect();
console.log('claim code:', welcome.claimCode);

process.on('SIGINT', async () => {
  await tesseron.disconnect();
  process.exit(0);
});

Where to go next

The action builder in full - chaining, output validation, annotations, timeouts.
Standard Schema validators - Zod vs Valibot vs ArkType, and JSON Schema interop.
The context API - progress, sampling, elicitation, logging.
Framework adapters: @tesseron/react.