Lampson as an engine

Recipe: taking orders by chat

An agent that answers a business's chat and takes the whole order: what and how many, delivery or pickup, the address, the name, how they pay, the summary, the confirmation and the order number. The order is saved, the stock goes down and the customer is remembered for next time.

It takes three files: the orders plugin (it ships with Lampson), your business's catalog and the agent.

If you want your own tools instead of a plugin, with your database and the customer taken from your app's context, see Recipe: a support agent.

1. The orders plugin§

It ships with Lampson in ~/lampson/plugins/orders/. Turn it on once (/plugins on orders in the terminal, or the plugins pill on the web). Its tools:

The plugin does the math, never the model: place_order prices everything again from the catalog, rejects a payment method you don't accept and won't save an order without an address or without stock.

The plugin also brings its instructions: the process for taking an order (always price with quote, ask only for what's missing, summarize and wait for a "yes" before saving). That's why your agent's prompt doesn't have to explain it.

2. The catalog§

.lampson/orders/catalog.json in your project. Orders (P-0001.json…) and customers (customers.json) are saved next to it.

{
  "store": "Panadería Sol",
  "hours": "lunes a sábado de 7 a 20 h; domingos de 8 a 13 h",
  "delivery": {"area": "hasta 5 km del local", "fee": 1500, "free_from": 15000, "eta": "1 a 2 horas"},
  "payment": ["efectivo", "transferencia", "tarjeta de débito"],
  "products": [
    {"sku": "PAN-INT", "name": "Pan integral de masa madre", "price": 3200, "unit": "unidad (700 g)", "stock": 14, "second_half": true},
    {"sku": "PAN-BLA", "name": "Pan blanco de campo", "price": 2400, "stock": 0, "notes": "vuelve mañana a las 7"},
    {"sku": "MED-LUN", "name": "Medialunas de manteca", "price": 900, "stock": 60, "pack": {"qty": 12, "price": 9600}},
    {"sku": "ALF-MAI", "name": "Alfajores de maicena", "price": 700, "stock": 40, "gluten_free": true}
  ],
  "policies": ["No hacemos descuentos fuera de las promos del catálogo."]
}

• pack: a price per quantity (a dozen for $9,600).
• second_half: buy 2, the second at half price.
• delivery.free_from: free delivery from that subtotal.
• notes, policies and any other field (gluten_free, vegan…) are read by the agent as they are.

3. The agent§

.lampson/agents/tienda.agent.json. Its prompt says who it is — the plugin brings the process:

{
  "id": "tienda",
  "description": "Atiende a los clientes de Panadería Sol por chat y toma sus pedidos",
  "base": "none",
  "system": "Eres quien atiende el chat de Panadería Sol, una panadería de barrio en Rosario. Los clientes escriben desde el celular. Tono: cálido, rioplatense (vos), breve. Sin markdown. Precios con punto de miles ($3.200). No hables de archivos ni herramientas.",
  "tools": [{"name": "plugin_orders_*", "approve": "auto"}],
  "permission": "strict",
  "steps": 10
}

"approve": "auto" lets only the orders tools run without anyone approving; everything else stays strict. → Agents

4. Connect it§

lampson channel on telegram      # or Chatwoot for WhatsApp/Instagram → /docs/channels
lampson key add --agent tienda   # or your app/bot through the API → /docs/api

A real conversation§

This is a real conversation with the agent above (model glm-5.3-flash), typed the way people type: several messages in a row, with pauses of 2 to 6 seconds. Each message came in on its own and the mailbox put them together. It's in Spanish, as it happened — a neighborhood bakery in Rosario, Argentina.

What was saved:

// .lampson/orders/P-0001.json (abridged)
{"id": "P-0001", "customer": {"name": "Martín Ferreyra"}, "delivery": "delivery",
 "address": "Entre Ríos 845, 2do A (al lado de la farmacia)", "payment": "transferencia",
 "lines": [{"sku": "MED-LUN", "qty": 12, "amount": 9600, "promo": "1 x pack of 12"},
           {"sku": "PAN-INT", "qty": 2, "amount": 4800, "promo": "1 x second at half price"},
           {"sku": "ALF-MAI", "qty": 2, "amount": 1400}],
 "delivery_fee": 0, "total": 15800, "status": "new"}

P-0002 saved "when": "mañana 2026-10-17 a las 8 h" and the note about the surprise. The stock went down (whole-wheat 14 → 12, medialunas 60 → 48, alfajores 40 → 38).

What the conversation shows:

• Bursts → one answer. Each block of 2 to 5 messages got one answer that covers everything. In the fifth, the address came in four messages over 24 seconds: the ones that arrived while the agent was working joined the same turn, and if they arrive while it is already writing the answer, Lampson drops it and answers again with everything.
• No made-up math. Every total came from quote, with the second-loaf promo, the dozen price and free delivery from $15,000.
• Out of stock, an alternative. White bread had stock 0: it said so, said when it's back and offered options.
• What it doesn't know, it doesn't invent. The account alias for the bank transfer isn't in the catalog, so it didn't make one up. Add it to policies and it will give it.
• Nothing is saved without a "yes". It showed the summary and waited for the confirmation.
• Timing: each answer came 14 to 25 seconds after the customer's last message: the 3 seconds the mailbox waits in case they keep typing, plus the model and the tools.

A returning customer§

Ana had bought before (that order came from a web shop, see below). She writes again:

find_customer found her by phone, with her previous orders.

No chat: an order coming from another system§

The plugin's same instructions cover the case with nobody on the other side: your web shop, a script or another agent sends the complete order through the API, and the agent checks it and saves it.

curl -X POST https://your-lampson/w/tienda/v1/messages -H "Authorization: Bearer lk_…" \
  -d '{"to": "tienda", "thread": "web:881", "text": "Pedido de la tienda web #881 (ya pagado y confirmado por el cliente). Cliente: Ana Gómez, tel 341 555 0101. Items: 1 x PAN-SG, 6 x ALF-MAI. Retira en el local. Pago: tarjeta de débito. Respondé solo con el número de pedido y el total, o con el problema."}'

{"text": "Pedido P-0003 registrado. Total: $8.300. Retira en el local (Av. Belgrano 1450), pago con tarjeta de débito.", "steps": 3, …}

Changing or cancelling an order§

While the order is "new" (the store hasn't started it), the customer can change or cancel it from the chat: update_order takes the whole new cart, re-prices it and moves the stock only by the difference; cancel_order sets it to "cancelled" and puts all the stock back. Every change goes into the order's history.

Once the store moves it to another status ("preparing", "sent"… by editing status in .lampson/orders/P-NNNN.json), the agent can't touch it anymore and tells the customer so.

A real customer, with the same agent:

And Martín, once the store was already making the cake (P-0002 in "preparing"):

(In Martín's first conversation the agent placed a separate order for the cake: update_order didn't exist yet. Now it changes the existing order.)

Limits today§

• The store changes an order's status (preparing, sent…) by hand in .lampson/orders/: there's no panel for that yet.
• The store handles payment; the plugin doesn't charge.
• For something else (appointments, bookings, quotes), copy the plugin's folder and change its tools and its INSTRUCTIONS.md: the same pattern works for any process.