@pattern-js/mod-chat

A complete, hosted chat application for Pattern agents — a transcript-style SPA over a lease-guarded, event-sourced turn pipeline. Brand it, point it at an agent, host it many times.

npm install @pattern-js/mod-chat

When to use

Reach for chatMod() when you want a finished assistant product, not a primitive: a real SPA (the strand rail shows tool calls live), conversations + a persisted per-turn event log, lease-guarded turns with Stop, image input, sign-in / guests, HITL approvals, and an admin "Conversations" surface — all wired.

When not: if you only need the agent machinery inside your own UI or endpoint, drop down to @pattern-js/mod-agents and wire agents.agent / agents.run yourself — this mod is the whole app on top of that, not a building block to compose into another surface.

Prerequisites

Add these alongside in pattern.config.json:

• @pattern-js/mod-store — conversations, turn docs, blobs, and the per-turn lease live here. ready throws without it.
• @pattern-js/mod-agents plus a model backend like @pattern-js/mod-agents-openai. The shipped pipeline's agents.run needs OPENAI_API_KEY (or wire vault.read → its apiKey).

Optional but assumed by the defaults: @pattern-js/mod-identity + @pattern-js/mod-auth-magic-link for the sign-in card the SPA renders — without them everyone is a guest, which is fine.

Config

import { chatMod } from "@pattern-js/mod-chat";

chatMod() // an assistant at /chat, guests allowed, the default agent

chatMod({
  agent: { name: "Aria", instructions: "Be concise and warm.", model: "gpt-4o" },
})

agent.{name,instructions,model} are the no-fork knobs. Every message runs the chat.turn.pipeline workflow — fork it in the admin to swap models, add guardrails, or narrow toolsets.

Full documentation: the Chat chapter at /docs (served by @pattern-js/mod-docs), or the source.