---
title: Chat basics
description: What happens between you hitting Send and the reply landing — composer, agent pick, model resolution, streaming, citations, and how a chat is stored.
---

This page is the mental model for everything in the Chat tab. It names the parts of the composer, traces a single message from key-press to streamed reply, and explains how a chat is stored once it lands. Once you have read it, the rest of the chat pages read as variations on the same flow.

The flow is mostly invisible — Tale stitches a half-dozen subsystems together to make a chat feel like a single conversation — but the seams matter when something behaves unexpectedly. Knowing which subsystem owns which step is the difference between filing a useful bug report and a vague one.

## The composer

The composer is the input strip at the bottom of the screen. Three controls matter: the agent picker on the left, the model picker beside it, and the textarea with **Send** on the right. The agent picker exposes every agent the org has marked **Visible in chat**, plus a default **Assistant** when no agent is picked. The model picker exposes every chat-tagged model the agent's policy allows; **Auto** lets Tale resolve at request time. Attachments come in via paste, drag-and-drop, or the upload control — see [Attachments](/platform/chat/attachments) for what is accepted.

## The agents picker

The agents picker filters by name as you type; the default is an agentless **Assistant** that uses the org's default chat model and no extra knowledge or tools. Picking an agent before the first message makes the agent sticky for the whole chat; picking one mid-chat applies it to the next message and everything after. There is no "back to no agent" toggle — pick **Assistant** to revert. The [Agents in chat](/platform/chat/agents-in-chat) page covers the rules in detail.

## The model picker

The model picker lists models the agent (or the org, when no agent is picked) is allowed to use. Each model carries a tag — **Chat**, **Vision**, **Image generation**, **Embedding** — that signals what it is good for. Picking a vision model when the message has no image is fine; picking a non-vision model when the message includes an image will silently drop the image. **Auto** picks the agent's primary; when the primary is rate-limited or unavailable, Tale falls back to whatever the agent's failover order names.

## Reply rendering and citations

The reply streams in token by token. Tool calls render as collapsed boxes the user can expand to read what the agent did; **Run code** outputs land in the Canvas on the right. When the agent retrieves knowledge, citations attach to the sentences they support — hovering over a citation shows the source title; clicking opens the source. The agent's instructions never appear in the rendered reply; they sit one layer down, shaping behaviour rather than text.

## Questions from the agent

An agent with the human-input tool can pause mid-task and ask you something — a **Question** card appears in the chat with the fields the agent needs, and generation waits until you answer. Fill the form and click **Submit response**, or click **Reply differently** to push back in free text instead. The answered card stays in the transcript at the point where the question was asked, so the exchange reads in order later. If your answer was wrong or incomplete, click **Edit response** on the answered card — the form reopens prefilled, and **Update response** re-runs the agent with the corrected answer superseding the old one. The card keeps every previous answer: flip through the versions with the arrows next to the response, the way edited messages work.

## Conversations versus chats

Within Chat, the unit is a **chat** — that is the word every button and toast uses. The data model behind it is called `threads`, and the URL slug is `threads/$threadId`; the docs follow the UI and say "chat" in body prose. The separate **Conversations** tab (one over in the sidebar) is the customer-channel inbox, not a list of chats. Two senses of "conversation", two surfaces — see [Conversations overview](/platform/conversations/overview) for the inbox sense.

## History and search

**History** is the list of every chat the user can resume in this org. New chats appear at the top; selecting one opens the full transcript. **Search chat** filters History by title; full-text search across message bodies is a per-chat operation, not org-wide. **Rename chat** sets a custom title that overrides the model-generated one; **Delete chat** moves the chat into [Trash](/platform/admin/governance/trash) where retention sweeps it after the grace window.

## Where this fits

Chat basics is the page everything else in this section refines: [Agents in chat](/platform/chat/agents-in-chat) goes deeper on the picker, [Attachments](/platform/chat/attachments) on what the upload does, [Voice mode](/platform/chat/voice-mode) on the STT and TTS handoffs around the same composer. If you came here to build an agent rather than use one, jump to [Agent concepts](/platform/agents/concepts) — the four-knob mental model is the foundation every chat with an agent depends on.
