# Research Timeline block

> Research timeline from search query via cited sources and repo files to a confidence rated answer

Shows how an AI agent reached its reply: steps land live, hover copy and open actions per row, publisher logos. ReUI Timeline, Badge; shadcn Card, Item, Spinner, Tooltip. For deep research, citations panel, grounded AI answers.

- Type: Pro block
- Category: [Agent Activity](https://web.dev.reui.io/blocks/ai-agents/agent-activity.md)
- Page: https://web.dev.reui.io/blocks/ai-agents/agent-activity/agent-activity-3
- MCP: `get_block("agent-activity-3")`
- Built with: Badge, Button, Card, Item, Marker, Skeleton, Spinner, Timeline, Tooltip
- Installs with a ReUI Pro or Ultimate license; setup: https://web.dev.reui.io/docs/license-setup

## Best for

A reply's evidence with no run controls: numbered sources with publisher logos, repo files with line counts and a confidence badge

## Agent notes

- Replace `RESEARCH`, `SOURCES`, `CHECKED` and `ANSWER`; each source `logo` is a brand mark from `@/components/ui/svgs` and each `dwellMs` sets the pace
- `ANSWER.confidence` always renders in a `success-light` badge whatever its text; map your confidence levels to badge variants
- A source title and Open source only fire a `toast` with the `brand`, so `url` is copied but never opened; Open file is a `toast` as well

## When not to use

- A plain vertical sequence of steps or events with no search, sources or answer: use [Timeline](https://web.dev.reui.io/components/timeline.md) (`get_component("timeline")`)
- A docs help sidebar that reads knowledge base articles before it writes an answer: use [Docs Support Assistant](https://web.dev.reui.io/blocks/ai-agents/ai-chat/ai-chat-12.md) (`get_block("ai-chat-12")`)

## Third-party libraries

- Sonner v2: [API reference](https://sonner.emilkowal.ski/toast), [docs](https://sonner.emilkowal.ski/getting-started)

## Install

```bash
npx shadcn@latest add @reui/agent-activity-3
```

## About Agent Activity blocks

### When to use

- A live step feed of one agent run that the person who started it can approve, pause or stop
- The research trail behind an answer: the search query, numbered sources, repo files and confidence
- A record of what a run touched and settled: MCP calls per server, refused scopes and failed items

### When not to use

- Operator pages across many runs: a run queue, an approval inbox or tool access settings: use the [Agents blocks](https://web.dev.reui.io/blocks/solutions/agents.md)
- The conversation around the run: the message thread, the prompt composer and the replies: use the [AI Chat blocks](https://web.dev.reui.io/blocks/ai-agents/ai-chat.md)
- A dated history of what people did, such as activity feeds, milestones or release notes: use the [Timeline blocks](https://web.dev.reui.io/blocks/application/timeline.md)

### Agent notes

- Each page.tsx pads a top aligned `min-h-svh` wrapper around `AgentActivity`, whose root caps at `max-w-xl` or `max-w-2xl`; drop the wrapper in your layout
- Each run is replayed from the block's data file on `setTimeout` timers; drive the same state from your agent's events instead
- Each block calls `toast` from `sonner` but mounts no toaster, so those messages stay hidden until your layout renders one

Every ReUI item has a twin like this one; the index is https://web.dev.reui.io/llms.txt. Agents with the ReUI MCP (https://web.dev.reui.io/docs/mcp) get the same guidance from the getters named above.