Files
Ben Taylor ea3e3fbfa6 fix(react-ui): let sidebar children fill the viewport height (#6410)
Fixes #261 (open since March 2024). Supersedes #4622 — @ashish4143
diagnosed the same wrappers and is credited as co-author on the commit.

## The bug

`CopilotSidebar` wraps consumer content in two divs:

- `.copilotKitSidebarContentWrapper` (`Sidebar.tsx`) — only sets
`overflow`, `margin-right`, `transition`
- `.copilotKitModalChildrenWrapper` (`Modal.tsx`) — **has no CSS rule
anywhere in the repo**

Both are auto-height blocks, so a child's `height: 100%` has no definite
containing block to resolve against and collapses to content height.

## The fix

An opt-in `fullHeightChildren` prop on `CopilotSidebar` that adds a
modifier class to the content wrapper. Two deliberate choices, both from
the review on #4622:

- **Opt-in, not default.** The content wrapper wraps the *entire*
consumer app. Making it a fixed-height flex column for everyone would
reflow apps that never asked for it.
- **A viewport unit, not `height: 100%`.** `100%` only resolves if every
ancestor (`html`/`body`/`#root`) also declares a height — react-ui
neither sets that nor can guarantee it, so `100%` would silently no-op
in a stock Next.js app. `min-height: 0` on the children wrapper clears
the flex-item `min-height: auto` floor so tall content scrolls inside
the child rather than stretching the wrapper past the viewport.

```tsx
<CopilotSidebar fullHeightChildren>
  <div style={{ height: "100%" }}>...</div>
</CopilotSidebar>
```

## Testing

**Unit** — `packages/react-ui/src/css/sidebar-full-height.test.ts` (4
tests), in the repo's existing CSS-contract style. Guards both halves:
the escape hatch's rules, and that the default wrapper stays
auto-height. Also asserts the height is *not* `100%`, since that's the
regression that would make the whole feature a silent no-op.

```
✓ src/css/sidebar-full-height.test.ts (4 tests)
Test Files  9 passed (9)   Tests  58 passed (58)     # full react-ui suite
```
`npx tsc --noEmit` → exit 0. `oxlint` on changed files → 0 warnings, 0
errors.

**Live in Chrome** — the acceptance criterion from the #4622 review: a
stock app where **nothing** declares a height on `html`/`body`/`#root`,
loading the real built `dist/index.css` (not the source CSS), standards
mode, 762px viewport. DOM per `Sidebar.tsx:92` + `Modal.tsx:143`.

| case | child `height:100%` measures |
|---|---|
| default (no opt-in) | **17px** — collapsed, i.e. behavior unchanged
for existing consumers |
| `fullHeightChildren` | **762px** — exactly the viewport |
| `fullHeightChildren`, content 3000px tall | **762px**, scrolls inside
the child (`min-height: 0` holds) |

Also confirmed on the opt-in path: `.copilotKitSidebar` stays `position:
fixed`, and the expanded push-aside `margin-right` is still `448px`
(28rem), so the sidebar's own layout is untouched.

**Docs** — `CopilotSidebar.mdx` is auto-generated from `Sidebar.tsx`;
regenerated via `scripts/docs/gen.ts` and committed only the new
`fullHeightChildren` entry (the generator also surfaces unrelated
pre-existing drift in other reference pages, left out of this PR).

## Not covered

The issue mentions a "works in Safari, not Chrome" symptom. I verified
in Chromium only — the mechanism above is spec behavior rather than a
Chrome quirk, but I haven't measured WebKit.
2026-08-07 11:36:09 -05:00
..
2026-04-10 23:38:59 +00:00
2026-08-07 01:25:14 +00:00

CopilotKit - React UI

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✨ Why CopilotKit?

  • Minutes to integrate - Get started quickly with our CLI
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  • Production-ready UI - Use customizable components or build with headless UI
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🧑‍💻 Real life use cases

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🖥️ Code Samples

Drop in these building blocks and tailor them to your needs.

Build with Headless APIs and Pre-Built Components

// Headless UI with full control
const { visibleMessages, appendMessage, setMessages, ... } = useCopilotChat();

// Pre-built components with deep customization options (CSS + pass custom sub-components)
<CopilotPopup
  instructions={"You are assisting the user as best as you can. Answer in the best way possible given the data you have."}
  labels={{ title: "Popup Assistant", initial: "Need any help?" }}
/>
// Frontend actions + generative UI, with full streaming support
useCopilotAction({
  name: "appendToSpreadsheet",
  description: "Append rows to the current spreadsheet",
  parameters: [
    { name: "rows", type: "object[]", attributes: [{ name: "cells", type: "object[]", attributes: [{ name: "value", type: "string" }] }] }
  ],
  render: ({ status, args }) => <Spreadsheet data={canonicalSpreadsheetData(args.rows)} />,
  handler: ({ rows }) => setSpreadsheet({ ...spreadsheet, rows: [...spreadsheet.rows, ...canonicalSpreadsheetData(rows)] }),
});

Integrate In-App CoAgents with LangGraph

// Share state between app and agent
const { agentState } = useCoAgent({
  name: "basic_agent",
  initialState: { input: "NYC" }
});

// agentic generative UI
useCoAgentStateRender({
  name: "basic_agent",
  render: ({ state }) => <WeatherDisplay {...state.final_response} />,
});

// Human in the Loop (Approval)
useCopilotAction({
  name: "email_tool",
  parameters: [
    {
      name: "email_draft",
      type: "string",
      description: "The email content",
      required: true,
    },
  ],
  renderAndWaitForResponse: ({ args, status, respond }) => {
    return (
      <EmailConfirmation
        emailContent={args.email_draft || ""}
        isExecuting={status === "executing"}
        onCancel={() => respond?.({ approved: false })}
        onSend={() =>
          respond?.({
            approved: true,
            metadata: { sentAt: new Date().toISOString() },
          })
        }
      />
    );
  },
});
// intermediate agent state streaming (supports both LangGraph.js + LangGraph python)
const modifiedConfig = copilotKitCustomizeConfig(config, {
  emitIntermediateState: [
    {
      stateKey: "outline",
      tool: "set_outline",
      toolArgument: "outline",
    },
  ],
});
const response = await ChatOpenAI({ model: "gpt-4o" }).invoke(
  messages,
  modifiedConfig,
);

Documentation

To get started with CopilotKit, please check out the documentation.