> ## Documentation Index
> Fetch the complete documentation index at: https://www.algolia.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Customize the chat loader

> Change the loader text or replace the loader in the InstantSearch.js chat widget.

export const customLabel_0 = "in beta"

export const FlavorSwitcher = ({current, baseHref = "", options = [], label = "InstantSearch framework"}) => {
  if (options.length === 0) {
    return <div className="not-prose" role="alert" style={{
      margin: "0.25rem 0 1.5rem",
      padding: "0.75rem",
      border: "1px solid #f59e0b",
      borderRadius: "0.625rem",
      color: "inherit",
      fontSize: "0.875rem"
    }}>
        FlavorSwitcher requires at least one option.
      </div>;
  }
  const selected = options.find(option => option.value === current) ?? options[0];
  return <div className="not-prose mint-flavor-switcher">
      <style>{`
        .mint-flavor-switcher {
          --mfs-bg: #ffffff;
          --mfs-bg-hover: #f4f4f5;
          --mfs-bg-current: #eef2ff;
          --mfs-border: #d4d4d8;
          --mfs-fg: #18181b;
          --mfs-muted: #71717a;
          --mfs-accent: #4f46e5;
          position: relative;
          width: min(100%, 19rem);
          margin: 0.25rem 0 1.5rem;
          color: var(--mfs-fg);
          font-size: 0.875rem;
          line-height: 1.25rem;
        }

        .dark .mint-flavor-switcher {
          --mfs-bg: #18181b;
          --mfs-bg-hover: #27272a;
          --mfs-bg-current: #272747;
          --mfs-border: #3f3f46;
          --mfs-fg: #fafafa;
          --mfs-muted: #a1a1aa;
          --mfs-accent: #a5b4fc;
        }

        .mint-flavor-switcher details {
          position: relative;
        }

        .mint-flavor-switcher summary {
          display: flex;
          min-height: 2.75rem;
          box-sizing: border-box;
          align-items: center;
          justify-content: space-between;
          gap: 0.75rem;
          padding: 0.625rem 0.75rem;
          border: 1px solid var(--mfs-border);
          border-radius: 0.625rem;
          background: var(--mfs-bg);
          color: var(--mfs-fg);
          cursor: pointer;
          font-weight: 600;
          list-style: none;
          transition: border-color 150ms ease, box-shadow 150ms ease;
        }

        .mint-flavor-switcher summary::-webkit-details-marker {
          display: none;
        }

        .mint-flavor-switcher summary:hover {
          border-color: var(--mfs-accent);
        }

        .mint-flavor-switcher summary:focus-visible {
          outline: 2px solid var(--mfs-accent);
          outline-offset: 2px;
        }

        .mint-flavor-switcher__label {
          overflow: hidden;
          text-overflow: ellipsis;
          white-space: nowrap;
        }

        .mint-flavor-switcher__chevron {
          flex: none;
          transition: transform 150ms ease;
        }

        .mint-flavor-switcher details[open] .mint-flavor-switcher__chevron {
          transform: rotate(180deg);
        }

        .mint-flavor-switcher__menu {
          position: absolute;
          z-index: 50;
          top: calc(100% + 0.375rem);
          left: 0;
          width: 100%;
          box-sizing: border-box;
          margin: 0;
          padding: 0.375rem;
          border: 1px solid var(--mfs-border);
          border-radius: 0.625rem;
          background: var(--mfs-bg);
          box-shadow: 0 12px 30px rgb(0 0 0 / 16%);
          list-style: none;
        }

        .mint-flavor-switcher__menu li {
          margin: 0;
          padding: 0;
        }

        .mint-flavor-switcher__option {
          display: grid;
          gap: 0.125rem;
          padding: 0.625rem 0.75rem;
          border-radius: 0.4rem;
          color: var(--mfs-fg);
          text-decoration: none;
        }

        .mint-flavor-switcher__option:hover {
          background: var(--mfs-bg-hover);
        }

        .mint-flavor-switcher__option:focus-visible {
          outline: 2px solid var(--mfs-accent);
          outline-offset: -2px;
        }

        .mint-flavor-switcher__option[aria-current="page"] {
          background: var(--mfs-bg-current);
          color: var(--mfs-accent);
        }

        .mint-flavor-switcher__name {
          font-weight: 600;
        }

        .mint-flavor-switcher__description {
          color: var(--mfs-muted);
          font-size: 0.8125rem;
        }

        @media (prefers-reduced-motion: reduce) {
          .mint-flavor-switcher summary,
          .mint-flavor-switcher__chevron {
            transition: none;
          }
        }
      `}</style>

      <details>
        <summary aria-label={`${label}: ${selected.label}`}>
          <span className="mint-flavor-switcher__label">{selected.label}</span>
          <svg className="mint-flavor-switcher__chevron" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
            <path d="m6 9 6 6 6-6" />
          </svg>
        </summary>

        <ul className="mint-flavor-switcher__menu" aria-label={label}>
          {options.map(option => {
    const isCurrent = option.value === selected.value;
    const href = option.href ?? `${baseHref.replace(/\/$/, "")}/${encodeURIComponent(option.value)}`;
    return <li key={option.value}>
                <a className="mint-flavor-switcher__option" href={href} aria-current={isCurrent ? "page" : undefined}>
                  <span className="mint-flavor-switcher__name">
                    {option.label}
                  </span>
                  {option.description ? <span className="mint-flavor-switcher__description">
                      {option.description}
                    </span> : null}
                </a>
              </li>;
  })}
        </ul>
      </details>
    </div>;
};

<div className="mint-flavor-switcher-slot not-prose">
  <FlavorSwitcher
    current="js"
    baseHref="/doc/guides/building-search-ui/going-further/chat-customization/loading-message"
    options={[
{ value: "js", label: "JavaScript", description: "InstantSearch.js" },
{ value: "react", label: "React", description: "React InstantSearch" },
]}
  />
</div>

<Callout icon="flask-conical" color="#14b8a6">
  This widget is **{customLabel_0 || "experimental"}** and is subject to change in minor versions.
</Callout>

The [`chat`](/doc/api-reference/widgets/chat/js) widget shows a loader while a chat turn is in progress.
The default loader includes a spinner, optional text, and skeleton lines.
Use `templates.loaderText` to change the text or
`templates.loader` to replace the loader.

To change when and where the loader renders, see [Control when and where the chat loader shows](/doc/guides/building-search-ui/going-further/chat-customization/loader-behavior/js).

## Change the loader text

The default loader doesn't show any text. Add some with `templates.loaderText`:

```js JavaScript icon=code theme={"system"}
chat({
  container: "#chat",
  agentId: "YOUR_AGENT_ID",
  templates: {
    loaderText: "Preparing an answer...",
  },
});
```

## Change the text by turn phase

Pass a function to `loaderText` to change the text based on the turn context.
Use `phase` to identify the current phase:

| Phase       | Meaning                                                                                                                      |
| ----------- | ---------------------------------------------------------------------------------------------------------------------------- |
| `submitted` | The prompt was submitted but no assistant part has arrived yet.                                                              |
| `tool`      | Running a tool call, such as a search.                                                                                       |
| `reasoning` | Reasoning before the answer starts, with [`showReasoning`](/doc/api-reference/widgets/chat/js#param-show-reasoning) enabled. |
| `thinking`  | Any other pause while the turn is in progress.                                                                               |

```js JavaScript icon=code theme={"system"}
chat({
  // ...
  templates: {
    loaderText: ({ phase }) => {
      switch (phase) {
        case "submitted":
          return "Reading your question...";
        case "tool":
          return "Working on your request...";
        case "reasoning":
          return "Working through the details...";
        default:
          return "Writing a response...";
      }
    },
  },
});
```

The function receives the same turn context as [`shouldShowLoader`](/doc/api-reference/widgets/chat/js#param-should-show-loader), without `defaultValue`.

## Replace the loader

Use the `loader` template to render your own loading state.
It receives:

* `translations`. The resolved loader translations.
* `context`. The same context as `loaderText` receives.
* `inline`. Whether the loader renders inside an assistant message. It's `true` when `loaderPosition` is `message-inline` and an assistant message is available.

```js JavaScript icon=code theme={"system"}
chat({
  // ...
  templates: {
    loader: ({ context }, { html }) =>
      html`<p>
        ${context.phase === "tool" ? "Searching..." : "Preparing an answer..."}
      </p>`,
  },
});
```

Use `inline` if your custom loader needs different markup or spacing when it appears inside a message.

## Reuse the default loader

Instead of writing the markup yourself, render the built-in loader with the `chatMessageLoader` template helper and override what you need.
It keeps the default spinner, skeleton lines, and animations.
Pass the received properties to `chatMessageLoader`, then override `translations`, `className`, or any element attribute:

```js JavaScript icon=code theme={"system"}
import { chatMessageLoader } from "instantsearch.js/es/templates";

chat({
  // ...
  templates: {
    loader: (props) =>
      chatMessageLoader({
        ...props,
        className: "my-Loader",
        translations: { loaderText: "Preparing an answer..." },
      }),
  },
});
```

## Rotate loading messages while the agent is working

Prefer `phase`, since it tracks the current phase of the turn. For long waits within one phase, cycle through a short set of messages with CSS. Render them all in the template, then fade between them:

```js JavaScript icon=code theme={"system"}
chat({
  // ...
  templates: {
    loader: (_, { html }) => html`
      <p class="my-Loader">
        <span>Working on your request...</span>
        <span>Reviewing the results...</span>
        <span>Writing a response...</span>
      </p>
    `,
  },
});
```

```css CSS icon=paintbrush expandable theme={"system"}
.my-Loader {
  display: grid;
}

.my-Loader span {
  grid-area: 1 / 1;
  opacity: 0;
  animation: my-Loader-cycle 7.5s infinite;
}

.my-Loader span:nth-child(2) {
  animation-delay: 2.5s;
}

.my-Loader span:nth-child(3) {
  animation-delay: 5s;
}

@keyframes my-Loader-cycle {
  0%,
  33% {
    opacity: 1;
  }
  34%,
  100% {
    opacity: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .my-Loader span {
    animation: none;
  }

  .my-Loader span:first-child {
    opacity: 1;
  }
}
```

Keep each message short, and don't describe work the agent isn't doing.

## Related

* [chat widget reference](/doc/api-reference/widgets/chat/js)
* [Control when and where the chat loader shows](/doc/guides/building-search-ui/going-further/chat-customization/loader-behavior/js)