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

# http_response_* session settings

> ClickHouse session settings in the http_response_* generated group.

export const SettingsInfoBlock = ({type, default_value, changeable_without_restart}) => {
  return <div className="not-prose" style={{
    display: "flex",
    flexWrap: "wrap",
    alignItems: "baseline",
    columnGap: "0.5rem",
    rowGap: "0.125rem",
    margin: "0.375rem 0",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <div style={{
    fontWeight: 600,
    opacity: 0.72
  }}>Type</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{type}</div>
      <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>Default</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{default_value}</div>
      {changeable_without_restart && <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>
          Changeable without restart
        </div>}
      {changeable_without_restart && <div style={{
    overflowWrap: "anywhere"
  }}>
          {changeable_without_restart}
        </div>}
    </div>;
};

These settings are available in [system.settings](/docs/reference/system-tables/settings) and are autogenerated from [source](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp).

<h2 id="http_response_buffer_size">
  http\_response\_buffer\_size
</h2>

<SettingsInfoBlock type="UInt64" default_value="0" />

The number of bytes to buffer in the server memory before sending a HTTP response to the client or flushing to disk (when http\_wait\_end\_of\_query is enabled).

<h2 id="http_response_headers">
  http\_response\_headers
</h2>

<SettingsInfoBlock type="Map" default_value="{}" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "24.12"},{"label": ""},{"label": "New setting."}]}]} />

Allows to add or override HTTP headers which the server will return in the response with a successful query result.
This only affects the HTTP interface.

If the header is already set by default, the provided value will override it.
If the header was not set by default, it will be added to the list of headers.
Headers that are set by the server by default and not overridden by this setting, will remain.

The setting allows you to set a header to a constant value. Currently there is no way to set a header to a dynamically calculated value.

Neither names nor values can contain ASCII control characters.

If you implement a UI application which allows users to modify settings but at the same time makes decisions based on the returned headers, it is recommended to restrict this setting to readonly.

Example: `SET http_response_headers = $${'Content-Type': 'image/png'}$$`