ssr:render Hook

The ssr:render hook runs after tags have been resolved and immediately before they are serialized into an SSRHeadPayload.

Hook Signature

export interface Hook {
  'ssr:render': (ctx: {
    tags: HeadTag[]
    options: RenderSSRHeadOptions
  }) => HookResult
}

Parameters

RenderSSRHeadOptions includes omitLineBreaks, resolvedTags, and tagWeight. At this stage, resolvedTags and tagWeight have already been used to select and order ctx.tags; changing them has no effect on the current render. Changing omitLineBreaks affects serialization.

Although the hook type permits a promise, serialization starts immediately after the hook call. Keep this hook synchronous.

Usage Example

import { defineHeadPlugin } from 'unhead/plugins'

export const ssrReportPlugin = defineHeadPlugin({
  key: 'ssr-report',
  hooks: {
    'ssr:render': ({ tags }) => {
      console.log(`Serializing ${tags.length} head tags`)
    }
  }
})

Use MinifyPlugin instead of setting omitLineBreaks directly when you also want to minify inline JavaScript, CSS, or JSON.