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Portable Text Serialization

sanity-io/portable-text-serialization

Render and serialize Portable Text to React, Svelte, Vue, Astro, HTML, Markdown, and plain text. Use when implementing Portable Text rendering in any frontend framework, building custom serializers for non-standard block types, converting Portable Text to HTML strings server-side, converting Portable Text to Markdown, extracting plain text from Portable Text, or troubleshooting rendering issues with marks, blocks, lists, or custom types.

6k tokens
context cost
the whole folder, loaded on every use
8
files
instructions only
0
copies elsewhere
how many repositories repackaged it
171
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/sanity-io/agent-toolkit --skill portable-text-serialization

What comes with it

20 599 bytes besides the instruction
rules/astro.md
rules/html.md
rules/markdown.md
rules/plain-text.md
rules/react.md
rules/svelte.md
rules/vue.md

The instruction itself

10 sections, as written by the author

Portable Text Serialization

Render Portable Text content across frameworks using the @portabletext/* library family. Each library follows the same component-mapping pattern: you provide a components object that maps PT node types to framework-specific renderers.

Portable Text Structure (Quick Reference)

PT is an array of blocks. Each block has _type, optional style, children (spans), markDefs, listItem, and level.

Root array
├── block (_type: "block")
│   ├── style: "normal" | "h1" | "h2" | "blockquote" | ...
│   ├── children: [span, span, ...]
│   │   └── span: { _type: "span", text: "...", marks: ["strong", "<markDefKey>"] }
│   ├── markDefs: [{ _key, _type: "link", href: "..." }, ...]
│   ├── listItem: "bullet" | "number" (optional)
│   └── level: 1, 2, 3... (optional, for nested lists)
├── custom block (_type: "image" | "code" | any custom type)
└── ...more blocks

Marks come in two forms:

  • Decorators: string values in marks[] like "strong", "em", "underline", "code"
  • Annotations: keys in marks[] referencing entries in markDefs[] (e.g., links, internal references)

Component Mapping Pattern (All Frameworks)

Every @portabletext/* library accepts a components object with these keys:

| Key | Renders | Props/Data |

|-----|---------|------------|

| types | Custom block/inline types (image, code, CTA) | value (the block data) |

| marks | Decorators + annotations | children + value (mark data) |

| block | Block styles (h1, normal, blockquote) | children |

| list | List wrappers (ul, ol) | children |

| listItem | List items | children |

| hardBreak | Line breaks within a block | — |

Framework-Specific Rules

Read the rule file matching your framework:

  • React / Next.js: rules/react.md@portabletext/react or next-sanity
  • Svelte / SvelteKit: rules/svelte.md@portabletext/svelte
  • Vue / Nuxt: rules/vue.md@portabletext/vue
  • Astro: rules/astro.mdastro-portabletext
  • HTML (server-side): rules/html.md@portabletext/to-html
  • Markdown: rules/markdown.md@portabletext/markdown
  • Plain text extraction: rules/plain-text.md@portabletext/toolkit

Additional Community Serializers

These are listed on portabletext.org but don't have dedicated rule files:

| Target | Package |

|--------|---------|

| React Native | @portabletext/react-native-portabletext |

| React PDF | @portabletext/react-pdf-portabletext |

| Solid | solid-portabletext |

| Qwik | portabletext-qwik |

| Shopify Liquid | portable-text-to-liquid |

| PHP | sanity-php (SanityBlockContent class) |

| Python | portabletext-html |

| C# / .NET | dotnet-portable-text |

| Dart / Flutter | flutter_sanity_portable_text |

Common Patterns (All Frameworks)

Custom Types Need Explicit Components

PT renderers only handle standard blocks by default. Custom types (image, code, callToAction, etc.) require explicit component mappings — they won't render otherwise.

Keep Components Object Stable

In React/Vue, define components outside the render function or memoize it. Recreating on every render causes unnecessary re-renders.

Handle Missing Components Gracefully

All libraries accept onMissingComponent to control behavior when encountering unknown types:

  • false — suppress warnings
  • Custom function — log or report

Querying PT with GROQ

Always expand references inside custom blocks:

body[]{
  ...,
  _type == "image" => {
    ...,
    asset->
  },
  markDefs[]{
    ...,
    _type == "internalLink" => {
      ...,
      "slug": @.reference->slug.current
    }
  }
}

How to use it

Copy the folder

Take sanity-io/portable-text-serialization from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.