# index.ts **[Source](https://github.com/ubugeeei-prod/ox-content/blob/main/npm/vite-plugin-ox-content/src/og-image/index.ts)** > 22 documented symbols. Read the signatures first, then expand each item for parameters, return types, and examples.
22 symbols 18 functions 3 interfaces 1 variables 38 parameters 6 members 17 returns
## Reference
fncomputeTemplateSource(options: ResolvedOgImageOptions, root: string): Promise<string>Computes a stable template source identifier for cache keys. For custom templat…2 paramsreturns Promise<string>

Computes a stable template source identifier for cache keys.

For custom templates, hashes the file content so cache invalidates when the template changes. For the default template, returns a fixed string.

Signature

async function computeTemplateSource(options: ResolvedOgImageOptions, root: string): Promise<string>

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Parameters

Returns

Promise<string>
fncreateSvelteCompilerPlugin(): import("rolldown").PluginCreates a rolldown plugin that compiles Svelte SFCs using svelte/compiler.returns import("rolldown").Plugin

Creates a rolldown plugin that compiles Svelte SFCs using svelte/compiler.

Signature

function createSvelteCompilerPlugin(): import("rolldown").Plugin

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Returns

import("rolldown").Plugin
fncreateVueCompilerPlugin(): import("rolldown").PluginCreates a rolldown plugin that compiles Vue SFCs using @vue/compiler-sfc.returns import("rolldown").Plugin

Creates a rolldown plugin that compiles Vue SFCs using @vue/compiler-sfc.

Signature

function createVueCompilerPlugin(): import("rolldown").Plugin

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Returns

import("rolldown").Plugin
fndefaultConcurrency(): numberHow many pages to render at once when the caller does not say. Rendering was se…returns number

How many pages to render at once when the caller does not say.

Rendering was serial by default, so a site paid one Chromium page render per page, end to end. Pages are cheap next to the browser itself, but they are not free — this stays well under the core count so a build machine keeps room for everything else.

Signature

function defaultConcurrency(): number

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Returns

number
fngenerateOgImages(pages: OgImagePageEntry[], options: ResolvedOgImageOptions, root: string): Promise<OgImageResult[]>Generates OG images for a batch of pages. Manages the full lifecycle: resolve t…3 paramsreturns Promise<OgImageResult[]>

Generates OG images for a batch of pages.

Manages the full lifecycle: resolve template → select renderer → render each page (with caching and concurrency).

All errors are non-fatal: failures are reported in results but never throw.

Signature

export async function generateOgImages(pages: OgImagePageEntry[], options: ResolvedOgImageOptions, root: string): Promise<OgImageResult[]>

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Parameters

Returns

Promise<OgImageResult[]>
fngetVizejsPlugin(): Promise<import("rolldown").Plugin[]>Loads @vizejs/vite-plugin as a rolldown plugin for Vue SFC compilation.returns Promise<import("rolldown").Plugin[]>

Loads @vizejs/vite-plugin as a rolldown plugin for Vue SFC compilation.

Signature

async function getVizejsPlugin(): Promise<import("rolldown").Plugin[]>

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Returns

Promise<import("rolldown").Plugin[]>
fnisBareSpecifier(id: string): booleanWhether id is a bare specifier, and so resolvable at runtime rather than someth…1 paramreturns boolean

Whether id is a bare specifier, and so resolvable at runtime rather than something the template bundle has to inline.

Template bundles are written to <root>/.cache/og-images/ and imported from there, so Node resolves anything left external against the project's own node_modules. Relative and absolute imports still bundle, which is what a template actually needs — its own components travel with it.

Signature

export function isBareSpecifier(id: string): boolean

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Parameters

  • id string

Returns

boolean
interfaceKeyedPageEntry extends OgImagePageEntryA page entry with its cache key computed once.1 member

A page entry with its cache key computed once.

Signature

interface KeyedPageEntry extends OgImagePageEntry

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Members

Properties
NameTypeDescription
key string
fnmapWithSessions<Item, Result>(items: readonly Item[], sessions: readonly OgBrowserSession[], render: (item: Item, session: OgBrowserSession) => Promise<Result>): Promise<Result[]>Runs render over items, one at a time per session, in input order. A shared cur…3 paramsreturns Promise<Result[]>

Runs render over items, one at a time per session, in input order.

A shared cursor rather than fixed batches: a batch waits for its slowest member before the next one starts, so one heavy card idled every other worker until it finished. Results are written by index, so the order the caller gets back does not depend on which session finished first.

Signature

export async function mapWithSessions<Item, Result>(items: readonly Item[], sessions: readonly OgBrowserSession[], render: (item: Item, session: OgBrowserSession) => Promise<Result>): Promise<Result[]>

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Parameters

Returns

Promise<Result[]>
interfaceOgImagePageEntryA single page entry for batch OG image generation.2 members

A single page entry for batch OG image generation.

Signature

export interface OgImagePageEntry

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Members

Properties
NameTypeDescription
outputPath string
Absolute path to write the output PNG
props OgImageTemplateProps
Props to pass to the template
interfaceOgImageResultResult of OG image generation for a single page.3 members

Result of OG image generation for a single page.

Signature

export interface OgImageResult

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Members

Properties
NameTypeDescription
cached boolean
erroroptional string
outputPath string
variableconst OX_CONTENT_PACKAGE = /^@ox-content\/vite-plugin(\/.*)?$/Matches this package and every subpath it exports. A template's natural runtime…

Matches this package and every subpath it exports.

A template's natural runtime is whatever renders it, and for the framework-less kinds that is this package: renderToString, raw, when and each live at its root, and the JSX runtime under ./jsx-runtime. Inlining them instead drags the entire plugin — chokidar, fsevents and all — into the template bundle, which is what made importing it fail outright.

Signature

const OX_CONTENT_PACKAGE = /^@ox-content\/vite-plugin(\/.*)?$/

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fnrenderSinglePage(entry: KeyedPageEntry, templateFn: OgImageTemplateFn, options: ResolvedOgImageOptions, cacheDir: string, session: OgBrowserSession, publicDir?: string): Promise<OgImageResult>Renders a single page to PNG, with cache support.6 paramsreturns Promise<OgImageResult>

Renders a single page to PNG, with cache support.

Signature

async function renderSinglePage(entry: KeyedPageEntry, templateFn: OgImageTemplateFn, options: ResolvedOgImageOptions, cacheDir: string, session: OgBrowserSession, publicDir?: string): Promise<OgImageResult>

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Parameters

Returns

Promise<OgImageResult>
fnrenderSingleSatoriPage(entry: KeyedPageEntry, templateFn: OgImageTemplateFn, options: ResolvedOgImageOptions, cacheDir: string, root: string): Promise<OgImageResult>Renders a single page to PNG using Satori, with cache support.5 paramsreturns Promise<OgImageResult>

Renders a single page to PNG using Satori, with cache support.

Signature

async function renderSingleSatoriPage(entry: KeyedPageEntry, templateFn: OgImageTemplateFn, options: ResolvedOgImageOptions, cacheDir: string, root: string): Promise<OgImageResult>

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Parameters

Returns

Promise<OgImageResult>
fnresolveReactTemplate(templatePath: string, root: string): Promise<OgImageTemplateFn>Resolves a React (.tsx/.jsx) template via SSR. Bundles with rolldown (JSX trans…2 paramsreturns Promise<OgImageTemplateFn>

Resolves a React (.tsx/.jsx) template via SSR.

Bundles with rolldown (JSX transform), then wraps with react-dom/server renderToReadableStream for async Server Component support.

Signature

async function resolveReactTemplate(templatePath: string, root: string): Promise<OgImageTemplateFn>

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Parameters

  • templatePath string
  • root string

Returns

Promise<OgImageTemplateFn>
fnresolveSvelteTemplate(templatePath: string, root: string): Promise<OgImageTemplateFn>Resolves a Svelte SFC template via SSR. Compiles the SFC with svelte/compiler (…2 paramsreturns Promise<OgImageTemplateFn>

Resolves a Svelte SFC template via SSR.

Compiles the SFC with svelte/compiler (server mode + runes), bundles with rolldown, then wraps with svelte/server render().

Signature

async function resolveSvelteTemplate(templatePath: string, root: string): Promise<OgImageTemplateFn>

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Parameters

  • templatePath string
  • root string

Returns

Promise<OgImageTemplateFn>
fnresolveTemplate(options: ResolvedOgImageOptions, root: string): Promise<OgImageTemplateFn>Resolves the template function from options. Dispatches by file extension: - .v…2 paramsreturns Promise<OgImageTemplateFn>

Resolves the template function from options.

Dispatches by file extension:

  • .vue → Vue SFC (SSR via vue/server-renderer)
  • .svelte → Svelte SFC (SSR via svelte/server)
  • .tsx/.jsx → React Server Component (SSR via react-dom/server)
  • others → TypeScript template (direct function export)

Signature

async function resolveTemplate(options: ResolvedOgImageOptions, root: string): Promise<OgImageTemplateFn>

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Parameters

Returns

Promise<OgImageTemplateFn>
fnresolveTsTemplate(templatePath: string, options: ResolvedOgImageOptions, root: string): Promise<OgImageTemplateFn>Resolves a plain TypeScript template (existing behavior).3 paramsreturns Promise<OgImageTemplateFn>

Resolves a plain TypeScript template (existing behavior).

Signature

async function resolveTsTemplate(templatePath: string, options: ResolvedOgImageOptions, root: string): Promise<OgImageTemplateFn>

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Parameters

Returns

Promise<OgImageTemplateFn>
fnresolveVueTemplate(templatePath: string, options: ResolvedOgImageOptions, root: string): Promise<OgImageTemplateFn>Resolves a Vue SFC template via SSR. Compiles the SFC with @vue/compiler-sfc (o…3 paramsreturns Promise<OgImageTemplateFn>

Resolves a Vue SFC template via SSR.

Compiles the SFC with @vue/compiler-sfc (or @vizejs/vite-plugin), bundles with rolldown, then wraps with createSSRApp + renderToString.

Signature

async function resolveVueTemplate(templatePath: string, options: ResolvedOgImageOptions, root: string): Promise<OgImageTemplateFn>

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Parameters

Returns

Promise<OgImageTemplateFn>
fntryServeAllFromCache(pages: KeyedPageEntry[], cacheDir: string): Promise<OgImageResult[] | null>Serves every page from cache when all of them are present. The probe is an exis…2 paramsreturns Promise<OgImageResult[] | null>

Serves every page from cache when all of them are present.

The probe is an existence check per key, not a read: on a partial hit this used to read and write every cached page before discovering the miss, then throw that work away and let the render loop redo it. Returns null when any page is missing, which is the signal that a renderer has to start.

Signature

async function tryServeAllFromCache(pages: KeyedPageEntry[], cacheDir: string): Promise<OgImageResult[] | null>

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Parameters

Returns

Promise<OgImageResult[] | null>
fntsTemplateBundleOptions(templatePath: string)Rolldown input options for a .ts template bundle. A .ts template is the framewo…1 param

Rolldown input options for a .ts template bundle.

A .ts template is the framework-less kind, so it has no single runtime to externalize the way the .vue, .svelte and .tsx paths do — anything from node_modules is better resolved at import time than inlined. Nothing on this path has a compiler plugin, so nothing here needed bundling to be loadable in the first place.

Signature

export function tsTemplateBundleOptions(templatePath: string)

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Parameters

  • templatePath string
fnwithCacheKeys(pages: OgImagePageEntry[], templateSource: string, options: ResolvedOgImageOptions): KeyedPageEntry[]Attaches the cache key to each entry. The key is a SHA-256 over the template so…3 paramsreturns KeyedPageEntry[]

Attaches the cache key to each entry.

The key is a SHA-256 over the template source and the page props. It used to be recomputed three times per page — once to probe, once to read, once to write — over props that can be a whole frontmatter object.

Signature

function withCacheKeys(pages: OgImagePageEntry[], templateSource: string, options: ResolvedOgImageOptions): KeyedPageEntry[]

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Parameters

Returns

KeyedPageEntry[]