<!-- source-hash: 5b535a89e6cfb9cb002c7fd306bbaa13 -->
Provides a lightweight React context (`RichMarkdownRuntimeContext`) that threads proxy endpoint URLs and an optional image-transform function from `<RichMarkdownRenderer>` down to its satellite embed clients, without depending on the chat runtime.

## Key Components

| Export | Type | Description |
|---|---|---|
| `RichMarkdownRuntime` | Interface | Defines the three proxy URLs and the `transformImageSrc` knob |
| `RichMarkdownRuntimeProvider` | React component | Wraps subtrees with resolved runtime values; memoizes to prevent unnecessary re-renders |
| `useRichMarkdownRuntime` | Hook | Reads the ambient runtime; returns hub-matching defaults when called outside any provider |

### `RichMarkdownRuntime` Interface Fields

| Field | Default | Description |
|---|---|---|
| `redditProxyUrl` | `/api/blog/reddit-proxy` | Proxy endpoint for Reddit embeds |
| `twitterProxyUrl` | `/api/blog/twitter-proxy` | Proxy endpoint for Twitter/X embeds |
| `ogScraperUrl` | `/api/og-scraper` | Endpoint for OG link-preview scraping |
| `transformImageSrc` | `() => null` (identity / no rewrite) | Hub-only Supabase image transformer; return `null` to use `src` as-is |

## Usage Example

**Hub usage — override the image transformer, inherit proxy defaults:**

```typescript
import { RichMarkdownRuntimeProvider } from './rich-markdown-runtime'

function BlogLayout({ children }: { children: React.ReactNode }) {
  return (
    <RichMarkdownRuntimeProvider
      transformImageSrc={(src, opts) =>
        supabaseImageTransform(src, opts)
      }
    >
      {children}
    </RichMarkdownRuntimeProvider>
  )
}
```

**Embedder usage — read the runtime inside a satellite client:**

```typescript
import { useRichMarkdownRuntime } from './rich-markdown-runtime'

function RedditEmbedClient({ postUrl }: { postUrl: string }) {
  const { redditProxyUrl } = useRichMarkdownRuntime()
  // Falls back to '/api/blog/reddit-proxy' if no provider is in scope
  const data = useFetch(`${redditProxyUrl}?url=${postUrl}`)
}
```

**Source:** [`rich-markdown-runtime.tsx`](https://github.com/flamingo-stack/openframe-oss-lib/blob/main/rich-markdown-runtime.tsx)