Add documentation for ToMarkdown supported formats endpoint

src/content/changelog/workers-ai/2025-10-23-new-markdown-conversion-endpoint.mdx

@@ -0,0 +1,38 @@
+---
+title: 'Workers AI Markdown Conversion: New endpoint to list supported formats'
+description: You can now programmatically get a list of all supported file formats that can be converted by our Markdown Conversion utility.
+date: 2025-10-23
+---
+
+Developers can now programmatically retrieve a list of all file formats supported by the [Markdown Conversion utility](/workers-ai/features/markdown-conversion/) in Workers AI.
+
+You can use the [`env.AI`](/workers-ai/configuration/bindings/) binding:
+
+```typescript
+await env.AI.toMarkdown().supported()
+```
+
+Or call the REST API:
+
+```bash
+curl https://api.cloudflare.com/client/v4/accounts/{ACCOUNT_ID}/ai/tomarkdown/supported \
+  -H 'Authorization: Bearer {API_TOKEN}'
+```
+
+Both return a list of file formats that users can convert into Markdown:
+
+```json
+[
+	{
+		"extension": ".pdf",
+		"mimeType": "application/pdf",
+	},
+	{
+		"extension": ".jpeg",
+		"mimeType": "image/jpeg",
+	},
+	...
+]
+```
+
+Learn more about our [Markdown Conversion utility](/workers-ai/features/markdown-conversion/).

src/content/docs/workers-ai/features/markdown-conversion.mdx

@@ -13,23 +13,23 @@ import { Code, Type, MetaInfo, Details, Render } from "~/components";
 
 For these reasons, document conversion plays an important role when designing and developing AI applications. Workers AI provides the `toMarkdown` utility method that developers can use from the [`env.AI`](/workers-ai/configuration/bindings/) binding or the REST APIs for quick, easy, and convenient conversion and summary of documents in multiple formats to Markdown language.
 
-## Methods and definitions
+## Methods
 
 ### async env.AI.toMarkdown()
 
-Takes a list of documents in different formats and converts them to Markdown.
+Takes a document or list of documents in different formats and converts them to Markdown.
 
 #### Parameter
 
-- <code>documents</code>: <Type text="array" />- An array of
-  `toMarkdownDocument`s.
+- <code>files</code>: <Type text="MarkdownDocument | MarkdownDocument[]" />- an instance of or an array of
+  `MarkdownDocument`s.
 
 #### Return values
 
-- <code>results</code>: <Type text="array" />- An array of
-  `toMarkdownDocumentResult`s.
+- <code>results</code>: <Type text="Promise<ConversionResult | ConversionResult[]>" />- An instance of or an array of
+  `ConversionResult`s.
 
-### `toMarkdownDocument` definition
+#### `MarkdownDocument` definition
 
 - `name` <Type text="string" />
 
@@ -39,23 +39,54 @@ Takes a list of documents in different formats and converts them to Markdown.
 
   - A new [Blob](https://developer.mozilla.org/en-US/docs/Web/API/Blob/Blob) object with the document content.
 
-### `toMarkdownDocumentResult` definition
+#### `ConversionResult` definition
 
 - `name` <Type text="string" />
 
   - Name of the converted document. Matches the input name.
 
+- `format` <Type text="'markdown' | 'error'" />
+
+  - The format of this `ConversionResult` object
+
 - `mimetype` <Type text="string" />
 
   - The detected [mime type](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/MIME_types/Common_types) of the document.
 
 - `tokens` <Type text="number" />
 
-  - The estimated number of tokens of the converted document.
+  - The estimated number of tokens of the converted document. Only present if `format` is equal to `markdown`.
 
 - `data` <Type text="string" />
 
-  - The content of the converted document in Markdown format.
+  - The content of the converted document in Markdown format. Only present if `format` is equal to `markdown`.
+
+- `error` <Type text="string" />
+
+  - The error message explaining why this conversion failed. Only present if `format` is equal to `error`.
+
+### async env.AI.toMarkdown().transform()
+
+This method is similar to `env.AI.toMarkdown` except that it is exposed through a new handle. It takes the same arguments and returns the same values.
+
+### async env.AI.toMarkdown().supported()
+
+Returns a list of file formats that are currently supported for markdown conversion. See [Supported formats](#supported-formats) for the full list of file formats that can be converted into Markdown.
+
+#### Return values
+
+- <code>results</code>: <Type text="SupportedFormat[]" />- An array of all formats supported for markdown conversion.
+
+#### `SupportedFormat` definition
+
+- `extension` <Type text="string" />
+
+  - Extension of files in this format.
+
+- `mimeType` <Type text="string" />
+
+  - The [mime type](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/MIME_types/Common_types) of files of this format
+
 
 ## Supported formats
 
@@ -65,6 +96,8 @@ This is the list of support formats. We are constantly adding new formats and up
 
 ## Example
 
+### Converting files
+
 In this example, we fetch a PDF document and an image from R2 and feed them both to `env.AI.toMarkdown`. The result is a list of converted documents. Workers AI models are used automatically to detect and summarize the image.
 
 ```typescript
@@ -79,6 +112,7 @@ export default {
 		const cat = await env.R2.get("cat.jpeg");
 
 		return Response.json(
+			// env.AI.toMarkdown().transform(...) would return the same result
 			await env.AI.toMarkdown([
 				{
 					name: "somatosensory.pdf",
@@ -119,17 +153,56 @@ This is the result:
 ]
 ```
 
+### Getting supported file formats
+
+```typescript
+import { Env } from "./env";
+
+export default {
+	async fetch(request: Request, env: Env, ctx: ExecutionContext) {
+		return Response.json(
+			await env.AI.toMarkdown().supported(),
+		);
+	},
+};
+```
+
+results in
+
+```json
+[
+	{
+		"extension": ".pdf",
+		"mimeType": "application/pdf",
+	},
+	{
+		"extension": ".jpeg",
+		"mimeType": "image/jpeg",
+	},
+	...
+]
+```
+
 ## REST API
 
 In addition to the Workers AI [binding](/workers-ai/configuration/bindings/), you can use the [REST API](/workers-ai/get-started/rest-api/):
 
+### Conversion
+
 ```bash
 curl https://api.cloudflare.com/client/v4/accounts/{ACCOUNT_ID}/ai/tomarkdown \
   -H 'Authorization: Bearer {API_TOKEN}' \
 	-F "[email protected]" \
 	-F "[email protected]"
 ```
 
+### Supported formats
+
+```bash
+curl https://api.cloudflare.com/client/v4/accounts/{ACCOUNT_ID}/ai/tomarkdown/supported \
+  -H 'Authorization: Bearer {API_TOKEN}' \
+```
+
 ## Pricing
 
 `toMarkdown` is free for most format conversions. In some cases, like image conversion, it can use Workers AI models for object detection and summarization, which may incur additional costs if it exceeds the Workers AI free allocation limits. See the [pricing page](/workers-ai/platform/pricing/) for more details.