> ## Documentation Index
> Fetch the complete documentation index at: https://moxn.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# upload_url

> Get a presigned URL for uploading a file to Moxn storage

Get a presigned upload URL for storing a file in Moxn's blob storage (Supabase). After uploading, use the returned `path` as a `key` in storage-type content blocks.

<Note>
  **This tool is primarily used by the stdio proxy.** When using `@moxn/mcp-kb` locally, the proxy handles file uploads automatically — you just pass a local file path in content blocks (`"type": "file", "path": "/local/path"`). Call `upload_url` directly only if you need manual control over the upload.

  In **HTTP/remote mode**, `upload_url` may not work reliably because the upload requires a direct connection to the Moxn storage service.
</Note>

## Parameters

| Parameter  | Type   | Required | Description                                                      |
| ---------- | ------ | -------- | ---------------------------------------------------------------- |
| `type`     | string | Yes      | MIME type of the file (e.g., `"image/png"`, `"application/pdf"`) |
| `filename` | string | No       | Optional filename for display in the UI                          |

## Supported MIME Types

* **Images:** `image/jpeg`, `image/png`, `image/gif`, `image/webp`, `image/svg+xml`
* **Documents:** `application/pdf`, `application/vnd.openxmlformats-officedocument.wordprocessingml.document` (docx), xlsx, pptx, doc, xls, ppt, odt, ods, rtf
* **Data:** `text/csv`
* **Text/Code:** `text/plain`, `text/markdown`, `application/json`, `application/xml`, `text/yaml`, `text/html`
* **Archives:** `application/zip`, `application/gzip`, `application/x-tar`
* **Other:** `application/epub+zip`

## Response

```json theme={null}
{
  "path": "uploads/workspace/uuid/filename.png",
  "token": "https://storage.example.com/presigned-put-url..."
}
```

* `path` — use this as the `key` field in `type: "storage"` content blocks
* `token` — a presigned PUT URL, valid for **1 hour**

## Manual Upload Workflow

```bash theme={null}
# 1. Get upload URL
# upload_url({type: "image/png", filename: "diagram.png"})
# → {path: "uploads/...", token: "https://..."}

# 2. Upload the file
curl -X PUT \
  -H "Content-Type: image/png" \
  --data-binary @diagram.png \
  "https://presigned-put-url..."

# 3. Use in a content block
# {"blockType": "image", "type": "storage", "mediaType": "image/png", "key": "uploads/..."}
```

## Stdio Proxy Automatic Upload

When using `@moxn/mcp-kb` (stdio), you don't need to call `upload_url` directly. Pass a local path in content blocks and the proxy handles the rest:

```json theme={null}
{"blockType": "image", "type": "file", "path": "/Users/me/screenshots/diagram.png"}
```

The proxy:

1. Reads the file from disk
2. Calls `upload_url` to get a presigned URL
3. Uploads the file
4. Transforms the block to `type: "storage"` before forwarding to the server

## Related

* [`sections`](/reference/mcp/sections) — use `type: "storage"` content blocks with the returned `path` as `key`