reserve_media_upload

Access and behavior

Write or Administrator OAuth consent and a member/administrator team role are required. Tools are listed and callable only when the current grant and role permit them.

Use the returned uploadUrl and headers for the separate storage PUT. Reserving an upload does not create a post. Keep signed URLs private and use them before expiry.

Arguments

Argument	Required	Type or meaning
`fileName`	Yes	Original file name, including its extension.
`contentType`	Yes	Supported MIME type matching the exact uploaded bytes.
`sizeBytes`	Yes	Exact file size in bytes; the uploaded body must match.
`alt`	No	Alternative text describing the image or video.

Complete input schema

{
  "type": "object",
  "properties": {
    "fileName": {
      "type": "string",
      "minLength": 1,
      "maxLength": 255
    },
    "contentType": {
      "type": "string",
      "enum": [
        "image/jpeg",
        "image/png",
        "image/webp",
        "video/mp4",
        "video/quicktime"
      ]
    },
    "sizeBytes": {
      "type": "integer",
      "minimum": 1,
      "maximum": 104857600
    },
    "alt": {
      "default": "",
      "type": "string",
      "maxLength": 2000
    }
  },
  "required": ["fileName", "contentType", "sizeBytes"],
  "additionalProperties": false
}

Example call

The client initializes the MCP connection before sending this JSON-RPC call. Example records are fictional.

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "reserve_media_upload",
    "arguments": {
      "fileName": "studio.jpg",
      "contentType": "image/jpeg",
      "sizeBytes": 245760,
      "alt": "A bright studio desk beside a window"
    }
  }
}

Example result

Posted returns this object in structuredContent and a JSON text content block. A tool failure sets isError; never treat an error as a completed mutation.

{
  "mediaId": "44444444-4444-4444-8444-444444444444",
  "uploadUrl": "https://storage.example.test/signed-upload",
  "headers": {
    "Content-Type": "image/jpeg"
  }
}

Connect a client

MCP reference

API Reference

reserve_media_upload

Workflow

Access and behavior

Arguments

Example call

Example result

​Workflow

​Access and behavior

​Arguments

​Example call

​Example result

​Related reference

Workflow

Access and behavior

Arguments

Example call

Example result

Related reference