---
title: "create_upload: Start an upload"
description: "Reserve an upload and get a presigned URL to PUT the bytes to."
canonical_url: "https://meetkuro.com/agents/tools/create_upload/"
updated: 2026-11-03
locale: "en"
tool: "create_upload"
scopes: ["generation.write"]
---

# create_upload

**Start an upload**

Reserve an upload and get a presigned URL to PUT the bytes to. Send the returned upload_headers on that PUT exactly as given — they are signed into the URL, and a missing one is a 403, not a network failure. Follow with complete_upload once the PUT succeeds.
Limits: images and audio up to 50 MB, video up to 250 MB.
If this client cannot make an HTTP request of its own, or the PUT is refused, use request_upload_link (or import_media for a file at a URL).

## Scope

- `generation.write` — Makes, edits, imports, shares and deletes media in the account.

## Behaviour

- **Writes**: Creates or changes items in the caller's own account.
- **Adds or updates**: Adds or updates; nothing the caller already has is deleted or overwritten.
- **Stays in the account**: Stays inside the caller's private Kuro account: any media provider it calls acts on Kuro's account, and the result is visible to no one else.

## Inputs

| Name | Type | Required | Details |
| --- | --- | --- | --- |
| `filename` | string | yes | at least 1 character; at most 220 characters |
| `mime_type` | string | yes | at least 1 character; at most 120 characters |
| `bytes` | integer | yes | > 0 |
| `checksum_sha256` | string | no | matches ^[0-9a-f]{64}$ |

## Example call

A `tools/call` request with the required arguments only, each a placeholder read off the schema. Replace them before sending.

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "create_upload",
    "arguments": {
      "filename": "<filename>",
      "mime_type": "<mime_type>",
      "bytes": 1
    }
  }
}
```

## Input schema

As the server sends it in `tools/list`:

```json
{
  "type": "object",
  "properties": {
    "filename": {
      "type": "string",
      "minLength": 1,
      "maxLength": 220
    },
    "mime_type": {
      "type": "string",
      "minLength": 1,
      "maxLength": 120
    },
    "bytes": {
      "type": "integer",
      "exclusiveMinimum": 0
    },
    "checksum_sha256": {
      "type": "string",
      "pattern": "^[0-9a-f]{64}$"
    }
  },
  "required": [
    "filename",
    "mime_type",
    "bytes"
  ],
  "additionalProperties": false
}
```

## Related tools

- [`complete_upload`](https://meetkuro.com/agents/tools/complete_upload.md): Verify uploaded bytes against their declared size, type and checksum, and return the upload ready to bind to a generation.
- [`request_upload_link`](https://meetkuro.com/agents/tools/request_upload_link.md): Get a link the user taps to send pictures or videos from their own phone or computer straight into the account, with no setup and no sign-in.
- [`import_media`](https://meetkuro.com/agents/tools/import_media.md): Fetch a file the client cannot upload itself and store it as an account upload.
- [`generate_clip`](https://meetkuro.com/agents/tools/generate_clip.md): Start a short video clip generation.

---

## About Kuro

Kuro is an AI picture studio: prompt-driven images, clips, voice-overs and music, and storyboard-backed films with consistent characters across every scene.

Agents connect over MCP and can generate directly:

```
claude mcp add kuro https://api.meetkuro.com/mcp --transport http
```

The app is at https://app.meetkuro.com and requires an account.

Each guide, model page, comparison and free tool page on this site (not a tool's variants, and not the index pages) has a Markdown twin at its own URL plus `.md`, and so do /benchmarks/, the English /agents/ page (as /agents.md) and the MCP tool reference. Every tool: https://meetkuro.com/agents/tools/