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

# Blob Upload Tokens

> Mint a short-lived upload token with POST /v1/upload-tokens so a browser can upload straight to Blob Storage without your API key.

<ParamField header="Authorization" type="string" placeholder="API Key" required>
  The API key for your account. You can find this in your [account settings](https://squarecloud.app/en/account/security).
</ParamField>

Upload Tokens lets your **server** mint a short-lived token that a **browser** or mobile app uses to upload directly to Blob Storage. The file never passes through your server, and your API key never leaves it. Requires the `blob:write` scope and a paid plan.

The token goes in the `Authorization` header of [Object Post](/en/blob-reference/endpoint/post) or the [chunked upload](/en/blob-reference/endpoint/chunked-init) routes, and works nowhere else (`403 UPLOAD_TOKEN_NOT_ALLOWED`). Everything you set when minting it is **pinned**: the browser can't change the name, prefix, visibility, expiry or metadata, send a larger file, or use another file type.

* Each upload spends one use: a call to Object Post, or opening a chunked upload (its parts and completion don't spend more).
* Without a `name`, the browser picks it and the name always gets a security hash, so a leaked token can never replace your existing files.
* The token stops working when its uses run out (`401 UPLOAD_TOKEN_USED`), when it expires or when the API key that minted it is revoked (`401 ACCESS_DENIED`).

<ParamField body="name" type="string">
  Pins the file name. Without it, the browser sends `name` in the query.
</ParamField>

<ParamField body="prefix" type="string">
  Pins the prefix. A browser that sends a different one gets `403 PREFIX_NOT_ALLOWED`.
</ParamField>

<ParamField body="private" type="boolean">
  Pins the visibility.
</ParamField>

<ParamField body="security_hash" type="boolean">
  Only with `name`: `false` lets the upload replace the file with that name. Otherwise the name always gets a hash.
</ParamField>

<ParamField body="expire" type="string | null">
  Pins the expiry (`30d`, `6h`), or `null` for none. Under 7 days needs Enterprise.
</ParamField>

<ParamField body="max_size" type="number">
  Maximum file size in bytes, from 512 to 10737418240 (10 GiB).
</ParamField>

<ParamField body="allowed_extensions" type="string[]">
  Accepted extensions, 1 to 20, lowercase and without the dot (`png`, `tar.gz`).
</ParamField>

<ParamField body="metadata" type="object">
  Metadata added to every file uploaded with the token. Pro and Enterprise only.
</ParamField>

<ParamField body="expires_in" type="number" default="900">
  How long the token lasts, from 60 to 3600 seconds.
</ParamField>

<ParamField body="max_uses" type="number" default="1">
  How many uploads the token allows, from 1 to 100.
</ParamField>

### Rate limits

<Note>120 tokens per minute (`RATE_LIMITED`, 429). Minting stores nothing, so one token per end-user upload is fine.</Note>

### Response

<ResponseField name="status" type="string">
  "success" if successful, "error" if not.
</ResponseField>

<ResponseField name="response" type="object">
  <Expandable title="Toggle object">
    <ResponseField name="token" type="string">
      The upload token (`squp_...`). Hand it to the browser.
    </ResponseField>

    <ResponseField name="expires_at" type="ISO 8601">
      When the token expires.
    </ResponseField>

    <ResponseField name="max_uses" type="number">
      How many uploads the token allows.
    </ResponseField>
  </Expandable>
</ResponseField>

<RequestExample>
  ```javascript Server (Node.js) theme={null}
  // Your backend: mint a token for the signed-in user and return it to the page.
  const res = await fetch('https://blob.squarecloud.app/v1/upload-tokens', {
    method: 'POST',
    headers: {
      Authorization: process.env.SQUARE_API_KEY,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      prefix: `avatars/${userId}`,
      allowed_extensions: ['png', 'jpg', 'webp'],
      max_size: 2 * 1024 * 1024,
      expires_in: 300,
    }),
  });
  const { response } = await res.json();
  // send response.token to the browser
  ```

  ```javascript Browser theme={null}
  const form = new FormData();
  form.append('file', input.files[0]);

  const res = await fetch('https://blob.squarecloud.app/v1/objects?name=avatar', {
    method: 'POST',
    headers: { Authorization: token },
    body: form,
  });
  const { response } = await res.json();
  // response.url is the public URL of the new file
  ```

  ```bash cURL theme={null}
  curl --request POST \
    --url 'https://blob.squarecloud.app/v1/upload-tokens' \
    --header 'Authorization: YOUR_API_KEY' \
    --header 'Content-Type: application/json' \
    --data '{ "prefix": "avatars", "allowed_extensions": ["png", "jpg"], "max_size": 2097152 }'
  ```
</RequestExample>

<ResponseExample>
  ```json theme={null}
  {
    "status": "success",
    "response": {
      "token": "squp_Tq7xLm2Vb9Rk4Wz1Nc8Hy5Js0Gd3Fp6Ae.Hq3mZ8vT1kLw9xRb",
      "expires_at": "2026-09-25T12:15:00.000Z",
      "max_uses": 1
    }
  }
  ```
</ResponseExample>

### Errors

| Code                                                                                                                                                              | HTTP | When                                                                        |
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---- | --------------------------------------------------------------------------- |
| `INVALID_BODY`                                                                                                                                                    | 400  | The body is not a JSON object.                                              |
| `INVALID_OBJECT_NAME` / `INVALID_OBJECT_PREFIX` / `INVALID_OBJECT_PRIVATE` / `INVALID_OBJECT_SECURITY_HASH` / `INVALID_OBJECT_EXPIRE` / `INVALID_OBJECT_METADATA` | 400  | A pinned value is invalid.                                                  |
| `INVALID_MAX_SIZE` / `INVALID_ALLOWED_EXTENSIONS` / `INVALID_EXPIRES_IN` / `INVALID_MAX_USES`                                                                     | 400  | A limit is out of range.                                                    |
| `UPLOAD_TOKEN_TOO_LARGE`                                                                                                                                          | 400  | Too many options for one token. Shorten the metadata or the extension list. |
| `PERMISSION_DENIED`                                                                                                                                               | 401  | The account has no active paid plan.                                        |
| `UPGRADE_REQUIRED`                                                                                                                                                | 403  | The expiry or metadata needs a higher plan.                                 |
| `RATE_LIMITED`                                                                                                                                                    | 429  | More than 120 tokens in a minute.                                           |

When the browser uploads: `401 UPLOAD_TOKEN_USED` (used up), `401 ACCESS_DENIED` (expired or revoked), `403 PREFIX_NOT_ALLOWED` (other prefix), `400 FILE_TYPE_NOT_ALLOWED` (extension not allowed) and `413 FILE_TOO_LARGE` (over `max_size`).