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

# Create an upload session

> Start a multipart upload for the project's source audio or video file.

Creates a multipart upload session. The service returns the part size and part count; the actual bytes are uploaded directly to object storage.

### Header

<ParamField header="accessKey" type="string" required>
  API key for authentication.
</ParamField>

### Path

<ParamField path="projectId" type="string" required>
  The project identifier.
</ParamField>

### Body

<ParamField body="filename" type="string" required>
  Original file name, non-empty, at most 512 characters.
</ParamField>

<ParamField body="size" type="number" required>
  Exact byte length of the file. Greater than `0` and not greater than `capabilities.maxSourceBytes`.
</ParamField>

<ParamField body="contentType" type="string">
  Optional. When omitted or blank the service uses `application/octet-stream`. At most 128 characters; CR/LF are rejected.
</ParamField>

### Response

<ResponseField name="uploadId" type="string">
  The upload session identifier. Use it for signing parts, polling status and completing.
</ResponseField>

<ResponseField name="projectId" type="string">
  Project identifier.
</ResponseField>

<ResponseField name="state" type="string">
  `CREATED` right after creation.
</ResponseField>

<ResponseField name="declaredSize" type="string">
  The declared size, as a **string**.
</ResponseField>

<ResponseField name="partSizeBytes" type="number">
  The size of each part, as decided by the service. Use it as returned.
</ResponseField>

<ResponseField name="totalParts" type="number">
  The number of parts to upload. Use it as returned.
</ResponseField>

<ResponseField name="expiresAt" type="string">
  When the session expires (24 hours by default).
</ResponseField>

<RequestExample>
  ```bash theme={null}
  curl --location 'https://api.myvocal.ai/sound_clone/api/v1/interpretation/projects/ip_.../uploads' \
  --header 'accessKey: <your_api_key>' \
  --header 'Content-Type: application/json' \
  --data '{
    "filename": "launch.mp4",
    "size": 18432611,
    "contentType": "video/mp4"
  }'
  ```
</RequestExample>

<ResponseExample>
  ```json 200 Success theme={null}
  {
    "code": 1,
    "message": "success",
    "data": {
      "uploadId": "iu_...",
      "projectId": "ip_...",
      "state": "CREATED",
      "declaredSize": "18432611",
      "partSizeBytes": 16777216,
      "totalParts": 2,
      "expiresAt": "2027-01-16T15:52:11",
      "requestId": "..."
    }
  }
  ```
</ResponseExample>

<Warning>
  Do not assume a fixed 16 MiB part size or a fixed 3 GiB limit. Read `partSizeBytes` and `totalParts` from this response and `maxSourceBytes` from `capabilities`.
</Warning>

### Common errors

* `code = 47125`: the file exceeded the size limit, or the declared size is not greater than zero / the request is empty.
* `code = 47101`: `filename` is missing or too long, or `contentType` is invalid.
* `code = 47102`: the project does not exist **or** is not owned by your account.
* `code = 47127`: object storage is unavailable — retry.