---
title: "Create a new namespace"
method: POST
path: "/v1/namespace/{id}/create"
tags: ["Namespace", "Metadata"]
---

# Create a new namespace

`POST /v1/namespace/{id}/create`

Create new namespace `id`.

During the creation process, the implementation may modify user-provided `properties`, 
such as adding additional properties like `created_at` to user-provided properties, 
omitting any specific property, or performing actions based on any property value.

## Path parameters

- `id` string, required

## Query parameters

- `delimiter` string

## Request body

- CreateNamespaceRequest
  - `id` string[]
  - `mode` string — There are three modes when trying to create a namespace, to differentiate the behavior when a namespace of the same name already exists. Case insensitive, supports both PascalCase and snake_case. Valid values are: * Create: the operation fails with 409. * ExistOk: the operation succeeds and the existing namespace is kept. * Overwrite: the existing namespace is dropped and a new empty namespace with this name is created.
  - `properties` unknown

## Response `200`

Result of creating a namespace

- CreateNamespaceResponse
  - `transaction_id` string — Optional transaction identifier
  - `properties` unknown

## Other responses

- `400` — Indicates a bad request error. It could be caused by an unexpected request body format or other forms of request validation failure, such as invalid json. Usually serves application/json content, although in some cases simple text/plain content might be returned by the server's middleware.
- `401` — Unauthorized. The request lacks valid authentication credentials for the operation.
- `403` — Forbidden. Authenticated user does not have the necessary permissions.
- `404` — A server-side problem that means can not find the specified resource.
- `406` — Not Acceptable / Unsupported Operation. The server does not support this operation.
- `409` — The request conflicts with the current state of the target resource.
- `503` — The service is not ready to handle the request. The client should wait and retry. The service may additionally send a Retry-After header to indicate when to retry.
- `5XX` — A server-side problem that might not be addressable from the client side. Used for server 5xx errors without more specific documentation in individual routes.

## Changes

- **2025-12-20** `5d6099d672d3` — 8 breaking, 8 warning, 8 info
  - the `code` response property's min was decreased from `400.00` to `0.00` for the response status `400`
  - the `code` response property's min was decreased from `400.00` to `0.00` for the response status `401`
  - the `code` response property's min was decreased from `400.00` to `0.00` for the response status `403`
  - the `code` response property's min was decreased from `400.00` to `0.00` for the response status `404`
  - …20 more
- **2025-12-11** `62ebe0595c5f` — 3 breaking
  - removed the enum value `create` of the request property `mode`
  - removed the enum value `exist_ok` of the request property `mode`
  - removed the enum value `overwrite` of the request property `mode`
- **2025-12-11** `6ad4337e3849` — 1 info
  - added the optional property `transaction_id` to the response with the `200` status
- **2025-08-20** `29b677664883` — 3 breaking, 3 info
  - removed the enum value `CREATE` of the request property `mode`
  - removed the enum value `EXIST_OK` of the request property `mode`
  - removed the enum value `OVERWRITE` of the request property `mode`
  - added the new `create` enum value to the request property `mode`
  - …2 more
- …earlier changes not shown

[Full history](https://skmtc.dev/lance-format/apis/lance-namespace-specification/changes/v1/namespace/:id/create/post.md)

---

[API](https://skmtc.dev/lance-format/apis/lance-namespace-specification.md) · [All operations](https://skmtc.dev/lance-format/apis/lance-namespace-specification/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/lance-format/lance-namespace-specification/revisions/5d6099d672d3/schema)