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

# Call VFS function

> Call a VFS function by name using the selected session and its permissions. Request arguments and the JSON response depend on the function. The response example shows headers only.

```http 200 Headers only
HTTP/1.1 200 OK
Content-Type: application/json
```

> [accordion] Errors
>
> | Status | Meaning |
> | - | - |
> | `400` | Bad request: malformed, a host not allowed, or a browser page from another origin |
> | `401` | The token is missing or wrong |
> | `403` | A policy or mount mode refused the call |
> | `404` | The workspace, session, job or file does not exist |
> | `422` | Validation Error |
> | `429` | Past a rate limit, or a new session past max\_sessions |
> | `413` | The request body, multipart part, or stdin exceeds its size limit. |
> | `500` | The job or server operation failed internally. Inspect detail and server logs before retrying. |
> | `507` | The filesystem operation exceeds its storage capacity or quota. |
>
> See [error examples and recovery steps](https://docs.mirage.strukto.ai/api/errors.md). The [complete OpenAPI contract](https://github.com/strukto-ai/mirage/blob/main/docs/openapi.yaml) includes every response schema.


## OpenAPI

````yaml /openapi.yaml post /v1/workspaces/{workspace_id}/vfs/{name}
openapi: 3.2.0
info:
  title: Mirage API
  version: '0.1'
servers:
  - url: http://127.0.0.1:8765
    description: A local server on its default port
security:
  - bearerAuth: []
tags:
  - name: Workspace operations
    x-group: Workspaces
  - name: Workspaces
    x-group: Lifecycle
    parent: Workspace operations
  - name: Sessions
  - name: Shell
    parent: Workspace operations
  - name: VFS
    parent: Workspace operations
  - name: Tools
  - name: Documents
    x-group: Agent Instructions
    parent: Workspace operations
  - name: Snapshots
  - name: Templates
    parent: Configuration
  - name: Saved VFS
    x-group: VFS
    parent: Configuration
  - name: Saved CLIs
    x-group: CLI
    parent: Configuration
  - name: Saved runtimes
    x-group: Runtime
    parent: Configuration
  - name: Saved machines
    x-group: Machine
    parent: Configuration
  - name: Configuration
  - name: Policies
    parent: Configuration
  - name: Asks
    parent: Workspace operations
    x-group: Approval requests
  - name: Lines
    parent: Workspace operations
    x-group: Commands
  - name: Jobs
    parent: Workspace operations
  - name: Processes
    parent: Workspace operations
  - name: Machines
    parent: Workspace operations
  - name: Server
  - name: Service
    parent: Server
  - name: Daemon
    parent: Server
  - name: Auth
paths:
  /v1/workspaces/{workspace_id}/vfs/{name}:
    post:
      tags:
        - VFS
      summary: Call VFS function
      description: >-
        Call a VFS function by name using the selected session and its
        permissions. Request arguments and the JSON response depend on the
        function. The response example shows headers only.
      operationId: custom_function_v1_workspaces__workspace_id__vfs__name__post
      parameters:
        - $ref: '#/components/parameters/workspaceId'
        - name: name
          in: path
          required: true
          schema:
            type: string
        - $ref: '#/components/parameters/sessionId'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                path:
                  type: string
                  description: The path the function acts on.
                kwargs:
                  type: object
                  description: The function's keyword arguments, Python only.
              required:
                - path
            example:
              path: /hello.txt
              kwargs: {}
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema: {}
components:
  parameters:
    workspaceId:
      name: workspace_id
      in: path
      required: true
      description: Workspace ID.
      schema:
        type: string
      example: demo
    sessionId:
      name: session_id
      in: query
      required: false
      description: Session ID to use. If omitted, the default session is used.
      schema:
        type: string
      example: analysis
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        The server's token (MIRAGE_AUTH_TOKEN) or a JWT. A daemon in the default
        local mode with no token accepts requests without one.

````

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