Parameter Widgets

Complete reference for parameter widget types and configuration options in valohai.yaml.

Parameter widgets control the user interface rendering and editing behavior of parameters in valohai.yaml definitions.

Widget Specification

The widget field accepts two formats:

String format:

widget: <widget-type>

Object format:

widget:
  type: <widget-type>
  settings:
    <widget-specific-settings>

When the widget field is omitted, the default widget is used.

---

Available Widget Types

default

A resizable text area that auto-expands based on content.

Type identifier: default (implicit when widget field is omitted)

Settings: None

Behavior:

• Renders as single-row text area by default

• Expands vertically as content is entered

• Accepts string input

Example:

parameters:
  - name: experiment_name
    type: string
    default: "baseline"

---

combobox

A searchable dropdown that combines predefined options with free-text input capability.

Type identifier: combobox

Settings:

• options (array of strings, optional): Predefined values displayed in dropdown

Behavior:

• Displays dropdown of predefined options when settings.options is provided

• Allows typing to filter displayed options

• Accepts custom values not in the options list

• Automatically adds current value to options list if not already present

• Falls back to default widget when settings.options is empty or undefined

Example:

parameters:
  - name: model_type
    type: string
    widget:
      type: combobox
      settings:
        options:
          - resnet50
          - vgg16
          - inception_v3

Example (shorthand without settings):

parameters:
  - name: model_type
    type: string
    widget: combobox

---

sql

A code editor with SQL syntax highlighting.

Type identifier: sql

Settings: None

Behavior:

• Renders as multi-line code editor

• Applies SQL syntax highlighting via PrismJS

• Uses monospace font

• Accepts string input

Example:

parameters:
  - name: filter_query
    type: string
    widget: sql
    default: "status = 'active'"

---

dockerfile

A code editor with Dockerfile syntax highlighting.

Type identifier: dockerfile

Settings: None

Behavior:

• Renders as multi-line code editor

• Applies Dockerfile syntax highlighting via PrismJS

• Uses monospace font

• Accepts string input

Example:

parameters:
  - name: custom_dockerfile
    type: string
    widget: dockerfile
    default: |
      FROM python:3.9
      RUN pip install numpy pandas

---

datumalias

A searchable dropdown populated with datum aliases from the current project.

Type identifier: datumalias

Settings: None

Behavior:

• Fetches datum aliases from project context

• Displays only non-deleted aliases

• Renders searchable dropdown

• Allows custom value entry

• Provides clearable selection

• Shows loading state during fetch

• Requires valid projectId in execution context

Example:

parameters:
  - name: input_data
    type: string
    widget: datumalias

---

Parameter Definition Fields

Parameter definitions support the following fields:

Field	Type	Required	Description
name	string	Yes	Parameter identifier used in command substitution
type	string	No	Data type: string, integer, float, flag. Defaults to string
default	varies	No	Default value matching the parameter type
optional	boolean	No	Whether parameter can be omitted. Defaults to false
description	string	No	Help text displayed in user interface
widget	string or object	No	Widget configuration as described above

Example with all fields:

parameters:
  - name: model_architecture
    type: string
    optional: false
    description: "Neural network architecture"
    default: "resnet50"
    widget:
      type: combobox
      settings:
        options:
          - resnet50
          - resnet101
          - vgg16
          - inception_v3

Widget Selection

Widget selection follows this precedence:

1. If widget field is specified, that widget type is used

2. If widget field is omitted, the default widget is used

There is no automatic widget selection based on parameter type or other fields.

Complete Examples

String parameter with default widget

parameters:
  - name: experiment_name
    type: string
    description: "Experiment identifier"
    default: "baseline"

Integer parameter with combobox

parameters:
  - name: batch_size
    type: integer
    default: 32
    widget:
      type: combobox
      settings:
        options:
          - 16
          - 32
          - 64
          - 128

SQL query parameter

parameters:
  - name: where_clause
    type: string
    description: "SQL WHERE clause for filtering"
    default: "created_at > '2025-01-01'"
    widget: sql

Dockerfile parameter with multi-line default

parameters:
  - name: base_image_config
    type: string
    widget: dockerfile
    default: |
      FROM python:3.11-slim
      RUN apt-get update && apt-get install -y git
      RUN pip install --upgrade pip

Datum alias parameter

parameters:
  - name: training_dataset
    type: string
    description: "Dataset alias for training data"
    widget: datumalias