Implementation:Evidentlyai Evidently CLI Legacy UI

Knowledge Sources	Evidentlyai_Evidently
Domains	CLI, UI, Data Monitoring
Last Updated	2026-02-14 12:00 GMT

Overview

CLI command that starts the legacy Evidently UI service with optional demo project generation and deterministic UUID support.

Description

The legacy_ui module provides two key components:

1. setup_deterministic_generation_uuid(seed) -- A utility function that patches Python's uuid.uuid4 and uuid6.uuid7 with deterministic, seeded implementations using the Faker library. This enables reproducible project creation for testing and CI purposes.
2. legacy_ui(...) -- A Typer CLI command registered as legacy_ui that starts the legacy Evidently UI web service. Before launching, it can optionally generate one or more demo projects into the workspace. If EXPERIMENTAL_DETERMINISTIC_UUID environment variable is set, all UUID generation becomes deterministic.

The command validates that requested demo project names exist, creates any missing demo projects in the workspace, and then launches the local UI server via run_local.

Usage

Use this command to start the legacy version of the Evidently monitoring UI, optionally pre-populated with demo projects. This is typically used during local development, demos, or when the legacy UI format is preferred over the newer service architecture.

Code Reference

Source Location

• Repository: Evidentlyai_Evidently
• File: src/evidently/cli/legacy_ui.py

Signature

def setup_deterministic_generation_uuid(seed: int = 8754):

@app.command("legacy_ui")
def legacy_ui(
    host: str = Option("127.0.0.1", help="Service host"),
    port: int = Option(8000, help="Service port"),
    workspace: str = Option("workspace", help="Path to workspace"),
    demo_projects: str = Option(
        "",
        "--demo-projects",
        help="Comma-separated list of demo projects to generate.",
    ),
    secret: Optional[str] = Option(None, help="Secret for writing operations"),
):

Import

from evidently.cli.legacy_ui import legacy_ui, setup_deterministic_generation_uuid

I/O Contract

Inputs

Name	Type	Required	Description
host	str	No (default: "127.0.0.1")	Host address to bind the UI service
port	int	No (default: 8000)	Port number for the UI service
workspace	str	No (default: "workspace")	Filesystem path for the workspace directory
demo_projects	str	No (default: "")	Comma-separated list of demo project names; use "all" for all available projects
secret	Optional[str]	No	Secret token for authenticating write operations

Outputs

Name	Type	Description
(side effect)	None	Starts a local web server hosting the legacy Evidently UI; raises BadParameter if an unknown demo project name is provided

Usage Examples

# Start legacy UI on default host/port
evidently legacy_ui

# Start with demo projects on custom port
evidently legacy_ui --port 9000 --demo-projects all

# Start with specific demo projects and a write secret
evidently legacy_ui --demo-projects "adult,bikes" --secret my_secret

Related Pages

• Environment:Evidentlyai_Evidently_Python_Core_Environment
• Evidentlyai_Evidently_CLI_Demo_Project - Standalone demo project generation command