Profiles

A profile is a named database connection configuration stored in ~/.wren/profiles.yml. Profiles work like dbt profiles — they separate connection credentials from project definitions so the same MDL project can connect to different databases in dev, staging, and production.

Why profiles

Without profiles, every wren command needs explicit connection flags:

wren --sql "SELECT 1" --connection-info '{"datasource":"postgres","host":"localhost","port":5432,...}'

With profiles, you configure the connection once and every command uses it automatically:

wren profile add my-db --ui
wren --sql "SELECT 1"

Profiles also keep credentials out of shell history and command-line arguments.

How profiles work

Profiles are stored in ~/.wren/profiles.yml with 0600 permissions (readable only by the owner). The file structure:

active: my-db
profiles:
  my-db:
    datasource: postgres
    host: localhost
    port: 5432
    database: analytics
    user: analyst
    password: secret
  prod:
    datasource: bigquery
    project_id: my-gcp-project
    dataset_id: production
    credentials: <base64-encoded service account key>

Only one profile can be active at a time. All wren commands use the active profile unless overridden with explicit flags.

Resolution order

When you run a wren command, the CLI resolves connection info in this order:

1. Explicit flags — --connection-info or --connection-file (highest priority)
2. Active profile — from ~/.wren/profiles.yml
3. Legacy fallback — ~/.wren/connection_info.json (for backward compatibility)

If none are found, the command fails with a connection error.

Creating a profile

Option A: Browser UI (recommended)

wren profile add my-db --ui

Opens a browser form with data-source-specific fields. Select the data source type, fill in the fields, and submit. Requires the ui extra:

pip install "wren-engine[ui]"

Option B: Interactive CLI

wren profile add my-db --interactive

Walks through prompts for data source type and all required fields. Sensitive fields (passwords, tokens) are hidden during input.

Option C: From file

Import from an existing JSON or YAML connection file:

wren profile add my-db --from-file connection.json

Both flat and envelope formats are accepted:

// Flat format
{"datasource": "postgres", "host": "localhost", "port": 5432, "database": "mydb", "user": "root", "password": "secret"}

// Envelope format (auto-unwrapped)
{"datasource": "duckdb", "properties": {"url": "/data", "format": "duckdb"}}

Option D: Minimal (datasource only)

wren profile add my-db --datasource postgres

Creates a profile with only the datasource field. Edit ~/.wren/profiles.yml manually to add connection fields.

Managing profiles

wren profile list                  # list all profiles (* = active)
wren profile switch prod           # change active profile
wren profile debug                 # show resolved config (secrets masked)
wren profile debug prod            # debug a specific profile
wren profile rm old-db             # remove a profile
wren profile rm old-db --force     # remove without confirmation

Activating on creation

Add --activate to set the profile as active immediately:

wren profile add prod --from-file prod.json --activate

If no profile is active when you add the first one, it becomes active automatically.

Supported data sources

Data source	Datasource value	Extra to install
PostgreSQL	postgres	wren-engine[postgres]
MySQL	mysql	wren-engine[mysql]
BigQuery	bigquery	wren-engine[bigquery]
Snowflake	snowflake	wren-engine[snowflake]
DuckDB	duckdb	(included by default)
ClickHouse	clickhouse	wren-engine[clickhouse]
Trino	trino	wren-engine[trino]
SQL Server	mssql	wren-engine[mssql]
Databricks	databricks	wren-engine[databricks]
Redshift	redshift	wren-engine[redshift]
Oracle	oracle	wren-engine[oracle]
Athena	athena	wren-engine[athena]
Apache Spark	spark	wren-engine[spark]

Install the extra for your data source before creating a profile:

pip install "wren-engine[postgres,ui,memory]"

Profile vs project

Profiles and projects serve different purposes and are stored separately:

	Profile	Project
What	Database connection credentials	MDL model definitions
Where	~/.wren/profiles.yml	<project>/wren_project.yml + models/
Scope	Global — shared across all projects	Per-project — version controlled
Secrets	Contains passwords, tokens, keys	No secrets — safe to commit
Switching	wren profile switch <name>	cd <project> or --path flag

This separation means:

• The same project can connect to dev, staging, or prod by switching profiles
• Projects are safe to commit to git without leaking credentials
• Credentials are centralized in one file with restricted permissions

Security

• profiles.yml is written with 0600 permissions (owner-only read/write)
• Writes are atomic (temp file + rename) to prevent corruption
• wren profile debug masks sensitive fields (password, credentials, secret, token)
• Credentials never appear in CLI output, shell history (when using profiles), or MDL manifests