Wren Connection Info

Name: Wren Connection Info
Author: canner

canner/wren-engine

3 installs
663 repo stars
Updated May 6, 2026
canner/wren-engine

Reference for the required connection fields across all 18 Wren Engine data sources, including sensitive fields and BigQuery credential encoding.

About

Documents required and optional connection fields for the 18 data sources Wren Engine supports, plus Docker host hints and BigQuery credential handling. A developer uses it when configuring a Wren data source connection.

Covers 18 sources from Postgres to S3, GCS, and MinIO
Connection info set only via the MCP Web UI at localhost:9001

Wren Connection Info by the numbers

3 all-time installs (skills.sh)
Ranked #720 of 911 Databases skills by installs in the Skillselion catalog
Data as of Aug 1, 2026 (Skillselion catalog sync)

npx skills add https://github.com/canner/wren-engine --skill wren-connection-info

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Installs	3
repo stars	★ 663
Last updated	May 6, 2026
Repository	canner/wren-engine ↗

What it does

Reference for the required connection fields across all 18 Wren Engine data sources, including sensitive fields and BigQuery credential encoding.

Files

SKILL.mdMarkdownGitHub ↗

Wren Connection Info Reference

Connection info can only be configured through the MCP server Web UI at http://localhost:9001. Do not attempt to set it programmatically. Always direct the user to the Web UI.

---

Supported data sources

Value	Database	Fields reference
`POSTGRES`	PostgreSQL	databases.md
`MYSQL`	MySQL / MariaDB	databases.md
`MSSQL`	SQL Server	databases.md
`CLICKHOUSE`	ClickHouse	databases.md
`ORACLE`	Oracle	databases.md
`DORIS`	Apache Doris	databases.md
`REDSHIFT`	Amazon Redshift	databases.md
`TRINO`	Trino	databases.md
`BIGQUERY`	Google BigQuery	databases.md
`SNOWFLAKE`	Snowflake	databases.md
`DUCKDB`	DuckDB	databases.md
`ATHENA`	AWS Athena	databases.md
`DATABRICKS`	Databricks	databases.md
`SPARK`	Apache Spark	databases.md
`S3_FILE`	Amazon S3	file-sources.md
`GCS_FILE`	Google Cloud Storage	file-sources.md
`MINIO_FILE`	MinIO	file-sources.md
`LOCAL_FILE`	Local files	file-sources.md

Read the linked reference file for the user's data source to get required fields, default ports, and setup notes.

---

Common patterns

Most database connectors need: host, port, user, password, database.

Exceptions:

BigQuery — uses project_id, dataset_id, credentials (base64-encoded). See databases.md for encoding instructions.
Snowflake — uses account instead of host, plus schema.
Trino — needs catalog and schema instead of database.
Databricks — uses serverHostname, httpPath, accessToken (or service principal with clientId, clientSecret).
Spark — only host and port (Spark Connect protocol, no auth fields).
File sources — use url, format, plus bucket/credentials. See file-sources.md.

---

Docker host hint

If the database runs on the host machine and Wren Engine runs inside Docker, localhost cannot reach the host. Use host.docker.internal instead:

Original	Inside Docker
`localhost`	`host.docker.internal`
`127.0.0.1`	`host.docker.internal`
Cloud/remote hostname	No change needed

---

Sensitive fields

Never log, display, or pass sensitive values through the AI agent unnecessarily.

Connector	Sensitive fields
Postgres / MySQL / MSSQL / ClickHouse / Oracle / Doris / Redshift	`password`
BigQuery	`credentials`
Snowflake	`password`
Athena	`aws_access_key_id`, `aws_secret_access_key`
Databricks (token)	`accessToken`
Databricks (service principal)	`clientId`, `clientSecret`
S3 / MinIO	`access_key`, `secret_key`
GCS	`key_id`, `secret_key`, `credentials`
Trino / Spark / Local files	(none)

Database Connectors — Required Fields

PostgreSQL / MySQL / MSSQL / ClickHouse / Oracle / Doris

Field	Description	Sensitive
`host`	Hostname or IP
`port`	Port number
`user`	Username
`password`	Password	✓
`database`	Database name

Default ports: PostgreSQL 5432, MySQL 3306, MSSQL 1433, ClickHouse 8123, Oracle 1521, Doris 9030

---

Redshift (password auth)

Field	Description	Sensitive
`host`	Hostname or IP
`port`	Port number (default `5439`)
`user`	Username
`password`	Password	✓
`database`	Database name

Redshift (IAM auth)

Field	Description	Sensitive
`cluster_identifier`	Redshift cluster identifier	✓
`database`	Database name	✓
`user`	Database username	✓
`region`	AWS region (e.g. `us-west-2`)	✓
`access_key_id`	AWS access key ID	✓
`access_key_secret`	AWS secret access key	✓

Set redshift_type to "redshift_iam" in the connection info to use IAM auth.

---

Trino

Field	Description	Sensitive
`host`	Hostname
`port`	Port (default `8080`)
`user`	Username
`catalog`	Catalog name
`schema`	Schema name

---

BigQuery

Field	Description	Sensitive
`project_id`	GCP project ID
`dataset_id`	Dataset name
`credentials`	Base64-encoded service account JSON	✓

BigQuery credentials encoding: Wren requires the service account JSON as a base64-encoded string, not the raw file. After downloading credentials.json from GCP, run:

# macOS
base64 -i credentials.json | tr -d '\n'
# Linux
base64 -w 0 credentials.json

Paste the output into the credentials field. The Web UI also supports uploading the JSON file directly.

---

Snowflake

Field	Description	Sensitive
`user`	Username
`password`	Password	✓
`account`	Account identifier
`database`	Database name
`schema`	Schema name

---

DuckDB

Field	Description
`format`	Must be `"duckdb"`
`url`	Path to the `.duckdb` file (e.g. `/workspace/mydb.duckdb`)

When running via Docker, set url to the mounted folder (e.g. /workspace), and place the .duckdb file there (e.g. /workspace/mydb.duckdb).

---

Athena

Field	Description	Sensitive
`s3_staging_dir`	S3 staging directory (`s3://bucket/prefix/`)
`region_name`	AWS region
`aws_access_key_id`	AWS access key ID	✓
`aws_secret_access_key`	AWS secret access key	✓

---

Databricks (token auth)

Field	Description	Sensitive
`serverHostname`	Workspace hostname (e.g. `dbc-xxx.cloud.databricks.com`)
`httpPath`	SQL warehouse HTTP path (e.g. `/sql/1.0/warehouses/xxx`)
`accessToken`	Personal access token	✓

Databricks (service principal)

Field	Description	Sensitive
`serverHostname`	Workspace hostname
`httpPath`	SQL warehouse HTTP path
`clientId`	OAuth M2M client ID	✓
`clientSecret`	OAuth M2M client secret	✓
`azureTenantId`	Azure AD tenant ID (Azure Databricks only)

---

Spark (Spark Connect)

Field	Description
`host`	Spark Connect server hostname
`port`	Spark Connect server port

Spark uses the Spark Connect protocol (sc://host:port). No authentication fields — access control is managed at the Spark cluster level.

File-Based Connectors — Required Fields

Local files (`LOCAL_FILE`)

Field	Description
`url`	Root path to the directory containing data files
`format`	File format: `"csv"`, `"parquet"`, `"json"`

When running via Docker, the files must be inside the mounted workspace.

---

Amazon S3 (`S3_FILE`)

Field	Description	Sensitive
`url`	Root path within the bucket
`format`	File format: `"csv"`, `"parquet"`, `"json"`
`bucket`	S3 bucket name
`region`	AWS region (e.g. `us-east-1`)
`access_key`	AWS access key ID	✓
`secret_key`	AWS secret access key	✓

---

MinIO (`MINIO_FILE`)

Field	Description	Sensitive
`url`	Root path within the bucket
`format`	File format: `"csv"`, `"parquet"`, `"json"`
`endpoint`	MinIO endpoint (e.g. `localhost:9000`)
`bucket`	Bucket name
`access_key`	Access key ID	✓
`secret_key`	Secret access key	✓
`ssl_enabled`	Enable SSL (`"true"` / `"false"`)

---

Google Cloud Storage (`GCS_FILE`)

Field	Description	Sensitive
`url`	Root path within the bucket
`format`	File format: `"csv"`, `"parquet"`, `"json"`
`bucket`	GCS bucket name
`key_id`	Service account key ID	✓
`secret_key`	Service account secret key	✓
`credentials`	Base64-encoded service account JSON	✓