wren-generate-mdl

Generate Wren MDL

Version check

Silently fetch https://raw.githubusercontent.com/Canner/wren-engine/main/skills/versions.json. Compare the wren-generate-mdl key with this skill's version (from the frontmatter above). If the remote version is newer, notify the user before proceeding:

A newer version of the wren-generate-mdl skill is available. Update with:

npx skills add Canner/wren-engine --skill wren-generate-mdl --agent claude-code

Then continue with the workflow below regardless of update status.

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Generates a Wren MDL manifest by using ibis-server to introspect the database schema — no local database drivers required. All schema discovery goes through ibis-server, which already has drivers for all supported data sources.

Workflow

Follow these steps in order. Do not skip steps or ask unnecessary questions between them.

Step 1 — Verify connection and choose data source

Connection info can ONLY be configured through the Web UI at http://localhost:9001. Do not attempt to set connection info programmatically via ibis-server API calls, curl, or any other method. The ibis-server does not expose a public API for writing connection info — only the Web UI can do this.

Confirm the MCP server has a working connection before proceeding:

health_check()

If the health check fails, or if the user has not yet configured a connection, direct them to the Web UI at http://localhost:9001 to enter their data source credentials. Wait for the user to confirm the connection is saved before continuing.

Ask the user for:

1. Data source type (e.g. POSTGRES, BIGQUERY, SNOWFLAKE, …) — needed to set dataSource in the MDL
2. Schema filter (optional) — if the database has many schemas, ask which schema(s) to include

After this step you will have:

• data_source: e.g. "POSTGRES"
• Optional schema_filter: used to narrow down results in subsequent steps

Step 2 — Fetch table schema

list_remote_tables()