monte-carlo-validation-notebook
Generates Jupyter notebooks that run Monte Carlo simulations to validate dbt model changes, producing SQL queries comparing before and after results for each modified table.
How to Install
This skill comes from a community source.
Tip: This skill works well with Sonnet. Run
/model sonnetbefore invoking for faster generation.
Generate a SQL Notebook with validation queries for dbt changes.
Arguments: $ARGUMENTS
When to Use
Use this skill when the user wants to validate dbt model or snapshot changes with Monte Carlo SQL Notebook queries, either from a GitHub PR or a local dbt repository.
Parse the arguments:
- Target (required): first argument — a GitHub PR URL or local dbt repo path
- MC Base URL (optional): --mc-base-url <URL> — defaults to https://getmontecarlo.com
- Models (optional): --models <model1,model2,...> — comma-separated list of model filenames (without .sql extension) to generate queries for. Only these models will be included. By default, all changed models are included up to a maximum of 10.
Setup
Prerequisites:
- gh (GitHub CLI) — required for PR mode. Must be authenticated (gh auth status).
- python3 — required for helper scripts.
- pyyaml — install with pip3 install pyyaml (or pip install pyyaml, uv pip install pyyaml, etc.)
Note: Generated SQL uses ANSI-compatible syntax that works across Snowflake, BigQuery, Redshift, and Athena. Minor adjustments may be needed for specific warehouse quirks.
This skill includes two helper scripts in ${CLAUDE_PLUGIN_ROOT}/skills/monte-carlo-validation-notebook/scripts/:
resolve_dbt_schema.py- Resolves dbt model output schemas fromdbt_project.ymlrouting rules and model config overrides.generate_notebook_url.py- Encodes notebook YAML into a base64 import URL and opens it in the browser.
Mode Detection
Auto-detect mode from the target argument:
- If target looks like a URL (contains :// or github.com) -> PR mode
- If target is a path (., /path/to/repo, relative path) -> Local mode
Context
This command generates a SQL Notebook containing validation queries for dbt changes. The notebook can be opened in the MC Bridge SQL Notebook interface for interactive validation.
The output is an import URL that opens directly in the notebook interface:
<MC_BASE_URL>/notebooks/import#<base64-encoded-yaml>
Key Features:
- Database Parameters: Two text parameters (prod_db and dev_db) for selecting databases
- Schema Inference: Automatically infers schema per model from dbt_project.yml and model configs
- Single-table queries: Basic validation queries using {{prod_db}}.<SCHEMA>.<TABLE>
- Comparison queries: Before/after queries comparing {{prod_db}} vs {{dev_db}}
- Flexible usage: Users can set both parameters to the same database for single-database analysis
Notebook YAML Spec Reference
Key structure:
version: 1
metadata:
id: string # kebab-case + random suffix
name: string # display name
created_at: string # ISO 8601
updated_at: string # ISO 8601
default_context: # optional database/schema context
database: string
schema: string
cells:
- id: string
type: sql | markdown | parameter
content: string # SQL, markdown, or parameter config (JSON)
display_type: table | bar | timeseries
Parameter Cell Spec
Parameter cells allow defining variables referenced in SQL via {{param_name}} syntax:
- id: param-prod-db
type: parameter
content:
name: prod_db # variable name
config:
type: text # free-form text input
default_value: "ANALYTICS"
placeholder: "Prod database"
display_type: table
Parameter types:
- text: Free-form text input (used for database names)
- schema_selector: Two dropdowns (database -> schema), value stored as DATABASE.SCHEMA
- dropdown: Select from predefined options
Task
Generate a SQL Notebook with validation queries based on the mode and target.
Phase 1: Get Changed Files
The approach differs based on mode:
If PR mode (GitHub PR):
- Extract the PR number and repo from the target URL.
-
Example:
https://github.com/monte-carlo-data/dbt/pull/3386-> owner=monte-carlo-data, repo=dbt, PR=3386 -
Fetch PR metadata using
gh:
gh pr view <PR#> --repo <owner>/<repo> --json number,title,author,mergedAt,headRefOid
- Fetch the list of changed files:
gh pr view <PR#> --repo <owner>/<repo> --json files --jq '.files[].path'
- Fetch the diff:
gh pr diff <PR#> --repo <owner>/<repo>
-
Filter the changed files list to only
.sqlfiles undermodels/orsnapshots/directories (at any depth — e.g.,models/,analytics/models/,dbt/models/). These are the dbt models to analyze. If no model SQL files were changed, report that and stop. -
For each changed model file, fetch the full file content at the head SHA: ```bash gh api repos/
/ /contents/ ?ref= --jq '.content' | python3 -c "import sys,base64; sys.stdout.write(base64.b64decode(sys.stdin.read()).decode()
Details
| Category | Data → data_proc |
| Source | community |
| SKILL.md | View on GitHub → |
| Repo Stars | N/A |
| Est. per Skill | N/A (shared across 1230 skills from this repo) |
| Difficulty | Intermediate |
| Risk Level | Safe |
Related Skills
Works Well With
Skills from the same repository — often designed to work together