Local Development

Build semantic models with whichever IDE and coding agent you prefer — Credible supports Cursor, VS Code, and Claude Code (running in VS Code), and works with the agent of your choice. The Credible Extension connects your IDE to the Credible platform, giving your agent the tools and context it needs to help you build, validate, and publish semantic models. Local development runs on an open stack — the MCP (Model Context Protocol) tools and agent skills your coding agent uses are open source in Malloy Publisher. See Built on Open Source below. The steps below use Cursor as the example, but the same workflow applies to the other IDEs and agents.

Prefer zero setup? You can also build in the app — entirely in your browser, no IDE required. It’s the fastest way to get started and best for more business-savvy, less-technical users; local development is best for engineers who want Git-based workflows and direct control over files. Both produce the same governed packages.

Prerequisites

Cursor, VS Code, or VS Code with Claude Code installed (latest version recommended)
Credible organization set up by an admin
Database connections configured by your admin — see Connect a Database

What the Credible Extension Provides

The Credible Extension configures your IDE workspace with everything the agent needs for semantic modeling:

Credible-Modeling MCP server — An environment-scoped MCP server that gives the agent access to your data warehouse metadata, so it can discover tables, suggest modeling approaches, and look up Malloy syntax
Modeling skills — Slash commands (e.g., /malloy-model, /malloy-discover, /credible-publish) that guide the agent through common workflows. The agent uses these automatically based on context
Agent rules — Malloy-aware coding rules that help your agent write correct Malloy syntax and follow best practices
Managed database connections — Access connections configured in the Credible App without storing credentials locally
Credible Service Panel — Browse your environment and its managed connections, down to individual schemas and tables

Installing the Credible Extension also installs the Malloy extension, which provides:

Syntax highlighting & compilation checks for .malloy, .malloynb, and .malloysql files
Schema | Explore | Preview buttons above any source definition
Run | Show SQL buttons above any query or run statement

Built on Open Source

The tools and skills your agent uses locally are not a black box. Credible contributed its MCP tools and agent skills to Malloy Publisher, the open-source server for Malloy models: retrieval tools that let an agent look up what your model actually defines, and skills encoding the discipline to use them well — query patterns, gotchas that trip up frontier models, and the rigor that separates a real answer from a plausible one. Every skill is readable in the open; fork them, or extend them with your organization’s institutional knowledge. Read the full story in We Open Sourced the Thing Everyone Else Is Selling.

Installation

In Cursor or VS Code, go to the Extensions view (Cmd+Shift+X on Mac, Ctrl+Shift+X on Windows/Linux), search for Credible, and install the extension — select Auto Update when prompted
Open the Explorer (Cmd+Shift+E on Mac, Ctrl+Shift+E on Windows/Linux), expand the Credible panel at the bottom of the sidebar, and click Sign In — then follow the steps in your browser
Back in your IDE, select your organization from the list (if you only belong to one, it’s selected automatically), then select your environment

Credible-Modeling MCP Server

The Credible Extension registers an environment-scoped Credible-Modeling MCP server automatically — no manual enabling required. In Cursor, the extension registers the server programmatically; in VS Code, it writes a workspace-scoped .vscode/mcp.json config.

Cursor
VS Code
Claude Code

To verify, open Cursor Settings (Cmd+Shift+J on Mac, Ctrl+Shift+J on Windows/Linux) → Tools & MCP. The server appears as extension-Credible-Modeling — Cursor uses this naming convention to indicate it was registered by an extension.

To verify, open the Command Palette (Cmd+Shift+P on Mac, Ctrl+Shift+P on Windows/Linux) and run “MCP: List Servers” — you should see Credible-Modeling in the list.

When you start Claude Code in your workspace, you’ll be prompted to allow Claude Code to run in the directory and to accept the Credible-Modeling MCP server. Accept both. Use /mcp at any time to view and manage your MCP servers.

Every time you change environments, the extension updates the MCP config automatically. If the agent can’t call MCP tools, reload the window (Cmd+Shift+P → “Reload Window”).

Credible Service Panel

The Credible Service Panel shows your current environment and its connections. Find it at the bottom of the Explorer view (Cmd+Shift+E on Mac, Ctrl+Shift+E on Windows/Linux):

The Credible Service Panel is part of the IDE extension, so it’s available in Cursor and VS Code only. If you use Claude Code from the terminal, manage your environment with the CLI or the Credible App instead.

Here you can view:

Your current environment — click it to switch environments
Connections: Managed database connections in the environment — expand one to browse its schemas and tables

The extension automatically discovers connections in your environment, eliminating the need to store database credentials locally.

Don't see the Credible Service panel?

The sidebar may be hidden by default in Cursor:

Open the Explorer panel (Cmd+Shift+E) (or Ctrl+Shift+E on Windows/Linux)
Look for the Credible panel at the bottom of the explorer sidebar

Panel controls

The Credible Extension can be configured via the Command Palette (Cmd+Shift+P) or clicking icons in the Credible Service panel:

Disable Credible: Turn off the extension for this workspace
Refresh: Reload your environment and its connections
Select Organization: Choose from your available organizations (auto-selects if you only belong to one)
Sign Out: Log out of Credible

Embed Data Files

You can include CSV or Parquet files directly in your packages. When you publish your package, these data files are published along with your models and become queryable via DuckDB. Embedding data files in your packages is valuable when you need to:

Package sample data - Example datasets for testing or demos
Build standalone models - Models that don’t require database connections
Version control data - Keep data synchronized with model changes in your package

Currently, embedded data files work best for standalone models. Support for querying embedded data alongside database connections (e.g., joining embedded lookup tables with warehouse data) is coming soon.

File Structure

Create a data/ folder in your package directory and add your files — CSV (.csv, with a header row) or Parquet (.parquet, more efficient for larger datasets):

my-package/
├── publisher.json
├── ecommerce.malloy
└── data/
    ├── country_codes.csv
    ├── product_categories.parquet
    └── exchange_rates.csv

Referencing Embedded Data in Models

Use duckdb.table() to reference embedded files in your Malloy models — the same syntax works for CSV and Parquet:

source: country_codes is duckdb.table('data/country_codes.csv') extend {
  dimension:
    country_code is code
    country_name is name
    region is geographic_region
}

Get Started

Environments

Semantic Modeling

Analyzing Data

Build with Data

Platform Administration

Concepts

Support

Reference

Prerequisites

What the Credible Extension Provides

Built on Open Source

Installation

Credible-Modeling MCP Server

Credible Service Panel

Embed Data Files

File Structure

Referencing Embedded Data in Models

Next Steps

Modeling Overview

Malloy Notebooks

​Prerequisites

​What the Credible Extension Provides

​Built on Open Source

​Installation

​Install the Credible Extension & Sign In

​Credible-Modeling MCP Server

​Credible Service Panel

​Embed Data Files

​File Structure

​Referencing Embedded Data in Models

​Next Steps

Modeling Overview

Malloy Notebooks

Prerequisites

What the Credible Extension Provides

Built on Open Source

Installation

Install the Credible Extension & Sign In

Credible-Modeling MCP Server

Credible Service Panel

Embed Data Files

File Structure

Referencing Embedded Data in Models

Next Steps