What is the primary benefit of using Malli schemas in Metabase?

Malli schemas provide runtime data validation and clear documentation for API endpoints, ensuring that both incoming requests and outgoing responses conform to expected data structures.

Should I use standard Malli predicates like pos-int??

While standard predicates work, it is recommended to use the Metabase-specific 'ms' namespace (e.g., ms/PositiveInt) as they are better integrated with the platform's infrastructure.

Why shouldn't I use ms/TemporalString for response schemas?

Response schemas in Metabase validate before JSON serialization. Since the data contains raw Java Time objects at that stage, you should use :any instead of a string-based schema.

How do I handle optional query parameters with this skill?

The skill guides you to use the {:optional true} property within a Malli map, often combined with [:maybe ...] and :default values to ensure robust parameter handling.

Metabase Malli Schema Architect

Name: Metabase Malli Schema Architect
Author: metabase

bymetabase

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45,683

API Development

Streamlines the addition of Malli validation schemas to Metabase API endpoints using standardized patterns and best practices.

About

This skill empowers developers to efficiently implement Malli data validation within the Metabase Clojure codebase. It provides specialized guidance on defining schemas for route parameters, query strings, and request bodies, ensuring type safety and robust error handling across the application. Crucially, the skill accounts for Metabase's unique validation lifecycle—distinguishing between request-side string coercion and response-side Java object validation—to prevent common serialization pitfalls and maintain consistent API documentation.

Key Features

45,683 GitHub stars
Handles complex parameter destructuring for route, query, and body data
Optimizes response schemas for internal Clojure data structures and Java Time objects
Generates standardized Malli schemas for Clojure-based API endpoints
Configures contextual error messages for user-friendly validation failures
Integrates Metabase-specific schema types from the internal ms namespace

Use Cases

Ensuring consistent data types across Metabase warehouse and collection APIs
Refactoring legacy Clojure endpoints to adopt modern Malli schema patterns
Hardening new Metabase API endpoints with strict input and output validation

About

Key Features

45,683 GitHub stars
Handles complex parameter destructuring for route, query, and body data
Optimizes response schemas for internal Clojure data structures and Java Time objects
Generates standardized Malli schemas for Clojure-based API endpoints
Configures contextual error messages for user-friendly validation failures
Integrates Metabase-specific schema types from the internal ms namespace

Use Cases

Ensuring consistent data types across Metabase warehouse and collection APIs
Refactoring legacy Clojure endpoints to adopt modern Malli schema patterns
Hardening new Metabase API endpoints with strict input and output validation