Release notes

January 2026

• Massive update: first-class objects and arrays support

// Before

const subObjectMapper = compileMapper<SubSource, SubTarget>({
  ...
})

const mapper = compileMapper<Source, Target>({
  subObject: transform(x => subObjectMapper.mapOne(x))
  ...
})

// After

const mapper = compileMapper<Source, Target>({
  subObject: map({
    ...
  }),
})

• Added directives:

• • map: transform objects and arrays
• • flatMap: transform objects with access to top fields
• • mapAfter: map with preprocessing
• • mapFrom: map with rename
• • nullableMap
• • optionalMap
• • nullableMapFrom
• • optionalMapFrom

• Added pipelining: see more here and here

• Updated docs

December 2025

• Heavily optimized Mapia with mapper pre-compilation. Added new Function(...) that affected massive impact - Mapia now faster up to 2000x times than class-validator and automapper
• Autopublish to NPM
• Migrated docs to Vitepress

May 2025

• Measured performance. Mapia is faster 40x than class-validator
• Added documentation
• Released first public version on NPM
• rewritten public API

// Before
const mapper: SimpleMapper<Source, Target> = { ... } satisfies SimpleMapper<Source, Target>

// After
const mapper = compileMapper<Source, Target>({...})

• added shapes feature

April 2025

Mapia started as an utility in our IT team