fn

TypeScript

function fn<TName>(name: TName): AxFunctionBuilder<{
}, unknown, false>;

Defined in: https://github.com/ax-llm/ax/blob/5b28f9093bb70863b59459bb6df5062d005bce41/src/ax/dsp/sig.ts#L2028

Creates a fluent builder for defining callable functions/tools with typed args, return schemas, namespaces, and optional AxAgent discovery examples.

Example

TypeScript

const search = fn('search')
  .description('Search the product catalog')
  .namespace('db')
  .arg('query', f.string('Search query'))
  .arg('limit', f.number('Maximum results').optional())
  .returnsField('results', f.string('Result item').array())
  .handler(async ({ query, limit = 5 }) => ({ results: [`hit: ${query}:${limit}`] }))
  .build();

Type Parameters

Type Parameter
`TName` extends `string`

Parameters

Parameter	Type
`name`	`TName`

Returns

AxFunctionBuilder<{ }, unknown, false>