Mental Model

You only need four ideas to work effectively with Bonsai.

Expressions are strings

You store or pass source text like order.total >= freeShippingThreshold. Bonsai parses and evaluates that string for you.

expr.evaluateSync('order.total >= freeShippingThreshold', { order, freeShippingThreshold })

Context is just data

The context object becomes the variable scope for the expression. There is no access to globals or hidden ambient state.

{ order: { total: 129, country: 'GB' }, freeShippingThreshold: 100 }

Pipes are for data flow

Transforms read naturally from left to right, which is why most formatting and collection work is easiest to express with |>.

customerName |> trim |> upper

Compile is a performance tool

If an expression will run many times, compile it once and keep the returned object around.

const rule = expr.compile('order.total >= freeShippingThreshold')

Simple rule of thumb: use transforms for "take this value and do something to it", and functions for "call a named operation with arguments".