Write it once
Price rules, formatting, API clients and validation helpers live in one place instead of being copied into every API.
Your code
Utility Classes & Process Initializers
Write shared code once and import it everywhere. Run setup code as soon as a sandbox starts.
A utility class is TypeScript that your custom APIs, hooks, events, schedulers and tests import by its path. A process initializer is code that runs when a sandbox starts, before any request, to prepare what your code needs, like a subscription to Redis or MQTT.
How it works
Create a class in a folder.
Give it a folder path and a unique name, write TypeScript, and export an instance. Interfaces can be exported too.
Import it where you need it.
import * as calc from 'utils/Calculator' (its folder and name) works in custom APIs, hooks, event listeners, schedulers and test cases, with autocompletion in the editor.
Keep versions.
Save several versions of a class and activate one. Every importer uses the active version at once.
Initializers prepare each sandbox.
When a sandbox starts, the active initializers run one after another, in your order and with their own time limit, before it takes any request.
What you get
Types included
Interfaces exported by a utility class can be used by every importer, and the editor suggests its functions.
Changes apply everywhere
Save or activate a version and the sandboxes load the new code, on every server of the cluster.
Listen to other systems
An initializer can connect to a message broker or a Redis channel and react to its messages, for as long as the sandbox lives.
Ready before the first call
Shortly after API Maker starts it warms up the sandboxes, so initializers do not wait for the first request.
An example
One tax rule for the whole shop
The checkout API, the invoice scheduler and the order hooks all need the same tax calculation. It lives in a utility class, and when the rate changes you save one new version.
class Calculator { add(x: number, y: number) { return x + y; } multiply(x: number, y: number) { return x * y; }}let temp = new Calculator();export = temp;import * as T from 'types';import * as calc from 'utils/Calculator';async function main(g: T.IAMGlobal) { return { sum: calc.add(3, 6), product: calc.multiply(3, 6) };}module.exports = main;Good to know
- Initializers run in the shared sandboxes of the account. Sandboxes of a separate sandbox group do not run them.
- An initializer runs again every time a sandbox is created or restarted: make it safe to run more than once.
Questions
What is the difference between an initializer and a scheduler?
A scheduler runs on its intervals, once in the cluster. An initializer runs once in every new sandbox, without any trigger, to set that sandbox up.
Can utility classes use g?
Yes, when the importer passes it: call your functions with g from the custom API, hook or scheduler that uses them.
Learn more
Documentation