Functions

Deploy TypeScript functions that run on Deno. Invoke them via HTTP from your Flutter app, or bind them to database events so they run automatically when data changes.

What are functions?

Koolbase Functions are serverless TypeScript functions that run on Deno in an isolated subprocess. They are ideal for logic that cannot run on the client — sending emails, processing payments, calling third-party APIs, or reacting to database changes.

Each function receives a ctx object that gives access to the incoming request, your project database, and any secrets you have configured.

The context object

Every function receives a single ctx argument:

ctx.requestobjectThe incoming request — body, headers, event type, collection, payload

ctx.db.insert()functionInsert a record into a collection

ctx.db.find()functionQuery records from a collection

ctx.db.update()functionUpdate a record by ID

ctx.db.delete()functionDelete a record by ID

Deno.env.get()functionAccess encrypted secrets injected at runtime

Two invocation modes

HTTP Invoke

Call the function directly from your Flutter app using the SDK. Useful for on-demand logic like sending a message, processing a form, or triggering a workflow.

DB Triggers

Bind the function to a database collection event — created, updated, or deleted. The function fires automatically whenever a matching record is mutated. No polling, no glue code.

In this section

Deploy a Function

Write and deploy TypeScript functions from the dashboard

HTTP Invoke

Call functions from Flutter via the SDK

DB Triggers

Fire functions automatically on database events

Test Mode

Test functions safely with a mock database

Secrets

Inject encrypted environment variables into functions

Retries & DLQ

Automatic retry system and dead letter queue

Limits & Timeouts

Function size, payload, and execution limits

Runtime: Deno 2.7.7

Functions run on Deno 2.7.7 in an isolated subprocess with --deny-read --deny-write flags. Network access is available for calling external APIs. File system access is restricted.