Observers

Model observers in Harpia let you hook into Prisma operations—such as creating, updating, or deleting records—and run custom logic when those actions occur. Observers are stored in the app/observers directory and are automatically loaded when the application starts. You can create one using the scaffold command:

bun g

When to Use

Observers are helpful for:

• Logging database changes
• Triggering side effects (like sending notifications)
• Integrating with third-party services

Supported Operations

You can observe any of the following Prisma operations:

• findUnique
• findUniqueOrThrow
• findFirst
• findFirstOrThrow
• findMany
• create
• createMany
• createManyAndReturn
• delete
• update
• deleteMany
• updateMany
• updateManyAndReturn
• upsert
• aggregate
• groupBy
• count

Example Setup

Each observer is just a file that registers a callback for a model and operation.

app/observers/UserCreate.observer.ts

import { Observer } from ".";

Observer.model("User", "create", ({ data }) => {
  console.log("New user created:", data);
});