A background task processing plugin for Elysia.js that executes async tasks after sending HTTP responses. Inspired by Starlette's background tasks.
Important
Currently only supports async functions. Synchronous functions are not supported at this time.
bun add elysia-backgroundimport { Elysia } from "elysia";
import { background } from "elysia-background";
async function sendConfirmationEmail(email: string, code: string) {
console.log(`Sending confirmation email to ${email} with code ${code}`);
}
const app = new Elysia()
.use(background())
.post("/sign-up", ({ backgroundTasks, body }) => {
// Do some processing
backgroundTasks.addTask(sendConfirmationEmail, body.email, "123456");
// Response sent immediately, tasks run in background
return { message: "Registration successful!" };
})
.listen(3000);Background tasks execute sequentially. If one task fails, execution stops and subsequent tasks are not executed.
Default Behavior:
Errors are logged to console with [elysia-background] Task failed: prefix.
Custom Error Handler:
const app = new Elysia()
.use(
background({
onError: (error) => {
console.error("Task failed:", error);
// You can send to monitoring service, etc.
},
})
)
.get("/test", ({ backgroundTasks }) => {
backgroundTasks.addTask(async () => {
throw new Error("Simulated task failure");
});
return { message: "Task added" };
});sequenceDiagram
participant Client
participant Elysia
participant Background
Client->>Elysia: HTTP Request
Elysia->>Background: Queue background tasks
Elysia->>Client: Send Response (immediate)
Note over Client: Response received instantly
Elysia->>Background: onAfterResponse triggers
Background->>Background: Execute Task 1
Background->>Background: Execute Task 2
Background->>Background: Execute Task 3
Note over Background: Tasks like:<br/>Send emails<br/>Update analytics<br/>Process data
Background tasks execute sequentially after the HTTP response is sent, ensuring reliable and predictable processing.
For detailed API documentation, see docs/api-reference.md.
See the examples folder for comprehensive usage examples.
# Install dependencies
bun install
# Lint and format
bun run lint
bun run format
# Run tests
bun test
# Build
bun run buildContributions are welcome! Please open an issue or submit a pull request.
MIT License - see LICENSE for details.
Inspired by Starlette's background tasks for Python's FastAPI ecosystem.