Elysia

Add Loki logging to your Elysia server with a single .use() call.

Installation

pnpm add @uloki/elysia

Quick Start

import { Elysia } from "elysia";
import { uloki } from "@uloki/elysia";

const app = new Elysia()
  .use(uloki({
    endpoint: "http://localhost:3100",
    labels: { app: "my-api" },
  }))
  .get("/", () => "ok")
  .listen(3000);

How It Works

The plugin hooks into Elysia's lifecycle:

onRequest — Captures request start time
onAfterResponse — Logs method, path, status, duration with auto-derived log level
onStop — Flushes remaining entries on server shutdown

Configuration

uloki({
  endpoint: "http://localhost:3100",          // Loki push endpoint
  labels: { app: "my-api" },                  // Default labels
  enabled: true,                              // Enable/disable
  batchSize: 10,                              // Entries per batch
  flushInterval: 5000,                        // Auto-flush interval (ms)
  redact: ["token", "password"],             // Redaction patterns
  requestLogging: true,                       // Auto-capture HTTP requests (default: true)
})

`requestLogging`

When true (default), every HTTP request is automatically logged with structured metadata:

method=GET path=/api/users status=200 duration_ms=12

Set to false if you only want manual logging.

Manual Logging

Access the logger via store.loki in any route handler:

app.get("/users/:id", ({ store, params }) => {
  store.loki.log({
    line: `User ${params.id} accessed`,
    labels: { action: "view_profile" },
  });

  return { id: params.id };
});

// Flush manually if needed
await store.loki.flush();

Complete Example

import { Elysia } from "elysia";
import { uloki } from "@uloki/elysia";

const app = new Elysia()
  .use(uloki({
    endpoint: "http://loki:3100",
    labels: { app: "my-service", env: "production" },
    batchSize: 20,
    flushInterval: 10000,
    redact: ["token", "secret", /Bearer\s+\S+/g],
  }))
  .get("/health", () => ({ status: "ok" }))
  .get("/users/:id", ({ store, params }) => {
    store.loki.log({
      line: `Fetching user ${params.id}`,
      labels: { action: "get_user" },
    });
    return { id: params.id };
  })
  .listen(3000);

console.log(`Server running at ${app.server?.url}`);

Requirements

Elysia >= 1.0
Node.js >= 22 (or Bun)

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