Very simple Loki client

loki-client.ts

// This is a very simple Grafana Loki client, should be compatibla with Grafana Loki and Victoria Logs.
// Please bear in mind that because this is "very simple", this is not optimized for production use
// at all, because it doesn't send the logs in batch.
//
// MIT License
//
// Copyright (c) 2025 Reinaldy Rafli <[email protected]>
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

const url = "https://your-loki-instance.dev/api/v1/push";
const job = "your job name";
export type LogLevel = "trace" | "debug" | "info" | "warn" | "error";

export function log(level: LogLevel, message: string, extras?: Record<string, string>) {
        const currentEpochInNanoseconds = BigInt(Date.now()) * BigInt(1e6);
        const body = JSON.stringify({
            streams: [
                {
                    stream: {
                        "job": job,
                        "level": level,
                    },
                    values: [
                        [currentEpochInNanoseconds.toString(), message, extras ?? {}]
                    ]
                }
            ]
        });

        const headers = {
            "Content-Type": "application/json",
            // place an Authorization header here if you need one
        };

        fetch(url, {
            method: "POST",
            headers: headers,
            body: body,
        }).catch(console.error);
    }
}