@logger/collector

Append-only JSONL log store and an HTTP server with ingest and read-only query. No external runtime dependencies.

Install

npm install @logger/collector --registry=http://192.168.0.15:4873

JsonlLogStore

import {JsonlLogStore} from '@logger/collector';

const store = new JsonlLogStore('.logging/logs.jsonl');

await store.append(record);                       // one JSON object per line (creates parent dirs)

const latest = await store.tail({                 // last N matching records, in file order
  limit: 10,
  level: 'error',
  app: 'shop',
  service: 'orders',
  scope: 'orders.refund',
  since: '2026-07-06T00:00:00.000Z',
  strict: false,
});

tail behavior:

Returns the last limit matching records (default 10).
A missing file returns [] (handy for fresh projects).
Invalid JSONL lines are skipped by default; set strict: true to throw on the first bad line.

Filters: level, app, service, scope, since (ISO-8601, inclusive on timestamp), plus limit and strict.

HTTP server

import {createHttpCollectorServer, JsonlLogStore} from '@logger/collector';

const server = createHttpCollectorServer(new JsonlLogStore('.logging/logs.jsonl'));
server.listen(4319);

Endpoints:

POST /ingest — body is a single LogRecord or an array of LogRecord objects. Responds 204 on success, 400 on a bad record.
GET /query?level=&app=&service=&scope=&since=&limit= — read-only tail. Returns a JSON array of matching records (same semantics as store.tail).

Standalone server (bin)

The package ships a logging-collector binary so the server can run without application code (e.g. inside a container):

logging-collector                                   # defaults: PORT=4319 LOG_FILE=/data/logs.jsonl HOST=0.0.0.0
PORT=4319 LOG_FILE=./logs.jsonl logging-collector

Environment:

Var	Default	Meaning
`PORT`	`4319`	TCP port to listen on.
`HOST`	`0.0.0.0`	Bind address.
`LOG_FILE`	`/data/logs.jsonl`	Backing JSONL file (created on first write).

SIGTERM / SIGINT close the server gracefully. For the Docker image, see the root README's "Docker (collector server)" section.