write_logger #

Version 0.0.5 — Colored console logging and daily file logging for Flutter apps, with optional encryption and automatic retention cleanup.

Features #

• Console logs with ANSI colors and a box border per entry (enableConsole: kDebugMode by default)
• Daily log files (log_yyyy-MM-dd.txt) with the same box layout
• Optional pluggable encryption for file message contents (AppEncryptionAdapter sample in example) — level / timestamp / tag stay plaintext
• Automatic deletion of logs older than N days
• All log levels written (no min-level filter)
• Tags for categorizing events — any string (e.g. cURL, Login cURL, Auth); no special colors or handling
• Extensible sinks (addSink)

Getting started #

dependencies:
  write_logger: ^0.0.5
  # or path / git:
  # write_logger:
  #   path: ../write_logger

Source: github.com/fakeeh-tech/WriteLogger

See CHANGELOG.md for release notes.

See the full demo in example/: every log level, sample cURL, open file, and in-app viewer.

cd example
flutter run

Use a terminal so ANSI colors show up.

Usage #

import 'package:flutter/foundation.dart';
import 'package:write_logger/write_logger.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await WriteLogger.init(
    WriteLoggerConfig(
      enableConsole: kDebugMode, // optional, default: kDebugMode
      retentionDays: 7,         // optional
      enableFile: true,         // optional
      // encryption: AppEncryptionAdapter(), // optional — see example sample
    ),
  );

  await WriteLogger.i('App started', tag: 'Bootstrap');
  await WriteLogger.w('Slow network');
  await WriteLogger.e('Failed', error: Exception('boom'));
}

Minimal init #

All config fields have defaults:

await WriteLogger.init();

enableConsole defaults to kDebugMode (on in debug, off in release/profile). Colors are always applied when the console sink is active.

Log a cURL from your app #

Build the cURL string in your HTTP layer (Dio interceptor, etc.), then pass it in. Color comes from the level only — the tag is a plain label for filtering:

final curl = "curl -X POST "
    "-H 'Content-Type: application/json' "
    "-H 'Authorization: ***' "
    "--data '{\"id\":1}' "
    "'https://api.example.com/v1/items'";

await WriteLogger.d(curl, tag: 'cURL');
// or a more specific label:
await WriteLogger.d(curl, tag: 'Login cURL');

Custom encryption #

Implement [EncryptionAdapter] in the host app and pass it to init. A full copy-paste sample lives in example/lib/app_encryption_adapter.dart.

import 'dart:convert';

import 'package:write_logger/write_logger.dart';

/// Sample only — replace with real AES / keystore crypto in production.
class AppEncryptionAdapter implements EncryptionAdapter {
  static const _prefix = 'WL1:';

  @override
  Future<String> encrypt(String plainText) async {
    final bytes = utf8.encode(plainText);
    return '$_prefix${base64Encode(bytes)}';
  }

  @override
  Future<String> decrypt(String cipherText) async {
    if (!cipherText.startsWith(_prefix)) return cipherText;
    final encoded = cipherText.substring(_prefix.length);
    return utf8.decode(base64Decode(encoded));
  }
}

await WriteLogger.init(
  WriteLoggerConfig(encryption: AppEncryptionAdapter()),
);

Omit encryption (or pass null) for plain-text files.

When encryption is on, only the message body (plus error / stack) is encrypted. Level, timestamp, and tag stay readable so you can scan the file for [cURL], [Login cURL], [Auth], etc. without decrypting:

┌───────────────────────────────────
│ [DEBUG] [2026-08-10 11:54:00] [Login cURL] WL1:aGVsbG8...
└───────────────────────────────────

Log layout #

Console and file use the same boxed layout:

┌───────────────────────────────────
│ [INFO] [2026-08-10 11:54:00] [BLOC TRANSITION] SplashBloc → ...
└───────────────────────────────────

Levels #

Or:

await WriteLogger.log('custom', level: WriteLogLevel.security);

Get today's file path #

final path = await WriteLogger.getLogFilePath();
// null on web, or when file logging is disabled

if (WriteLogger.supportsFileLogging) {
  // mobile / desktop file logs available
}

Opening or sharing the file (OS viewer, share sheet) belongs in the host app. The example shows openLogFile() via open_filex and an in-app viewer.

Web (console-only) #

On Flutter web, dart:io is unavailable. The package still compiles and logs to the console (debug mode); file sink, retention, and getLogFilePath() are skipped / return null even if enableFile: true.

Config reference #

Log directory and file-name prefix are managed by the package (app documents directory + log_, e.g. log_2026-08-06.txt) — not configurable.

ANSI colors are always on for console output.

Pass host-app values (e.g. Remote Config retention days) into WriteLoggerConfig — this package does not depend on Firebase.

Example app #

The example/ project demonstrates:

• Every log helper and WriteLogger.log() for all WriteLogLevel values
• Log sample cURL — app-provided curl string with any tag (demo uses cURL)
• Open file — open today’s log with the OS default app (open_filex)
• View in app — read and display log contents in a screen
• Encryption sample — AppEncryptionAdapter

License #

MIT. See LICENSE.

Additional information #

Designed for Flutter apps that need durable, optionally encrypted device logs plus colored console output during development. On web, logging is console-only.

Current package version: 0.0.5.