Custom Logger

The App will provide a default logger, but you can also provide your own. The default Logger instance will be set to ConsoleLogger from the Microsoft.Teams.Common package.

The App will provide a default logger, but you can also provide your own. The default Logger instance will be set to Python's standard logging module, using logging.getLogger(__name__) per module. from the microsoft-teams-common package.

The App will provide a default logger, but you can also provide your own. The default Logger instance will be set to ConsoleLogger from the @microsoft/teams.common package.

using Microsoft.Teams.Apps;
using Microsoft.Teams.Common.Logging;
using Microsoft.Teams.Plugins.AspNetCore.Extensions;

var builder = WebApplication.CreateBuilder(args);

var appBuilder = App.Builder()
    .AddLogger(new ConsoleLogger())

builder.AddTeams(appBuilder)

var app = builder.Build();
var teams = app.UseTeams();

The Python SDK uses standard logging — there's no custom logger to inject into App. To see SDK log output, attach a handler to the microsoft_teams logger hierarchy. The SDK ships a ConsoleFormatter with color-coded output if you want it:

import logging
import os
from microsoft_teams.common import ConsoleFormatter

handler = logging.StreamHandler()
handler.setFormatter(ConsoleFormatter())
logging.getLogger("microsoft_teams").addHandler(handler)
logging.getLogger("microsoft_teams").setLevel(
    os.getenv("LOG_LEVEL", "INFO").upper()
)

import { App } from '@microsoft/teams.apps';
import { ConsoleLogger } from '@microsoft/teams.common';

// initialize app with custom console logger
// set to debug log level
const app = new App({
  logger: new ConsoleLogger('echo', { level: 'debug' }),
});

app.on('message', async ({ send, activity, log }) => {
  log.debug(activity);
  await send({ type: 'typing' });
  await send(`you said "${activity.text}"`);
});

(async () => {
  await app.start();
})();

Python's standard logging levels apply: DEBUG, INFO, WARNING, ERROR, CRITICAL.

Available levels, from most to least severe: error, warn, info, debug, trace. The default is info. Setting level: 'debug' emits error, warn, info, and debug — but not trace.

Use ConsoleFilter to limit which loggers emit, matched by name with * wildcards:

from microsoft_teams.common import ConsoleFilter, ConsoleFormatter

handler = logging.StreamHandler()
handler.setFormatter(ConsoleFormatter())
handler.addFilter(ConsoleFilter("microsoft_teams*"))  # only SDK loggers
logging.getLogger().addHandler(handler)

Each logger has a name. The pattern option filters which loggers emit, with * as a wildcard. Prefix a pattern with - to exclude. Combine with commas.

new ConsoleLogger('my-app', { pattern: '@teams*' });        // only SDK loggers
new ConsoleLogger('my-app', { pattern: '*,-@teams/http*' }); // everything except HTTP

The Python SDK does not read logging environment variables on its own. If you want LOG_LEVEL to control verbosity, read it yourself at startup:

import os
logging.getLogger().setLevel(os.getenv("LOG_LEVEL", "INFO").upper())

The TypeScript SDK's ConsoleLogger reads two environment variables at construction:

Env vars override options passed to the constructor. If you do not pass a logger to App, the SDK creates a default ConsoleLogger named @teams/app — so LOG_LEVEL=debug alone is enough to enable debug output.

Gotcha: LOG is a name filter, not a toggle. Setting LOG to a pattern that doesn't match the default @teams/app (for example LOG=my-app*) silences the default logger. If in doubt, unset LOG to match everything.

Child Loggers

Call log.child('scope') on an existing logger to get a scoped logger. Its name is parent/scope, and pattern/level are inherited.

app.on('message', async ({ log }) => {
  const msgLog = log.child('message-handler');
  msgLog.debug('processing'); // logged as "@teams/app/message-handler"
});