How to send LiteLLM Proxy Logs to file

[kmilo9999]

Hello all. quick LiteLLM Proxy question here.
I see that the application system logs are being sent to stdout. Is there a way to send them to a file instead? I tried setting the LITELLM_LOG_FILE environment variable, but it doesn’t seem to be working. I’d appreciate the help. In fact, checking the source code, LITELLM_LOG_FILE  is only referenced in the documentation, but I dont see it being used in the code.

[pratikrath126]

LITELLM_LOG_FILE isn t implemented in the code (it s mentioned in docs but not used). For now, you can:\n\n- Redirect stdout when starting the proxy: litellm --config config.yaml > /path/to/litellm.log 2>&1\n- Or use a custom callback that writes logs to a file\n- Or use a built-in callback like s3/gcs/azure to ship logs\n\nIf you just want local file logging, stdout redirection is the simplest.

[kmilo9999]

Thanks for the quick reply.

[LeeTeng2001]

wow... I consider this to be a huge bug

[stef41]

You're right — LITELLM_LOG_FILE is only referenced in documentation but not implemented in the proxy code. The proxy uses Python's standard logging module, so you can redirect logs to a file using standard logging configuration.

Option 1: Set LITELLM_LOG env var + redirect stdout

# This controls verbosity (DEBUG/INFO)
export LITELLM_LOG=DEBUG

# Redirect stdout/stderr to file in your k8s/Docker config
litellm --config config.yaml 2>&1 | tee /var/log/litellm.log

Option 2: Custom logging_config in your LiteLLM config

Create a logging config in your config.yaml:

general_settings:
  custom_logging: true

Then set up Python logging before starting the proxy, e.g., in a wrapper script:

import logging
import logging.handlers

# Configure file handler for all litellm loggers
handler = logging.handlers.RotatingFileHandler(
    "/var/log/litellm/proxy.log",
    maxBytes=50_000_000,  # 50MB
    backupCount=5,
)
handler.setFormatter(logging.Formatter(
    "%(asctime)s %(name)s %(levelname)s %(message)s"
))

# Add handler to root logger and litellm logger
logging.getLogger("LiteLLM").addHandler(handler)
logging.getLogger("LiteLLM Proxy").addHandler(handler)
logging.getLogger("LiteLLM Router").addHandler(handler)

Option 3: Use a sidecar (recommended for k8s)

In production k8s, the standard practice is to keep logs on stdout and use a log collector (Fluentd, Fluent Bit, Vector, etc.) to ship them to your log aggregation system. This is generally preferred over writing to files inside containers.

Option 4: Use LiteLLM's callback system

LiteLLM supports logging callbacks that capture request/response data. This is separate from system logs but may be what you actually need:

litellm_settings:
  success_callback: ["langfuse"]  # or custom callback
  failure_callback: ["langfuse"]

If you specifically need the system/debug logs in a file and not request logs, Option 2 is the way to go.