# Logging
Hayhooks provides comprehensive logging capabilities for monitoring, debugging, and auditing pipeline execution and server operations.
## Log Levels
### Available Levels
- **TRACE**: Detailed information for debugging
- **DEBUG**: Detailed information for debugging
- **INFO**: General information about server operations
- **SUCCESS**: Success messages
- **WARNING**: Warning messages that don't stop execution
- **ERROR**: Error messages that affect functionality
- **CRITICAL**: Critical errors that may cause server failure
### Setting Log Level
```bash
export LOG=debug # or LOG=DEBUG
hayhooks run
```
Or in your `.env` file:
```ini
LOG=info # or LOG=INFO
```
Or inline:
```bash
LOG=debug hayhooks run
```
## Log Configuration
### Environment Variables
#### LOG
- **Default**: `info`
- **Description**: Minimum log level to display (consumed by Loguru)
- **Options**: `debug`, `info`, `warning`, `error`
> Note: Hayhooks does not expose `HAYHOOKS_LOG_FORMAT` or `HAYHOOKS_LOG_FILE` env vars; formatting/handlers are configured internally in the code.
### Custom Log Format
> If you need custom formatting, handle it in your host app via Loguru sinks.
## File Logging
### Basic File Logging
> Configure file sinks in your host app using `log.add(...)`.
### Rotating File Logs
If you embed Hayhooks programmatically and want custom logging, set up logging in your host app and direct Hayhooks logs there.
## Pipeline Logging
The `log` object in Hayhooks is a [Loguru](https://loguru.readthedocs.io/) logger instance. You can use all Loguru features and capabilities in your pipeline code.
### Basic Usage
```python
from hayhooks import log
class PipelineWrapper(BasePipelineWrapper):
def setup(self) -> None:
log.info("Setting up pipeline")
# ... setup code
def run_api(self, query: str) -> str:
log.debug("Processing query: {query}")
try:
result = self.pipeline.run({"prompt": {"query": query}})
log.info("Pipeline execution completed successfully")
return result["llm"]["replies"][0]
except Exception as e:
log.error("Pipeline execution failed: {}", e)
raise
```
### Execution Time Logging
```python
import time
from hayhooks import log
class PipelineWrapper(BasePipelineWrapper):
def run_api(self, query: str) -> str:
start_time = time.time()
result = self.pipeline.run({"prompt": {"query": query}})
execution_time = time.time() - start_time
log.info("Pipeline executed in {} seconds", execution_time.round(2))
return result["llm"]["replies"][0]
```
For more advanced logging patterns (structured logging, custom sinks, formatting, etc.), refer to the [Loguru documentation](https://loguru.readthedocs.io/).
## Next Steps
- [API Reference](api-reference.md) - Complete API documentation
- [Environment Variables](environment-variables.md) - Configuration options
