# How to Debug Channel Failures Using Verbose Logging in Agent Reach

> Debug channel failures in Agent Reach with verbose logging. Enable the -v flag to reveal request URLs, status codes, and exception traces for faster troubleshooting.

- Repository: [Pnant/Agent-Reach](https://github.com/Panniantong/Agent-Reach)
- Tags: how-to-guide
- Published: 2026-07-15

---

**Enable the `-v` or `--verbose` flag on any Agent Reach CLI command to surface Loguru debug logs from the `BaseChannel` methods and reveal the exact request URLs, HTTP status codes, and exception traces that caused a channel failure.**

Agent Reach routes every request to a channel (e.g., Twitter, YouTube, Reddit) through a common CLI entry point that silences Loguru output by default to keep the console clean. When you need to debug channel failures using verbose logging in Agent Reach, the `-v` flag reconfigures the logger to emit detailed diagnostic information on **stderr**, including internal call stacks, request payloads, and parsing errors from the `BaseChannel` implementation.

## How Verbose Logging Works Internally

Understanding the three-stage logging pipeline helps you interpret the output when tracing failures.

### CLI Configuration in [`agent_reach/cli.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/cli.py)

When you invoke the CLI with `-v`, the `_configure_logging()` function removes Loguru’s default handler and installs a new sink that writes to stderr. This happens only when `verbose=True`, ensuring that debug noise stays hidden during normal operation.

### Channel Base Class in [`agent_reach/channels/base.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/channels/base.py)

Every channel inherits from `BaseChannel`, which initializes a shared `self.logger = logger` reference. This instance is the same Loguru logger used across all channel implementations, meaning debug statements you add to any platform-specific file automatically respect the verbose setting.

### Central Error Handling in [`agent_reach/core.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/core.py)

The core routing logic wraps each channel request in a `try/except` block. When a channel raises an exception, [`core.py`](https://github.com/Panniantong/Agent-Reach/blob/main/core.py) calls `logger.error` before re-raising the exception. Without verbose mode, these logs are suppressed; with `-v`, you see the full stack trace and the specific method (`can_handle`, `read`, `search`, or `check`) that triggered the failure.

## Enabling Verbose Mode from the Command Line

Pass `-v` or `--verbose` to any Agent Reach command to activate detailed logging. This works for both diagnostic checks and content retrieval operations.

```bash

# Run health checks with full debug output

agent-reach doctor -v

# Debug a specific channel request

agent-reach read https://twitter.com/example/status/12345 -v

# Search with verbose logging

agent-reach search "python tutorials" --channel youtube -v

```

When active, the CLI prints timestamps, log levels, and source locations for every internal operation.

## Adding Custom Debug Statements to Channels

You can instrument your own channels or patch existing ones to capture intermediate state. Because all channels share the same Loguru instance, any `logger.debug` call appears immediately when `-v` is used.

```python

# agent_reach/channels/twitter.py

from loguru import logger

class TwitterChannel(BaseChannel):
    
    def read(self, url: str) -> str:
        logger.debug("TwitterChannel.read called with URL {}", url)
        response = self._http_get(url)
        logger.debug("HTTP status: {}", response.status_code)
        logger.debug("Response snippet: {}", response.text[:200])
        # Existing parsing logic...

        return cleaned_text

```

Running the command with `-v` produces output like:

```

2026-07-15 12:34:56.789 | DEBUG    | __main__:TwitterChannel.read:42 - TwitterChannel.read called with URL https://twitter.com/example/status/12345
2026-07-15 12:34:56.791 | DEBUG    | __main__:TwitterChannel.read:44 - HTTP status: 200
2026-07-15 12:34:56.792 | DEBUG    | __main__:TwitterChannel.read:45 - Response snippet: {"data":{...

```

If a failure occurs, the error trace appears:

```

2026-07-15 12:34:56.800 | ERROR    | __main__:BaseChannel.check:78 - Channel check failed: ConnectionError(...)

```

## Interpreting Verbose Output for Root Cause Analysis

When debugging channel failures, scan the verbose output for these specific diagnostic elements:

- **Request URLs**: Verify the exact endpoint being called (e.g., Twitter API v2 vs. legacy endpoints).
- **HTTP status codes**: Identify authentication failures (401), rate limits (429), or missing resources (404).
- **Response snippets**: Inspect raw JSON or HTML to detect schema changes that break parsing logic.
- **Exception traces**: Follow the stack trace from [`core.py`](https://github.com/Panniantong/Agent-Reach/blob/main/core.py) back to the specific channel method that raised the error.

The [`doctor.py`](https://github.com/Panniantong/Agent-Reach/blob/main/doctor.py) module also respects the verbose flag, making it useful for verifying that environment variables and network connectivity are configured correctly before testing specific channels.

## Summary

- **Use `-v` or `--verbose`** on any Agent Reach CLI command to expose Loguru debug logs that are suppressed by default.
- **Key files involved**: [`agent_reach/cli.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/cli.py) configures logging, [`agent_reach/channels/base.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/channels/base.py) provides the shared logger, and [`agent_reach/core.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/core.py) handles error propagation.
- **Diagnostic data exposed**: Request URLs, HTTP status codes, response payloads, and full exception traces from `BaseChannel` methods (`can_handle`, `read`, `search`, `check`).
- **Extensible**: Add `logger.debug` calls to any channel file; they appear automatically when verbose mode is active.

## Frequently Asked Questions

### What is the verbose flag in Agent Reach?

The `-v` or `--verbose` flag is a CLI option that reconfigures the Loguru logger to output **DEBUG** and **ERROR** level messages to stderr. According to the [`agent_reach/cli.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/cli.py) source code, this flag triggers `_configure_logging()` to remove the default handler and add a visible sink, allowing you to see internal operations from `BaseChannel` methods and network requests.

### Why don't I see debug logs without the verbose flag?

By default, Agent Reach removes Loguru’s default handler during CLI startup to keep the console clean for end users. The `logger` instance in [`agent_reach/channels/base.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/channels/base.py) still emits debug messages, but without a configured sink, they are discarded. Passing `-v` restores the handler so logs appear on stderr.

### Which Agent Reach commands support verbose logging?

All commands that use the standard CLI entry point support the flag, including `doctor`, `read`, and `search`. The [`agent_reach/doctor.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/doctor.py) module specifically checks the verbose setting to provide detailed health check output, while [`agent_reach/core.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/core.py) ensures that channel exceptions are logged regardless of which command triggered them.

### How do I add debug logging to a custom channel?

Import `logger` from `loguru` and call `logger.debug()` with your message and variables. Since `BaseChannel` initializes `self.logger` as the shared Loguru instance, your custom channel inherits this reference automatically. When you run any command with `-v`, your custom debug statements will appear alongside the framework’s internal logs, making it easy to trace data flow through your implementation.