# How to Debug Unavailable Channels in Agent Reach Doctor Output

> Learn how to debug unavailable channels in Agent Reach doctor output by examining probe logic and verbose logs. Resolve connectivity issues effectively.

- Repository: [Pnant/Agent-Reach](https://github.com/Panniantong/Agent-Reach)
- Tags: how-to-guide
- Published: 2026-06-22

---

**The Agent Reach Doctor reports a channel as unavailable when its `check()` method returns a non-`ok` status or raises an exception, which you can diagnose by running with `--verbose` and inspecting the probe logic in `agent_reach/channels/<platform>.py`.**

The `doctor` command in the Panniantong/Agent-Reach repository validates every configured channel by executing health checks and rendering a Rich-styled status table. When a channel displays a red **X** or shows as unavailable, the output indicates either a missing dependency, misconfigured credentials, or a failed backend probe that prevents the channel from initializing.

## How the Doctor Command Works

The Doctor command (`python -m agent_reach.cli doctor`) orchestrates channel validation through three phases defined in [`agent_reach/doctor.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/doctor.py).

First, `get_all_channels()` (lines 12‑20) collects every concrete subclass of `BaseChannel` from the channels directory. Then, the Doctor iterates through these channels and invokes each `check()` method inside a `try/except` block (lines 21‑27). If a channel raises an exception, the Doctor captures the error and records `status="error"`.

The results dictionary (lines 28‑34) stores `status`, `message`, `tier`, `backends`, and the runtime-selected `active_backend` for each channel. Finally, `format_report()` (lines 47‑99) groups channels by tier and applies color-coding: green **✅** for `status="ok"`, yellow **!** for `"warn"`, and red **X** for statuses `"off"` or `"error"`.

## Root Causes of Unavailable Channels

Channels appear unavailable when the `check()` implementation cannot validate its required environment. According to the source code, failures originate in four primary areas.

### Missing External Tools

When a required binary (such as `yt-dlp` for YouTube or a platform-specific CLI) is not found in `PATH`, the channel’s `check()` method returns `status="off"`. The [`agent_reach/doctor.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/doctor.py) stores this state along with a message indicating the tool is not installed. Channels verify availability using `shutil.which()` followed by a lightweight `probe_command` defined in [`agent_reach/probe.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/probe.py).

### Misconfigured Credentials

If a channel requires API keys or cookie files but finds none, the `check()` method returns `status="warn"`. This typically triggers a yellow warning icon rather than a red X. The validation logic calls `Config.get_secret()` from [`agent_reach/config.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/config.py) to verify that required secrets exist in `~/.agent-reach/config.yaml` or environment variables.

### Backend Probe Failures

Channels that rely on external executables validate them through [`agent_reach/probe.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/probe.py). When `probe_command()` encounters a non-zero exit code or missing binary, it returns an error tuple that forces `status="error"`. The Doctor clears any stale `active_backend` value on error (lines 24‑26) to prevent leaking invalid cached states.

### File Permission Issues

While not directly affecting channel status, the Doctor checks [`config.yaml`](https://github.com/Panniantong/Agent-Reach/blob/main/config.yaml) permissions (lines 15‑24) and appends a security warning if the file is world-readable. Running `chmod 600 ~/.agent-reach/config.yaml` resolves this alert.

## Step-by-Step Debugging Workflow

Follow this systematic approach to resolve unavailable channels identified by the Doctor.

1. **Run the Doctor with verbose output**

   Use the `--verbose` flag implemented in [`agent_reach/cli.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/cli.py) to view raw result dictionaries before formatting:

   ```bash
   python -m agent_reach.cli doctor --verbose
   ```

   This reveals the exact `status` string and exception `message` for each failing channel.

2. **Inspect the channel’s `check()` implementation**

   Navigate to the specific channel file (e.g., [`agent_reach/channels/youtube.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/channels/youtube.py) or [`agent_reach/channels/twitter.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/channels/twitter.py)). Locate the `check()` method to identify which binary it probes and which configuration keys it requires.

3. **Confirm the backend binary exists**

   Verify the tool is installed and executable:

   ```bash
   which yt-dlp
   yt-dlp --version
   ```

   The Doctor uses both `shutil.which()` and an execution probe, so the binary must run successfully, not merely exist in path.

4. **Run the probe manually**

   Replicate the Doctor’s validation using the probe module:

   ```bash
   python -m agent_reach.probe yt-dlp --version
   ```

   If this command fails, the error output matches what the Doctor captures.

5. **Check configuration overrides**

   Each channel respects a `<CHANNEL>_backend` environment override defined in `Channel.ordered_backends` ([`agent_reach/channels/base.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/channels/base.py)). Ensure you haven’t forced an invalid backend:

   ```bash
   echo $YOUTUBE_BACKEND  # Should be empty or a valid backend name

   ```

6. **Validate credentials**

   Ensure required secrets are present. The `check()` method calls `Config.get_secret()` to verify cookies or API tokens. Add missing values to `~/.agent-reach/config.yaml`.

7. **Re-run the Doctor**

   After installing missing tools or correcting configuration, execute the Doctor again to confirm the channel displays a green **✅**.

## Common Pitfalls and Solutions

| Pitfall | Solution |
|---------|----------|
| **Stale virtual-environment shim** | Delete broken shims or reinstall the tool; verify with `probe_command` rather than just `which`. |
| **Incorrect backend override** | Remove the environment variable (e.g., `unset YOUTUBE_BACKEND`) or delete the key from [`config.yaml`](https://github.com/Panniantong/Agent-Reach/blob/main/config.yaml). |
| **World-readable config file** | Run `chmod 600 ~/.agent-reach/config.yaml` to satisfy the security check in [`doctor.py`](https://github.com/Panniantong/Agent-Reach/blob/main/doctor.py). |
| **Platform-specific dependencies** | Some channels only support Unix systems; check for `sys.platform` guards in the channel’s `check()` method before running on Windows. |

## Code Examples

The following snippets demonstrate how to reproduce and override channel checks programmatically.

**Reproduce a failing probe for the YouTube channel:**

```python
from agent_reach.probe import probe_command

# The YouTube channel declares `yt-dlp` as its primary backend

result = probe_command(["yt-dlp", "--version"])
print(result)   # => ('error', 'yt-dlp: command not found')  # typical failure case

```

**Override the backend for the Reddit channel:**

```python
import os
os.environ["REDDIT_BACKEND"] = "praw"   # forces the 'praw' backend to the front

from agent_reach.doctor import check_all
from agent_reach.config import Config

report = check_all(Config())
print(report["reddit"])

# => {'status': 'ok', 'active_backend': 'praw', ...}

```

**Quick CLI check for all missing backends:**

```bash
python - <<'PY'
from agent_reach.doctor import check_all, format_report
from agent_reach.config import Config
print(format_report(check_all(Config())))
PY

```

## Summary

- The Doctor command aggregates health data by calling `check()` on every `BaseChannel` subclass and wrapping calls in exception handlers.
- A red **X** indicates `status="off"` (missing dependency) or `status="error"` (probe/execution failure).
- Use `--verbose` to expose raw error messages before they are formatted into the Rich table.
- Validate binaries with [`agent_reach/probe.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/probe.py) and verify credentials through `Config.get_secret()`.
- Clear stale backend overrides by unsetting `<CHANNEL>_backend` environment variables.

## Frequently Asked Questions

### What does a red X mean in the Agent Reach Doctor output?

A red **X** appears when a channel’s `check()` method returns `status="off"` or `status="error"` according to [`agent_reach/doctor.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/doctor.py). This signals either a missing external tool or an exception during the health probe.

### How do I see the exact error message for an unavailable channel?

Run `python -m agent_reach.cli doctor --verbose`. The verbose flag prints raw Python dictionaries containing the `message` field captured from exceptions or probe failures before the Rich formatter processes them.

### Why does a channel show as "error" even when the binary exists?

The Doctor validates binaries using `probe_command` in [`agent_reach/probe.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/probe.py), not just `shutil.which()`. If the binary exists but crashes on execution (e.g., a stale virtual-environment shim), the probe returns an error status. Run the binary manually or use `python -m agent_reach.probe <command>` to verify it exits cleanly.

### Can I disable channels I do not plan to use?

The Doctor automatically discovers all concrete channel subclasses, but it does not require unavailable channels to function. You can ignore red **X** marks for channels you do not need, or set `<CHANNEL>_backend=none` if the channel supports a null backend override, though availability depends on the specific implementation in [`agent_reach/channels/base.py`](https://github.com/Panniantong/Agent-Reach/blob/main/agent_reach/channels/base.py).