How to Debug Why a Specific Channel Isn't Working in Agent Reach

Use the built-in doctor CLI to identify whether the failure stems from missing backends, broken binaries, missing runtimes, or authentication issues, then inspect the specific channel's check() method in agent_reach/channels/<platform>.py to resolve the root cause.

Agent Reach abstracts every internet platform into a channel that inherits from the abstract Channel base class. When a specific channel stops working, the bug usually hides in one of three areas: backend availability, runtime configuration, or user configuration overrides. The probe_command logic in agent_reach/probe.py and the per-channel check() methods provide a systematic path to debug why a specific channel isn't working in Agent Reach.

Run the Built-In Diagnostics Doctor

Start by running the health check aggregator to see the current status of all channels:

python -m agent_reach.cli doctor

The doctor command (implemented in agent_reach/doctor.py) iterates over every registered channel and calls its check() method. It prints a status table that categorizes each channel as ok, warn, error, or off. Identify the failing channel in this output and note the diagnostic message provided.

Locate the Channel Implementation

Each concrete channel lives in its own file under agent_reach/channels/. For example:

• agent_reach/channels/twitter.py
• agent_reach/channels/youtube.py

Open the file for your failing channel and examine the check() method. This method defines the specific backends the channel tries and the conditions that produce each status. The source code reveals exactly which command-line tools and environment variables are required.

Verify Backend Availability

The core probing logic resides in agent_reach/probe.py. The probe_command function executes a lightweight health check (usually --version or a status subcommand) and classifies the result into four states:

• missing – The command is not on your PATH
• broken – The command exists but cannot execute (common with stale virtual-environment shims)
• timeout / error – The command runs but exits with an error or hangs
• ok – The command is healthy and responsive

Confirm the backend binary is accessible:

which <backend-cmd>

If the command is missing, install it according to the hint in the doctor output (often uv tool install or pipx reinstall). If the command exists but is broken, reinstall the package to refresh the shim.

Check Runtime Configuration and Credentials

Beyond the binary itself, channels often require specific runtimes or authentication tokens. The check() method in each channel file validates these dependencies.

YouTube: Requires a JavaScript runtime. The channel checks shutil.which("deno") and shutil.which("node"). If neither is found, install Node.js or Deno:

# Install Node.js via nvm

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash
nvm install --lts

Twitter: Requires authentication tokens. Verify these environment variables are set:

echo $TWITTER_AUTH_TOKEN
echo $TWITTER_CT0

If these are unset, export them as shown in the doctor's hint, or ensure you have a valid browser login for OpenCLI.

Inspect Config Overrides

The Channel base class in agent_reach/channels/base.py implements ordered_backends(), which respects user overrides. If you have set a <channel>_backend key in config.yaml or the corresponding environment variable, that backend is forced to the front of the candidate list, potentially hiding a functional fallback.

Check your configuration for stale overrides:

# Check environment

echo $TWITTER_BACKEND

# Check config.yaml

cat ~/.config/agent_reach/config.yaml | grep backend

Remove or correct the override and re-run the doctor.

Manually Test the Backend

To bypass Agent Reach's abstraction and test the backend directly, execute the same command that probe_command uses:

yt-dlp --version            # YouTube backend

twitter status              # Twitter CLI backend

bird check                  # Bird CLI backend

Any error output from these commands provides additional clues beyond the generic status messages.

Summary

• Run the doctor: Use python -m agent_reach.cli doctor to identify which channel is failing and why.
• Check the source: Inspect the channel's check() method in agent_reach/channels/<platform>.py to see required backends and credentials.
• Verify binaries: Use which and manual execution to confirm backend commands are on your PATH and not broken.
• Validate runtimes: Ensure required runtimes (Node.js, Deno) and authentication tokens are installed and exported.
• Audit overrides: Remove or correct <channel>_backend overrides in config.yaml or environment variables that might be forcing a non-functional backend.

Frequently Asked Questions

Why does the doctor show "warn" instead of "error" for my channel?

A warn status means the backend binary is installed and executable, but the channel's check() method detected a non-critical issue, such as missing authentication credentials or an optional runtime dependency. The channel may still function partially, but you should follow the hint in the doctor output to resolve the warning and restore full functionality.

How do I find which backends a specific channel supports?

Open the channel's implementation file in agent_reach/channels/<platform>.py (for example, twitter.py or youtube.py). The check() method or the class attribute backends lists the command-line tools the channel attempts to use. The ordered_backends() method in agent_reach/channels/base.py determines the precedence order, including any user overrides.

Can I force Agent Reach to use a specific backend if the default fails?

Yes. Set the <channel>_backend configuration option in your config.yaml or export it as an uppercase environment variable (e.g., TWITTER_BACKEND=twitter-cli). This forces ordered_backends() to prioritize that specific backend. However, ensure the forced backend is actually installed and functional, or you will mask working fallbacks.

What if the doctor reports "ok" but the channel still fails during actual use?

The check() method performs lightweight health probes (often just --version checks) that verify binary presence and basic execution, but they do not exhaustively test all API endpoints or authentication workflows. If the doctor shows ok but operations fail, manually run the backend command with a real operation (e.g., twitter status or yt-dlp <url>) to see the actual error output, and verify that any required environment variables contain valid, non-expired tokens.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}