How to Upgrade Platform Backends When APIs Change in Agent Reach

When upstream APIs change in Agent Reach, you modify the channel's backends priority list, implement a _check_<backend>() probe method to validate the new CLI, and verify the upgrade using the built-in doctor command.

Agent Reach isolates each internet platform behind a channel class that routes calls to one of several candidate backends. When an upstream API introduces breaking changes—such as new authentication flows, renamed CLI commands, or deprecations—you must follow a specific code-centric workflow to upgrade the platform backend. This process leverages health probes and priority-based routing defined in agent_reach/channels/<platform>.py to ensure seamless transitions.

Understanding Channel-Based Backend Routing

Each platform lives in its own channel file (e.g., agent_reach/channels/twitter.py). The channel declares an ordered list of candidate backends in the class attribute backends, which defines the probe priority—the first backend returning an "ok" status wins.

The base class in agent_reach/channels/base.py provides the ordered_backends() helper (lines 45-59). This method respects a user-override config key (<channel>_backend) while iterating through the default list, allowing users to pin specific backends even after upgrades.

Step 1: Update the Backend Priority List

Add the new backend identifier to the backends class attribute in the target channel. Insert it at the front of the list to give it highest priority, or place it according to your fallback strategy.

# agent_reach/channels/twitter.py

class TwitterChannel(Channel):
    # New backend takes precedence over legacy options

    backends = ["new-twitter-cli", "twitter-cli", "OpenCLI", "bird CLI (legacy)"]
    # ...

Step 2: Implement the Health Probe Method

Add a private method _check_<backend>() that uses agent_reach.probe.probe_command to execute a lightweight command and interpret its exit status. The method must return one of:

• None → backend not installed
• ("ok", msg) → fully usable
• ("warn", msg) → installed but misconfigured
• ("error", msg) → installed but broken

    def _check_new_twitter_cli(self):
        """Probe the new CLI introduced after the API change."""
        probe = probe_command(
            "new-twitter", ["health"], timeout=15, package="new-twitter-cli"
        )
        if probe.status == "missing":
            return None               # not installed

        if not probe.ok:
            return "error", f"new-twitter-cli broken: {probe.hint}"
        # New API prints "status: ready" on success

        if "status: ready" in probe.output:
            return "ok", "new-twitter-cli fully usable."
        return "warn", "new-twitter-cli installed but not ready."

Step 3: Integrate the Probe into the Channel's Check Method

Inside check(), iterate over self.ordered_backends(config) and call the appropriate _check_* method for each backend. Collect results and select the first "ok" (falling back to "warn" then "error"). The generic loop in TwitterChannel.check() (lines 29-48) demonstrates this pattern:

    def check(self, config=None):
        self.active_backend = None
        findings = []

        for backend in self.ordered_backends(config):
            if backend == "new-twitter-cli":
                result = self._check_new_twitter_cli()
            elif backend == "twitter-cli":
                result = self._check_twitter_cli()
            # ... existing branches unchanged

            
            if result and result[0] == "ok":
                self.active_backend = backend
                break

Step 4: Adjust OpenCLI Backends (If Applicable)

For platforms relying on the generic OpenCLI backend, update the shared probing logic in agent_reach/backends/opencli.py. When the OpenCLI API changes—such as adding new flags or output formats—modify the opencli_status() function (lines 99-115) to parse the new output:

def opencli_status(timeout: int = 10) -> OpenCLIStatus:
    # ... unchanged version probe ...

    
    daemon_probe = probe_command(
        "opencli", ["daemon", "status"], timeout=timeout, package=OPENCLI_PACKAGE
    )
    output = daemon_probe.output if daemon_probe.ok else ""

    # New API adds "Extension: sleeping" - treat sleeping as usable

    for line in output.splitlines():
        line = line.strip().lower()
        if line.startswith("extension:"):
            if "sleeping" in line:
                st.extension_connected = True
            else:
                st.extension_connected = "connected" in line
    return st

Step 5: Validate with Tests and the Doctor

Add test cases in tests/ to validate backend detection, mocking probe_command as needed. The test suite for Twitter backends in tests/test_twitter_channel.py (lines 29-46) provides a reference implementation.

Run the full test suite:

pytest -q

Then execute the doctor command to perform a final sanity check on all channels:

$ python -m agent_reach.cli doctor

# twitter → active backend: new-twitter-cli

The doctor aggregates channel checks and reports the active_backend set by each channel, confirming that your new backend is correctly detected and prioritized.

Step 6: Bump the Version

Update the version string in three locations to publish a new release:

• pyproject.toml
• agent_reach/__init__.py
• CLI test files (as enumerated in the repository's CLAUDE.md)

Summary

• Channel architecture isolates platforms in agent_reach/channels/<platform>.py with an ordered backends list defining probe priority
• Health probes use _check_<backend>() methods with probe_command to validate CLI availability and functionality
• Integration requires updating the check() method to route to new probe methods when iterating through ordered_backends()
• OpenCLI platforms share probing logic in agent_reach/backends/opencli.py that may need updates for generic API changes
• Verification combines pytest unit tests with the python -m agent_reach.cli doctor command to confirm active backend selection

Frequently Asked Questions

How do I force Agent Reach to use a specific backend instead of auto-detecting?

Set the <channel>_backend configuration key to pin a specific backend. The ordered_backends() helper in agent_reach/channels/base.py checks for this override before iterating through the default priority list, allowing users to bypass auto-detection even after upgrades.

What happens if multiple backends are installed but one is broken?

The health-first probing system collects results from all candidate backends and selects the first "ok" status. If no backend returns "ok", it falls back to "warn" then "error". This ensures that a broken but installed backend never masks a fully functional one downstream in the priority list.

Where should I add tests for a new backend?

Add test cases in tests/test_<platform>_channel.py that mock probe_command to simulate various installation states (missing, ok, warn, error). Reference tests/test_twitter_channel.py (lines 29-46) for the standard pattern of validating backend detection without requiring actual CLI installations.

When do I need to modify OpenCLI instead of the channel-specific files?

Update agent_reach/backends/opencli.py only when the upstream API change affects the generic OpenCLI interface itself—such as changes to the daemon status output format or new global flags. Platform-specific changes (like a new Twitter CLI) belong in the channel's agent_reach/channels/<platform>.py file.

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