OpenCode Background Processes Plugin (fork from zenobi-us/opencode-background)

The original npm package @zenobius/opencode-background from https://github.com/zenobi-us/opencode-background isn't being maintained or updated, so I've stepped in with a maintained fork/version.

Until (or if) the original gets attention, use the @mbanucu version instead.

Demo: How to use @mbanucu/opencode-background

Here is the code for the echo_server.py:

import http.server
import socketserver
from datetime import datetime
import json

class EchoHandler(http.server.BaseHTTPRequestHandler):
    def do_POST(self):
        content_length = int(self.headers['Content-Length'])
        post_data = self.rfile.read(content_length)
        msg = post_data.decode('utf-8')
        print(msg, flush=True)
        now = datetime.now().astimezone().isoformat(timespec='seconds')
        try:
            server_ip, server_port = self.connection.getsockname()[:2]
            server_info = f'{server_ip}:{server_port}'
        except Exception:
            server_info = 'unknown'
        log_object = {
            'timestamp': now,
            'message': msg,
            'client_ip': self.client_address[0],
            'server': server_info
        }
        log_line = json.dumps(log_object, indent=2)
        with open('echo_server.log', 'a') as f:
            f.write(log_line + '\n')
        self.send_response(200)
        self.send_header('Content-Type', 'application/json')
        self.end_headers()
        self.wfile.write(log_line.encode('utf-8'))

if __name__ == '__main__':
    with socketserver.TCPServer(("", 0), EchoHandler) as httpd:
        port = httpd.server_address[1]
        print(f"Server running on port {port}", flush=True)
        httpd.serve_forever()

Links

• Fork/Maintained repo: https://github.com/MBanucu/opencode-background
• Original repo: https://github.com/zenobi-us/opencode-background
• npm package (recommended): https://www.npmjs.com/package/@mbanucu/opencode-background
• Original npm package: https://www.npmjs.com/package/@zenobius/opencode-background
• How to install plugins from npm in OpenCode: https://opencode.ai/docs/plugins/#from-npm

OpenCode Background Processes Plugin

A flexible background process management plugin for OpenCode, offering robust process tracking and lifecycle management.

Installation

Basics

For basic information on installing and using plugins in OpenCode, see the official documentation. You don't have to read it, but it is helpful if you want to keep your system clean.

From npm

Create or edit your OpenCode configuration file (typically ~/.config/opencode/opencode.json):

{
  "plugins": ["@mbanucu/opencode-background"]
}

This installs the plugin from npm. See the documentation for more details on npm installations.

via Nix

If you have Nix installed, you can install the plugin directly using:

nix run github:MBanucu/opencode-background#install

This will automatically install the plugin to the correct location (~/.config/opencode/plugin/).

This installs the plugin as a local file. See the documentation for more details on local file installations.

To uninstall:

nix run github:MBanucu/opencode-background#uninstall

This will remove the plugin files from ~/.config/opencode/plugin/.

Testing the Nix Development Environment

The Nix flake includes a dev shell with an integrated bun.lock file watcher that automatically manages bun.nix for dependency locking. Testing can be done manually or via automated flake checks.

Manual Testing

To test the watcher functionality manually:

1. Enter the dev shell:

   nix develop

2. The watcher will start automatically and log to bun-watcher.log.

3. Test file operations (in another terminal or after exiting the shell):

   # Remove generated files
   rm bun.nix bun.lock
   
   # Reinstall dependencies to recreate them
   bun install
   
   # Move files to test detection
   mkdir -p move-bun-here
   mv bun.nix move-bun-here/
   mv bun.lock move-bun-here/
   
   # Reinstall to recreate
   bun install
   
   # Clean up
   rm -rf move-bun-here/

4. Exit the dev shell:

   exit

5. Check the log file for watcher activity:

   cat bun-watcher.log

The watcher detects file creations, deletions, and moves, regenerating bun.nix as needed and logging warnings for external modifications.

Automated Testing

The flake includes automated checks that run the devShell watcher in isolated environments and test various scenarios:

• watcher-init: Verifies the watcher initializes correctly
• watcher-external-delete: Tests detection and correction of external file deletion
• watcher-corruption: Tests detection and correction of file corruption
• watcher-file-move: Tests detection and correction of file moves

Run all checks:

nix flake check

To see detailed output for individual checks (including test results and logs):

nix build .#checks.x86_64-linux.watcher-init --print-build-logs
nix build .#checks.x86_64-linux.watcher-external-delete --print-build-logs
nix build .#checks.x86_64-linux.watcher-corruption --print-build-logs
nix build .#checks.x86_64-linux.watcher-file-move --print-build-logs

The automated tests run in Nix build environments and successfully validate watcher functionality, including file operation detection within the sandbox constraints.

Usage

Example 1: Build Pipeline Management

I need to run and monitor multiple background processes for a build pipeline:

1. Start a long-running build process tagged as ["build", "critical"] that runs: `bun build ./src/index.ts --outdir dist --target bun`
2. Start a test runner tagged as ["test", "validation"] that runs: `bun test --watch`
3. Start a global process tagged as ["lint"] for linting: `mise run lint` (should persist across sessions)
4. List all current processes and show me their statuses
5. List only the processes tagged with "critical" or "validation"
6. Kill the test runner process, then list remaining processes
7. Show all currently running processes one more time to verify

Walk me through each step so I can see how the plugin handles concurrent processes, filtering, and termination.

Demonstrates:

• Creating multiple background processes
• Using tags for categorization
• Global vs session-specific processes
• Listing and filtering by tags
• Process termination
• Real-time status tracking

Example 2: Web Server and Concurrent Testing

Let's test running a web server in the background using json-server:
- Start a json-server instance with: bunx json-server --watch db.json
- Tag it as ["server", "json-api"] for easy management
- Test that it's still running
- Execute a sync cmd (without background) to curl results from the server
- Test that it's still running
- Run a subagent that runs cmds to test the server too
- Confirm the subagent's results

Demonstrates:

• Long-running background services (JSON API server)
• Interleaving background processes with foreground commands
• Process monitoring across concurrent operations
• Subagent coordination with background processes
• Data persistence through process lifecycle
• Full CRUD operations validation while service runs continuously
• Real-time process status verification

Example 3: Do not use the npm version of @zenobius/opencode-background

Features

• 🚀 Create background processes with real-time output tracking
• 🏷️ Tag and categorize processes
• 🔍 Advanced process filtering
• 🔪 Selective process termination
• 🌐 Global and session-specific process support
• :recycle: Automatic cleanup on session end and application close

Usage in OpenCode

Creating a Background Process

⚙ createBackgroundProcess
  command=/tmp/long-process.sh
  name="Long Running Process"
  tags=["long-process", "processing"]
  global=false  # Optional: default is false

Process Types

• Session-Specific Processes (default):

  • Automatically terminated when the session ends
  • Useful for temporary, session-bound operations
  • Tracked in-memory for the current session

• Global Processes:

  • Persist across sessions
  • Continues running until explicitly stopped
  • Useful for long-running services or background operations

Listing Processes

# List processes in current session
⚙ listBackgroundProcesses
  sessionId=current_session_id

# List processes with specific tags
⚙ listBackgroundProcesses
  tags=["processing"]

Killing Processes

# Kill a specific process
⚙ killProcesses
  processId=specific-process-id

# Kill all processes in a session
⚙ killProcesses
  sessionId=current_session_id

Plugin Methods

createBackgroundProcess

• command: Shell command to execute
• name (optional): Descriptive name for the process
• tags (optional): List of tags to categorize the process
• global (optional):
  • false (default): Session-specific process
  • true: Process persists across sessions

listBackgroundProcesses

• sessionId (optional): Filter processes by session
• status (optional): Filter processes by status
• tags (optional): Filter processes by tags

killProcesses

• processId (optional): Kill a specific process
• sessionId (optional): Kill processes in a specific session
• status (optional): Kill processes with a specific status
• tags (optional): Kill processes with specific tags

Considerations

• Processes are tracked in-memory using a singleton BackgroundProcessManager
• Output stream captures up to the last 100 lines of process output
• Processes can be in states: pending, running, completed, failed, cancelled
• Processes include detailed metadata: start/completion times, error tracking
• ALL processes are killed when OpenCode closes
• Processes generate unique IDs automatically if not specified

Contributing

Contributions are welcome! Please file issues or submit pull requests on the GitHub repository.

License

MIT License. See the LICENSE file for details.