Creating Opencode Plugins

export const MyPlugin = async (context) => {
  // context: { project, client, $, directory, worktree }

  return {
    event: async ({ event }) => {
      // event: { type: 'event.name', data: {...} }

      switch(event.type) {
        case 'file.edited':
          // Handle file edits
          break;
        case 'tool.execute.before':
          // Pre-process tool execution
          break;
      }
    }
  };
};

{
  "name": "env-protection",
  "description": "Prevents sharing .env files",
  "version": "1.0.0",
  "author": "Security Team",
  "plugin": {
    "file": "plugin.js",
    "location": "global"
  },
  "hooks": {
    "file": ["file.edited"],
    "permission": ["permission.replied"]
  }
}

// .opencode/plugin/env-protection.js

export const EnvProtectionPlugin = async ({ project, client }) => {
  const sensitivePatterns = [
    /\.env$/,
    /\.env\..+$/,
    /credentials\.json$/,
    /\.secret$/,
  ];

  const isSensitiveFile = (filePath) => {
    return sensitivePatterns.some(pattern => pattern.test(filePath));
  };

  return {
    event: async ({ event }) => {
      switch (event.type) {
        case 'file.edited': {
          const { path } = event.data;

          if (isSensitiveFile(path)) {
            console.warn(`⚠️  Sensitive file edited: ${path}`);
            console.warn('This file should not be shared or committed.');
          }
          break;
        }

        case 'permission.replied': {
          const { action, target, decision } = event.data;

          // Block read/share operations on sensitive files
          if ((action === 'read' || action === 'share') &&
              isSensitiveFile(target) &&
              decision === 'allow') {

            console.error(`🚫 Blocked ${action} operation on sensitive file: ${target}`);

            // Override permission decision
            return {
              override: true,
              decision: 'deny',
              reason: 'Sensitive file protection policy'
            };
          }
          break;
        }
      }
    }
  };
};

// .opencode/plugin/notify.js

export const NotifyPlugin = async ({ project, $ }) => {
  let commandStartTime = null;

  return {
    event: async ({ event }) => {
      switch (event.type) {
        case 'command.executed': {
          const { command, args, status } = event.data;
          commandStartTime = Date.now();

          console.log(`▶️  Executing: ${command} ${args.join(' ')}`);
          break;
        }

        case 'tool.execute.after': {
          const { tool, duration, success } = event.data;

          if (duration > 5000) {
            // Notify for long-running operations
            await $`osascript -e 'display notification "Completed in ${duration}ms" with title "${tool}"'`;
          }

          console.log(`✅ ${tool} completed in ${duration}ms`);
          break;
        }
      }
    }
  };
};

// .opencode/plugin/custom-tools.js

export const CustomToolsPlugin = async ({ client }) => {
  // Register custom tool on initialization
  await client.registerTool({
    name: 'lint',
    description: 'Run linter on current file with auto-fix option',
    parameters: {
      type: 'object',
      properties: {
        fix: {
          type: 'boolean',
          description: 'Auto-fix issues'
        }
      }
    },
    handler: async ({ fix }) => {
      const result = await $`eslint ${fix ? '--fix' : ''} .`;
      return {
        output: result.stdout,
        errors: result.stderr
      };
    }
  });

  return {
    event: async ({ event }) => {
      // Monitor tool usage
      if (event.type === 'tool.execute.before') {
        console.log(`🔧 Tool: ${event.data.tool}`);
      }
    }
  };
};