oh-my-opencode-slim/src/hooks/delegate-task-retry/hook.ts

import type { PluginInput } from '@opencode-ai/plugin';
import {
  DELEGATE_TASK_ERROR_PATTERNS,
  type DetectedError,
  detectDelegateTaskError,
} from './patterns';

function extractAvailableList(output: string): string | null {
  const match = output.match(/Allowed agents:\s*(.+)$/m);
  if (match) return match[1].trim();

  const available = output.match(/Available[^:]*:\s*(.+)$/m);
  if (available) return available[1].trim();

  return null;
}

function buildRetryGuidance(errorInfo: DetectedError): string {
  const pattern = DELEGATE_TASK_ERROR_PATTERNS.find(
    (p) => p.errorType === errorInfo.errorType,
  );

  if (!pattern) {
    return '\n[delegate-task retry] Fix parameters and retry with corrected arguments.';
  }

  const available = extractAvailableList(errorInfo.originalOutput);

  const lines = [
    '',
    '[delegate-task retry suggestion]',
    `Error type: ${errorInfo.errorType}`,
    `Fix: ${pattern.fixHint}`,
  ];

  if (available) {
    lines.push(`Available: ${available}`);
  }

  lines.push(
    'Retry now with corrected parameters. Example:',
    'task(description="...", prompt="...", category="unspecified-low", run_in_background=false, load_skills=[])',
  );

  return lines.join('\n');
}

export function createDelegateTaskRetryHook(_ctx: PluginInput) {
  return {
    'tool.execute.after': async (
      input: { tool: string },
      output: { output: unknown },
    ): Promise<void> => {
      const toolName = input.tool.toLowerCase();
      const isDelegateTool = toolName === 'task';
      if (!isDelegateTool) return;

      if (typeof output.output !== 'string') return;

      const detected = detectDelegateTaskError(output.output);
      if (!detected) return;

      output.output += `\n${buildRetryGuidance(detected)}`;
    },
  };
}