Function writeHookOutput

hooks/ponytail-runtime.js:33–59

(event, mode, context = '')

}

function writeHookOutput(event, mode, context = '') {
  if (isCopilot) {
    // Copilot reads additionalContext on SessionStart; ignores output elsewhere.
    process.stdout.write(JSON.stringify(
      event === 'SessionStart' && context ? { additionalContext: context } : {}));
    return;
  }
  if (isCodex) {
    const output = { systemMessage: `PONYTAIL:${mode.toUpperCase()}` };
    if (context) {
      output.hookSpecificOutput = {
        hookEventName: event,
        additionalContext: context,
      };
    }
    process.stdout.write(JSON.stringify(output));
    return;
  }
  // Native Claude: SessionStart accepts raw stdout, but SubagentStart needs the
  // hookSpecificOutput JSON form or the context is dropped.
  if (event === 'SubagentStart') {
    process.stdout.write(JSON.stringify(
      { hookSpecificOutput: { hookEventName: event, additionalContext: context } }));
    return;
  }
  process.stdout.write(context);
}

module.exports = {
  clearMode,