Native Gemini protocol

export API_ROOT_URL="https://gateway.example.com"
export API_MODEL="YOUR_MODEL_ID"
# API_KEY must already be set in the process environment.

const { API_ROOT_URL, API_KEY, API_MODEL } = process.env;
if (!API_ROOT_URL || !API_KEY || !API_MODEL) {
  throw new Error('Set API_ROOT_URL, API_KEY, and API_MODEL first.');
}
// This example accepts a bare model ID, without models/ or an action suffix.
if (!/^[A-Za-z0-9._-]+$/.test(API_MODEL) || ['.', '..'].includes(API_MODEL)) {
  throw new Error('Use a bare model ID containing letters, digits, dots, underscores, or hyphens.');
}

try {
  const response = await fetch(`${API_ROOT_URL.replace(/\/+$/, '')}/v1beta/models/${encodeURIComponent(API_MODEL)}:generateContent`, {
    method: 'POST', redirect: 'error', signal: AbortSignal.timeout(60_000),
    headers: { 'Content-Type': 'application/json', 'x-goog-api-key': API_KEY },
    body: JSON.stringify({
      systemInstruction: { parts: [{ text: 'Answer briefly in plain text.' }] },
      contents: [{ role: 'user', parts: [{ text: 'Say hello in one short sentence.' }] }],
    }),
  });
  if (!response.ok) {
    console.error(`Request failed (HTTP ${response.status}). No automatic retry.`);
    process.exitCode = 1;
  } else {
    const result = await response.json();
    if (result.error || result.promptFeedback?.blockReason
      || !Array.isArray(result.candidates) || result.candidates.length !== 1) {
      throw new Error('Blocked or missing candidate.');
    }
    const candidate = result.candidates[0];
    if (candidate.finishReason !== 'STOP' || candidate.content?.role !== 'model'
      || !Array.isArray(candidate.content.parts) || candidate.content.parts.length === 0) {
      throw new Error('No complete text response.');
    }
    const text = candidate.content.parts.map((part: Record<string, unknown>) => {
      if (!part || typeof part.text !== 'string' || Object.keys(part).some(
        (key) => !['text', 'thought', 'thoughtSignature'].includes(key),
      ) || (part.thought !== undefined && typeof part.thought !== 'boolean')) {
        throw new Error('Unsupported content part.');
      }
      return part.thought === true ? '' : part.text;
    }).join('');
    if (!text.trim()) throw new Error('Empty visible text.');
    console.log(text);
  }
} catch {
  console.error('Gemini request failed or did not produce complete plain text. No automatic retry.');
  process.exitCode = 1;
}
export {};