openclaw/extensions/gradium/tts.ts

// Gradium plugin module implements tts behavior.
import { assertOkOrThrowProviderError } from "openclaw/plugin-sdk/provider-http";
import { readResponseWithLimit } from "openclaw/plugin-sdk/response-limit-runtime";
import { fetchWithSsrFGuard } from "openclaw/plugin-sdk/ssrf-runtime";
import { GRADIUM_API_HOSTNAME, normalizeGradiumBaseUrl } from "./shared.js";

const DEFAULT_TTS_MAX_BYTES = 16 * 1024 * 1024;

export async function gradiumTTS(params: {
  text: string;
  apiKey: string;
  baseUrl: string;
  voiceId: string;
  outputFormat: "wav" | "opus" | "ulaw_8000" | "pcm" | "pcm_24000" | "alaw_8000";
  timeoutMs: number;
  maxBytes?: number;
}): Promise<Buffer> {
  const {
    text,
    apiKey,
    baseUrl,
    voiceId,
    outputFormat,
    timeoutMs,
    maxBytes = DEFAULT_TTS_MAX_BYTES,
  } = params;
  const normalizedBaseUrl = normalizeGradiumBaseUrl(baseUrl);
  const url = `${normalizedBaseUrl}/api/post/speech/tts`;

  const { response, release } = await fetchWithSsrFGuard({
    url,
    init: {
      method: "POST",
      headers: {
        "x-api-key": apiKey,
        "Content-Type": "application/json",
      },
      body: JSON.stringify({
        text,
        voice_id: voiceId,
        only_audio: true,
        output_format: outputFormat,
        json_config: JSON.stringify({ padding_bonus: 0 }),
      }),
    },
    timeoutMs,
    requireHttps: true,
    // Keep the transport boundary independent from config normalization so a
    // future validator relaxation cannot silently widen credential egress.
    policy: { hostnameAllowlist: [GRADIUM_API_HOSTNAME] },
    auditContext: "gradium.tts",
  });

  try {
    await assertOkOrThrowProviderError(response, "Gradium API error");

    return await readResponseWithLimit(response, maxBytes, {
      onOverflow: ({ maxBytes: maxBytesLocal }) =>
        new Error(`Gradium TTS audio response exceeds ${maxBytesLocal} bytes`),
    });
  } finally {
    await release();
  }
}