speech-generation

ElevenLabs Text-to-Speech (via Letta)

Generate natural speech from text - supports 90+ languages, multiple models for quality vs latency tradeoffs. Examples default to eleven_v4, the latest and highest-quality model.

This skill is adapted from ElevenLabs' text-to-speech skill (elevenlabs/skills, MIT; see LICENSE). Instead of calling ElevenLabs with your own key, you call Letta's hosted endpoint POST /v1/audio/speech. It forwards the request to ElevenLabs with Letta's key and charges the organization's Letta credits, so you do not need an ElevenLabs API key. The request body uses the same field names as ElevenLabs "Create speech"; the voice ID goes in the body.

Quick Start

base_url="${LETTA_BASE_URL%/}"

curl -sS -X POST "$base_url/v1/audio/speech" \
  -H "Authorization: Bearer $LETTA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello, welcome to ElevenLabs!","voice_id":"JBFqnCBsd6RMkjVDRZzb","model_id":"eleven_v4"}' \
  > speech-response.json

python3 - <<'PY'
import base64, json

with open("speech-response.json") as f:
    response = json.load(f)
if "audio_b64" not in response:
    raise SystemExit(response.get("message", response))

with open("output.mp3", "wb") as f:
    f.write(base64.b64decode(response["audio_b64"]))
print("saved output.mp3")
PY

Use the runtime-provided LETTA_BASE_URL and LETTA_API_KEY together. Build URLs relative to ${LETTA_BASE_URL%/} and do not hardcode https://api.letta.com. If either variable is missing, the user needs to authenticate with Letta Cloud; do not ask for an ElevenLabs key.

Share the saved file the way your current surface supports: attach or upload it to the conversation or channel you are replying in. Never paste the base64 into a reply. Keep credit amounts out of replies unless the user asks about cost.

Models