# Sinch API Voice Callout

> Make an outbound voice call (TTS callout) via Sinch Voice API

- Skill: `sinch/sinch-api-voice-callout` (Agent Skill)
- Install (CLI): `npx skillmds@latest add sinch/sinch-api-voice-callout`
- Raw SKILL.md: https://api.skillmd.com/api/skills/sinch/sinch-api-voice-callout/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: sinch (https://skillmd.com/u/sinch)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/sinch/sinch-api-voice-callout

---


# Voice Callout (TTS Call)

Place an outbound voice call using the Sinch Voice API. Supports text-to-speech (TTS) callouts to a phone number. Uses Application Key + Secret (not Conversation API credentials).

**IMPORTANT: Execute this command directly. Do NOT generate script files. Perform the API call immediately.**

## Input

- `--to` / `-t`: Destination phone number (E.164) - required
- `--text` / `-T`: Text to be spoken (TTS) - required
- `--cli` / `-c`: Caller ID / CLI (E.164) - optional
- `--locale` / `-l`: TTS locale (e.g. en-US) - optional, default en-US

Arguments: $ARGUMENTS

## Instructions

**Execute these steps directly - do not write code or scripts:**

0. If $ARGUMENTS empty: ask for destination number, text to speak, optional caller ID and locale. Otherwise parse.

1. Validate: --to (E.164), --text (non-empty). Optional: --cli (E.164), --locale.

2. Get VOICE_APPLICATION_KEY and VOICE_APPLICATION_SECRET from env (or equivalent Voice app credentials). Voice API uses Application Key/Secret, not OAuth2. If missing, report "Voice API is not configured. Set VOICE_APPLICATION_KEY and VOICE_APPLICATION_SECRET."

3. Request body: method "ttsCallout", ttsCallout: destination (type "number", endpoint), cli, locale, text.

4. POST https://calling.api.sinch.com/calling/v1/callouts with Basic Auth (ApplicationKey:ApplicationSecret) or signed request, Content-Type application/json.

5. On success: "✅ Call initiated" with call ID. Handle 400, 401, 403 with clear messages.

6. Handle all errors gracefully.

## Examples

```
/sinch-api-voice-callout --to=+14155551234 --text="Hello, this is a test call from Sinch."
/sinch-api-voice-callout -t +14155551234 -T "Your verification code is 1 2 3 4" --locale=en-US
```

## API Reference

- **Base URL**: https://calling.api.sinch.com/calling/v1
- **Endpoint**: POST /callouts
- **Auth**: Basic (application key:secret) or Application Signed Request
- **Documentation**: https://developers.sinch.com/docs/voice/

## Notes

- Voice API uses Application Key + Secret from Voice app in Sinch Dashboard, not project OAuth2.
- Regional endpoints available: calling-use1, calling-euc1, calling-apse1, etc.