Getting Started

All API requests require authentication via API key or JWT:

• API Key: Authorization: Token <API_KEY>
• JWT: Authorization: Bearer <JWT>

Base servers:

• REST & STT/TTS WebSocket: https://api.deepgram.com
• Voice Agent WebSocket: https://agent.deepgram.com

Common Mistakes to Avoid

All APIs

1. Feature flags are query params — except for Voice Agent and Flux mid-session updates. For /v1/listen, /v2/listen, and /v1/speak, initial options go on the URL. The request body carries only audio data (REST) or audio frames (WebSocket). Two exceptions: /v1/agent/converse has no URL query params at all (all config goes in the Settings message); and /v2/listen supports a Configure message after connection to update EOT thresholds and keyterms mid-session. Also note that /v2/listen has a much smaller param set than /v1/listen — flags like smart_format, diarize, and punctuate are not available.

2. Rate limits are concurrent connections, not total requests. A 429 means too many simultaneous open connections, not too high a request volume. Diarization and other compute-heavy features reduce your concurrency allowance further.

STT WebSocket (/v1/listen)

3. Send KeepAlive as a text frame, not binary. The connection closes after 10 seconds of no audio. Send {"type":"KeepAlive"} as a text (JSON) frame every 3–5 seconds during silence. Sending it as a binary frame causes transcription delays — the audio pipeline chokes — not a silent no-op.

4. Never send empty byte payloads. Sending a zero-length binary frame to /v1/listen is treated as a close — it terminates the connection. Always check that your audio packet has length before sending.

5. encoding must match the actual audio format. If encoding=linear16 but you're sending opus, you'll get a DATA-0000 error or garbled output. Omit encoding entirely when sending containerized formats (mp3, wav, ogg) — Deepgram detects them automatically.

6. Timestamps reset on reconnect. Each new WebSocket connection restarts timestamps at 00:00:00. For real-time apps, maintain a timestamp offset across reconnections or you'll silently corrupt your transcript timeline.

TTS WebSocket (/v1/speak)

7. Don't send empty text. A Speak message with an empty text field returns a 400 error. Always validate input before sending.

8. Character rate limiting (DATA-0001) means slow down, not retry. If you hit this, reduce how fast you're submitting text chunks — don't immediately retry or you'll compound the problem.

Voice Agent (/v1/agent/converse)

9. Send the Settings message before any audio. The agent ignores everything until it receives and acknowledges the Settings configuration. Message ordering is strictly required.

Flux model

10. Use /v2/listen and model=flux-general-en. /v1/listen does not support Flux. model=flux alone is not a valid value. Do not include language or encoding params for containerized audio.

11. Use Configure to update EOT thresholds and keyterms mid-session. Unlike /v1/listen, Flux supports live reconfiguration after connection — no need to reconnect to change turn detection sensitivity or boost new keyterms:

    Copy & paste — that's itCopy

    { "type": "Configure", "thresholds": { "eot_threshold": "0.8", "eot_timeout_ms": "3000" }, "keyterms": ["Deepgram"] }

    The server responds with ConfigureSuccess (echoing back applied values) or ConfigureFailure. Omitted threshold fields keep their current values.

Authentication

12. JWT TTL applies only to the initial handshake. Tokens default to 30 seconds. Once the WebSocket connection is established, the token expiring does not close it — tokens are only needed for the upgrade request.