Use Inference APIs with Open WebUI

One connection gives Open WebUI chat models, speech-to-text and text-to-speech from Inference APIs — useful when the local Whisper or TTS engine is too slow on a CPU host.

Settings

Setting	Value
Base URL	`https://api.inferenceapis.com/v1` (also `/openai/v1`)
API key	From API Keys; send as `Authorization: Bearer …`
Chat model ids	`openai/gpt-oss-120b`, `deepseek-ai/DeepSeek-V4-Flash`, `zai-org/GLM-5.3-Flash`, `meta-llama/Llama-3.3-70B-Instruct-Turbo` — all models
Audio model ids	`openai/whisper-large-v3` (transcription), `hexgrad/Kokoro-82M` (speech)

Configuration

Chat: environment variables

OPENAI_API_BASE_URL=https://api.inferenceapis.com/v1
OPENAI_API_KEY=$INFERENCE_API_KEY
# or Admin Panel → Settings → Connections → OpenAI API → add https://api.inferenceapis.com/v1

Speech-to-text (replaces local Whisper)

AUDIO_STT_ENGINE=openai
AUDIO_STT_OPENAI_API_BASE_URL=https://api.inferenceapis.com/v1
AUDIO_STT_OPENAI_API_KEY=$INFERENCE_API_KEY
AUDIO_STT_MODEL=openai/whisper-large-v3

Text-to-speech

AUDIO_TTS_ENGINE=openai
AUDIO_TTS_OPENAI_API_BASE_URL=https://api.inferenceapis.com/v1
AUDIO_TTS_OPENAI_API_KEY=$INFERENCE_API_KEY
AUDIO_TTS_MODEL=hexgrad/Kokoro-82M
AUDIO_TTS_VOICE=af_heart

Verify

Admin Panel → Settings → Connections → click the verify icon next to the connection; the model list should populate.

Gotchas

Open WebUI lists every id from /v1/models including aliases; hide the ones you do not want under Admin → Settings → Models.
The same variables can be set in the Admin Panel → Settings → Audio page instead of the environment.

If something fails

401 — key missing or wrong · 402 insufficient_balance — add credits on Billing · 404 model_not_found — check the id against the model list (aliases such as gpt-oss-120b work too) · 503 model_unavailable — the model is being enabled. Full details in the API docs.