Audio and video input

The gateway accepts audio and video input for models that declare the modality — check input_modalities in GET /v1/models. Sending audio or video to any other model fails fast with 400 invalid_request_error before anything is billed. Output is still text only. Today that means the Gemini family (google/gemini-*): every catalog Gemini model accepts image, audio, and video input.

Audio

Chat Completions

Use OpenAI-style input_audio parts: base64 data plus a format token (wav or mp3; aiff, aac, ogg and flac also pass through):

curl https://api.impossibl.com/v1/chat/completions \
  -H "Authorization: Bearer imp-rt-..." \
  -H 'content-type: application/json' \
  -d '{
    "model": "google/gemini-2.5-flash",
    "messages": [{
      "role": "user",
      "content": [
        { "type": "text", "text": "Transcribe this recording." },
        { "type": "input_audio", "input_audio": { "data": "UklGRiQ...", "format": "wav" } }
      ]
    }]
  }'

Responses API

The same input_audio shape, paired with input_text:

curl https://api.impossibl.com/v1/responses \
  -H "Authorization: Bearer imp-rt-..." \
  -H 'content-type: application/json' \
  -d '{
    "model": "google/gemini-2.5-flash",
    "input": [{
      "role": "user",
      "content": [
        { "type": "input_text", "text": "Summarize this recording." },
        { "type": "input_audio", "input_audio": { "data": "UklGRiQ...", "format": "wav" } }
      ]
    }]
  }'

Video

Chat Completions

Use video_url parts (the de-facto extension Qwen and Zhipu clients already send). The url is a data: URI or an http(s) URL. YouTube URLs pass straight through to Gemini; any other video URL is fetched by the gateway and sent inline, so it must fit Gemini’s ~20MB inline request limit:

curl https://api.impossibl.com/v1/chat/completions \
  -H "Authorization: Bearer imp-rt-..." \
  -H 'content-type: application/json' \
  -d '{
    "model": "google/gemini-2.5-flash",
    "messages": [{
      "role": "user",
      "content": [
        { "type": "text", "text": "What happens in this video?" },
        { "type": "video_url", "video_url": { "url": "https://www.youtube.com/watch?v=dQw4w9WgXcQ" } }
      ]
    }]
  }'

A data: URI carries the video inline: data:video/mp4;base64,....

Gemini-native endpoint

/v1beta/models/{model}:generateContent accepts Google’s own shapes: inlineData for base64 audio/video (routed by mimeType) and fileData for video URLs:

curl "https://api.impossibl.com/v1beta/models/google%2Fgemini-2.5-flash:generateContent" \
  -H "Authorization: Bearer imp-rt-..." \
  -H 'content-type: application/json' \
  -d '{
    "contents": [{
      "role": "user",
      "parts": [
        { "text": "Summarize this video." },
        { "fileData": { "mimeType": "video/mp4", "fileUri": "https://www.youtube.com/watch?v=dQw4w9WgXcQ" } }
      ]
    }]
  }'

Billing

Audio and video are tokenized by the provider (Gemini: ~32 tokens per second of audio, ~300 per second of video) and billed as input tokens. Some models price audio input above the text rate — pricing.audio_input_per_mtok_usd in GET /v1/models shows the rate where one applies (e.g. google/gemini-2.5-flash bills audio at

1.00/1M vs

0.30 text). Video frames bill at the model’s input rate, but a video’s audio track is tokenized separately and bills at the audio rate where the model declares one.

Get started

Core concepts

Using the API

Audio

Chat Completions

Responses API

Video

Chat Completions

Gemini-native endpoint

Billing

​Audio

​Chat Completions

​Responses API

​Video

​Chat Completions

​Gemini-native endpoint

​Billing

Audio

Chat Completions

Responses API

Video

Chat Completions

Gemini-native endpoint

Billing