---
summary: "Inbound image/audio/video understanding (optional) with provider + CLI fallbacks"
read_when:
  - Designing or refactoring media understanding
  - Tuning inbound audio/video/image preprocessing
title: "Media Understanding"
---

# Media Understanding

Fased can **summarize inbound media** (image/audio/video) before the reply
pipeline runs. It auto-detects local tools or provider keys when available, and
you can disable or customize it. If understanding is off, models still receive
the original files or URLs as usual.

This is a Gateway media/tool pipeline. It is not the **Advanced > Nodes**
diagnostics tab. Use **Agent > Services** for friendly provider setup when
available, **Agent > Tools** for per-Agent tool access, and **Advanced > Config**
only for raw `tools.media` overrides.

## Goals

- Optional: turn inbound media into short text for faster routing and better
  command parsing.
- Preserve original media delivery to the model (always).
- Support **provider APIs** and **CLI fallbacks**.
- Allow multiple models with ordered fallback for error, size, and timeout cases.

## High‑level behavior

1. Collect inbound attachments (`MediaPaths`, `MediaUrls`, `MediaTypes`).
2. For each enabled capability (image/audio/video), select attachments per
   policy. Default: **first**.
3. Choose the first eligible model entry (size + capability + auth).
4. If a model fails or the media is too large, **fall back to the next entry**.
5. On success:
   - `Body` becomes `[Image]`, `[Audio]`, or `[Video]` block.
   - Audio sets `{{Transcript}}`; command parsing uses caption text when present,
     otherwise the transcript.
   - Captions are preserved as `User text:` inside the block.

If understanding fails or is disabled, **the reply flow continues** with the
original body and attachments.

## Config overview

`tools.media` supports **shared models** plus per‑capability overrides:

- `tools.media.models`: shared model list (use `capabilities` to gate).
- `tools.media.image` / `tools.media.audio` / `tools.media.video`:
  - defaults (`prompt`, `maxChars`, `maxBytes`, `timeoutSeconds`, `language`)
  - provider overrides (`baseUrl`, `headers`, `providerOptions`)
  - Deepgram audio options via `tools.media.audio.providerOptions.deepgram`
  - optional **per‑capability `models` list** (preferred before shared models)
  - `attachments` policy (`mode`, `maxAttachments`, `prefer`)
  - `scope` (optional gating by channel/chatType/session key)
- `tools.media.concurrency`: max concurrent capability runs. Default: **2**.

```json5
{
  tools: {
    media: {
      models: [
        /* shared list */
      ],
      image: {
        /* optional overrides */
      },
      audio: {
        /* optional overrides */
      },
      video: {
        /* optional overrides */
      },
    },
  },
}
```

### Model entries

Each `models[]` entry can be **provider** or **CLI**:

```json5
{
  type: "provider", // default if omitted
  provider: "openai",
  model: "gpt-5.5",
  prompt: "Describe the image in <= 500 chars.",
  maxChars: 500,
  maxBytes: 10485760,
  timeoutSeconds: 60,
  capabilities: ["image"], // optional, used for multi‑modal entries
  profile: "vision-profile",
  preferredProfile: "vision-fallback",
}
```

```json5
{
  type: "cli",
  command: "gemini",
  args: [
    "-m",
    "gemini-3-flash",
    "--allowed-tools",
    "read_file",
    "Read the media at {{MediaPath}} and describe it in <= {{MaxChars}} characters.",
  ],
  maxChars: 500,
  maxBytes: 52428800,
  timeoutSeconds: 120,
  capabilities: ["video", "image"],
}
```

CLI templates can also use:

- `{{MediaDir}}` (directory containing the media file)
- `{{OutputDir}}` (scratch dir created for this run)
- `{{OutputBase}}` (scratch file base path, no extension)

## Defaults and limits

Recommended defaults:

- `maxChars`: **500** for image/video (short, command‑friendly)
- `maxChars`: **unset** for audio (full transcript unless you set a limit)
- `maxBytes`:
  - image: **10MB**
  - audio: **20MB**
  - video: **50MB**

Rules:

- If media exceeds `maxBytes`, that model is skipped and the **next model is tried**.
- If the model returns more than `maxChars`, output is trimmed.
- `prompt` defaults to simple "Describe the {media}." plus the `maxChars`
  guidance for image/video only.
- If `<capability>.enabled: true` but no models are configured, Fased tries the
  **active reply model** when its provider supports the capability.

### Auto-detect media understanding (default)

If `tools.media.<capability>.enabled` is **not** set to `false` and you haven’t
configured models, Fased auto-detects in this order and **stops at the first
working option**:

1. **Local CLIs** (audio only; if installed)
   - `sherpa-onnx-offline` (requires `SHERPA_ONNX_MODEL_DIR` with
     encoder/decoder/joiner/tokens)
   - `whisper-cli` (`whisper-cpp`; uses `WHISPER_CPP_MODEL` or the bundled tiny
     model)
   - `whisper` (Python CLI; downloads models automatically)
2. **Gemini CLI** (`gemini`) using `read_many_files`
3. **Provider keys**
   - Audio: OpenAI → Groq → Deepgram → Google
   - Image: OpenAI → Anthropic → Google → MiniMax
   - Video: Google

To disable auto-detection, set:

```json5
{
  tools: {
    media: {
      audio: {
        enabled: false,
      },
    },
  },
}
```

Binary detection is best-effort across macOS/Linux/Windows. Ensure the CLI is on
`PATH` (Fased expands `~`), or set an explicit CLI model with a full command
path.

## Capabilities (optional)

If you set `capabilities`, the entry only runs for those media types. For shared
lists, Fased can infer defaults:

- `openai`, `anthropic`, `minimax`: **image**
- `google` (Gemini API): **image + audio + video**
- `groq`: **audio**
- `deepgram`: **audio**

For CLI entries, **set `capabilities` explicitly** to avoid surprising matches.
If you omit `capabilities`, the entry is eligible for the list it appears in.

## Provider support (Fased integrations)

- **Image**: OpenAI, Anthropic, Google, and others through the Fased provider
  registry. Any image-capable model in the registry works.
- **Audio**: OpenAI, Groq, Deepgram, Google, and Mistral for provider
  transcription, including Whisper, Deepgram, Gemini, and Voxtral paths.
- **Video**: Google Gemini API for provider video understanding.

## Recommended providers

**Image**

- Prefer your active model if it supports images.
- Good defaults: `openai/gpt-5.5`, `anthropic/claude-opus-4.7`,
  `google/gemini-3.1-pro-preview`.

**Audio**

- `openai/gpt-4o-mini-transcribe`, `groq/whisper-large-v3-turbo`,
  `deepgram/nova-3`, or `mistral/voxtral-mini-latest`.
- CLI fallback: `whisper-cli` (whisper-cpp) or `whisper`.
- Deepgram is configured through `tools.media.audio` as a media transcription
  provider, not as an Agent model provider.

**Video**

- `google/gemini-3-flash-preview` (fast),
  `google/gemini-3.1-pro-preview` (richer).
- CLI fallback: `gemini` CLI (supports `read_file` on video/audio).

## Attachment policy

Per‑capability `attachments` controls which attachments are processed:

- `mode`: `first` (default) or `all`
- `maxAttachments`: cap the number processed (default **1**)
- `prefer`: `first`, `last`, `path`, `url`

When `mode: "all"`, outputs are labeled `[Image 1/2]`, `[Audio 2/2]`, etc.

## Config examples

### 1) Shared models list + overrides

```json5
{
  tools: {
    media: {
      models: [
        { provider: "openai", model: "gpt-5.5", capabilities: ["image"] },
        {
          provider: "google",
          model: "gemini-3-flash-preview",
          capabilities: ["image", "audio", "video"],
        },
        {
          type: "cli",
          command: "gemini",
          args: [
            "-m",
            "gemini-3-flash",
            "--allowed-tools",
            "read_file",
            "Read the media at {{MediaPath}} and describe it in <= {{MaxChars}} characters.",
          ],
          capabilities: ["image", "video"],
        },
      ],
      audio: {
        attachments: { mode: "all", maxAttachments: 2 },
      },
      video: {
        maxChars: 500,
      },
    },
  },
}
```

### 2) Audio + Video only (image off)

```json5
{
  tools: {
    media: {
      audio: {
        enabled: true,
        models: [
          { provider: "openai", model: "gpt-4o-mini-transcribe" },
          {
            type: "cli",
            command: "whisper",
            args: ["--model", "base", "{{MediaPath}}"],
          },
        ],
      },
      video: {
        enabled: true,
        maxChars: 500,
        models: [
          { provider: "google", model: "gemini-3-flash-preview" },
          {
            type: "cli",
            command: "gemini",
            args: [
              "-m",
              "gemini-3-flash",
              "--allowed-tools",
              "read_file",
              "Read the media at {{MediaPath}} and describe it in <= {{MaxChars}} characters.",
            ],
          },
        ],
      },
    },
  },
}
```

### 3) Optional image understanding

```json5
{
  tools: {
    media: {
      image: {
        enabled: true,
        maxBytes: 10485760,
        maxChars: 500,
        models: [
          { provider: "openai", model: "gpt-5.5" },
          { provider: "anthropic", model: "claude-opus-4.7" },
          {
            type: "cli",
            command: "gemini",
            args: [
              "-m",
              "gemini-3-flash",
              "--allowed-tools",
              "read_file",
              "Read the media at {{MediaPath}} and describe it in <= {{MaxChars}} characters.",
            ],
          },
        ],
      },
    },
  },
}
```

### 4) Multi-modal single entry (explicit capabilities)

```json5
{
  tools: {
    media: {
      image: {
        models: [
          {
            provider: "google",
            model: "gemini-3.1-pro-preview",
            capabilities: ["image", "video", "audio"],
          },
        ],
      },
      audio: {
        models: [
          {
            provider: "google",
            model: "gemini-3.1-pro-preview",
            capabilities: ["image", "video", "audio"],
          },
        ],
      },
      video: {
        models: [
          {
            provider: "google",
            model: "gemini-3.1-pro-preview",
            capabilities: ["image", "video", "audio"],
          },
        ],
      },
    },
  },
}
```

## Status output

When media understanding runs, `/status` includes a short summary line:

```
📎 Media: image ok (openai/gpt-5.5) · audio skipped (maxBytes)
```

This shows per‑capability outcomes and the chosen provider/model when applicable.

## Notes

- Understanding is **best‑effort**. Errors do not block replies.
- Attachments are still passed to models even when understanding is disabled.
- Use `scope` to limit where understanding runs (e.g. only DMs).

## Related docs

- [Configuration](/gateway/configuration)
- [Image & Media Support](/nodes/images)
