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Video Generation Provider Plugins

إضافات مزوّد توليد الفيديو

Advanced5 min readLesson 233 questions✓ 2026-08-18
Before you read

What this page is, and what it holds.

This page covers Video Generation Provider Plugins. You will use hermes tools here; about 5 minutes to read. A plugin runs with the agent's full permissions. Do not install one you cannot read.

11sections
4code examples
1tables
1commands
927source words
The official one-line description

How to build a video-generation backend plugin for Hermes Agent

What you will be able to do

Outcomes taken from this page, not a template.

  • Understand what الإضافات is and when you need it.
  • Run hermes tools and understand what happens next.
  • Read the table and take only the row that applies to you.
Identifiers you will meet

Exactly as they appear in Hermes.

Commands
  • hermes tools
Page map

Jump to the part you need.

  1. 01The unified surface (one tool, two modalities)
  2. 02How discovery works
  3. 03Directory structure
  4. 04The VideoGenProvider ABC
  5. 05The plugin manifest
  6. 06The `videogenerate` schema
  7. 07Model families and endpoint routing (the FAL pattern)
  8. 08Selection precedence
  9. 09Response shape
  10. 10Where to save artifacts
  11. 11Testing
The full official page

Nothing summarised away.

The documentation body below is reproduced from the official source so commands and identifiers stay exact. Each section carries a short note describing what it contains.

Video-gen provider plugins register a backend that services every video_generate tool call. Built-in providers (xAI, FAL, DeepInfra) ship as plugins. Add a new one, or override a bundled one, by dropping a directory into plugins/video_gen/<name>/.

The unified surface (one tool, two modalities)

Explains the idea itself. Read it slowly; the later sections build on it.

The video_generate tool exposes two modalities through one parameter:

  • Text-to-video — call with prompt only. The provider routes to its text-to-video endpoint.
  • Image-to-video — call with prompt + image_url. The provider routes to its image-to-video endpoint.

Edit and extend are intentionally out of scope. Most backends don't support them and the inconsistency would force per-backend prose into the agent's tool description.

How discovery works

Commands you type in a terminal. Understand what one does before copying it. Commands here: hermes tools.

Hermes scans for video-gen backends in three places:

  1. Bundled — <repo>/plugins/video_gen/<name>/ (auto-loaded with kind: backend)
  2. User — ~/.hermes/plugins/video_gen/<name>/ (opt-in via plugins.enabled)
  3. Pip — packages declaring a hermes_agent.plugins entry point

Each plugin's register(ctx) function calls ctx.register_video_gen_provider(...). The active provider is picked by video_gen.provider in config.yaml; hermes tools → Video Generation walks users through selection. Unlike image_generate, there is no in-tree legacy backend — every provider is a plugin.

Directory structure

Explains the idea itself. Read it slowly; the later sections build on it.

Text3 lines
plugins/video_gen/my-backend/
├── __init__.py      # VideoGenProvider subclass + register()
└── plugin.yaml      # Manifest with kind: backend

The VideoGenProvider ABC

Explains the idea itself. Read it slowly; the later sections build on it.

Subclass agent.video_gen_provider.VideoGenProvider. Required: name property and generate() method.

Python105 lines
# plugins/video_gen/my-backend/__init__.py
from typing import Any, Dict, List, Optional


from agent.video_gen_provider import (
    VideoGenProvider,
    error_response,
    success_response,
)


class MyVideoGenProvider(VideoGenProvider):
    @property
    def name(self) -> str:
        return "my-backend"

    @property
    def display_name(self) -> str:
        return "My Backend"

    def is_available(self) -> bool:
        return bool(os.environ.get("MY_API_KEY"))

    def list_models(self) -> List[Dict[str, Any]]:
        # Each entry is a model FAMILY — a name the user picks once.
        # Your provider's generate() routes within the family based on
        # whether image_url was passed.
        return [
            {
                "id": "fast",
                "display": "Fast",
                "speed": "~30s",
                "strengths": "Cheapest tier",
                "price": "$0.05/s",
                "modalities": ["text", "image"],  # advisory
            },
        ]

    def default_model(self) -> Optional[str]:
        return "fast"

    def capabilities(self) -> Dict[str, Any]:
        return {
            "modalities": ["text", "image"],
            "aspect_ratios": ["16:9", "9:16"],
            "resolutions": ["720p", "1080p"],
            "min_duration": 1,
            "max_duration": 10,
            "supports_audio": False,
            "supports_negative_prompt": True,
            "max_reference_images": 0,
        }

    def get_setup_schema(self) -> Dict[str, Any]:
        return {
            "name": "My Backend",
            "badge": "paid",
            "tag": "Short description shown in `hermes tools`",
            "env_vars": [
                {
                    "key": "MY_API_KEY",
                    "prompt": "My Backend API key",
                    "url": "https://mybackend.example.com/keys",
                },
            ],
        }

    def generate(
        self,
        prompt: str,
        *,
        model: Optional[str] = None,
        image_url: Optional[str] = None,
        reference_image_urls: Optional[List[str]] = None,
        duration: Optional[int] = None,
        aspect_ratio: str = "16:9",
        resolution: str = "720p",
        negative_prompt: Optional[str] = None,
        audio: Optional[bool] = None,
        seed: Optional[int] = None,
        **kwargs: Any,  # always ignore unknown kwargs for forward-compat
    ) -> Dict[str, Any]:
        # ROUTE: image_url presence picks the endpoint.
        if image_url:
            endpoint = "my-backend/image-to-video"
            modality_used = "image"
        else:
            endpoint = "my-backend/text-to-video"
            modality_used = "text"

        # ... call your API ...

        return success_response(
            video="https://your-cdn/output.mp4",
            model=model or "fast",
            prompt=prompt,
            modality=modality_used,
            aspect_ratio=aspect_ratio,
            duration=duration or 5,
            provider=self.name,
        )


def register(ctx) -> None:
    ctx.register_video_gen_provider(MyVideoGenProvider())

The plugin manifest

Settings you configure once. Change one at a time so you can see what each does.

YAML8 lines
# plugins/video_gen/my-backend/plugin.yaml
name: my-backend
version: 1.0.0
description: "My video generation backend"
author: Your Name
kind: backend
requires_env:
  - MY_API_KEY

The `videogenerate` schema

A lookup table. Do not read it all; find the row that applies to you. Commands here: hermes tools.

The tool exposes one schema across every backend. Providers ignore parameters they don't support.

ParameterWhat it does
promptText instruction (required)
image_urlWhen set → image-to-video; when omitted → text-to-video
reference_image_urlsStyle/character refs (provider-dependent)
durationSeconds — provider clamps
aspect_ratio"16:9", "9:16", "1:1", ... — provider clamps
resolution"480p" / "540p" / "720p" / "1080p" — provider clamps
negative_promptContent to avoid (Pixverse/Kling only)
audioNative audio (Veo3 / Pixverse pricing tier)
seedReproducibility
modelOverride the active model/family

The provider's capabilities() advertises which of these are honored. The agent sees the active backend's capabilities in the tool description, dynamically rebuilt when the user changes backend via hermes tools.

Model families and endpoint routing (the FAL pattern)

Commands you type in a terminal. Understand what one does before copying it. Commands here: hermes tools.

When your backend has multiple endpoints per "model" — like FAL, where every family (Veo 3.1, Pixverse v6, Kling O3) has both a /text-to-video and an /image-to-video URL — represent each family as one catalog entry. Your generate() picks the right endpoint based on whether image_url was passed:

Python12 lines
FAMILIES = {
    "veo3.1": {
        "text_endpoint": "fal-ai/veo3.1",
        "image_endpoint": "fal-ai/veo3.1/image-to-video",
        # ... family-specific capability flags ...
    },
}

def generate(self, prompt, *, image_url=None, model=None, **kwargs):
    family_id, family = _resolve_family(model)
    endpoint = family["image_endpoint"] if image_url else family["text_endpoint"]
    # ... build payload from family's declared capability flags, call endpoint ...

The user picks veo3.1 once in hermes tools. The agent never thinks about endpoints — it just passes (or doesn't pass) image_url.

Selection precedence

Explains the idea itself. Read it slowly; the later sections build on it.

For per-instance model knobs (see plugins/video_gen/fal/__init__.py):

  1. model= keyword from the tool call
  2. <PROVIDER>_VIDEO_MODEL env var
  3. video_gen.<provider>.model in config.yaml
  4. video_gen.model in config.yaml (when it's one of your IDs)
  5. Provider's default_model()

Response shape

Explains the idea itself. Read it slowly; the later sections build on it.

success_response() and error_response() produce the dict shape every backend returns. Use them — don't hand-roll the dict.

Success keys: success, video (URL or absolute path), model, prompt, modality ("text" or "image"), aspect_ratio, duration, provider, plus extra.

Error keys: success, video (None), error, error_type, model, prompt, aspect_ratio, provider.

Where to save artifacts

Explains the idea itself. Read it slowly; the later sections build on it.

If your backend returns base64, use save_b64_video() to write under $HERMES_HOME/cache/videos/. For raw bytes from a follow-up HTTP fetch, use save_bytes_video(). Otherwise return the upstream URL directly — the gateway resolves remote URLs on delivery.

Testing

Explains the idea itself. Read it slowly; the later sections build on it.

Drop a smoke test under tests/plugins/video_gen/test_<name>_plugin.py. The xAI and FAL tests show the pattern — register, verify catalog, exercise routing both with and without image_url, assert clean error responses on missing auth.

Knowledge check

3 questions answered by this page alone.

Every option is a real identifier from the Hermes documentation. The wrong ones are real too, just from other pages.

1. In this lesson's table, what is the “What it does” for “imageurl”?
2. Which of these headings does not appear in this lesson?
3. Which configuration key appears in this lesson's examples?