vlm-model-enabler

name	vlm-model-enabler
description	Enables VLM models for GenAI VLM pipelines.
argument-hint	HuggingFace model_id and task (e.g. google/gemma-3n-E2B-it image-text-to-text), or a path to an already converted OpenVINO IR model directory (model_dir).

VLM Model Enabler

Enables a new VLM model in the GenAI VLM pipeline. Follows a strict 4-step workflow with checkpoints.

Input

• HuggingFace model_id and task (e.g. google/gemma-3n-E2B-it image-text-to-text), or path to an already exported OpenVINO IR directory.
• Recommended prerequisite: .model_analysis/<model_type>_analysis.md produced by the model-analysis agent. If absent, the caller (or the user, if running this skill standalone) should invoke model-analysis first to avoid duplicating upstream inspection here. This skill does not invoke other agents itself.

Working Directory

All intermediate assets go in .model_enabler/. Create it if it does not exist.

Rules

• Create .py files for all experiments — avoid inline multi-line Python snippets; keep shell commands minimal and only for build/run steps.
• After each step, verify all checkpoint files exist before proceeding. If any are missing, create them.
• Use the todo list tool to track step progress.

Reference

• genai-vlm-architecture.md — GenAI VLM pipeline interfaces and new-model checklist. Read the "Adding a New Model — Checklist" section before Step 2.
• model-inference-text-to-text.md — Supplementary test templates and debugging tips for text-only mode (Step 2).
• model-inference-image-text.md — Supplementary test templates, preprocessing utilities list, and debugging tips for image-text mode (Step 3).

---

Step 1 — GenAI Enablement Design

Goal: Map the model into the GenAI VLM pipeline using the upstream analysis report.

1.1 Obtain the analysis report

Read .model_analysis/<model_type>_analysis.md.

If it does not exist, prefer asking the caller to invoke the model-analysis agent first (it is the canonical source for upstream facts). If that is not possible — e.g. running this skill standalone without the agent available — produce an equivalent report yourself by following the procedure in .github/agents/model-analysis.agent.md and write the result to the same path. Do not skip this artifact; later steps depend on it.

1.2 Design the mapping

Using the report, decide:

• Closest GenAI model: compare the report's sub-model layout, preprocessing, and special tokens against existing implementations in src/cpp/src/visual_language/*/classes.hpp. Pick the closest one as the reference.
• Required changes: list files to create or modify (enum in vlm_config.hpp, new <model_type>/classes.{hpp,cpp}, factory registrations, etc.). Use genai-vlm-architecture.md "Adding a New Model — Checklist" as the structure.
• Gaps: anything in the report that existing GenAI infrastructure does not cover (custom position IDs, extra LM inputs, dynamic image tiling, etc.).

Checkpoint

Append a ## GenAI Enablement Design section to .model_analysis/<model_type>_analysis.md:

## GenAI Enablement Design
- Closest GenAI model: <name> — because <reason>
- Required changes:
  - <file>: <what changes>
- Gaps: <items needing new infrastructure>

Do not proceed to Step 2 until this section exists.

---

Step 2 — Text-Only Inference

Goal: VLMPipeline generates correct text with text-only input, matching optimum-intel exactly.

2.1 Implement C++ changes

Follow the checklist in genai-vlm-architecture.md "Adding a New Model":

1. Add enum to vlm_config.hpp, string mapping to vlm_config.cpp
2. Create <model_type>/classes.hpp and <model_type>/classes.cpp
3. Register in vision_encoder.cpp and inputs_embedder.cpp factories
4. Add friend class to inputs_embedder.hpp
5. Implement stubs: VisionEncoder::encode() throws, get_inputs_embeds() handles text-only path
6. Handle any model-specific requirements (custom position IDs, extra LM inputs, etc.)

2.2 Build

pip install --pre -U . --extra-index-url https://storage.openvinotoolkit.org/simple/wheels/nightly

Fix all compilation errors.

2.3 Verify

Create and run .model_enabler/test_text_only_compare.py — compare GenAI vs optimum-intel with do_sample=False on 3 prompts.

Checkpoint

• Build succeeds
• .model_enabler/test_text_only_compare.py shows exact match on all prompts

Do not proceed to Step 3 until text-only output matches optimum-intel exactly.

---

Step 3 — Image-Text Inference

Goal: VLMPipeline generates correct text with image input, semantically close to optimum-intel.

3.1 Implement vision preprocessing + encoding

Replace the VisionEncoder stub. Key references:

• preprocessor_config.json for resize/normalization params
• clip.hpp/clip.cpp for available resize utilities (bilinear_resize, bicubic_resize, etc.)
• The closest model implementation identified in Step 1

3.2 Implement embedding merge

Update get_inputs_embeds() to handle the non-empty images case: insert vision embeddings at placeholder token positions.

3.3 Build and verify

Rebuild, then create and run:

• .model_enabler/test_image_text_compare.py — compare GenAI vs optimum-intel on 3 image prompts

Checkpoint

• Build succeeds
• .model_enabler/test_image_text_compare.py shows semantically similar outputs

---

Final Deliverables

Before declaring the model enabled:

• .model_analysis/<model_type>_analysis.md exists with the ## GenAI Enablement Design section
• All test scripts exist and pass in .model_enabler/