---
library_name: transformers
pipeline_tag: image-text-to-text
tags:
  - vision-language
  - qwen3.5-vl
  - phone-agent
  - tool-use
---

# PhoneBuddy-4B

PhoneBuddy-4B is the main PhoneBuddy Real+Mock reinforcement-learning checkpoint.

Project page: https://phonebuddyai.github.io/

GitHub: https://github.com/PhoneBuddyAI/phonebuddy

## Model Details

- Model family: Qwen3.5 VL style checkpoint
- `model_type`: `qwen3_5`
- Processor: `Qwen3VLProcessor`
- Checkpoint role: main Real+Mock RL checkpoint
- Tool-call format: Qwen-style XML as defined in `chat_template.jinja`

The model card and repository are initially published as private for validation.

## Tool-Call Format

PhoneBuddy-4B follows the Qwen-style XML tool-call format defined by the bundled `chat_template.jinja`, for example:

```xml
<tool_call>
<function=example_function_name>
<parameter=example_parameter_1>
value_1
</parameter>
</function>
</tool_call>
```

Use the tokenizer or processor chat template from this repository when constructing prompts with tools.

## Loading Environment

These checkpoints use Qwen3.5 VL style model metadata:

- `model_type`: `qwen3_5`
- Architecture: `Qwen3_5ForConditionalGeneration`
- Processor: `Qwen3VLProcessor`
- Tokenizer metadata: `TokenizersBackend`

Use the matching Qwen3.5 VL / PhoneBuddy training or inference environment that registers these classes. In a generic public Transformers environment, compatibility depends on whether that build includes `qwen3_5` and the tokenizer backend used by this checkpoint.

A minimal processor load can be tested with:

```python
from transformers import AutoProcessor

repo_id = "PhoneBuddyAI/PhoneBuddy-4B"
processor = AutoProcessor.from_pretrained(repo_id, trust_remote_code=False)
```

Full config, tokenizer, and model loading should be done in an environment that supports the classes above. For example, public `transformers==4.57.6` does not register `model_type=qwen3_5`, and `AutoTokenizer` does not import `TokenizersBackend`; in that environment those failures indicate version/class compatibility, not missing checkpoint files.

## Intended Use

PhoneBuddy is designed for research on phone agents, multimodal tool use, and visual action reasoning. See the project page and GitHub repository for code and usage details.