No support for OpenAI-like API type

[Andreea1998]

Describe the bug
OpenAI-like API type is not supported and error is given

To Reproduce
Steps to reproduce the behavior:

1. I followed your setup steps from https://github.com/test-zeus-ai/testzeus-hercules

• agents_llm_config.json configuration:

{
        "mistral": {
                "planner_agent": {
                        "model_name": "mistralai/Mistral-Small-3.1-24B-Instruct-2503",
                        "model_api_key": "XXX",
                        "model_base_url": "<local_vllm>",
            "model_api_type": "openai",
            "llm_config_params": {
                "cache_seed": null,
                "temperature": 0.0,
                "seed": 12345
            }
                },
                "nav_agent": {
                        "model_name": "mistralai/Mistral-Small-3.1-24B-Instruct-2503",
                        "model_api_key": "XXX",
                        "model_base_url": "<local_vllm>",
            "model_api_type": "openai",
            "llm_config_params": {
                "cache_seed": null,
                "temperature": 0.0,
                "seed": 12345
            }
}
}
}

• .env coniguration:

AGENTS_LLM_CONFIG_FILE=agents_llm_config.json
AGENTS_LLM_CONFIG_FILE_REF_KEY=mistral

TOKENIZERS_PARALLELISM=false
MODE=prod
HEADLESS=false
RECORD_VIDEO=false
TAKE_SCREENSHOTS=true
BROWSER_TYPE=chromium
CAPTURE_NETWORK=true
HF_HOME=./.cache

2. Used unchanged example from opt/input/test.feature.
3. I used these commands

A.

make run

This error is given:

openai.BadRequestError: Error code: 400 - {'detail': '400: Open WebUI: Server Connection Error'}

Full log: make_run.log

or
B.

testzeus-hercules --input-file opt/input/test.feature --output-path opt/output --test-data-path opt/test_data  --agents-llm-config-file ./agents_llm_config.json --agents-llm-config-file-ref-key mistral

This error is given:

pydantic_core._pydantic_core.ValidationError: 1 validation error for _LLMConfig
config_list.0.openai.model
  Field required [type=missing, input_value={'api_type': 'openai'}, input_type=dict]

Full log: testzeus.log

Expected behavior
I'm using Mistral model served using vllm https://github.com/vllm-project/vllm which is OpenAI-like
Using "openai" as "model_api_type" doesn't seem to work, but I expected to.
Maybe a different api_type should be used for OpenAI-like models

Desktop

• OS: MacOS
• Version Sonoma 14.6