Principle:Volcengine Verl Tool Configuration

Knowledge Sources	verl OpenAI Function Calling
Domains	Agentic_AI, Tool_Use, Configuration
Last Updated	2026-02-07 14:00 GMT

Overview

A YAML-based configuration system that defines available tools, their schemas, and instantiation parameters for multi-turn agentic RL training.

Description

Tool Configuration in verl uses a registry pattern where tools are defined in YAML configuration files and instantiated at runtime. Each tool definition specifies:

• class_name: Fully qualified Python class path (must subclass BaseTool)
• config: Tool-specific configuration (type: native/mcp/api)
• tool_schema: OpenAI-compatible function schema describing the tool's name, parameters, and description

The tool registry loads these definitions and creates tool instances that the multi-turn rollout engine can invoke when the model generates tool-calling tokens.

Usage

Use tool configuration when setting up multi-turn training with external tools. Tools are configured via YAML files referenced in the training config as actor_rollout_ref.rollout.multi_turn.tool_config_path.

Theoretical Basis

The tool configuration follows a plugin/registry pattern:

# Abstract tool configuration flow
# 1. Define tools in YAML
tools_config = load_yaml("tool_config.yaml")
# 2. Registry instantiates tools
for tool_def in tools_config["tools"]:
    tool_class = import_class(tool_def["class_name"])
    tool = tool_class(config=tool_def["config"])
    register(tool, schema=tool_def["tool_schema"])
# 3. Tools are available to the rollout engine

Related Pages

Implemented By

• Implementation:Volcengine_Verl_Initialize_Tools_From_Config