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ORS vs MCP

The Model Context Protocol (MCP) and Open Reward Standard (ORS) are both protocols for connecting language models to external systems, but they serve different purposes.

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Overview

Model Context Protocol (MCP): -Purpose: Connect LLMs to tools, data sources, and workflows -Focus: General-purpose tool access -Use case: Extending LLM capabilities with external APIs, databases, file systems Open Reward Standard (ORS): -Purpose: Connect agents to reinforcement learning environments -Focus: RL training and agent evaluation -Use case: Training agents with reward signals, structured evaluation benchmarks

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Key Differences

FeatureMCPORS
Primary PurposeTool access, data integrationRL training environments
Episode TerminationNo conceptfinished signal
RewardsNo conceptNumeric feedback for RL
TasksNo conceptOrganized problems to solve
SplitsNo conceptTrain/validation/test organization
Session ManagementBasicEpisode-centric (RL trajectories)
Tool CallingYesYes Yes
ProtocolJSON-RPC over stdio/SSEHTTP/REST + SSE
Primary UsersApplication developersRL researchers, benchmark creators

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Detailed Comparison

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Tool Calling

Both protocols support tool calling with similar interfaces: MCP Tool Spec: 
{
  "name": "read_file",
  "description": "Read contents of a file",
  "inputSchema": {
    "type": "object",
    "properties": {
      "path": {"type": "string"}
    }
  }
}
ORS Tool Spec: 
{
  "name": "read_file",
  "description": "Read contents of a file",
  "input_schema": {
    "type": "object",
    "properties": {
      "path": {"type": "string"}
    }
  }
}
Nearly identical! ORS intentionally aligns with MCP’s tool specification format.

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Tool Responses

MCP Response: 
{
  "content": [
    {"type": "text", "text": "File contents here"}
  ]
}
ORS Response: 
{
  "blocks": [
    {"type": "text", "text": "File contents here"}
  ],
  "reward": 0.0,
  "finished": false
}
ORS adds:
  • reward -For RL training feedback
  • finished -For episode termination

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Episode Structure

MCP: No concept of episodes. Stateless or loosely stateful tool calls. ORS: Episodes are first-class: -Session = RL episode -Episode continues until finished: true -One complete trajectory through environment -Clear start (task) and end (finished signal)

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Task Organization

MCP: No built-in task organization. ORS: Tasks and splits: -Tasks: Individual problems to solve -Splits: train/validation/test categorization -Enables proper ML workflows -Prevents overfitting during training

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When to Use MCP

Use MCP when you need: General-purpose tool access -Connect LLM to file system, databases, APIs -Extend LLM with custom tools -Build assistants with external capabilities Application development -Desktop AI applications -Productivity tools -Chatbots with tool access Simple stateless interactions -One-off tool calls -Workflow automation -Data retrieval and processing Example: A coding assistant that can read files, search code, and run commands to help developers.

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When to Use ORS

Use ORS when you need: RL training -Train agents with reinforcement learning -Need reward signals for learning -Multi-step decision making with feedback Agent evaluation -Structured benchmarks -Train/test split organization -Reproducible evaluation metrics Episode-based interactions -Tasks with clear start and end -State maintained across multiple steps -Success/failure outcomes Example: Training an agent to solve programming challenges, where each problem is an episode with a reward signal for correct solutions.

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Can They Work Together?

Yes! MCP and ORS serve complementary purposes:

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Scenario: Code Execution Environment

An ORS environment for coding tasks could use MCP tools: 
class CodingEnvironment(Environment):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        # Use MCP client to access file system
        self.mcp_client = MCPClient()

    @tool
    def read_file(self, params) -> ToolOutput:
        # Use MCP tool internally
        content = self.mcp_client.call_tool("filesystem", "read", {
            "path": params.path
        })

        return ToolOutput(
            blocks=[TextBlock(text=content)],
            reward=0.0,  # ORS reward
            finished=False  # ORS episode control
        )

    @tool
    def submit_solution(self, params) -> ToolOutput:
        # Check solution, return ORS reward
        correct = check_solution(params.code)
        return ToolOutput(
            blocks=[TextBlock(text="Correct!" if correct else "Incorrect")],
            reward=1.0 if correct else 0.0,
            finished=True  # End ORS episode
        )
Pattern: Use MCP for tool infrastructure, ORS for episode/reward structure.

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Migration Considerations

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From MCP to ORS

If you have MCP tools and want RL training:
  1. Wrap tools in ORS environment
  2. Add reward logic
  3. Add finished signals
  4. Organize into tasks and splits
  5. Keep tool specifications (mostly compatible)

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From ORS to MCP

If you have ORS environment and want simpler tool access:
  1. Extract tool definitions
  2. Remove episode/reward logic
  3. Simplify to stateless tool calls
  4. Use MCP protocol instead of HTTP

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Protocol Details

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MCP Protocol

  • Transport: stdio, SSE, or custom
  • Message format: JSON-RPC 2.0
  • Connection: Client-server
  • State: Optional (server-managed)

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ORS Protocol

  • Transport: HTTP + Server-Sent Events
  • Message format: REST + JSON
  • Connection: Stateless HTTP with session headers
  • State: Episode-centric (required)

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Community and Ecosystem

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MCP

  • Maintained by: Anthropic
  • Focus: General AI application development
  • Integrations: Claude Desktop, Zed, other AI apps
  • Tools: Growing ecosystem of MCP servers

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ORS

  • Maintained by: OpenReward community
  • Focus: RL research and agent evaluation
  • Integrations: RL training frameworks
  • Environments: Growing collection of RL benchmarks

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Example Use Cases

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MCP Use Cases

  1. Code Editor Integration -Read/write files -Search codebase -Run tests -Git operations
  2. Database Access -Query databases -Fetch data -Update records -Generate reports
  3. API Integration -Call external APIs -Process responses -Aggregate data -Workflow automation

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ORS Use Cases

  1. Math Problem Solving -Train agents on GSM8K -Reward correct answers -Multi-step reasoning -Benchmark performance
  2. Code Generation -Train coding agents -Reward passing tests -Multi-file modifications -Evaluate on held-out problems
  3. Web Navigation -Train agents to browse websites -Reward goal completion -Multi-step navigation -Benchmark on real websites

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Summary

Use MCP for:
  • General tool access
  • Application development
  • Workflow automation
  • Data integration
Use ORS for:
  • RL training
  • Agent evaluation
  • Benchmark creation
  • Reward-based learning
Use Both for:
  • Complex RL environments that need rich tool ecosystems
  • Training agents with access to external services
  • Research requiring both learning and tool use

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Next Steps

ORS Quick Start

Build your first ORS server

ORS Specification

Deep dive into ORS protocol

MCP Documentation

Learn about Model Context Protocol

Implementation Guide

Implement an ORS server
Key Takeaway: MCP and ORS solve different problems. MCP connects LLMs to tools. ORS connects agents to RL training environments. Both are valuable, and they can work together in sophisticated systems.