The MCP Layer

How modular agent-server interaction works

At the heart of PILSO OS lies the Model Context Protocol (MCP) — a standardized interface between intelligent agents and operational tools.

The MCP Layer is where intent becomes action.

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What is the Model Context Protocol?

MCP defines how language models (LLMs) interact with external tools in a modular, composable, and secure way. Each MCP server is a standalone service that exposes one or more tools an agent can use — such as compiling a contract, checking a token balance, or preparing a transaction.

Instead of hardcoding logic inside the agent, PILSO delegates each step of execution to specialized, isolated MCP servers that handle just one task well.

This architecture allows you to:

• Extend functionality without modifying agent logic

• Limit trust and risk per server

• Debug, test, and audit each module independently

• Build new capabilities in a plug-and-play way

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Anatomy of an MCP Server

Each MCP server typically consists of:

Component	Description
Tool Definition	JSON or code definition that describes what the tool does and what arguments it needs
Execution Handler	The logic to actually perform the task (e.g. encode a transaction, compile a contract, fetch chain data)
Schema Validator	Ensures correct input/output formatting
Logging/Telemetry (optional)	Tracks usage for auditing or debugging
Rate Limiting (optional)	Prevents abuse or misfire from agents

All servers follow a predictable I/O format:

• Input: tool name + arguments

• Output: payload or next-step instruction

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Agent-to-Tool Call (Example)

{
  "tool": "erc20.transfer",
  "args": {
    "token": "USDC",
    "to": "0x123...abc",
    "amount": "100"
  }
}

The agent makes this call via the MCP runtime, which resolves the erc20-mcp server, sends the request, and waits for a result (a transaction payload, in this case).

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Core Server Modules in PILSO

Server	Purpose
metamask-mcp	Prepares transactions to be signed by MetaMask
chainlist-mcp	Fetches chain IDs, RPC endpoints, explorer info
erc20-mcp	Handles token transfers, approvals, balances
solc-mcp	Compiles Solidity smart contracts

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Lifecycle of a Tool Call

1. Prompt → “Send 100 USDC to Alice”
2. Agent selects tool: erc20.transfer
3. MCP runtime prepares call to erc20-mcp
4. Server validates input → prepares tx data
5. Response: raw transaction payload
6. User signs via wallet
7. Tx is broadcasted

Every call is deterministic, isolated, and scoped — giving agents the ability to act without giving them control.

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Why the MCP Layer is the Heart of PILSO

• It’s the execution engine behind every intelligent agent instruction

• It enables safe automation without risk of key exposure

• It creates a composable plug-in system for any blockchain tool or protocol

• It future-proofs PILSO for evolving agent architectures, zk tooling, and more complex coordination flows

If agents are the pilots, MCP tools are the cockpit controls — and you decide which ones to give them access to.