solc-mcp: Contract Compile

The solc-mcp module allows agents to securely compile Solidity smart contracts without relying on third-party explorers or IDEs.

It wraps the official solc-js compiler in a controlled MCP server that can:

• Compile a given Solidity source string

• Return the ABI, bytecode, and metadata

• Detect syntax and compiler errors

• Support version pinning (via pragma or param)

This lets your agents prepare smart contracts for deployment or audit — completely from natural language prompts.

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What It Does

• Receives raw Solidity contract source

• Resolves the appropriate solc version

• Compiles source with safe defaults

• Returns ABI, bytecode, errors (if any)

This server does not deploy contracts — it only compiles them.

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Architecture

Agent → solc-mcp → solc-js → Compiled Output → signer (optional)

• Used before passing bytecode to metamask-mcp for deployment

• Can also be used for simulation or code validation

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Tool Name: solc.compile

Request

{
  "tool": "solc.compile",
  "args": {
    "source": "// SPDX-License-Identifier: MIT\npragma solidity ^0.8.19;\ncontract Hello { string public greet = 'hi'; }"
  }
}

Response

{
  "abi": [ { "inputs": [], "name": "greet", "outputs": [{ "type": "string" }], ... } ],
  "bytecode": "0x608060405234...",
  "compilerVersion": "0.8.19",
  "warnings": [],
  "errors": []
}

If there are compile-time issues, the errors array will be populated with structured messages from the compiler.

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Server Setup

To run solc-mcp locally:

git clone https://github.com/pilso-os/mcp-servers
cd mcp-servers/solc-mcp
npm install
npm start

Default port: 3050

Update your pilso.config.json:

"tools": [
  "http://localhost:3050"
]

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Compiler Version Resolution

By default, solc-mcp:

• Parses pragma directives to match the required version

• Falls back to solc@latest if unspecified

• Uses solc-js via npm package or binary cache

Optional flag:

"version": "0.8.17"

You can force a version via explicit parameter in the request.

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Output Format

Field	Description
abi	Standard ABI JSON
bytecode	Hex-encoded deployable bytecode
compilerVersion	Actual compiler version used
warnings	Non-blocking issues
errors	Critical blocking issues (if any)

All outputs are structured to be consumed directly by metamask-mcp or logged for agent interpretation.

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Test Call Locally

npx pilso call \
  --tool solc.compile \
  --args '{"source": "pragma solidity ^0.8.19; contract A { uint x; }"}'

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Safety Notes

• Compilation is fully isolated — no contract is ever deployed from this tool

• It can be safely exposed to most agent roles, including developer, auditor, and reviewer

• Avoid giving compile + sign access to general-purpose roles unless tightly scoped

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Future Additions

• Support for source map + opcode output

• AI-assisted static analysis hooks

• Bytecode diff tools for version comparison

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✅ Summary

Property	Value
Tool name	solc.compile
Port	3050 (default)
Signature	No — compiles only
Chain Support	EVM-based chains only
Depends on	solc-js, pragma resolution

The solc-mcp module gives your PILSO agent the power to understand, compile, and prepare contracts — safely and reproducibly, from source code to deployable bytecode.