MCP Code Execution

Transform any MCP server into executable, type-safe TypeScript tools using progressive loading pattern. Achieve 98% token savings by loading only what you need.

[!TIP] Inspired by Anthropic’s engineering blog post on Code Execution with MCP.

The Problem

Traditional MCP integration loads ALL tools from a server (~30,000 tokens), even when you only need one or two. This wastes context window space and slows down AI agents.

The Solution

Progressive loading generates one TypeScript file per tool (~500-1,500 tokens each). AI agents discover and load only what they need via simple ls and cat commands.

Result: 98% token savings + autonomous execution + type safety

Installation

From crates.io (recommended)

cargo install mcp-execution-cli

[!IMPORTANT] Requires Rust 1.91 or later for building from source.

Usage

Generate TypeScript Tools

# 1. Configure MCP server in ~/.claude/mcp.json
# 2. Generate tools
mcp-execution-cli generate --from-config github

# Output: ~/.claude/servers/github/
#   - createIssue.ts
#   - updateIssue.ts
#   - ... (one file per tool)

Progressive Loading

# List available tools
ls ~/.claude/servers/github/

# Load only what you need (98% token savings!)
cat ~/.claude/servers/github/createIssue.ts

# Execute autonomously
node ~/.claude/servers/github/createIssue.ts --repo="owner/repo" --title="Bug"

[!NOTE] Each tool file is self-contained with full TypeScript interfaces and JSDoc documentation.

Key Features

Workspace Crates

Dependency Graph:

mcp-execution-cli → {mcp-execution-codegen, mcp-execution-introspector, mcp-execution-files, mcp-execution-core, mcp-execution-skill}
mcp-execution-server → {mcp-execution-codegen, mcp-execution-introspector, mcp-execution-files, mcp-execution-core, mcp-execution-skill}
mcp-execution-codegen → {mcp-execution-introspector, mcp-execution-core}
mcp-execution-files → mcp-execution-codegen
mcp-execution-introspector → {rmcp, mcp-execution-core}
mcp-execution-skill → mcp-execution-core

CLI Commands

See mcp-cli README for full reference.

# Generate TypeScript tools from config (recommended)
mcp-execution-cli generate --from-config github

# Preview what would be generated without writing to disk
mcp-execution-cli generate --from-config github --dry-run

# Introspect MCP server from config
mcp-execution-cli introspect --from-config github

# Introspect with detailed schemas
mcp-execution-cli introspect --from-config github --detailed

# Manual configuration (alternative)
mcp-execution-cli introspect docker --arg=run --arg=-i --env=TOKEN=xxx

# Shell completions
mcp-execution-cli completions bash

[!TIP] Use --from-config to load server settings from ~/.claude/mcp.json instead of manual arguments.

[!IMPORTANT] v0.9 breaking change: generate --http and introspect --http now require either --from-config, a positional command, or --http/--sse, not a combination. If you were combining a positional command with --http or --sse, use one or the other exclusively.

[!WARNING] v0.10 breaking change: _meta.json metadata schema version bumped from 1 to 2. Files generated before this release will no longer parse and must be regenerated. Run mcp-execution-cli generate --from-config to update your generated tool files.

[!WARNING] v0.10 breaking change: server IDs and tool names must now consist only of Unicode Identifier_Status=Allowed characters. A remote MCP server exposing a tool named with a space or @/+/(/&/``/etc. now fails introspection outright instead of being silently accepted — this closes a spoofing risk where a hostile server could publish a tool name that is visually near-identical to a legitimate one.

Performance

Documentation

• Progressive Loading Tutorial - Complete guide
• Claude Code Integration - SKILL.md generation (mcp-execution-cli skill)

Development

cargo build --workspace        # Build
cargo nextest run --workspace  # Test
cargo clippy --workspace       # Lint
cargo +nightly fmt --workspace # Format

[!NOTE] All development follows Microsoft Rust Guidelines.

MSRV Policy

Minimum Supported Rust Version: 1.91

MSRV increases are considered minor version bumps.

License

Licensed under either of Apache License 2.0 or MIT license at your option.