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Code Execution with MCP (CE-MCP) Research Findings

Date: 2025-12-09 Status: Validated - documcp is CE-MCP Compatible ✅

Executive Summary​

After comprehensive research into the Code Execution with MCP (CE-MCP) paradigm, we've confirmed that documcp's existing architecture is fully compatible with Code Mode clients without requiring architectural changes.

Key Discoveries​

1. CE-MCP is Client-Side, Not Server-Side​

The CE-MCP paradigm described in the architectural guide is implemented by MCP clients (Claude Code, Cloudflare Workers AI, pctx), not servers:

ResponsibilityImplementationStatus for documcp
Code generationMCP Client✅ Client handles
Tool discoveryMCP Client (generates filesystem structure)✅ Compatible
Sandboxed executionMCP Client (isolates, Docker, etc.)✅ Client handles
Security (AgentBound-style)MCP Client (MCP Guardian, etc.)✅ Client handles
Summary filteringMCP Client✅ Compatible
Tool definitions & schemasMCP Server (documcp)✅ Already implemented
Tool executionMCP Server (documcp)✅ Already implemented

2. What MCP Servers Provide​

According to Anthropic and Cloudflare's documentation:

"MCP is designed for tool-calling, but it doesn't actually have to be used that way. The 'tools' that an MCP server exposes are really just an RPC interface with attached documentation."

MCP servers (like documcp) provide:

  • Standard MCP protocol tools ✅ (documcp has 25+ tools)
  • Tool schemas and documentation ✅ (Zod-validated)
  • JSON-RPC interface ✅ (MCP SDK handles this)

That's it! The client SDK handles everything else.

3. How Code Mode Works​

Client-Side Transformation:

  1. Client connects to MCP server and receives tool definitions
  2. Client converts tool definitions → TypeScript/Python code APIs
  3. Client creates filesystem structure for tool discovery (e.g., ./servers/google-drive/getDocument.ts)
  4. LLM navigates filesystem and reads only needed tool definitions
  5. LLM generates orchestration code using the tool APIs
  6. Client executes code in secure sandbox (isolate, Docker, etc.)
  7. Only final summary returned to LLM context

Result: 98.7% token reduction, 75x cost reduction, 60% faster execution

4. MCP SDK 1.24.0 New Features​

PR #69 upgrades us from v0.6.0 → v1.24.0, bringing:

  • SEP-1686: Tasks API - New MCP primitive for long-running agent operations
  • Better SSE (Server-Sent Events) handling
  • OAuth enhancements (client credentials flow)
  • Improved type safety and Zod V4 compatibility

Validation Results​

✅ SDK Upgrade Successful​

  • All tests pass: 91.67% coverage
  • No breaking changes detected
  • TypeScript compilation successful
  • Build successful

✅ documcp Architecture Validates​

Why documcp is already Code Mode compatible:

  1. Stateless Design (ADR-001): Perfect for Code Mode workflows
  2. Modular Tools (ADR-006): Each tool is independent and composable
  3. Zod Validation: Provides excellent schema docs for code generation
  4. JSON-RPC: Standard MCP protocol, works with all clients
  5. MCP Resources (ADR-007): Perfect for summary-only result filtering

Architectural Implications​

What documcp Does NOT Need​

❌ Filesystem-based tool discovery system (client does this) ❌ Sandbox execution environment (client does this) ❌ AgentBound security framework (client does this) ❌ Code generation layer (client does this) ❌ Tool wrappers (client generates these) ❌ Major architectural changes

What documcp COULD Optimize (Optional)​

These are optional enhancements for better Code Mode UX, not requirements:

  1. Tool Categorization - Add metadata tags for easier discovery
  2. Concise Descriptions - Optimize tool descriptions for token efficiency
  3. Result Summarization - Return more concise results where appropriate
  4. MCP Tasks Integration - Use new Tasks API for long-running operations
  5. Resource Optimization - Better use of MCP resources for intermediate results

Immediate (Completed ✅)​

  • Merge PR #69 (SDK upgrade to 1.24.0)
  • Run tests to validate compatibility
  • Document CE-MCP findings

Short-Term (This Sprint)​

  • Create ADR-011: CE-MCP Compatibility and Code Mode Support
  • Update ADR-001: Add Code Mode compatibility note
  • Update ADR-006: Add tool organization recommendations
  • Update ADR-007: Add resource optimization for Code Mode
  • Test with Code Mode client (Claude Code, pctx)
  • Create CE-MCP usage documentation

Medium-Term (Optional Optimizations)​

  • Research which tools benefit from MCP Tasks API
  • Add tool categorization metadata
  • Optimize tool descriptions for token efficiency
  • Implement result summarization for large outputs
  • Create example Code Mode workflows

References​

Conclusion​

documcp's existing architecture is fully Code Mode compatible. The stateless, tool-based design aligns perfectly with the CE-MCP paradigm. No architectural changes are required—only optional optimizations to enhance the user experience with Code Mode clients.

The CE-MCP paradigm validates our architectural decisions in ADR-001, ADR-006, and ADR-007. The focus should now shift to testing with Code Mode clients and documenting best practices for developers using documcp in Code Mode workflows.