MCP TypeScript Implementation (MCP-PIF) is an MCP server that provides a JSON-native lambda calculus runtime with metacircular evaluation for large language models. The server acts as a computational engine, giving AI models access to pure, deterministic computing without granting unrestricted system or shell execution privileges. Software engineers, AI researchers, and agent developers use this server to equip language models with inspectable, self-modifying, and evolvable tools. By exposing core lambda calculus primitives alongside metaprogramming constructs such as quote, eval, and code introspection, the server allows models to author new functional operations, inspect their definitions, and run computations safely. The runtime enforces execution fuel limits to prevent runaway loops and uses step-by-step continuations for handling deeper recursive tasks cleanly across protocol requests. The system separates effectful tool registration from purely functional tool execution, isolating core invariants while giving models a sandboxed mathematical substrate for arithmetic, logical evaluations, list processing, and dynamic algorithm evolution.
Category: AI & LLM Tooling
Tags: framework, protocol, sdk, typescript
Visit MCP TypeScript Implementation
cabal build in the repository root directory. 3. Verify the build by testing the runtime with cabal run mcp-pif or enable evaluation tracing using MCP_DEBUG=1 cabal run mcp-pif. 4. Open your MCP client configuration file (such as Claude Desktop or Cursor) and register the server under the mcpServers object: json { "mcpServers": { "mcp-pif": { "command": "cabal", "args": ["run", "mcp-pif"], "cwd": "/path/to/MCP-PIF" } } } 5. Replace /path/to/MCP-PIF with the absolute path to your cloned repository. 6. Restart your MCP client to connect the runtime.Part of MCP Servers
MCP-PIF is a JSON-native lambda calculus execution runtime exposed as an MCP server. It gives language models a safe computational environment for creating, executing, and introspecting pure functional tools. Instead of running arbitrary shell scripts or external code interpreters, models interact with homoiconic lambda primitives that guarantee deterministic, fuel-bounded execution.
You can build and run the server locally using Haskell Cabal. Clone the repository and execute cabal build in your terminal. After building, start the server using cabal run mcp-pif. You can also configure MCP clients such as Claude Desktop to launch this command automatically over standard input and output.
The server provides three primary MCP tools: evolve, run, and help. The evolve tool registers new lambda functions into the tool registry. The run tool executes registered tools or inline lambda expressions against user inputs. The help tool returns detailed documentation for categories like list primitives and arithmetic.
The runtime limits direct recursion using an execution fuel counter capped at 10,000 steps to prevent infinite execution. For deeper recursions that exceed fuel limits, the server supports a continue primitive that pauses evaluation and returns a continuation structure to the MCP client for iterative stepping with accumulators.
MCP-PIF adheres to the standard Model Context Protocol specification over standard input and output. It works with any compliant MCP client, including Claude Desktop, Cursor, and custom developer frameworks that support stdio MCP transport configurations.