Paulo Victor Gomes

Posted on Aug 1

Why I’m Betting on UTCP as a Serious Alternative to MCP

#mcp #ai #utcp

Over the past few years, I’ve worked on large-scale distributed systems where messaging, streaming, observability, and backpressure weren’t just technical details. They were daily blockers. Every protocol decision mattered, especially as teams scaled and complexity grew.

That’s why when MCP (Model Context Protocol) was introduced in late 2024, I was genuinely excited. It brought a structured way to manage AI model contexts, enabling execution orchestration, consistent context propagation, and model-aware communication. In many ways, MCP filled a much-needed gap in the AI stack.

But like any new protocol, it still has room to evolve.

Recently, I spent some time reviewing a new proposal called UTCP (Unified Transport Control Protocol). After reading the RFC and supporting documentation, I believe it deserves serious consideration. Not because MCP is broken, but because UTCP addresses a different set of system-level needs that will likely become more relevant over time.

If you’re working with MCP today or planning to adopt it, I think it’s worth understanding what UTCP is offering. Here’s why.

🧠 A Simple Code Comparison: MCP vs UTCP in Clojure

Before jumping to recommendations, here’s a simplified Clojure example that helps explain the difference in scope and philosophy between MCP and UTCP.

This code is conceptual. It’s not connected to real-world libraries. The goal is to visualize the design mindset of each protocol.

MCP – Wrapping Context Around Model Execution

(defn run-inference \[model input context\]  
  (let \[merged-context (merge {:trace-id (java.util.UUID/randomUUID)} context)\]  
    {:model model  
     :input input  
     :context merged-context  
     :result (str "Inference result for input: " input)}))

;; Example usage  
(run-inference "gpt-4" "Summarize this article" {:user-id "abc123"})

Explanation:

MCP helps structure model requests by embedding metadata such as trace IDs, user roles, or request origin. The focus is on organizing context per call.

UTCP – Streaming-Aware Transport with Flow Control

(defn send-stream \[stream metadata\]  
  (let \[session-id (java.util.UUID/randomUUID)\]  
    (doseq \[chunk stream\]  
      (if (\< (rand) 0.95) ;; simulate backpressure  
        (println "Transmitting chunk:" chunk "with session:" session-id)  
        (println "Backpressure triggered, delaying chunk:" chunk)))  
    {:status :ok  
     :session session-id  
     :trace (str "Trace ID: " (:trace-id metadata))}))

;; Example usage  
(send-stream \["Hello" "world" "this" "is" "UTCP"\] {:trace-id "xyz789"})

Explanation:

UTCP focuses on message flow, backpressure handling, and streaming behavior. It’s meant for transporting data in motion across services.

Quick Comparison

Feature	MCP	UTCP
Purpose	Contextual model execution	Streaming-aware transport and control
Handles Streams?	No	Yes
Observability	Context passed manually	Tracing built-in
Backpressure	Not handled	Handled natively
Usage Style	Wrap model calls	Transmit and control stream behavior

Why I Think UTCP Is Worth Watching

Designed for Streaming from the Start

UTCP handles continuous data flows as a first-class concern. It fits naturally into systems where data is not just requested but streamed, processed, and forwarded in near real-time.

Observability Is Built Into the Protocol

UTCP includes native support for:

Tracing identifiers
Telemetry at each node
A simple message recorder to track flow paths

You don’t need extra tooling or manual hooks to understand how your system behaves.

Clear Separation of Layers

UTCP introduces a modular protocol structure:

Transport Layer for message delivery and retries
Control Layer for routing and QoS
Extension Layer for optional features like compression, authentication, or domain-specific plugins

This makes it easier to evolve and maintain in production environments.

Built-In Backpressure Handling

Consumers can signal capacity to upstream producers directly within the protocol. That avoids the need for application-level workarounds and keeps message flow stable even under load.

Multiple Reliability Modes

UTCP allows you to choose what level of message delivery makes sense:

At-most-once
At-least-once
Exactly-once (through optional extensions)

This kind of flexibility helps you avoid overengineering while still covering critical paths.

Attention to Security and Governance

The protocol includes:

Support for tagging and metadata for policy enforcement
Hooks for authentication and authorization
Audit-friendly structure out of the box

This is essential for teams operating in regulated industries or complex internal environments.

My Recommendation

Am I saying you should drop MCP and move to UTCP, even though MCP just launched?

Not really.

I understand it’s an overwhelming amount of information, and we’re still learning how to extract more value from MCP. It’s early days, and MCP still has a lot of potential to fulfill.

So my point is this: keep your eye on UTCP. It’s being built by people solving the right problems. If more people contribute to it, test it, and share feedback, we might end up with something that grows through the community. And who knows — maybe one day it becomes more powerful than anything released by the big tech players.

If you’re someone who cares about protocol design, system behavior, and software that lasts, I think UTCP is worth your time.

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