---
title: Four planes, one protocol
url: https://revworx.ai/insights/four-planes-one-protocol/
date: 2026-10-27T23:42:28+00:00
modified: 2026-11-06T21:04:54+00:00
lang: en_US
---

# Four planes, one protocol

Most GTM stacks are described as a list of tools. This one is described as a picture: four layers, which the architecture calls planes, sitting between you and the work. You speak to the top one. It reaches down through the other three to get things done, and it comes back to you only when a decision is yours to make.

![Figure 1. The four planes, read from the top down](https://revworx.ai/wp-content/uploads/cra-figure-1-four-planes.png)

## Each plane answers one question

- **Cognition: who decides?** The Cognition Plane is the part you talk to. It holds the reasoning: a supervising agent, its specialists, the context it keeps about your business and the guardrails and approval gates that keep it inside the lines. A weekly pipeline review, a draft of outreach copy or a request for a new integration lands here first.
- **Tool: what can it do?** The Tool Plane is every capability the system can reach, whether a CRM, an ad platform, a meeting transcript service or the website itself. All of them are reached through one protocol, the Model Context Protocol (MCP). Because the protocol is uniform, capabilities can be added or replaced one at a time. Because they are discovered only when needed, adding more neither slows the system nor raises its running cost.
- **Execution: where does it run?** The Execution Plane is the infrastructure the tools run on. Here it is owned rather than rented, and it is reachable through the same protocol as everything else. That is what lets the system extend and repair itself: set up a server, deploy to it, inspect it, restart it.
- **Data: what does it know?** The Data Plane draws a line between the records your business owns, which live outside every tool, and the external sources it merely reads.

## The line that makes it composable

That last line is the one to hold on to. When the record lives outside every tool, you can swap a tool and the record is untouched. Composable is not a slogan here. It is a property you can test: replace one part and see whether anything else has to move.

## One protocol between them

Four planes would be a diagram and nothing more if every connection between them were built by hand. A single protocol is what turns the picture into a working system. The top plane does not need to know how a capability is built, only that it can be discovered and called the same way as every other one.

## How to use the picture

The rest of the architecture is organized around these four questions. Part One explains why this is possible now. Part Two takes each plane in turn. Part Three covers where the system meets people. Part Four states what it covers and what it is not.

Vendor names appear only where the architecture describes its current implementation, because the pattern outlives any particular choice.

Key takeaway

Four planes, one protocol between them. You talk to the top; it reaches the rest. Keep the picture in mind and every later section is a closer look at one part of it.

Read the full section: [The architecture at a glance](/architecture/1/)

Cite as: revWorx (2026). A Composable Reference Architecture for Autonomous GTM Operations, First Edition, §1. revworx.ai.