When business and IT adapt their ERP themselves, the in-client assistant is often enough. When IT builds custom clients, apps, or integrations, it needs the same tool layer outside the standard client. That is what Nuclos MCP is for.

Roles in short:

• Nuclos Workspace is the offer: the environment for modeling, configuration, and self-build.
• Nuclosian is the AI assistant in the web client (configuration mode). Proposals with a diff and approval before anything is applied.
• Nuclos MCP is the open tool layer for developers. The same facts and actions Nuclosian uses in the client are available for custom clients, apps, and IDE connections.

MCP as a protocol is the foundation. This guide explains what that means in Nuclos and which entry point fits which team.

The decision you are making

Three typical situations:

1. Business configures in the client. Status models, screens, and rules are created where the team already works. Nuclosian is enough. No separate developer stack required.
2. IT builds custom surfaces. Mobile apps, industry clients, internal portals, or automation pipelines need the same access to model and data, but outside the web client. That is when Nuclos MCP comes in.
3. Both in parallel. Business works in the client; IT delivers custom clients on the same catalog. One governance model, two surfaces.

Most teams start with Nuclosian. MCP is the next step, not the first.

What Nuclos MCP actually unlocks

The catalog bundles the domains that matter for configuration and operations, including:

• Status models and transitions
• Server rules and assignments
• Layouts and screens
• Entities and metadata
• Records (read and write)
• Write actions with a confirmation path

AI assistants and custom applications call these tools deliberately. They work with real server data, not invented assumptions. The foundation is the platform metadata and low-code model; see Low-code in ERP and Nuclos 5: platform, open source, and AI.

Why this is not “just chat on the ERP”

Uncontrolled chat over operational transactions without approval is not the current product surface. Nuclos separates concerns on purpose:

• Read can proceed freely within the logged-in user’s permissions.
• Write needs confirmation: show the diff, then apply.
• Destructive or secret actions can be locked (allow-list). Credential tools stay locked.
• Audit records who triggered what and when.
• Foreign content in record fields or external text is treated as untrusted (prompt-injection protection).

The agent loop does not run in the browser. LLM keys stay on the server. Tools act in the logged-in user’s session, not through a service account with special privileges. Cloud LLM or a local model is selectable; fields can optionally be masked before anything leaves the premises.

In short: the same governance logic as in the client. MCP does not change the rights model. It adds a tool layer on top.

Nuclosian or Nuclos MCP?

Next steps

• Offer and demo entry: Nuclos Workspace
• Technical depth for IT: Dev Portal
• Short protocol definition: What is MCP?

Nuclos MCP is the tool layer for self-build. It is not the marketing name for Workspace, and not a promise of autonomous AI for productive end users without a superuser and config gate.