NEXUS · P-204

Accept a stage. See what changes.

One pump, two interfaces, shared rules. Three actions make the NEXUS principle tangible.

Pump P-204 commissioning

The first commissioning stage

Local simulation

1Action
2Shared state
3Protection

YOUR NEXT STEP

Accept the pressure test

In this scenario, the test has finished. Accept it as a participant in World.

Action result

Use the button above to see the result here.

What this checksA command changes the stage only according to core rules.

Try entering data

Try a number or a word. This checks the type, not physical truth.

Saved value: 0

View technical details

Inspectable state

Events in this simulation

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Technical walkthrough →Actions are cleared when the page is reloaded.

Explore the step-by-step explanation

Step 01 / 06

Start from one shared baseline

P-204 begins at Pressure Test. World and Companion read one process from Core.

BASELINE

Action in the scenario

Open Golden Demo V1 in both clients.

Core → World / Companion

Core response

Pressure Test is active in the engine. Acceptance is pending and overall readiness is BLOCKED.

What this step demonstrates

Both views refer to the same process rather than creating separate copies.

What it does not prove

PENDING in the Pressure Test presentation does not mean the process has yet to start: its stage is already ACTIVE.

What participants see

NEXUS CoreP-204

The authority for state

Process: PUMP-P204-COMMISSIONING
Current stage: Pressure Test
Overall readiness: BLOCKED

The process is not ready: the remaining stages are still ahead.

World

Spatial client

Pressure Test · PENDING

Same process

Companion

Web client

Pressure Test · PENDING

Same process

Technical details

{
  "illustrative": true,
  "processCode": "PUMP-P204-COMMISSIONING",
  "processIdentity": "unchanged",
  "processStatus": "ACTIVE",
  "activeStage": "Pressure Test",
  "pressureTestStatus": "PENDING",
  "overallReadiness": "BLOCKED",
  "context": {
    "commissioning.pressure": 0,
    "inspection.comment": "Awaiting pressure test acceptance."
  }
}

The full path

Pressure Test→ Active
Electrical ReadinessAhead
Mechanical ReadinessAhead
Ready for CommissioningAhead

Step 02 / 06

World sends a command. Core decides.

A participant sends Accept Pressure Test. The core checks access context and the current stage, then performs the transition.

ACCEPTED

Action in the scenario

World → Accept Pressure Test.

World → Core

Core response

Pressure Test is complete. Electrical Readiness is active. The process identifier is unchanged.

What this step demonstrates

Rules execute in the core. The client cannot assign itself a new state.

What it does not prove

This transition does not check physical pressure or leakage. The template has no pressure-threshold condition.

What participants see

NEXUS CoreP-204

The authority for state

Process: PUMP-P204-COMMISSIONING
Current stage: Electrical Readiness
Overall readiness: BLOCKED

The process is not ready: the remaining stages are still ahead.

World

Spatial client

Electrical Readiness · ACTIVE

Same process

Companion

Web client

Re-read happens in the next step

Data from the previous read

Technical details

{
  "illustrative": true,
  "processCode": "PUMP-P204-COMMISSIONING",
  "processIdentity": "unchanged",
  "processStatus": "ACTIVE",
  "activeStage": "Electrical Readiness",
  "pressureTestStatus": "COMPLETED",
  "overallReadiness": "BLOCKED",
  "context": {
    "commissioning.pressure": 0,
    "inspection.comment": "Awaiting pressure test acceptance."
  }
}

The full path

Pressure Test✓ Completed
Electrical Readiness→ Active
Mechanical ReadinessAhead
Ready for CommissioningAhead

Step 03 / 06

Companion reads the same result

The web client requests the state again. World and Companion do not need to talk directly: both use Core.

MATCHED

Action in the scenario

Companion → Refresh.

Companion → Core

Core response

The second client also shows Pressure Test completed and Electrical Readiness active.

What this step demonstrates

The read returns the same process at its new stage.

What it does not prove

This checks a read after refresh. It does not prove instant synchronization or offline guarantees.

What participants see

NEXUS CoreP-204

The authority for state

Process: PUMP-P204-COMMISSIONING
Current stage: Electrical Readiness
Overall readiness: BLOCKED

The process is not ready: the remaining stages are still ahead.

World

Spatial client

Electrical Readiness · ACTIVE

Same process

Companion

Web client

Electrical Readiness · ACTIVE

Same process

Technical details

{
  "illustrative": true,
  "processCode": "PUMP-P204-COMMISSIONING",
  "processIdentity": "unchanged",
  "processStatus": "ACTIVE",
  "activeStage": "Electrical Readiness",
  "pressureTestStatus": "COMPLETED",
  "overallReadiness": "BLOCKED",
  "context": {
    "commissioning.pressure": 0,
    "inspection.comment": "Awaiting pressure test acceptance."
  }
}

The full path

Pressure Test✓ Completed
Electrical Readiness→ Active
Mechanical ReadinessAhead
Ready for CommissioningAhead

Step 04 / 06

A value passes its type check

Companion saves the number 16.2 and a comment about the inspection. Core accepts data of the permitted types.

VALIDATED

Action in the scenario

Save commissioning.pressure = 16.2 and inspection.comment.

Companion → Core

Core response

NUMBER and STRING are accepted. The process does not jump to another stage.

What this step demonstrates

Context fields follow their contract. A string in place of a number would be rejected.

What it does not prove

These are participant-entered values. A type check does not establish that the no-leakage comment is true.

What participants see

NEXUS CoreP-204

The authority for state

Process: PUMP-P204-COMMISSIONING
Current stage: Electrical Readiness
Overall readiness: BLOCKED

The process is not ready: the remaining stages are still ahead.

World

Spatial client

Electrical Readiness · ACTIVE

Same process

Companion

Web client

Electrical Readiness · ACTIVE

Same process

Recorded value

16.2

A context value, not a sensor reading. The contract specifies no unit.

Technical details

{
  "illustrative": true,
  "processCode": "PUMP-P204-COMMISSIONING",
  "processIdentity": "unchanged",
  "processStatus": "ACTIVE",
  "activeStage": "Electrical Readiness",
  "pressureTestStatus": "COMPLETED",
  "overallReadiness": "BLOCKED",
  "context": {
    "commissioning.pressure": 16.2,
    "inspection.comment": "Pressure test passed. No leakage detected."
  }
}

The full path

Pressure Test✓ Completed
Electrical Readiness→ Active
Mechanical ReadinessAhead
Ready for CommissioningAhead

Step 05 / 06

A forbidden change stays forbidden

A participant attempts to change mission.title through context. That field is protected from this update.

REJECTED

Action in the scenario

Attempt to write a new value to mission.title.

Companion → Core

Core response

Core returns IMMUTABLE_CONTEXT_VARIABLE:mission.title. Context data and its history remain unchanged.

What this step demonstrates

The boundary is enforced by the core. A different interface cannot make an invalid operation valid.

What it does not prove

This shows one protected-field rejection, not an exhaustive review of permissions or possible attacks.

What participants see

NEXUS CoreP-204

The authority for state

Process: PUMP-P204-COMMISSIONING
Current stage: Electrical Readiness
Overall readiness: BLOCKED

The process is not ready: the remaining stages are still ahead.

World

Spatial client

Electrical Readiness · ACTIVE

Same process

Companion

Web client

Electrical Readiness · ACTIVE

Same process

Recorded value

16.2

A context value, not a sensor reading. The contract specifies no unit.

Technical details

{
  "illustrative": true,
  "processCode": "PUMP-P204-COMMISSIONING",
  "processIdentity": "unchanged",
  "processStatus": "ACTIVE",
  "activeStage": "Electrical Readiness",
  "pressureTestStatus": "COMPLETED",
  "overallReadiness": "BLOCKED",
  "context": {
    "commissioning.pressure": 16.2,
    "inspection.comment": "Pressure test passed. No leakage detected."
  },
  "rejection": "IMMUTABLE_CONTEXT_VARIABLE:mission.title"
}

The full path

Pressure Test✓ Completed
Electrical Readiness→ Active
Mechanical ReadinessAhead
Ready for CommissioningAhead

Step 06 / 06

One transition shown. The process is not ready.

Two clients agree on one state. Allowed data is recorded; the protected field is unchanged. Other stages remain.

PARTIAL PATH

Action in the scenario

Compare the resulting state with the scope of this scenario.

Core → World / Companion

Core response

Electrical Readiness is active. Overall readiness is still BLOCKED.

What this step demonstrates

The demonstration connects a command, a server-side rule and an inspectable state.

What it does not prove

It does not establish completed commissioning or a physical equipment outcome.

What participants see

NEXUS CoreP-204

The authority for state

Process: PUMP-P204-COMMISSIONING
Current stage: Electrical Readiness
Overall readiness: BLOCKED

The process is not ready: the remaining stages are still ahead.

World

Spatial client

Electrical Readiness · ACTIVE

Same process

Companion

Web client

Electrical Readiness · ACTIVE

Same process

Recorded value

16.2

A context value, not a sensor reading. The contract specifies no unit.

Technical details

{
  "illustrative": true,
  "processCode": "PUMP-P204-COMMISSIONING",
  "processIdentity": "unchanged",
  "processStatus": "ACTIVE",
  "activeStage": "Electrical Readiness",
  "pressureTestStatus": "COMPLETED",
  "overallReadiness": "BLOCKED",
  "context": {
    "commissioning.pressure": 16.2,
    "inspection.comment": "Pressure test passed. No leakage detected."
  }
}

The full path

Pressure Test✓ Completed
Electrical Readiness→ Active
Mechanical ReadinessAhead
Ready for CommissioningAhead

Basis and boundaries

This walkthrough follows Golden Demo V1, its template migration, service and NEXUS Core integration tests. Source reviewed on 28 September 2026. The states shown illustrate expected behavior; they are not server responses from this session.

The scenario checks

An allowed transition after participant, organization and current-stage validation.
Preservation of the process identifier and reads through Core by two clients.
Typed context validation and rejection of a protected-field change.

Outside this scenario

No physical pump, PLC, DCS or SCADA is connected. The no-leakage comment is entered by a participant, not measured by the system.
Only the first transition is shown. BLOCKED does not become READY after Pressure Test.
This does not establish operational impact, savings or readiness for industrial use.
The original demo has an owner-only reset that clears its demo history. Restart on this page simply returns to step one.

Basis of this walkthrough

This explanation is based on internal documentation and NEXUS Core source code. The repository is private; the public scenario explanation and its limitations are provided on this page.

P-204 scenario contract
Process and stage template
Command handling rules
Integration tests

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