fix

app/controllers/cwmp_controller.ts

@@ -131,6 +131,10 @@ export default class CwmpController {
     const paramValues = informData?.ParameterList?.ParameterValueStruct || []
     if (paramValues.length > 0) {
       device.updateFromValues(paramValues)
+      // Some writable parameters arrive in the Inform before GPN has classified them.
+      // updateFromValues falls back to storing unknowns as read-only properties.
+      // Reclassify known-writable Inform parameters as parameters (writable).
+      device.reclassifyInformWritables(paramValues)
     }
 
     device.setTmpParamValues(paramValues)

app/domain/device/device.ts

@@ -255,6 +255,33 @@ export class Device {
     this._properties.delete(name)
   }
 
+  /**
+   * Parameters that arrive in the Inform payload are writable by definition
+   * (the CPE reports them because the ACS is supposed to manage them).
+   * updateFromValues() defaults unknowns to properties (read-only), so we
+   * promote the known-writable Inform params back to parameters here.
+   *
+   * Known writable Inform parameters (TR-098 and TR-181):
+   *   - *.ProvisioningCode
+   *   - *.ParameterKey
+   */
+  public reclassifyInformWritables(paramValues: any[]): void {
+    const WRITABLE_PATTERNS = [
+      /(^|\.)ProvisioningCode$/,
+      /(^|\.)ParameterKey$/,
+    ]
+    for (const pv of paramValues || []) {
+      const name = typeof pv?.Name === 'string' ? pv.Name : pv?.Name?._ || null
+      if (!name) continue
+      if (!WRITABLE_PATTERNS.some((re) => re.test(name))) continue
+      // Only act if it ended up as a property (wrong classification)
+      if (!this._properties.has(name)) continue
+      const prop = this._properties.get(name)!
+      this._properties.delete(name)
+      this._parameters.set(name, new DeviceParameter(name, prop.value, prop.type))
+    }
+  }
+
   public getConnectionRequestURL(): URL | null {
     for (const property of this._properties.values()) {
       const url = property.getConnectionRequestURL()

app/services/cwmp/main_state_machine.ts

@@ -59,9 +59,10 @@ class IdleState extends DeviceState {
       '[IdleState] GPN allowed — proceeding to discovery'
     )
 
-    // Discover mandatory subtrees via GPN.
-    // DeviceInfo is always included so that HardwareVersion, SoftwareVersion,
-    // ModelName, etc. are classified (writable vs read-only) on every session.
+    // GPN is supported: discover mandatory subtrees to classify parameters.
+    // DeviceInfo. is always included so HardwareVersion, SoftwareVersion, ModelName etc.
+    // are classified (writable vs read-only) from the device itself.
+    // If GPN is not supported, the catalog handles classification (reclassifyDeviceFromCatalog).
     const dataModel = device.dataModel
     if (dataModel === 'tr-181') {
       return {
@@ -80,7 +81,7 @@ class IdleState extends DeviceState {
         response: '',
       }
     }
-    // Unknown data model — skip GPN test, go to CriticalReadsState
+    // Unknown data model — skip GPN, go to CriticalReadsState
     return { nextState: new CriticalReadsState(), response: '' }
   }
 }

tests/unit/domain/device.spec.ts

@@ -226,3 +226,67 @@ describe('Device', () => {
     expect(d.getParameter('Device.X')!.value).toBe('new')
   })
 })
+
+describe('Device.reclassifyInformWritables', () => {
+  it('promotes ProvisioningCode from property to parameter', () => {
+    const d = makeDevice()
+    // Simulate what updateFromValues does on Inform: stores as property (unknown writability)
+    d.setProperty(new DeviceProperty('InternetGatewayDevice.DeviceInfo.ProvisioningCode', 'abc'))
+
+    d.reclassifyInformWritables([
+      { Name: 'InternetGatewayDevice.DeviceInfo.ProvisioningCode', Value: { _: 'abc' } },
+    ])
+
+    expect(d.getParameter('InternetGatewayDevice.DeviceInfo.ProvisioningCode')).not.toBeNull()
+    expect(d.getProperty('InternetGatewayDevice.DeviceInfo.ProvisioningCode')).toBeNull()
+  })
+
+  it('promotes ParameterKey from property to parameter', () => {
+    const d = makeDevice()
+    d.setProperty(new DeviceProperty('InternetGatewayDevice.ManagementServer.ParameterKey', ''))
+
+    d.reclassifyInformWritables([
+      { Name: 'InternetGatewayDevice.ManagementServer.ParameterKey', Value: { _: '' } },
+    ])
+
+    expect(d.getParameter('InternetGatewayDevice.ManagementServer.ParameterKey')).not.toBeNull()
+    expect(d.getProperty('InternetGatewayDevice.ManagementServer.ParameterKey')).toBeNull()
+  })
+
+  it('does not touch params that are already parameters', () => {
+    const d = makeDevice()
+    d.setParameter(new DeviceParameter('Device.DeviceInfo.ProvisioningCode', 'existing'))
+
+    d.reclassifyInformWritables([
+      { Name: 'Device.DeviceInfo.ProvisioningCode', Value: { _: 'existing' } },
+    ])
+
+    expect(d.getParameter('Device.DeviceInfo.ProvisioningCode')!.value).toBe('existing')
+    expect(d.getProperty('Device.DeviceInfo.ProvisioningCode')).toBeNull()
+  })
+
+  it('does not reclassify unknown names (e.g. SoftwareVersion stays property)', () => {
+    const d = makeDevice()
+    d.setProperty(new DeviceProperty('InternetGatewayDevice.DeviceInfo.SoftwareVersion', 'v1'))
+
+    d.reclassifyInformWritables([
+      { Name: 'InternetGatewayDevice.DeviceInfo.SoftwareVersion', Value: { _: 'v1' } },
+    ])
+
+    // SoftwareVersion is NOT in the writable list — should stay as property
+    expect(d.getProperty('InternetGatewayDevice.DeviceInfo.SoftwareVersion')).not.toBeNull()
+    expect(d.getParameter('InternetGatewayDevice.DeviceInfo.SoftwareVersion')).toBeNull()
+  })
+
+  it('handles Name as object node (XMLParser artefact)', () => {
+    const d = makeDevice()
+    d.setProperty(new DeviceProperty('Device.DeviceInfo.ProvisioningCode', 'code'))
+
+    d.reclassifyInformWritables([
+      { Name: { _: 'Device.DeviceInfo.ProvisioningCode' }, Value: { _: 'code' } },
+    ])
+
+    expect(d.getParameter('Device.DeviceInfo.ProvisioningCode')).not.toBeNull()
+    expect(d.getProperty('Device.DeviceInfo.ProvisioningCode')).toBeNull()
+  })
+})