diff --git a/EnoceanCLI.ps1 b/EnoceanCLI.ps1
index 8d91e6d..fd668f9 100644
--- a/EnoceanCLI.ps1
+++ b/EnoceanCLI.ps1
@@ -244,6 +244,7 @@ elseif ($Action -eq "Write") {
 
             # Associer par index sequentiel : device[0] -> DeviceId_1, device[1] -> DeviceId_2, etc.
             $xmlFiles = @()
+            $deviceIdMap = @{}  # Paires ancien -> nouveau pour mise a jour GFx
             for ($i = 0; $i -lt $existingDevices.Count; $i++) {
                 $seqIndex = $i + 1
                 $deviceIdCol = "DeviceId_$seqIndex"
@@ -281,6 +282,11 @@ elseif ($Action -eq "Write") {
                     Content = $result.ModifiedXml
                 }
 
+                # Collecter la paire ancien -> nouveau pour le GFx
+                if ($result.OldDeviceId -ne $newDeviceId) {
+                    $deviceIdMap[$result.OldDeviceId] = $newDeviceId
+                }
+
                 Update-Stats -Counter DevicesProcessed
                 Write-Log -Message "[$hostname] Device $($device.Name) : $($result.OldDeviceId) -> $newDeviceId" -Level INFO
             }
@@ -290,7 +296,7 @@ elseif ($Action -eq "Write") {
                 continue
             }
 
-            # Creer le ZIP et l'envoyer
+            # Creer le ZIP enocean et l'envoyer
             $zipBytes = New-EnoceanZip -XmlFiles $xmlFiles
             $zipFilename = Get-ZipFilename -ZipBytes $zipBytes
 
@@ -304,7 +310,42 @@ elseif ($Action -eq "Write") {
                 -Username $creds.Username `
                 -Password $creds.Password
 
-            Write-Log -Message "[$hostname] Configuration envoyee avec succes" -Level SUCCESS
+            Write-Log -Message "[$hostname] Configuration enocean envoyee avec succes" -Level SUCCESS
+
+            # Mise a jour du Project.gfx (fichier source du programme)
+            if ($deviceIdMap.Count -gt 0) {
+                Write-Log -Message "[$hostname] Mise a jour du Project.gfx..." -Level INFO
+
+                $gfxBytes = Invoke-EnoceanGet `
+                    -BaseUrl $baseUrl `
+                    -ApiBasePath $apiBasePath `
+                    -ResourcePath "files/common/localDevice/project/Project.gfx?encode=bin" `
+                    -Username $creds.Username `
+                    -Password $creds.Password `
+                    -RawBytes
+
+                $mainXml = Read-GfxMainXml -GfxBytes $gfxBytes
+
+                $gfxResult = Update-GfxDeviceIds -MainXmlContent $mainXml -DeviceIdMap $deviceIdMap
+
+                if ($gfxResult.ReplaceCount -gt 0) {
+                    $newGfxBytes = Update-GfxZip -GfxBytes $gfxBytes -ModifiedMainXml $gfxResult.ModifiedXml
+
+                    Send-MultipartFile `
+                        -BaseUrl $baseUrl `
+                        -ApiBasePath $apiBasePath `
+                        -ResourcePath "files/common/localDevice/project" `
+                        -FileBytes $newGfxBytes `
+                        -Filename "Project.gfx" `
+                        -Username $creds.Username `
+                        -Password $creds.Password
+
+                    Write-Log -Message "[$hostname] Project.gfx mis a jour ($($gfxResult.ReplaceCount) DeviceId modifie(s))" -Level SUCCESS
+                }
+                else {
+                    Write-Log -Message "[$hostname] Project.gfx : aucun DeviceId trouve a modifier" -Level WARN
+                }
+            }
         }
         catch {
             Write-Log -Message "[$hostname] ERREUR : $($_.Exception.Message)" -Level ERROR
diff --git a/README.md b/README.md
index 2643bfb..0bc9486 100644
--- a/README.md
+++ b/README.md
@@ -89,7 +89,7 @@ Avec un mot de passe :
 ### Action Write — Écrire les DeviceId sur les automates
 
 ```powershell
-.\EnoceanCLI.ps1 -Action Write -CsvInput ".\enocean_2026-03-03_23h07.csv" -Password "MonMotDePasse"
+.\EnoceanCLI.ps1 -Action Write -CsvInput ".\enocean_2026-03-04_10h07.csv" -Password "MonMotDePasse"
 ```
 
 **Ce qui se passe** :
@@ -194,7 +194,7 @@ Relancer un Read pour confirmer que les DeviceId ont bien changé :
 Chaque exécution génère un fichier log dans le dossier courant :
 
 ```
-enocean_2026-03-04_14h30.log
+enocean_2026-03-04_15h30.log
 ```
 
 ### Niveaux de log
@@ -210,7 +210,7 @@ enocean_2026-03-04_14h30.log
 
 ```
 [2026-03-04 00:17:43] [INFO]    === EnoceanCLI demarre - Action: Write ===
-[2026-03-04 00:17:43] [INFO]    [MON-AUTOMATE-01] https://10.60.105.42/api/rest/v1 (user: admin)
+[2026-03-04 00:17:43] [INFO]    [MON-AUTOMATE-01] https://192.168.1.11/api/rest/v1 (user: admin)
 [2026-03-04 00:17:43] [INFO]    [MON-AUTOMATE-01] 3 device(s) existant(s) sur l'automate
 [2026-03-04 00:17:43] [INFO]    [MON-AUTOMATE-01] Device enoceandevice1.xml : 12345678 -> 99864513
 [2026-03-04 00:17:43] [INFO]    [MON-AUTOMATE-01] Device enoceandevice2.xml : 87654321 -> 65313272
@@ -260,7 +260,7 @@ L'automate n'a pas de capteurs EnOcean configurés. L'action Write ne peut pas m
 
 ### Timeout ou erreur de connexion
 
-- Vérifier que l'automate est joignable (`ping 10.60.x.x`)
+- Vérifier que l'automate est joignable (`ping 192.168.1.x`)
 - Vérifier les identifiants (Username / Password)
 - Vérifier que le port est correct (HTTP 80 ou HTTPS 443)
 
diff --git a/modules/ApiClient.psm1 b/modules/ApiClient.psm1
index 08bb897..884469c 100644
--- a/modules/ApiClient.psm1
+++ b/modules/ApiClient.psm1
@@ -65,7 +65,9 @@ function Invoke-EnoceanGet {
 
         [Parameter(Mandatory)]
         [AllowEmptyString()]
-        [string]$Password
+        [string]$Password,
+
+        [switch]$RawBytes
     )
 
     $headers = Get-AuthHeader -Username $Username -Password $Password
@@ -75,6 +77,14 @@ function Invoke-EnoceanGet {
 
     $response = Invoke-WebRequest -Uri $url -Method GET -Headers $headers -UseBasicParsing -TimeoutSec 30
 
+    # Retourner les bytes bruts si demande (pour fichiers binaires comme .gfx)
+    if ($RawBytes) {
+        if ($response.Content -is [byte[]]) {
+            return , $response.Content
+        }
+        return , [System.Text.Encoding]::UTF8.GetBytes($response.Content)
+    }
+
     # Si la reponse est un byte[] (encode=bin), decoder en string UTF-8 sans BOM
     if ($response.Content -is [byte[]]) {
         return [System.Text.Encoding]::UTF8.GetString($response.Content).TrimStart([char]0xFEFF)
@@ -82,7 +92,7 @@ function Invoke-EnoceanGet {
     return $response.Content
 }
 
-function Send-EnoceanConfig {
+function Send-MultipartFile {
     [CmdletBinding()]
     param(
         [Parameter(Mandatory)]
@@ -92,10 +102,13 @@ function Send-EnoceanConfig {
         [string]$ApiBasePath,
 
         [Parameter(Mandatory)]
-        [byte[]]$ZipBytes,
+        [string]$ResourcePath,
 
         [Parameter(Mandatory)]
-        [string]$ZipFilename,
+        [byte[]]$FileBytes,
+
+        [Parameter(Mandatory)]
+        [string]$Filename,
 
         [Parameter(Mandatory)]
         [string]$Username,
@@ -106,17 +119,15 @@ function Send-EnoceanConfig {
     )
 
     $authHeaders = Get-AuthHeader -Username $Username -Password $Password
-    $url = "$BaseUrl$ApiBasePath/files/bacnet/inputConfiguration"
+    $url = "$BaseUrl$ApiBasePath/$($ResourcePath.TrimStart('/'))"
 
-    Write-Log -Message "POST $url (fichier: $ZipFilename, taille: $($ZipBytes.Length) octets)" -Level INFO
+    Write-Log -Message "POST $url (fichier: $Filename, taille: $($FileBytes.Length) octets)" -Level INFO
 
     # Construction multipart manuelle
     $boundary = [System.Guid]::NewGuid().ToString("N")
     $encoding = [System.Text.Encoding]::ASCII
 
-    # Partie avant le fichier
-    $headerPart = "--$boundary`r`nContent-Disposition: form-data; name=`"File`"; filename=`"$ZipFilename`"`r`nContent-Type: application/octet-stream`r`n`r`n"
-    # Partie finale
+    $headerPart = "--$boundary`r`nContent-Disposition: form-data; name=`"File`"; filename=`"$Filename`"`r`nContent-Type: application/octet-stream`r`n`r`n"
     $footerPart = "`r`n--$boundary--`r`n"
 
     $headerBytes = $encoding.GetBytes($headerPart)
@@ -125,7 +136,7 @@ function Send-EnoceanConfig {
     # Assembler le body complet en byte[]
     $bodyStream = New-Object System.IO.MemoryStream
     $bodyStream.Write($headerBytes, 0, $headerBytes.Length)
-    $bodyStream.Write($ZipBytes, 0, $ZipBytes.Length)
+    $bodyStream.Write($FileBytes, 0, $FileBytes.Length)
     $bodyStream.Write($footerBytes, 0, $footerBytes.Length)
     $bodyBytes = $bodyStream.ToArray()
     $bodyStream.Close()
@@ -165,4 +176,37 @@ function Send-EnoceanConfig {
     }
 }
 
-Export-ModuleMember -Function Initialize-ApiClient, Get-AuthHeader, Invoke-EnoceanGet, Send-EnoceanConfig
+function Send-EnoceanConfig {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)]
+        [string]$BaseUrl,
+
+        [Parameter(Mandatory)]
+        [string]$ApiBasePath,
+
+        [Parameter(Mandatory)]
+        [byte[]]$ZipBytes,
+
+        [Parameter(Mandatory)]
+        [string]$ZipFilename,
+
+        [Parameter(Mandatory)]
+        [string]$Username,
+
+        [Parameter(Mandatory)]
+        [AllowEmptyString()]
+        [string]$Password
+    )
+
+    Send-MultipartFile `
+        -BaseUrl $BaseUrl `
+        -ApiBasePath $ApiBasePath `
+        -ResourcePath "files/bacnet/inputConfiguration" `
+        -FileBytes $ZipBytes `
+        -Filename $ZipFilename `
+        -Username $Username `
+        -Password $Password
+}
+
+Export-ModuleMember -Function Initialize-ApiClient, Get-AuthHeader, Invoke-EnoceanGet, Send-MultipartFile, Send-EnoceanConfig
diff --git a/modules/XmlParser.psm1 b/modules/XmlParser.psm1
index 6841279..d71f571 100644
--- a/modules/XmlParser.psm1
+++ b/modules/XmlParser.psm1
@@ -97,4 +97,34 @@ function Update-EnoceanDeviceId {
     }
 }
 
-Export-ModuleMember -Function Get-DeviceListFromJson, Parse-EnoceanDeviceXml, New-EnoceanDeviceXml, Update-EnoceanDeviceId
+function Update-GfxDeviceIds {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)]
+        [string]$MainXmlContent,
+
+        [Parameter(Mandatory)]
+        [hashtable]$DeviceIdMap  # @{ "ancien_id" = "nouveau_id" }
+    )
+
+    $modifiedXml = $MainXmlContent
+    $replaceCount = 0
+
+    foreach ($oldId in $DeviceIdMap.Keys) {
+        $newId = $DeviceIdMap[$oldId]
+        $pattern = "<DeviceId>$oldId</DeviceId>"
+        $replacement = "<DeviceId>$newId</DeviceId>"
+
+        if ($modifiedXml -match [regex]::Escape($pattern)) {
+            $modifiedXml = $modifiedXml -replace [regex]::Escape($pattern), $replacement
+            $replaceCount++
+        }
+    }
+
+    return @{
+        ModifiedXml  = $modifiedXml
+        ReplaceCount = $replaceCount
+    }
+}
+
+Export-ModuleMember -Function Get-DeviceListFromJson, Parse-EnoceanDeviceXml, New-EnoceanDeviceXml, Update-EnoceanDeviceId, Update-GfxDeviceIds
diff --git a/modules/ZipBuilder.psm1 b/modules/ZipBuilder.psm1
index 48275e9..fe0a228 100644
--- a/modules/ZipBuilder.psm1
+++ b/modules/ZipBuilder.psm1
@@ -52,4 +52,74 @@ function Get-ZipFilename {
     return "fullConfig.$hashString.zip"
 }
 
-Export-ModuleMember -Function New-EnoceanZip, Get-ZipFilename
+function Read-GfxMainXml {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)]
+        [byte[]]$GfxBytes
+    )
+
+    $memStream = New-Object System.IO.MemoryStream(, $GfxBytes)
+    $archive = New-Object System.IO.Compression.ZipArchive($memStream, [System.IO.Compression.ZipArchiveMode]::Read)
+
+    $entry = $archive.GetEntry("Main.xml")
+    if (-not $entry) {
+        $archive.Dispose()
+        $memStream.Close()
+        throw "Main.xml non trouve dans le fichier GFx"
+    }
+
+    $entryStream = $entry.Open()
+    $reader = New-Object System.IO.StreamReader($entryStream, [System.Text.Encoding]::UTF8)
+    $content = $reader.ReadToEnd()
+    $reader.Close()
+    $entryStream.Close()
+    $archive.Dispose()
+    $memStream.Close()
+
+    return $content
+}
+
+function Update-GfxZip {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)]
+        [byte[]]$GfxBytes,
+
+        [Parameter(Mandatory)]
+        [string]$ModifiedMainXml
+    )
+
+    # Copier les bytes dans un MemoryStream modifiable
+    $memStream = New-Object System.IO.MemoryStream
+    $memStream.Write($GfxBytes, 0, $GfxBytes.Length)
+    $memStream.Position = 0
+
+    $archive = New-Object System.IO.Compression.ZipArchive($memStream, [System.IO.Compression.ZipArchiveMode]::Update, $true)
+
+    # Supprimer l'ancien Main.xml et recreer avec le contenu modifie
+    $entry = $archive.GetEntry("Main.xml")
+    if ($entry) {
+        $entry.Delete()
+    }
+
+    $newEntry = $archive.CreateEntry("Main.xml", [System.IO.Compression.CompressionLevel]::Optimal)
+    $entryStream = $newEntry.Open()
+    $utf8NoBom = New-Object System.Text.UTF8Encoding($false)
+    $writer = New-Object System.IO.StreamWriter($entryStream, $utf8NoBom)
+    $writer.Write($ModifiedMainXml)
+    $writer.Flush()
+    $writer.Close()
+    $entryStream.Close()
+
+    $archive.Dispose()
+
+    $newBytes = $memStream.ToArray()
+    $memStream.Close()
+
+    Write-Log -Message "GFx mis a jour en memoire : $($newBytes.Length) octets" -Level INFO
+
+    return $newBytes
+}
+
+Export-ModuleMember -Function New-EnoceanZip, Get-ZipFilename, Read-GfxMainXml, Update-GfxZip