diff --git a/scripts/chorus-dev.bat b/scripts/chorus-dev.bat
new file mode 100644
index 0000000..efbe708
--- /dev/null
+++ b/scripts/chorus-dev.bat
@@ -0,0 +1,9 @@
+@echo off
+setlocal
+
+set "CHORUS_SHELL=pwsh.exe"
+where "%CHORUS_SHELL%" >nul 2>nul
+if errorlevel 1 set "CHORUS_SHELL=powershell.exe"
+
+"%CHORUS_SHELL%" -NoLogo -NoProfile -ExecutionPolicy Bypass -File "%~dp0chorus-dev.ps1" %*
+exit /b %ERRORLEVEL%
diff --git a/scripts/chorus-dev.ps1 b/scripts/chorus-dev.ps1
new file mode 100644
index 0000000..4d81066
--- /dev/null
+++ b/scripts/chorus-dev.ps1
@@ -0,0 +1,374 @@
+[CmdletBinding()]
+param(
+    [Parameter(Position = 0)]
+    [ValidateSet("start", "stop", "restart", "status", "start-mock")]
+    [string]$Command = "start",
+
+    [Parameter(Position = 1)]
+    [string]$EnvironmentFile
+)
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = "Stop"
+
+if ([string]::IsNullOrWhiteSpace($env:LOCALAPPDATA)) {
+    throw "LOCALAPPDATA is required."
+}
+
+$script:RepoRoot = [IO.Path]::GetFullPath((Join-Path $PSScriptRoot ".."))
+$script:EnvironmentFile = $EnvironmentFile
+$script:StateRoot = Join-Path $env:LOCALAPPDATA "Chorus\dev"
+$script:BinRoot = Join-Path $script:StateRoot "bin"
+$script:LogRoot = Join-Path $script:StateRoot "logs"
+
+function Write-Step {
+    param([string]$Message)
+    Write-Host "[chorus] $Message"
+}
+
+function Get-StatePath {
+    param([ValidateSet("portal", "mock")][string]$Name)
+    return Join-Path $script:StateRoot "$Name.json"
+}
+
+function Read-State {
+    param([ValidateSet("portal", "mock")][string]$Name)
+    $path = Get-StatePath $Name
+    if (-not (Test-Path -LiteralPath $path -PathType Leaf)) {
+        return $null
+    }
+    try {
+        return Get-Content -LiteralPath $path -Raw | ConvertFrom-Json
+    }
+    catch {
+        throw "State file is invalid: $path"
+    }
+}
+
+function Remove-State {
+    param([ValidateSet("portal", "mock")][string]$Name)
+    $path = Get-StatePath $Name
+    if (Test-Path -LiteralPath $path -PathType Leaf) {
+        Remove-Item -LiteralPath $path -Force
+    }
+}
+
+function Get-ManagedProcess {
+    param(
+        [ValidateSet("portal", "mock")][string]$Name,
+        [switch]$Quiet
+    )
+    $state = Read-State $Name
+    if ($null -eq $state) {
+        return $null
+    }
+    $process = Get-Process -Id ([int]$state.pid) -ErrorAction SilentlyContinue
+    if ($null -eq $process) {
+        Remove-State $Name
+        return $null
+    }
+    $expected = [IO.Path]::GetFullPath([string]$state.executable)
+    $actual = $null
+    try {
+        $actual = [IO.Path]::GetFullPath([string]$process.Path)
+    }
+    catch {
+        if (-not $Quiet) {
+            throw "Cannot verify executable path for $Name process $($state.pid); refusing to manage it."
+        }
+        return $null
+    }
+    if (-not [string]::Equals($expected, $actual, [StringComparison]::OrdinalIgnoreCase)) {
+        if (-not $Quiet) {
+            throw "PID $($state.pid) does not run the recorded $Name executable; refusing to manage it."
+        }
+        return $null
+    }
+    return [pscustomobject]@{ State = $state; Process = $process }
+}
+
+function Import-ChorusEnvironment {
+    if ([string]::IsNullOrWhiteSpace($EnvironmentFile)) {
+        if (-not [string]::IsNullOrWhiteSpace($env:CHORUS_ENV_FILE)) {
+            $script:EnvironmentFile = $env:CHORUS_ENV_FILE
+        }
+        else {
+            $script:EnvironmentFile = Join-Path (Split-Path $script:RepoRoot -Parent) "chorus-tools\chorus-test.env.ps1"
+        }
+    }
+    $resolved = Resolve-Path -LiteralPath $script:EnvironmentFile -ErrorAction SilentlyContinue
+    if ($null -eq $resolved) {
+        throw "Environment file not found: $script:EnvironmentFile"
+    }
+    $script:EnvironmentFile = $resolved.Path
+    . $script:EnvironmentFile
+    if ([string]::IsNullOrWhiteSpace($env:CHORUS_DSN)) {
+        throw "CHORUS_DSN is required in the environment file."
+    }
+}
+
+function Get-GoCommand {
+    if (-not [string]::IsNullOrWhiteSpace($env:CHORUS_GO)) {
+        $candidate = Resolve-Path -LiteralPath $env:CHORUS_GO -ErrorAction SilentlyContinue
+        if ($null -eq $candidate -or -not (Test-Path -LiteralPath $candidate.Path -PathType Leaf)) {
+            throw "CHORUS_GO does not point to an executable file."
+        }
+        return $candidate.Path
+    }
+    $command = Get-Command go.exe -ErrorAction SilentlyContinue
+    if ($null -ne $command) {
+        return $command.Source
+    }
+    $portable = Join-Path (Split-Path $script:RepoRoot -Parent) "chorus-tools\go1.26.5\bin\go.exe"
+    if (Test-Path -LiteralPath $portable -PathType Leaf) {
+        return $portable
+    }
+    throw "Go was not found. Add go.exe to PATH or set CHORUS_GO."
+}
+
+function Get-Endpoint {
+    param(
+        [string]$Value,
+        [string]$Fallback,
+        [string]$Name
+    )
+    if ([string]::IsNullOrWhiteSpace($Value)) {
+        $Value = $Fallback
+    }
+    if ($Value -notmatch '^(?<host>127\.0\.0\.1|localhost|\[::1\]):(?<port>\d{1,5})$') {
+        throw "$Name must use a loopback host and explicit port."
+    }
+    $port = [int]$Matches.port
+    if ($port -lt 1 -or $port -gt 65535) {
+        throw "$Name port is outside 1-65535."
+    }
+    return [pscustomobject]@{ Address = $Value; Host = $Matches.host.Trim('[', ']'); Port = $port }
+}
+
+function Test-TcpPort {
+    param([string]$HostName, [int]$Port, [int]$TimeoutMilliseconds = 500)
+    $client = [Net.Sockets.TcpClient]::new()
+    try {
+        $task = $client.ConnectAsync($HostName, $Port)
+        if (-not $task.Wait($TimeoutMilliseconds)) {
+            return $false
+        }
+        return $client.Connected
+    }
+    catch {
+        return $false
+    }
+    finally {
+        $client.Dispose()
+    }
+}
+
+function Assert-DatabaseAvailable {
+    $hostName = $env:CHORUS_MYSQL_HOST
+    $portText = $env:CHORUS_MYSQL_PORT
+    if ([string]::IsNullOrWhiteSpace($hostName) -or [string]::IsNullOrWhiteSpace($portText)) {
+        if ($env:CHORUS_DSN -notmatch '@tcp\((?<host>[^:()]+):(?<port>\d+)\)') {
+            throw "Set CHORUS_MYSQL_HOST and CHORUS_MYSQL_PORT, or use a TCP CHORUS_DSN."
+        }
+        $hostName = $Matches.host
+        $portText = $Matches.port
+    }
+    if ($hostName -notin @("127.0.0.1", "localhost", "::1")) {
+        throw "The development launcher only accepts a local MySQL host."
+    }
+    $port = 0
+    if (-not [int]::TryParse($portText, [ref]$port) -or $port -lt 1 -or $port -gt 65535) {
+        throw "CHORUS_MYSQL_PORT is invalid."
+    }
+    if (-not (Test-TcpPort $hostName $port 2000)) {
+        throw "Local MySQL is not reachable on the configured host and port."
+    }
+}
+
+function Assert-PortAvailable {
+    param($Endpoint, [string]$Name)
+    if (Test-TcpPort $Endpoint.Host $Endpoint.Port) {
+        throw "$Name cannot start because $($Endpoint.Address) is already in use."
+    }
+}
+
+function Build-Component {
+    param(
+        [ValidateSet("portal", "mock")][string]$Name,
+        [string]$Package
+    )
+    $go = Get-GoCommand
+    New-Item -ItemType Directory -Path $script:BinRoot -Force | Out-Null
+    $output = Join-Path $script:BinRoot "chorus-$Name.exe"
+    Write-Step "Building $Name..."
+    Push-Location $script:RepoRoot
+    try {
+        & $go build -o $output $Package
+        if ($LASTEXITCODE -ne 0 -or -not (Test-Path -LiteralPath $output -PathType Leaf)) {
+            throw "Failed to build $Name."
+        }
+    }
+    finally {
+        Pop-Location
+    }
+    return [IO.Path]::GetFullPath($output)
+}
+
+function Wait-Portal {
+    param($Endpoint, [Diagnostics.Process]$Process, [string]$ErrorLog)
+    $urlHost = if ($Endpoint.Host -eq "::1") { "[::1]" } else { $Endpoint.Host }
+    $url = "http://${urlHost}:$($Endpoint.Port)/login"
+    $handler = [Net.Http.HttpClientHandler]::new()
+    $handler.UseProxy = $false
+    $client = [Net.Http.HttpClient]::new($handler)
+    $client.Timeout = [TimeSpan]::FromSeconds(2)
+    try {
+        for ($attempt = 0; $attempt -lt 30; $attempt++) {
+            if ($Process.HasExited) {
+                throw "Portal exited during startup. See $ErrorLog"
+            }
+            try {
+                $response = $client.GetAsync($url).GetAwaiter().GetResult()
+                if ([int]$response.StatusCode -eq 200) {
+                    $response.Dispose()
+                    return $url
+                }
+                $response.Dispose()
+            }
+            catch {
+                Start-Sleep -Milliseconds 300
+            }
+        }
+        throw "Portal health check timed out. See $ErrorLog"
+    }
+    finally {
+        $client.Dispose()
+        $handler.Dispose()
+    }
+}
+
+function Start-Component {
+    param(
+        [ValidateSet("portal", "mock")][string]$Name,
+        [string]$Package,
+        $Endpoint
+    )
+    $existing = Get-ManagedProcess $Name
+    if ($null -ne $existing) {
+        Write-Step "$Name is already running (PID $($existing.State.pid))."
+        return
+    }
+    Assert-PortAvailable $Endpoint $Name
+    $executable = Build-Component $Name $Package
+    New-Item -ItemType Directory -Path $script:LogRoot -Force | Out-Null
+    $stamp = Get-Date -Format "yyyyMMdd-HHmmss"
+    $stdout = Join-Path $script:LogRoot "$Name-$stamp.out.log"
+    $stderr = Join-Path $script:LogRoot "$Name-$stamp.err.log"
+    $process = Start-Process -FilePath $executable -WorkingDirectory $script:RepoRoot -RedirectStandardOutput $stdout -RedirectStandardError $stderr -PassThru -WindowStyle Hidden
+    $state = [ordered]@{
+        name = $Name
+        pid = $process.Id
+        executable = $executable
+        address = $Endpoint.Address
+        stdout = $stdout
+        stderr = $stderr
+        started_at = (Get-Date).ToString("o")
+    }
+    $state | ConvertTo-Json | Set-Content -LiteralPath (Get-StatePath $Name) -Encoding UTF8
+    try {
+        if ($Name -eq "portal") {
+            $url = Wait-Portal $Endpoint $process $stderr
+            Write-Step "Portal URL: $url"
+        }
+        else {
+            for ($attempt = 0; $attempt -lt 20; $attempt++) {
+                if ($process.HasExited) {
+                    throw "Mock provider exited during startup. See $stderr"
+                }
+                if (Test-TcpPort $Endpoint.Host $Endpoint.Port) {
+                    Write-Step "Mock provider listening on $($Endpoint.Address)."
+                    break
+                }
+                Start-Sleep -Milliseconds 250
+            }
+            if (-not (Test-TcpPort $Endpoint.Host $Endpoint.Port)) {
+                throw "Mock provider health check timed out. See $stderr"
+            }
+        }
+    }
+    catch {
+        if (-not $process.HasExited) {
+            Stop-Process -Id $process.Id -Force -ErrorAction SilentlyContinue
+        }
+        Remove-State $Name
+        throw
+    }
+    Write-Step "$Name PID: $($process.Id)"
+    Write-Step "$Name logs: $stdout and $stderr"
+}
+
+function Stop-Component {
+    param([ValidateSet("portal", "mock")][string]$Name)
+    $managed = Get-ManagedProcess $Name
+    if ($null -eq $managed) {
+        Write-Step "$name is not running."
+        return
+    }
+    Write-Step "Stopping $Name (PID $($managed.State.pid))..."
+    Stop-Process -Id $managed.Process.Id -Force
+    $managed.Process.WaitForExit(5000) | Out-Null
+    Remove-State $Name
+    Write-Step "$Name stopped."
+}
+
+function Show-Status {
+    foreach ($name in @("portal", "mock")) {
+        $managed = Get-ManagedProcess $name -Quiet
+        if ($null -eq $managed) {
+            Write-Step "${name}: stopped"
+        }
+        else {
+            Write-Step "${name}: running (PID $($managed.State.pid), $($managed.State.address))"
+            Write-Step "$name logs: $($managed.State.stdout) and $($managed.State.stderr)"
+        }
+    }
+}
+
+New-Item -ItemType Directory -Path $script:StateRoot -Force | Out-Null
+
+try {
+    switch ($Command) {
+        "status" {
+            Show-Status
+        }
+        "stop" {
+            Stop-Component "mock"
+            Stop-Component "portal"
+        }
+        "start" {
+            Import-ChorusEnvironment
+            Assert-DatabaseAvailable
+            $portalEndpoint = Get-Endpoint $env:CHORUS_LISTEN_ADDRESS "127.0.0.1:8080" "CHORUS_LISTEN_ADDRESS"
+            $env:CHORUS_LISTEN_ADDRESS = $portalEndpoint.Address
+            Start-Component "portal" "./portal" $portalEndpoint
+        }
+        "start-mock" {
+            Import-ChorusEnvironment
+            $mockEndpoint = Get-Endpoint $env:CHORUS_MOCK_ADDR "127.0.0.1:18080" "CHORUS_MOCK_ADDR"
+            $env:CHORUS_MOCK_ADDR = $mockEndpoint.Address
+            Start-Component "mock" "./cmd/chorus-mock-provider" $mockEndpoint
+        }
+        "restart" {
+            Stop-Component "portal"
+            Import-ChorusEnvironment
+            Assert-DatabaseAvailable
+            $portalEndpoint = Get-Endpoint $env:CHORUS_LISTEN_ADDRESS "127.0.0.1:8080" "CHORUS_LISTEN_ADDRESS"
+            $env:CHORUS_LISTEN_ADDRESS = $portalEndpoint.Address
+            Start-Component "portal" "./portal" $portalEndpoint
+        }
+    }
+}
+catch {
+    [Console]::Error.WriteLine("[chorus] ERROR: " + $_.Exception.Message)
+    exit 1
+}