diff --git a/docs/REMOTE_COMMANDER_R3_RUNTIME_QUALIFICATION.md b/docs/REMOTE_COMMANDER_R3_RUNTIME_QUALIFICATION.md
new file mode 100644
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+# ContinuityOS Remote Commander R3 — Windows Runtime Qualification
+
+## Baseline
+
+R3 originally started from merged `master` `5a72da36f104421010718da96681c3304fc48fe1`.
+
+After R24 / PR #199 merged, R3 was synchronized by a normal merge commit from new `master`:
+
+`5e6887a3109590e190d5427a3205c3f99e9b5a3f`
+
+No rebase or force-push was used.
+
+Qualification was performed from a separate clean Windows checkout so the parallel R24 / PR #199 worktree and branch were not modified.
+
+## Official tunnel-client artifact
+
+Validated release:
+
+- repository: `openai/tunnel-client`
+- release: `v0.0.14`
+- asset: `tunnel-client-v0.0.14-windows-amd64.zip`
+- expected SHA-256: `784ab8da7b5a88f0109f1fd8aaf0a1c86067430b896dddf307ef7e3cc49fa1a5`
+- observed SHA-256: exact match
+- binary version: `0.0.14+0f870e50a973fa820d4c409000059e181e8d242b`
+
+The official binary advertises `sample_mcp_stdio_local` and the MCP command profile contract used by ContinuityOS R2.
+
+## Credential-free Windows result
+
+The merged launcher `scripts/windows/ContinuityOS-RemoteTunnel.ps1` produced:
+
+- schema: `continuityos.remote_tunnel_plan/v1`
+- MCP transport: `stdio`
+- MCP tool profile: `chatgpt-pro-readonly`
+- public MCP listener: `false`
+- health/UI listener: `127.0.0.1:8080`
+- health/UI scope: `loopback`
+- direct shell: `false`
+- control-plane key present: `false`
+
+The real Windows stdio MCP process was then exercised over JSON-RPC. It advertised exactly:
+
+- `capability_status`
+- `system_info`
+- `fs_list`
+- `fs_read`
+
+A bounded `fs_read` of a benign repository file succeeded. A direct call to hidden write tool `remember` was rejected by the server-side profile boundary.
+
+Observed local state after the R24 synchronization:
+
+`LOCAL_READONLY_RUNTIME_GREEN`
+
+The post-sync Windows regression set covering R3 Remote Commander plus the merged R24 witnessed-replay tests passed: `44 passed`.
+
+## Fail-closed credential gate
+
+With `CONTROL_PLANE_API_KEY` and `CONTROL_PLANE_TUNNEL_ID` absent:
+
+- launcher `Doctor` exited non-zero and identified the missing runtime API key;
+- launcher `Init` exited non-zero before creating a tunnel profile;
+- no secret-like value was printed.
+
+This is intentional. R3 does not manufacture, recover, persist, or log OpenAI runtime credentials.
+
+## Reproducible harness
+
+Run:
+
+```powershell
+.\scripts\windows\Test-ContinuityOS-RemoteRuntime.ps1 \
+  -ExpectedHead <exact-commit-sha> \
+  -TunnelClient C:\path\to\tunnel-client.exe
+```
+
+The harness fails closed unless the Git worktree is clean, the expected head matches when provided, the launcher plan preserves the read-only boundary, the official tunnel-client stdio sample is available, the MCP advertises exactly four read-only tools, a benign read succeeds, and a hidden write call is rejected.
+
+## Remaining live qualification
+
+The following is **not yet claimed**:
+
+`Init -> Doctor -> Run -> ChatGPT connector discovery -> tools/list -> benign read through the live OpenAI tunnel`
+
+That step requires operator-provided:
+
+- `CONTROL_PLANE_API_KEY` with Tunnels Read + Use;
+- `CONTROL_PLANE_TUNNEL_ID` for the intended OpenAI workspace.
+
+Until those values exist at runtime, `live_tunnel_qualified=false`.
+
+## Parallel branch isolation
+
+R24 / PR #199 merged independently into master before R3. Its file set had zero overlap with the R3 Remote Commander files. R3 then synchronized from that merged master with a normal merge commit; R3 did not modify the historical R24 branch, rebase it, or force-push it.
diff --git a/scripts/windows/Test-ContinuityOS-RemoteRuntime.ps1 b/scripts/windows/Test-ContinuityOS-RemoteRuntime.ps1
new file mode 100644
index 0000000..b89db3c
--- /dev/null
+++ b/scripts/windows/Test-ContinuityOS-RemoteRuntime.ps1
@@ -0,0 +1,153 @@
+[CmdletBinding()]
+param(
+    [string]$RepoRoot = "",
+    [string]$RemoteRoot = "",
+    [string]$ProbeRelativePath = "README.md",
+    [string]$TunnelClient = "tunnel-client",
+    [string]$Python = "python",
+    [string]$ExpectedHead = ""
+)
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = "Stop"
+
+if ([string]::IsNullOrWhiteSpace($RepoRoot)) {
+    $RepoRoot = (Resolve-Path (Join-Path $PSScriptRoot "..\..")).Path
+}
+
+function Require-Command {
+    param([Parameter(Mandatory = $true)][string]$Name)
+    $resolved = Get-Command $Name -ErrorAction Stop
+    if (-not $resolved.Source) {
+        throw "Cannot resolve executable path for $Name"
+    }
+    return $resolved.Source
+}
+
+$repo = (Resolve-Path -LiteralPath $RepoRoot).Path
+if ([string]::IsNullOrWhiteSpace($RemoteRoot)) {
+    $RemoteRoot = $repo
+}
+$root = (Resolve-Path -LiteralPath $RemoteRoot).Path
+$probe = Join-Path $root $ProbeRelativePath
+if (-not (Test-Path -LiteralPath $probe -PathType Leaf)) {
+    throw "ProbeRelativePath must identify an existing file inside RemoteRoot."
+}
+
+$pythonExe = Require-Command -Name $Python
+$tunnelExe = Require-Command -Name $TunnelClient
+$launcher = Join-Path $repo "scripts\windows\ContinuityOS-RemoteTunnel.ps1"
+if (-not (Test-Path -LiteralPath $launcher -PathType Leaf)) {
+    throw "ContinuityOS Remote Tunnel launcher is missing."
+}
+
+Push-Location $repo
+try {
+    $head = (git rev-parse HEAD).Trim()
+    $dirty = @(git status --porcelain)
+    if ($LASTEXITCODE -ne 0) {
+        throw "Unable to read Git baseline."
+    }
+    if ($dirty.Count -ne 0) {
+        throw "Runtime qualification requires a clean Git worktree."
+    }
+    if (-not [string]::IsNullOrWhiteSpace($ExpectedHead) -and $head -ne $ExpectedHead) {
+        throw "Git HEAD does not match ExpectedHead."
+    }
+
+    $plan = (
+        & $launcher -Mode Plan -RemoteRoot $root -TunnelClient $tunnelExe -Python $pythonExe |
+            Out-String
+    ) | ConvertFrom-Json
+
+    if ($plan.schema -ne "continuityos.remote_tunnel_plan/v1") {
+        throw "Unexpected launcher plan schema."
+    }
+    if ($plan.mcp_transport -ne "stdio" -or
+        $plan.mcp_tool_profile -ne "chatgpt-pro-readonly" -or
+        $plan.public_mcp_listener -ne $false -or
+        $plan.health_listener_scope -ne "loopback" -or
+        $plan.direct_shell -ne $false) {
+        throw "Launcher plan violates the R3 safety contract."
+    }
+
+    $tunnelVersion = (& $tunnelExe --version 2>&1 | Select-Object -First 1).ToString().Trim()
+    $quickstart = (& $tunnelExe help quickstart 2>&1 | Out-String)
+    if ($LASTEXITCODE -ne 0 -or $quickstart -notmatch "sample_mcp_stdio_local") {
+        throw "tunnel-client quickstart does not advertise the local stdio sample."
+    }
+    $sample = (& $tunnelExe profiles samples show sample_mcp_stdio_local 2>&1 | Out-String)
+    if ($LASTEXITCODE -ne 0 -or $sample -notmatch "mcp.command|mcp-command") {
+        throw "tunnel-client local stdio sample contract is unavailable."
+    }
+
+    $requests = @(
+        @{jsonrpc="2.0"; id=1; method="initialize"; params=@{}},
+        @{jsonrpc="2.0"; id=2; method="tools/list"; params=@{}},
+        @{jsonrpc="2.0"; id=3; method="tools/call"; params=@{name="capability_status"; arguments=@{}}},
+        @{jsonrpc="2.0"; id=4; method="tools/call"; params=@{name="fs_read"; arguments=@{path=$ProbeRelativePath; max_bytes=2048}}},
+        @{jsonrpc="2.0"; id=5; method="tools/call"; params=@{name="remember"; arguments=@{text="must not write"}}}
+    )
+    $payload = (($requests | ForEach-Object { $_ | ConvertTo-Json -Compress -Depth 8 }) -join [Environment]::NewLine) + [Environment]::NewLine
+    $mcpArgs = @(
+        "-m", "continuityos.remote_mcp_server",
+        "--db", ":memory:",
+        "--enable-remote",
+        "--tool-profile", "chatgpt-pro-readonly",
+        "--remote-root", $root
+    )
+    $raw = $payload | & $pythonExe @mcpArgs
+    if ($LASTEXITCODE -ne 0) {
+        throw "Remote MCP stdio qualification failed."
+    }
+    $responses = @($raw | ForEach-Object { $_ | ConvertFrom-Json })
+    $toolsResponse = $responses | Where-Object { $_.id -eq 2 } | Select-Object -First 1
+    $statusResponse = $responses | Where-Object { $_.id -eq 3 } | Select-Object -First 1
+    $readResponse = $responses | Where-Object { $_.id -eq 4 } | Select-Object -First 1
+    $denyResponse = $responses | Where-Object { $_.id -eq 5 } | Select-Object -First 1
+
+    $tools = @($toolsResponse.result.tools | ForEach-Object { $_.name })
+    $expectedTools = @("capability_status", "system_info", "fs_list", "fs_read")
+    if (($tools -join ",") -ne ($expectedTools -join ",")) {
+        throw "Unexpected ChatGPT Pro tool surface."
+    }
+    $status = $statusResponse.result.content[0].text | ConvertFrom-Json
+    if ($status.mode -ne "read_only_host_surface" -or $status.mutating_execution.available -ne $false) {
+        throw "Capability status does not report a read-only host surface."
+    }
+    $readHasError = $readResponse.result.PSObject.Properties.Name -contains "isError"
+    if ($readHasError -and $readResponse.result.isError -eq $true) {
+        throw "Benign fs_read probe failed."
+    }
+    $hiddenWriteDenied = (
+        $denyResponse.result.isError -eq $true -and
+        $denyResponse.result.content[0].text -match "tool hidden by remote tool profile"
+    )
+    if (-not $hiddenWriteDenied) {
+        throw "Hidden write tool was not rejected."
+    }
+
+    [pscustomobject]@{
+        schema = "continuityos.remote_runtime_qualification/v1"
+        status = "LOCAL_READONLY_RUNTIME_GREEN"
+        git_head = $head
+        git_clean = $true
+        tunnel_client_version = $tunnelVersion
+        tunnel_client_stdio_sample = $true
+        mcp_transport = $plan.mcp_transport
+        mcp_tool_profile = $plan.mcp_tool_profile
+        advertised_tools = $tools
+        benign_read = "pass"
+        hidden_write_denied = $true
+        public_mcp_listener = $plan.public_mcp_listener
+        health_listener = $plan.health_listener
+        health_listener_scope = $plan.health_listener_scope
+        direct_shell = $plan.direct_shell
+        control_plane_key_present = -not [string]::IsNullOrWhiteSpace($env:CONTROL_PLANE_API_KEY)
+        tunnel_id_present = -not [string]::IsNullOrWhiteSpace($env:CONTROL_PLANE_TUNNEL_ID)
+        live_tunnel_qualified = $false
+    } | ConvertTo-Json -Depth 6
+}
+finally {
+    Pop-Location
+}
diff --git a/tests/test_remote_runtime_windows_script.py b/tests/test_remote_runtime_windows_script.py
new file mode 100644
index 0000000..28b0cba
--- /dev/null
+++ b/tests/test_remote_runtime_windows_script.py
@@ -0,0 +1,54 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+
+SCRIPT = (
+    Path(__file__).resolve().parents[1]
+    / "scripts"
+    / "windows"
+    / "Test-ContinuityOS-RemoteRuntime.ps1"
+)
+
+
+def _source() -> str:
+    if not SCRIPT.is_file():
+        pytest.skip("source-tree-only Windows runtime harness is not shipped in the wheel")
+    return SCRIPT.read_text(encoding="utf-8")
+
+
+def test_runtime_harness_requires_clean_git_baseline():
+    source = _source()
+    assert "git rev-parse HEAD" in source
+    assert "git status --porcelain" in source
+    assert "ExpectedHead" in source
+    assert "Runtime qualification requires a clean Git worktree." in source
+
+
+def test_runtime_harness_proves_readonly_tool_boundary():
+    source = _source()
+    assert "--tool-profile" in source
+    assert "chatgpt-pro-readonly" in source
+    assert '@("capability_status", "system_info", "fs_list", "fs_read")' in source
+    assert 'name="remember"' in source
+    assert "tool hidden by remote tool profile" in source
+    assert "LOCAL_READONLY_RUNTIME_GREEN" in source
+
+
+def test_runtime_harness_does_not_claim_live_tunnel():
+    source = _source()
+    assert "live_tunnel_qualified = $false" in source
+    assert "control_plane_key_present" in source
+    assert "tunnel_id_present" in source
+    assert "CONTROL_PLANE_API_KEY" in source
+    assert "CONTROL_PLANE_TUNNEL_ID" in source
+
+
+def test_runtime_harness_keeps_public_surface_closed():
+    source = _source()
+    assert "public_mcp_listener" in source
+    assert "health_listener_scope" in source
+    assert '"loopback"' in source
+    assert "direct_shell" in source