diff --git a/docs/faust-toolchain-boundary.md b/docs/faust-toolchain-boundary.md
index 2a717a1..5027d99 100644
--- a/docs/faust-toolchain-boundary.md
+++ b/docs/faust-toolchain-boundary.md
@@ -91,6 +91,25 @@ search; `FaustHome` then supplies `share/faust` if the prefix is not the file's
 grandparent. The loader prepends `lib` and `bin` to `PATH` using the platform
 path separator.
 
+## Linux Native Toolchain
+
+Built and run on Debian 13 (2026-11-03). Faust `aa30fd7` (2.90.20), LLVM 19
+(`LLVM_CONFIG=/usr/lib/llvm-19/bin/llvm-config`, `INCLUDE_DYNAMIC=ON`,
+`backends/most.cmake`), installed to a prefix; `make -j4`. The first link
+failed with `cannot find -lPolly -lPollyISL -lzstd`; the install prefix that
+resulted has `lib/libfaust.so` but `share/faust` holds only the architecture
+files, not `stdfaust.lib` and the other `.lib` files (they live in the separate
+faustlibraries repo). Compiling any patch that imports `stdfaust.lib` then
+fails with `unable to open file stdfaust.lib`. Point `AQUASYNTH_FAUST_HOME` at a
+home whose `lib/` has `libfaust.so` and whose `share/faust` has both.
+
+`tools/FaustRender` renders one `.dsp` with an `rpm` control to WAVs plus
+`manifest.json` (hashes, peak, rms, non-finite flag). It measures; it does not
+listen. `docs/renders/thruster-v5-manifest.json` is its output for
+`patches/thruster/thruster.dsp` at PR #3 head `c6561da`, 4 s per case. The render is
+deterministic (two reruns byte-identical); the 2026-10-31 sweep file is a 6 s
+render, which is why its hash differs from a 4 s sweep.
+
 ## Invariants
 
 - AquaSynth remains the authority for what a patch means.
diff --git a/docs/renders/thruster-v5-manifest.json b/docs/renders/thruster-v5-manifest.json
new file mode 100644
index 0000000..1907dea
--- /dev/null
+++ b/docs/renders/thruster-v5-manifest.json
@@ -0,0 +1,46 @@
+{
+  "patch": "thruster",
+  "dspSha256": "8afc045eab94f396e21d96a262c5d71910103acd51da5913d3eb3036b48a5809",
+  "sampleRate": 48000,
+  "blockFrames": 512,
+  "seconds": 4,
+  "rpmControl": "rpm",
+  "os": "Debian GNU/Linux 13 (trixie)",
+  "faustHome": "/var/lib/mind-aqua-self/faust-home-overlay-20261031",
+  "faustLibrary": "/var/lib/mind-aqua-self/faust-home-overlay-20261031/lib/libfaust.so",
+  "cases": [
+    {
+      "label": "low-rpm600",
+      "file": "thruster-low-rpm600.wav",
+      "rpmStart": 600,
+      "rpmEnd": 600,
+      "frames": 192000,
+      "peak": 0.18832043,
+      "rms": 0.07348131804614891,
+      "nonFinite": false,
+      "sha256": "4aeaa1f4d9aa5d63025dd8b3d45b25fc6b030a366ba05237c0021b508308e0ba"
+    },
+    {
+      "label": "high-rpm4800",
+      "file": "thruster-high-rpm4800.wav",
+      "rpmStart": 4800,
+      "rpmEnd": 4800,
+      "frames": 192000,
+      "peak": 0.3635283,
+      "rms": 0.14323418081979195,
+      "nonFinite": false,
+      "sha256": "390874aa1d5c4d50f251fa0735b82f859bba43ffee4236fd24d5b06a4733ef7d"
+    },
+    {
+      "label": "sweep-600-4800",
+      "file": "thruster-sweep-600-4800.wav",
+      "rpmStart": 600,
+      "rpmEnd": 4800,
+      "frames": 192000,
+      "peak": 0.34473976,
+      "rms": 0.11363349353245127,
+      "nonFinite": false,
+      "sha256": "ad8d1508aa2b37b5038a6acfcfb21fc46ae04f0180adcd6ea60edc7e918e4068"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/tools/FaustRender/FaustRender.csproj b/tools/FaustRender/FaustRender.csproj
new file mode 100644
index 0000000..9dd3508
--- /dev/null
+++ b/tools/FaustRender/FaustRender.csproj
@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\AquaSynth.Faust\AquaSynth.Faust.csproj" />
+  </ItemGroup>
+</Project>
diff --git a/tools/FaustRender/Program.cs b/tools/FaustRender/Program.cs
new file mode 100644
index 0000000..1f0861b
--- /dev/null
+++ b/tools/FaustRender/Program.cs
@@ -0,0 +1,90 @@
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Security.Cryptography;
+using System.Text.Json;
+using AquaSynth.Faust;
+
+// Offline probe: render one Faust source with a swept `rpm` control to mono 16-bit WAVs through the
+// native libfaust path, and write manifest.json (hashes, levels, toolchain). It measures peak, rms and
+// NaN only; it cannot say how anything sounds.
+// usage: FaustRender <patch.dsp> <outDir> <seconds> <label>=<rpmA>[:<rpmB>] ...
+const int Rate = 48000, Frames = 512;
+if (args.Length < 4) { Console.Error.WriteLine("usage: FaustRender <patch.dsp> <outDir> <seconds> <label>=<rpmA>[:<rpmB>] ..."); return 2; }
+var dspPath = Path.GetFullPath(args[0]);
+var outDir = Path.GetFullPath(args[1]);
+var seconds = double.Parse(args[2]);
+var source = File.ReadAllText(dspPath);
+Directory.CreateDirectory(outDir);
+
+var home = AquaSynthFaustToolchain.Find();
+Console.WriteLine($"faust home: {home ?? "(not found)"}");
+using var compiler = new AquaSynthPatchCompiler(new AquaSynthNativeOptions(SampleRate: Rate));
+var name = Path.GetFileNameWithoutExtension(dspPath);
+if (!compiler.TryCompileSource(new AquaSynthCompileIdentity(name, name, ""), source, (float)seconds, out var patch0, out var cerr))
+{
+    Console.Error.WriteLine("COMPILE FAILED: " + cerr);
+    return 1;
+}
+
+using var patch = patch0!;
+var rpmPath = patch.ControlPaths.First(p => p.EndsWith("rpm"));
+var cases = new List<object>();
+foreach (var spec in args.Skip(3))
+{
+    var eq = spec.IndexOf('=');
+    var label = spec[..eq];
+    var range = spec[(eq + 1)..].Split(':');
+    var a = float.Parse(range[0]);
+    var b = range.Length > 1 ? float.Parse(range[1]) : a;
+
+    using var stream = patch.CreateStreamingPatch();
+    var buf = GC.AllocateArray<float>(Frames, pinned: true);
+    var ptrs = GC.AllocateArray<IntPtr>(1, pinned: true);
+    unsafe { ptrs[0] = (IntPtr)Unsafe.AsPointer(ref buf[0]); }
+    var outP = Marshal.UnsafeAddrOfPinnedArrayElement(ptrs, 0);
+    var blocks = (int)(seconds * Rate) / Frames;
+    var ctl = new Dictionary<string, float>();
+    var pcm = new short[blocks * Frames];
+    double sum = 0; float peak = 0; var nan = false;
+    for (var blk = 0; blk < blocks; blk++)
+    {
+        ctl[rpmPath] = a + (b - a) * blk / Math.Max(1, blocks - 1);
+        stream.ProcessBlock(Frames, IntPtr.Zero, outP, ctl);
+        for (var i = 0; i < Frames; i++)
+        {
+            var v = buf[i];
+            nan |= float.IsNaN(v) || float.IsInfinity(v);
+            peak = Math.Max(peak, Math.Abs(v));
+            sum += (double)v * v;
+            pcm[blk * Frames + i] = (short)(Math.Clamp(v, -1f, 1f) * 32767);
+        }
+    }
+
+    var wav = Path.Combine(outDir, $"{name}-{label}.wav");
+    using (var w = new BinaryWriter(File.Create(wav)))
+    {
+        var db = pcm.Length * 2;
+        w.Write("RIFF"u8); w.Write(36 + db); w.Write("WAVEfmt "u8); w.Write(16); w.Write((short)1); w.Write((short)1);
+        w.Write(Rate); w.Write(Rate * 2); w.Write((short)2); w.Write((short)16); w.Write("data"u8); w.Write(db);
+        foreach (var s in pcm) w.Write(s);
+    }
+
+    cases.Add(new
+    {
+        label, file = Path.GetFileName(wav), rpmStart = a, rpmEnd = b, frames = pcm.Length,
+        peak, rms = Math.Sqrt(sum / pcm.Length), nonFinite = nan,
+        sha256 = Convert.ToHexString(SHA256.HashData(File.ReadAllBytes(wav))).ToLowerInvariant()
+    });
+    Console.WriteLine($"{wav} rpm={a}->{b} peak={peak:F3} rms={Math.Sqrt(sum / pcm.Length):F4} nonFinite={nan}");
+}
+
+var manifest = new
+{
+    patch = name, dspSha256 = Convert.ToHexString(SHA256.HashData(File.ReadAllBytes(dspPath))).ToLowerInvariant(),
+    sampleRate = Rate, blockFrames = Frames, seconds, rpmControl = rpmPath,
+    os = RuntimeInformation.OSDescription, faustHome = home,
+    faustLibrary = home is null ? null : AquaSynthFaustToolchain.FindLibrary(home),
+    cases
+};
+File.WriteAllText(Path.Combine(outDir, "manifest.json"), JsonSerializer.Serialize(manifest, new JsonSerializerOptions { WriteIndented = true }));
+return 0;