diff --git a/README.md b/README.md
index e55f248..e4b5519 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,7 @@ A custom Nix overlay and flake providing additional packages not found in upstre
 | `graphify` | Turn any folder of code, docs, papers, images, or videos into a queryable knowledge graph | AI Coding Agents |
 | `haivemind` | Multi-model AI consensus, aggregation, and fusion runner for popular AI CLIs | AI Coding Agents |
 | `hipengine` | ROCm-native local LLM inference engine with torch-free runtime for AMD RDNA GPUs | AI Inference |
+| `marmel` | Autonomous agentic coding assistant with Manager + specialist subagent orchestration over any OpenAI-compatible LLM backend | AI Coding Agents |
 | `mcp-gateway` | Universal Model Context Protocol gateway that sits between AI client and MCP tools/servers | MCP Servers |
 | `nftables-analyzer` | Analyze nftables firewall rules and evaluate traffic queries | Networking |
 | `nftablesbuilder` | Web interface to manage nftables rules with drag-and-drop rule creation | Networking |
diff --git a/packages/marmel/default.nix b/packages/marmel/default.nix
new file mode 100644
index 0000000..291b4f4
--- /dev/null
+++ b/packages/marmel/default.nix
@@ -0,0 +1,5 @@
+{
+  pkgs,
+  ...
+}:
+pkgs.callPackage ./package.nix { }
diff --git a/packages/marmel/package.nix b/packages/marmel/package.nix
new file mode 100644
index 0000000..28d9310
--- /dev/null
+++ b/packages/marmel/package.nix
@@ -0,0 +1,76 @@
+{
+  lib,
+  rustPlatform,
+  fetchFromGitHub,
+  cacert,
+}:
+
+rustPlatform.buildRustPackage rec {
+  pname = "marmel";
+  # Upstream publishes no git tags or releases, so this is pinned to a commit.
+  # The version shape matches what `nix-update --version=branch=main` generates
+  # for a tagless repository.
+  version = "unstable-2026-09-13";
+
+  src = fetchFromGitHub {
+    owner = "Na1w";
+    repo = "marmel";
+    rev = "fd551ae3198d427b0f0df3429f88764c49095b23";
+    hash = "sha256-nghvUF0EdqTGWT6GMG5oW1iK76r9vgvYeUj98hNraIo=";
+  };
+
+  cargoHash = "sha256-sUSsxcj4m4uJ28RKdJWKsb+MlVW6GkWjZdhKPFKlE/Y=";
+
+  nativeCheckInputs = [ cacert ];
+
+  # The test suite builds `reqwest::Client`s, and rustls rejects construction
+  # outright when no system trust store is found ("No CA certificates were
+  # loaded from the system"). The sandbox has no /etc/ssl, so point the tests
+  # at nixpkgs' bundle. Build-time only; the installed binary still uses the
+  # host's trust store at runtime.
+  preCheck = ''
+    export SSL_CERT_FILE=${cacert}/etc/ssl/certs/ca-bundle.crt
+  '';
+
+  # Serialise the test harness. The lib suite shares process-global worker
+  # registries and steer/abort buses (src/orchestrator/workers.rs,
+  # src/orchestrator/bus.rs, src/orchestrator/preemption.rs), so the
+  # manager-loop tests fail nondeterministically when the harness runs them on
+  # parallel threads: rebuilding one unchanged derivation yielded 3 failures,
+  # then 1 failure, then 0 with serial threads. All 325 tests still run — none
+  # are skipped or filtered. Drop this flag once upstream makes that state
+  # per-instance.
+  cargoTestFlags = [
+    "--"
+    "--test-threads=1"
+  ];
+
+  # Role prompts are embedded with `include_str!`, so the binary needs no
+  # runtime data files. The annotated example configs are the de-facto
+  # first-run documentation, since a backend URL and model are mandatory.
+  postInstall = ''
+    install -Dm644 marmel.toml.example $out/share/doc/${pname}/examples/marmel.toml.example
+    install -Dm644 marmel.toml.cloud $out/share/doc/${pname}/examples/marmel.toml.cloud
+  '';
+
+  passthru = {
+    category = "AI Coding Agents";
+    updateScript = [
+      "nix-update"
+      "--flake"
+      ".#marmel"
+      "--version=branch=main"
+    ];
+  };
+
+  meta = {
+    description = "Autonomous agentic coding assistant with Manager + specialist subagent orchestration over any OpenAI-compatible LLM backend";
+    homepage = "https://github.com/Na1w/marmel";
+    # Upstream README states MIT, but the repository ships no LICENSE file and
+    # Cargo.toml has no license field.
+    license = lib.licenses.mit;
+    sourceProvenance = with lib.sourceTypes; [ fromSource ];
+    mainProgram = "marmel";
+    platforms = lib.platforms.unix;
+  };
+}