diff --git a/pkgs/by-name/op/openapi-down-convert/package.nix b/pkgs/by-name/op/openapi-down-convert/package.nix
new file mode 100644
index 000000000000..77d0cb66e054
--- /dev/null
+++ b/pkgs/by-name/op/openapi-down-convert/package.nix
@@ -0,0 +1,45 @@
+{
+  lib,
+  fetchFromGitHub,
+  buildNpmPackage,
+  nodejs,
+  versionCheckHook,
+  nix-update-script,
+}:
+
+buildNpmPackage (finalAttrs: {
+  pname = "openapi-down-convert";
+  version = "0.14.1";
+
+  src = fetchFromGitHub {
+    owner = "apiture";
+    repo = "openapi-down-convert";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-8csxj2HfOb9agDmwNmksNaiQhRd+3D1tf0vWU2w+XWw=";
+  };
+
+  npmDepsHash = "sha256-5VgFAiphahDKz3ZhzNEdQOFxvhvDy+S/qOClqBgMzSg=";
+
+  postInstall = ''
+    find $out/lib -type f \( -name '*.ts' \) -delete
+    rm -r $out/lib/node_modules/@apiture/openapi-down-convert/node_modules/typescript
+    rm $out/lib/node_modules/@apiture/openapi-down-convert/node_modules/.bin/*
+  '';
+
+  nativeInstallCheckInputs = [
+    versionCheckHook
+  ];
+  versionCheckProgramArg = "--version";
+  doInstallCheck = true;
+
+  passthru.updateScript = nix-update-script { };
+
+  meta = {
+    description = "Convert an OpenAPI 3.1.x document to OpenAPI 3.0.x format";
+    homepage = "https://github.com/apiture/openapi-down-convert";
+    changelog = "https://github.com/apiture/openapi-down-convert/releases/tag/v${finalAttrs.version}";
+    license = lib.licenses.isc;
+    maintainers = with lib.maintainers; [ fliegendewurst ];
+    mainProgram = "openapi-down-convert";
+  };
+})