diff --git a/esy.lock/index.json b/esy.lock/index.json
index a07cce0..3ccee46 100644
--- a/esy.lock/index.json
+++ b/esy.lock/index.json
@@ -1,5 +1,5 @@
 {
-  "checksum": "ffe903d165082ab60be24550d1dae31b",
+  "checksum": "9d770610ebf28d090c00e576f71d8236",
   "root": "pollinate@link-dev:./package.json",
   "node": {
     "pollinate@link-dev:./package.json": {
@@ -19,6 +19,7 @@
         "@opam/ppx_deriving@opam:5.2.1@089e5dd3",
         "@opam/ppx_compare@opam:v0.14.0@fbd22977",
         "@opam/ppx_bin_prot@opam:v0.14.0@4a83bcd2",
+        "@opam/odoc@opam:2.1.0@d39daa6f",
         "@opam/lwt_ppx@opam:2.0.3@125707d0", "@opam/lwt@opam:5.5.0@30354e4c",
         "@opam/dune@opam:2.9.3@f57a6d69",
         "@opam/bin_prot@opam:v0.14.0@2d7601e9"
@@ -64,13 +65,13 @@
       },
       "overrides": [],
       "dependencies": [
-        "ocaml@4.13.1000@d41d8cd9", "@opam/easy-format@opam:1.3.2@1ea9f987",
-        "@opam/dune@opam:2.9.3@f57a6d69", "@opam/cppo@opam:1.6.8@7e48217d",
+        "ocaml@4.13.1000@d41d8cd9", "@opam/easy-format@opam:1.3.3@5d74d95b",
+        "@opam/dune@opam:2.9.3@f57a6d69", "@opam/cppo@opam:1.6.9@db929a12",
         "@opam/biniou@opam:1.2.1@420bda02",
         "@esy-ocaml/substs@0.0.1@d41d8cd9"
       ],
       "devDependencies": [
-        "ocaml@4.13.1000@d41d8cd9", "@opam/easy-format@opam:1.3.2@1ea9f987",
+        "ocaml@4.13.1000@d41d8cd9", "@opam/easy-format@opam:1.3.3@5d74d95b",
         "@opam/dune@opam:2.9.3@f57a6d69", "@opam/biniou@opam:1.2.1@420bda02"
       ]
     },
@@ -183,6 +184,34 @@
       ],
       "devDependencies": [ "ocaml@4.13.1000@d41d8cd9" ]
     },
+    "@opam/tyxml@opam:4.5.0@0a609297": {
+      "id": "@opam/tyxml@opam:4.5.0@0a609297",
+      "name": "@opam/tyxml",
+      "version": "opam:4.5.0",
+      "source": {
+        "type": "install",
+        "source": [
+          "archive:https://opam.ocaml.org/cache/sha256/c6/c69accef5df4dd89d38f6aa0baad01e8fda4e9e98bb7dad61bec1452c5716068#sha256:c69accef5df4dd89d38f6aa0baad01e8fda4e9e98bb7dad61bec1452c5716068",
+          "archive:https://github.com/ocsigen/tyxml/releases/download/4.5.0/tyxml-4.5.0.tbz#sha256:c69accef5df4dd89d38f6aa0baad01e8fda4e9e98bb7dad61bec1452c5716068"
+        ],
+        "opam": {
+          "name": "tyxml",
+          "version": "4.5.0",
+          "path": "esy.lock/opam/tyxml.4.5.0"
+        }
+      },
+      "overrides": [],
+      "dependencies": [
+        "ocaml@4.13.1000@d41d8cd9", "@opam/uutf@opam:1.0.3@47c95a18",
+        "@opam/seq@opam:base@d8d7de1d", "@opam/re@opam:1.10.4@c4910ba6",
+        "@opam/dune@opam:2.9.3@f57a6d69", "@esy-ocaml/substs@0.0.1@d41d8cd9"
+      ],
+      "devDependencies": [
+        "ocaml@4.13.1000@d41d8cd9", "@opam/uutf@opam:1.0.3@47c95a18",
+        "@opam/seq@opam:base@d8d7de1d", "@opam/re@opam:1.10.4@c4910ba6",
+        "@opam/dune@opam:2.9.3@f57a6d69"
+      ]
+    },
     "@opam/topkg@opam:1.0.5@0aa59f51": {
       "id": "@opam/topkg@opam:1.0.5@0aa59f51",
       "name": "@opam/topkg",
@@ -301,20 +330,20 @@
         "@opam/base@opam:v0.14.3@b3ddb868"
       ]
     },
-    "@opam/spawn@opam:v0.15.0@4a27a4cb": {
-      "id": "@opam/spawn@opam:v0.15.0@4a27a4cb",
+    "@opam/spawn@opam:v0.15.1@85e9d6f1": {
+      "id": "@opam/spawn@opam:v0.15.1@85e9d6f1",
       "name": "@opam/spawn",
-      "version": "opam:v0.15.0",
+      "version": "opam:v0.15.1",
       "source": {
         "type": "install",
         "source": [
-          "archive:https://opam.ocaml.org/cache/sha256/31/310fb2a50ac7f64c738182cbabd9d27c1aeae1a08107fe14da8d35a87cbb57c7#sha256:310fb2a50ac7f64c738182cbabd9d27c1aeae1a08107fe14da8d35a87cbb57c7",
-          "archive:https://github.com/janestreet/spawn/archive/v0.15.0.tar.gz#sha256:310fb2a50ac7f64c738182cbabd9d27c1aeae1a08107fe14da8d35a87cbb57c7"
+          "archive:https://opam.ocaml.org/cache/sha256/9a/9afdee314fab6c3fcd689ab6eb5608d6b78078e6dede3953a47debde06c19d50#sha256:9afdee314fab6c3fcd689ab6eb5608d6b78078e6dede3953a47debde06c19d50",
+          "archive:https://github.com/janestreet/spawn/archive/v0.15.1.tar.gz#sha256:9afdee314fab6c3fcd689ab6eb5608d6b78078e6dede3953a47debde06c19d50"
         ],
         "opam": {
           "name": "spawn",
-          "version": "v0.15.0",
-          "path": "esy.lock/opam/spawn.v0.15.0"
+          "version": "v0.15.1",
+          "path": "esy.lock/opam/spawn.v0.15.1"
         }
       },
       "overrides": [],
@@ -370,12 +399,12 @@
       "overrides": [],
       "dependencies": [
         "ocaml@4.13.1000@d41d8cd9", "@opam/sexplib0@opam:v0.14.0@155c136c",
-        "@opam/parsexp@opam:v0.14.2@1d15b9d2", "@opam/num@opam:1.4@15ff926d",
+        "@opam/parsexp@opam:v0.14.2@1d15b9d2", "@opam/num@opam:1.4@54b259a0",
         "@opam/dune@opam:2.9.3@f57a6d69", "@esy-ocaml/substs@0.0.1@d41d8cd9"
       ],
       "devDependencies": [
         "ocaml@4.13.1000@d41d8cd9", "@opam/sexplib0@opam:v0.14.0@155c136c",
-        "@opam/parsexp@opam:v0.14.2@1d15b9d2", "@opam/num@opam:1.4@15ff926d",
+        "@opam/parsexp@opam:v0.14.2@1d15b9d2", "@opam/num@opam:1.4@54b259a0",
         "@opam/dune@opam:2.9.3@f57a6d69"
       ]
     },
@@ -448,20 +477,20 @@
         "ocaml@4.13.1000@d41d8cd9", "@opam/dune@opam:2.9.3@f57a6d69"
       ]
     },
-    "@opam/re@opam:1.10.3@0585c65d": {
-      "id": "@opam/re@opam:1.10.3@0585c65d",
+    "@opam/re@opam:1.10.4@c4910ba6": {
+      "id": "@opam/re@opam:1.10.4@c4910ba6",
       "name": "@opam/re",
-      "version": "opam:1.10.3",
+      "version": "opam:1.10.4",
       "source": {
         "type": "install",
         "source": [
-          "archive:https://opam.ocaml.org/cache/sha256/84/846546967f3fe31765935dd40a6460a9424337ecce7b12727fcba49480790ebb#sha256:846546967f3fe31765935dd40a6460a9424337ecce7b12727fcba49480790ebb",
-          "archive:https://github.com/ocaml/ocaml-re/releases/download/1.10.3/re-1.10.3.tbz#sha256:846546967f3fe31765935dd40a6460a9424337ecce7b12727fcba49480790ebb"
+          "archive:https://opam.ocaml.org/cache/sha256/83/83eb3e4300aa9b1dc7820749010f4362ea83524742130524d78c20ce99ca747c#sha256:83eb3e4300aa9b1dc7820749010f4362ea83524742130524d78c20ce99ca747c",
+          "archive:https://github.com/ocaml/ocaml-re/releases/download/1.10.4/re-1.10.4.tbz#sha256:83eb3e4300aa9b1dc7820749010f4362ea83524742130524d78c20ce99ca747c"
         ],
         "opam": {
           "name": "re",
-          "version": "1.10.3",
-          "path": "esy.lock/opam/re.1.10.3"
+          "version": "1.10.4",
+          "path": "esy.lock/opam/re.1.10.4"
         }
       },
       "overrides": [],
@@ -943,7 +972,7 @@
         "@opam/ppxlib@opam:0.25.0@8553d2e8",
         "@opam/ppx_derivers@opam:1.2.1@e2cbad12",
         "@opam/ocamlfind@opam:1.9.3@781b30f3",
-        "@opam/dune@opam:2.9.3@f57a6d69", "@opam/cppo@opam:1.6.8@7e48217d",
+        "@opam/dune@opam:2.9.3@f57a6d69", "@opam/cppo@opam:1.6.9@db929a12",
         "@esy-ocaml/substs@0.0.1@d41d8cd9"
       ],
       "devDependencies": [
@@ -1279,6 +1308,43 @@
         "@opam/dune@opam:2.9.3@f57a6d69", "@opam/astring@opam:0.8.5@1300cee8"
       ]
     },
+    "@opam/odoc@opam:2.1.0@d39daa6f": {
+      "id": "@opam/odoc@opam:2.1.0@d39daa6f",
+      "name": "@opam/odoc",
+      "version": "opam:2.1.0",
+      "source": {
+        "type": "install",
+        "source": [
+          "archive:https://opam.ocaml.org/cache/sha256/65/65a2523a50ee368164f1f24f75866a6a36cdb0d00039c3006ec824351d4e4967#sha256:65a2523a50ee368164f1f24f75866a6a36cdb0d00039c3006ec824351d4e4967",
+          "archive:https://github.com/ocaml/odoc/releases/download/2.1.0/odoc-2.1.0.tbz#sha256:65a2523a50ee368164f1f24f75866a6a36cdb0d00039c3006ec824351d4e4967"
+        ],
+        "opam": {
+          "name": "odoc",
+          "version": "2.1.0",
+          "path": "esy.lock/opam/odoc.2.1.0"
+        }
+      },
+      "overrides": [],
+      "dependencies": [
+        "ocaml@4.13.1000@d41d8cd9", "@opam/tyxml@opam:4.5.0@0a609297",
+        "@opam/result@opam:1.5@1c6a6533",
+        "@opam/odoc-parser@opam:1.0.0@b1029bdf",
+        "@opam/fpath@opam:0.7.3@674d8125", "@opam/fmt@opam:0.9.0@87213963",
+        "@opam/dune@opam:2.9.3@f57a6d69", "@opam/cppo@opam:1.6.9@db929a12",
+        "@opam/cmdliner@opam:1.1.1@03763729",
+        "@opam/astring@opam:0.8.5@1300cee8",
+        "@esy-ocaml/substs@0.0.1@d41d8cd9"
+      ],
+      "devDependencies": [
+        "ocaml@4.13.1000@d41d8cd9", "@opam/tyxml@opam:4.5.0@0a609297",
+        "@opam/result@opam:1.5@1c6a6533",
+        "@opam/odoc-parser@opam:1.0.0@b1029bdf",
+        "@opam/fpath@opam:0.7.3@674d8125", "@opam/fmt@opam:0.9.0@87213963",
+        "@opam/dune@opam:2.9.3@f57a6d69",
+        "@opam/cmdliner@opam:1.1.1@03763729",
+        "@opam/astring@opam:0.8.5@1300cee8"
+      ]
+    },
     "@opam/octavius@opam:1.2.2@2205cc65": {
       "id": "@opam/octavius@opam:1.2.2@2205cc65",
       "name": "@opam/octavius",
@@ -1323,7 +1389,7 @@
       "overrides": [],
       "dependencies": [
         "ocaml@4.13.1000@d41d8cd9", "@opam/dune@opam:2.9.3@f57a6d69",
-        "@opam/cppo@opam:1.6.8@7e48217d",
+        "@opam/cppo@opam:1.6.9@db929a12",
         "@opam/base-bytes@opam:base@19d0c2ff",
         "@esy-ocaml/substs@0.0.1@d41d8cd9"
       ],
@@ -1410,7 +1476,7 @@
       "dependencies": [
         "ocaml@4.13.1000@d41d8cd9", "@opam/uutf@opam:1.0.3@47c95a18",
         "@opam/uuseg@opam:14.0.0@7d21466b",
-        "@opam/stdio@opam:v0.14.0@a5affb43", "@opam/re@opam:1.10.3@0585c65d",
+        "@opam/stdio@opam:v0.14.0@a5affb43", "@opam/re@opam:1.10.4@c4910ba6",
         "@opam/odoc-parser@opam:1.0.0@b1029bdf",
         "@opam/ocp-indent@opam:1.8.1@e32a3c50",
         "@opam/ocaml-version@opam:3.4.0@b6cd49e1",
@@ -1429,7 +1495,7 @@
       "devDependencies": [
         "ocaml@4.13.1000@d41d8cd9", "@opam/uutf@opam:1.0.3@47c95a18",
         "@opam/uuseg@opam:14.0.0@7d21466b",
-        "@opam/stdio@opam:v0.14.0@a5affb43", "@opam/re@opam:1.10.3@0585c65d",
+        "@opam/stdio@opam:v0.14.0@a5affb43", "@opam/re@opam:1.10.4@c4910ba6",
         "@opam/odoc-parser@opam:1.0.0@b1029bdf",
         "@opam/ocp-indent@opam:1.8.1@e32a3c50",
         "@opam/ocaml-version@opam:3.4.0@b6cd49e1",
@@ -1597,8 +1663,8 @@
       "overrides": [],
       "dependencies": [
         "ocaml@4.13.1000@d41d8cd9", "@opam/yojson@opam:1.7.0@69d87312",
-        "@opam/spawn@opam:v0.15.0@4a27a4cb",
-        "@opam/result@opam:1.5@1c6a6533", "@opam/re@opam:1.10.3@0585c65d",
+        "@opam/spawn@opam:v0.15.1@85e9d6f1",
+        "@opam/result@opam:1.5@1c6a6533", "@opam/re@opam:1.10.4@c4910ba6",
         "@opam/ppx_yojson_conv_lib@opam:v0.15.0@773058a7",
         "@opam/pp@opam:1.1.2@89ad03b5",
         "@opam/ocamlformat-rpc-lib@opam:0.19.0@125cf11d",
@@ -1608,8 +1674,8 @@
       ],
       "devDependencies": [
         "ocaml@4.13.1000@d41d8cd9", "@opam/yojson@opam:1.7.0@69d87312",
-        "@opam/spawn@opam:v0.15.0@4a27a4cb",
-        "@opam/result@opam:1.5@1c6a6533", "@opam/re@opam:1.10.3@0585c65d",
+        "@opam/spawn@opam:v0.15.1@85e9d6f1",
+        "@opam/result@opam:1.5@1c6a6533", "@opam/re@opam:1.10.4@c4910ba6",
         "@opam/ppx_yojson_conv_lib@opam:v0.15.0@773058a7",
         "@opam/pp@opam:1.1.2@89ad03b5",
         "@opam/ocamlformat-rpc-lib@opam:0.19.0@125cf11d",
@@ -1642,8 +1708,8 @@
         "ocaml@4.13.1000@d41d8cd9", "@opam/dune@opam:2.9.3@f57a6d69"
       ]
     },
-    "@opam/num@opam:1.4@15ff926d": {
-      "id": "@opam/num@opam:1.4@15ff926d",
+    "@opam/num@opam:1.4@54b259a0": {
+      "id": "@opam/num@opam:1.4@54b259a0",
       "name": "@opam/num",
       "version": "opam:1.4",
       "source": {
@@ -1826,7 +1892,7 @@
         "@opam/ocaml-syntax-shims@opam:1.0.0@9f361fbb",
         "@opam/mmap@opam:1.2.0@b0f60a84",
         "@opam/dune-configurator@opam:2.9.3@174e411b",
-        "@opam/dune@opam:2.9.3@f57a6d69", "@opam/cppo@opam:1.6.8@7e48217d",
+        "@opam/dune@opam:2.9.3@f57a6d69", "@opam/cppo@opam:1.6.9@db929a12",
         "@opam/base-unix@opam:base@87d0b2eb",
         "@opam/base-threads@opam:base@36803084",
         "@esy-ocaml/substs@0.0.1@d41d8cd9"
@@ -2054,23 +2120,28 @@
       ],
       "devDependencies": [ "@opam/dune@opam:2.9.3@f57a6d69" ]
     },
-    "@opam/easy-format@opam:1.3.2@1ea9f987": {
-      "id": "@opam/easy-format@opam:1.3.2@1ea9f987",
+    "@opam/easy-format@opam:1.3.3@5d74d95b": {
+      "id": "@opam/easy-format@opam:1.3.3@5d74d95b",
       "name": "@opam/easy-format",
-      "version": "opam:1.3.2",
+      "version": "opam:1.3.3",
       "source": {
         "type": "install",
         "source": [
-          "archive:https://opam.ocaml.org/cache/sha256/34/3440c2b882d537ae5e9011eb06abb53f5667e651ea4bb3b460ea8230fa8c1926#sha256:3440c2b882d537ae5e9011eb06abb53f5667e651ea4bb3b460ea8230fa8c1926",
-          "archive:https://github.com/mjambon/easy-format/releases/download/1.3.2/easy-format-1.3.2.tbz#sha256:3440c2b882d537ae5e9011eb06abb53f5667e651ea4bb3b460ea8230fa8c1926"
+          "archive:https://opam.ocaml.org/cache/sha256/ea/eafccae911c26ca23e4ddacee3eaa54654d20f973b8680f84b708cef43adc416#sha256:eafccae911c26ca23e4ddacee3eaa54654d20f973b8680f84b708cef43adc416",
+          "archive:https://github.com/mjambon/easy-format/releases/download/1.3.3/easy-format-1.3.3.tbz#sha256:eafccae911c26ca23e4ddacee3eaa54654d20f973b8680f84b708cef43adc416"
         ],
         "opam": {
           "name": "easy-format",
-          "version": "1.3.2",
-          "path": "esy.lock/opam/easy-format.1.3.2"
+          "version": "1.3.3",
+          "path": "esy.lock/opam/easy-format.1.3.3"
         }
       },
-      "overrides": [],
+      "overrides": [
+        {
+          "opamoverride":
+            "esy.lock/overrides/opam__s__easy_format_opam__c__1.3.3_opam_override"
+        }
+      ],
       "dependencies": [
         "ocaml@4.13.1000@d41d8cd9", "@opam/dune@opam:2.9.3@f57a6d69",
         "@esy-ocaml/substs@0.0.1@d41d8cd9"
@@ -2180,20 +2251,20 @@
         "ocaml@4.13.1000@d41d8cd9", "@opam/dune@opam:2.9.3@f57a6d69"
       ]
     },
-    "@opam/cppo@opam:1.6.8@7e48217d": {
-      "id": "@opam/cppo@opam:1.6.8@7e48217d",
+    "@opam/cppo@opam:1.6.9@db929a12": {
+      "id": "@opam/cppo@opam:1.6.9@db929a12",
       "name": "@opam/cppo",
-      "version": "opam:1.6.8",
+      "version": "opam:1.6.9",
       "source": {
         "type": "install",
         "source": [
-          "archive:https://opam.ocaml.org/cache/md5/fe/fed401197d86f9089e89f6cbdf1d660d#md5:fed401197d86f9089e89f6cbdf1d660d",
-          "archive:https://github.com/ocaml-community/cppo/archive/v1.6.8.tar.gz#md5:fed401197d86f9089e89f6cbdf1d660d"
+          "archive:https://opam.ocaml.org/cache/md5/d2/d23ffe85ac7dc8f0afd1ddf622770d09#md5:d23ffe85ac7dc8f0afd1ddf622770d09",
+          "archive:https://github.com/ocaml-community/cppo/archive/v1.6.9.tar.gz#md5:d23ffe85ac7dc8f0afd1ddf622770d09"
         ],
         "opam": {
           "name": "cppo",
-          "version": "1.6.8",
-          "path": "esy.lock/opam/cppo.1.6.8"
+          "version": "1.6.9",
+          "path": "esy.lock/opam/cppo.1.6.9"
         }
       },
       "overrides": [],
@@ -2283,11 +2354,11 @@
       },
       "overrides": [],
       "dependencies": [
-        "ocaml@4.13.1000@d41d8cd9", "@opam/easy-format@opam:1.3.2@1ea9f987",
+        "ocaml@4.13.1000@d41d8cd9", "@opam/easy-format@opam:1.3.3@5d74d95b",
         "@opam/dune@opam:2.9.3@f57a6d69", "@esy-ocaml/substs@0.0.1@d41d8cd9"
       ],
       "devDependencies": [
-        "ocaml@4.13.1000@d41d8cd9", "@opam/easy-format@opam:1.3.2@1ea9f987",
+        "ocaml@4.13.1000@d41d8cd9", "@opam/easy-format@opam:1.3.3@5d74d95b",
         "@opam/dune@opam:2.9.3@f57a6d69"
       ]
     },
@@ -2515,7 +2586,7 @@
       "dependencies": [
         "ocaml@4.13.1000@d41d8cd9", "@opam/uutf@opam:1.0.3@47c95a18",
         "@opam/stdlib-shims@opam:0.3.0@72c7bc98",
-        "@opam/re@opam:1.10.3@0585c65d",
+        "@opam/re@opam:1.10.4@c4910ba6",
         "@opam/ocaml-syntax-shims@opam:1.0.0@9f361fbb",
         "@opam/fmt@opam:0.9.0@87213963", "@opam/dune@opam:2.9.3@f57a6d69",
         "@opam/cmdliner@opam:1.1.1@03763729",
@@ -2525,7 +2596,7 @@
       "devDependencies": [
         "ocaml@4.13.1000@d41d8cd9", "@opam/uutf@opam:1.0.3@47c95a18",
         "@opam/stdlib-shims@opam:0.3.0@72c7bc98",
-        "@opam/re@opam:1.10.3@0585c65d",
+        "@opam/re@opam:1.10.4@c4910ba6",
         "@opam/ocaml-syntax-shims@opam:1.0.0@9f361fbb",
         "@opam/fmt@opam:0.9.0@87213963", "@opam/dune@opam:2.9.3@f57a6d69",
         "@opam/cmdliner@opam:1.1.1@03763729",
diff --git a/esy.lock/opam/cppo.1.6.8/opam b/esy.lock/opam/cppo.1.6.9/opam
similarity index 58%
rename from esy.lock/opam/cppo.1.6.8/opam
rename to esy.lock/opam/cppo.1.6.9/opam
index c9d7f68..9c51ec6 100644
--- a/esy.lock/opam/cppo.1.6.8/opam
+++ b/esy.lock/opam/cppo.1.6.9/opam
@@ -1,37 +1,39 @@
 opam-version: "2.0"
-maintainer: "martin@mjambon.com"
+synopsis: "Code preprocessor like cpp for OCaml"
+description: """\
+Cppo is an equivalent of the C preprocessor for OCaml programs.
+It allows the definition of simple macros and file inclusion.
+
+Cppo is:
+
+* more OCaml-friendly than cpp
+* easy to learn without consulting a manual
+* reasonably fast
+* simple to install and to maintain"""
+maintainer: [
+  "Martin Jambon <martin@mjambon.com>" "Yishuai Li <yishuai@upenn.edu>"
+]
 authors: "Martin Jambon"
 license: "BSD-3-Clause"
 homepage: "https://github.com/ocaml-community/cppo"
-doc: "https://ocaml-community.github.io/cppo/"
+doc: "https://ocaml-community.github.io/cppo"
 bug-reports: "https://github.com/ocaml-community/cppo/issues"
 depends: [
   "ocaml" {>= "4.02.3"}
-  "dune" {>= "1.0"}
+  "dune" {>= "1.10"}
   "base-unix"
 ]
 build: [
   ["dune" "subst"] {dev}
   ["dune" "build" "-p" name "-j" jobs]
   ["dune" "runtest" "-p" name "-j" jobs] {with-test}
+  ["dune" "build" "-p" name "@doc"] {with-doc}
 ]
 dev-repo: "git+https://github.com/ocaml-community/cppo.git"
-synopsis: "Code preprocessor like cpp for OCaml"
-description: """
-Cppo is an equivalent of the C preprocessor for OCaml programs.
-It allows the definition of simple macros and file inclusion.
-
-Cppo is:
-
-* more OCaml-friendly than cpp
-* easy to learn without consulting a manual
-* reasonably fast
-* simple to install and to maintain
-"""
 url {
-  src: "https://github.com/ocaml-community/cppo/archive/v1.6.8.tar.gz"
+  src: "https://github.com/ocaml-community/cppo/archive/v1.6.9.tar.gz"
   checksum: [
-    "md5=fed401197d86f9089e89f6cbdf1d660d"
-    "sha512=069bbe0ef09c03b0dc4b5795f909c3ef872fe99c6f1e6704a0fa97594b1570b3579226ec67fe11d696ccc349a4585055bbaf07c65eff423aa45af28abf38c858"
+    "md5=d23ffe85ac7dc8f0afd1ddf622770d09"
+    "sha512=26ff5a7b7f38c460661974b23ca190f0feae3a99f1974e0fd12ccf08745bd7d91b7bc168c70a5385b837bfff9530e0e4e41cf269f23dd8cf16ca658008244b44"
   ]
-}
+}
\ No newline at end of file
diff --git a/esy.lock/opam/easy-format.1.3.2/opam b/esy.lock/opam/easy-format.1.3.3/opam
similarity index 68%
rename from esy.lock/opam/easy-format.1.3.2/opam
rename to esy.lock/opam/easy-format.1.3.3/opam
index f55c2c8..5926060 100644
--- a/esy.lock/opam/easy-format.1.3.2/opam
+++ b/esy.lock/opam/easy-format.1.3.3/opam
@@ -1,17 +1,4 @@
 opam-version: "2.0"
-build: [
-  ["dune" "subst"] {dev}
-  ["dune" "build" "-p" name "-j" jobs]
-  ["dune" "runtest" "-p" name "-j" jobs] {with-test}
-  ["dune" "build" "-p" name "@doc"] {with-doc}
-]
-maintainer: ["martin@mjambon.com" "rudi.grinberg@gmail.com"]
-authors: ["Martin Jambon"]
-bug-reports: "https://github.com/mjambon/easy-format/issues"
-homepage: "https://github.com/mjambon/easy-format"
-doc: "https://mjambon.github.io/easy-format/"
-license: "BSD-3-Clause"
-dev-repo: "git+https://github.com/mjambon/easy-format.git"
 synopsis:
   "High-level and functional interface to the Format module of the OCaml standard library"
 description: """
@@ -32,15 +19,40 @@ nodes:
 Atoms represent any text that is guaranteed to be printed as-is. Lists can model
 any sequence of items such as arrays of data or lists of definitions that are
 labelled with something like "int main", "let x =" or "x:"."""
+maintainer: ["martin@mjambon.com" "rudi.grinberg@gmail.com"]
+authors: ["Martin Jambon"]
+license: "BSD-3-Clause"
+homepage: "https://github.com/mjambon/easy-format"
+doc: "https://mjambon.github.io/easy-format/"
+bug-reports: "https://github.com/mjambon/easy-format/issues"
 depends: [
-  "dune" {>= "1.10"}
-  "ocaml" {>= "4.02.3"}
+  "dune" {>= "2.9"}
+  "ocaml" {>= "4.08"}
+  "odoc" {with-doc}
 ]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "--promote-install-files=false"
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+  ["dune" "install" "-p" name "--create-install-files" name]
+]
+dev-repo: "git+https://github.com/mjambon/easy-format.git"
 url {
   src:
-    "https://github.com/mjambon/easy-format/releases/download/1.3.2/easy-format-1.3.2.tbz"
+    "https://github.com/mjambon/easy-format/releases/download/1.3.3/easy-format-1.3.3.tbz"
   checksum: [
-    "sha256=3440c2b882d537ae5e9011eb06abb53f5667e651ea4bb3b460ea8230fa8c1926"
-    "sha512=e39377a2ff020ceb9ac29e8515a89d9bdbc91dfcfa871c4e3baafa56753fac2896768e5d9822a050dc1e2ade43c8967afb69391a386c0a8ecd4e1f774e236135"
+    "sha256=eafccae911c26ca23e4ddacee3eaa54654d20f973b8680f84b708cef43adc416"
+    "sha512=611b3124f6a0ec6406b7bda8018a94c9c4a9da9d22495a5c34a6312bf7f0f0607a9529b276f7039ce3f3b15a955dac413d6d1229a55d5ac291302a3ddd5807e5"
   ]
 }
+x-commit-hash: "56c57e69ef067d1cc4e31029d31e77e55b46be95"
diff --git a/esy.lock/opam/num.1.4/opam b/esy.lock/opam/num.1.4/opam
index 0e39879..253f84e 100644
--- a/esy.lock/opam/num.1.4/opam
+++ b/esy.lock/opam/num.1.4/opam
@@ -13,9 +13,13 @@ depends: [
 conflicts: ["base-num"]
 build: make
 install: [
-  make
-  "install" {!ocaml:preinstalled}
-  "findlib-install" {ocaml:preinstalled}
+  ["ocamlfind" "remove" "num"]
+  ["ocamlfind" "remove" "num-top"]
+  [
+    make
+    "install" {!ocaml:preinstalled}
+    "findlib-install" {ocaml:preinstalled}
+  ]
 ]
 dev-repo: "git+https://github.com/ocaml/num.git"
 url {
@@ -24,4 +28,4 @@ url {
     "md5=cda2b727e116a0b6a9c03902cc4b2415"
     "sha512=0cc9be8ad95704bb683b4bf6698bada1ee9a40dc05924b72adc7b969685c33eeb68ccf174cc09f6a228c48c18fe94af06f28bebc086a24973a066da620db8e6f"
   ]
-}
\ No newline at end of file
+}
diff --git a/esy.lock/opam/odoc.2.1.0/opam b/esy.lock/opam/odoc.2.1.0/opam
new file mode 100644
index 0000000..6b1df40
--- /dev/null
+++ b/esy.lock/opam/odoc.2.1.0/opam
@@ -0,0 +1,60 @@
+opam-version: "2.0"
+homepage: "http://github.com/ocaml/odoc"
+doc: "https://ocaml.github.io/odoc/"
+bug-reports: "https://github.com/ocaml/odoc/issues"
+license: "ISC"
+
+authors: [
+  "Thomas Refis <trefis@janestreet.com>"
+  "David Sheets <sheets@alum.mit.edu>"
+  "Leo White <leo@lpw25.net>"
+  "Anton Bachin <antonbachin@yahoo.com>"
+  "Jon Ludlam <jon@recoil.org>"
+  "Jules Aguillon <juloo.dsi@gmail.com>"
+  "Lubega Simon <lubegasimon73@gmail.com>"
+]
+maintainer: "Jon Ludlam <jon@recoil.org>"
+dev-repo: "git+https://github.com/ocaml/odoc.git"
+
+synopsis: "OCaml documentation generator"
+description: """
+Odoc is a documentation generator for OCaml. It reads doc comments,
+delimited with `(** ... *)`, and outputs HTML. 
+"""
+
+depends: [
+  "odoc-parser" {>= "0.9.0"}
+  "astring"
+  "cmdliner" {>= "1.0.0"}
+  "cppo" {build & >= "1.1.0"}
+  "dune" {>= "2.9.1"}
+  "fpath"
+  "ocaml" {>= "4.02.0"}
+  "result"
+  "tyxml" {>= "4.3.0"}
+  "fmt"
+
+  "ocamlfind" {with-test}
+  "yojson" {with-test}
+  ("ocaml" {< "4.04.1" & with-test} | "sexplib0" {with-test})
+  "conf-jq" {with-test}
+
+  "ppx_expect" {with-test}
+  "bos" {with-test}
+
+  "bisect_ppx" {dev & > "2.5.0"}
+  ("ocaml" {< "4.03.0" & dev} | "mdx" {dev})
+]
+
+build: [
+  ["dune" "subst"] {dev}
+  ["dune" "build" "-p" name "-j" jobs]
+]
+url {
+  src: "https://github.com/ocaml/odoc/releases/download/2.1.0/odoc-2.1.0.tbz"
+  checksum: [
+    "sha256=65a2523a50ee368164f1f24f75866a6a36cdb0d00039c3006ec824351d4e4967"
+    "sha512=cf4d7e884b94a9b9c4bcb62d4423d7289d7bbbf2642c5eacf9577b76eb835cf6ecc79d2384d36d174d2e9d8f758b5082c0c4bf8f66b5c6db4e9805dc3fc9ee1a"
+  ]
+}
+x-commit-hash: "d654ee2a4ff3e1465dcf92b882c26de71f7a9986"
diff --git a/esy.lock/opam/re.1.10.3/opam b/esy.lock/opam/re.1.10.4/opam
similarity index 66%
rename from esy.lock/opam/re.1.10.3/opam
rename to esy.lock/opam/re.1.10.4/opam
index c65d450..9dad661 100644
--- a/esy.lock/opam/re.1.10.3/opam
+++ b/esy.lock/opam/re.1.10.4/opam
@@ -8,19 +8,19 @@ authors: [
   "Rudi Grinberg"
   "Gabriel Radanne"
 ]
-license: "LGPL-2.0 with OCaml linking exception"
+license: "LGPL-2.0-or-later WITH OCaml-LGPL-linking-exception"
 homepage: "https://github.com/ocaml/ocaml-re"
 bug-reports: "https://github.com/ocaml/ocaml-re/issues"
 dev-repo: "git+https://github.com/ocaml/ocaml-re.git"
 
 build: [
-  ["dune" "subst"] {pinned}
+  ["dune" "subst"] {dev}
   ["dune" "build" "-p" name "-j" jobs]
   ["dune" "runtest" "-p" name "-j" jobs] {with-test}
 ]
 
 depends: [
-  "ocaml" {>= "4.02"}
+  "ocaml" {>= "4.03"}
   "dune" {>= "2.0"}
   "ounit" {with-test}
   "seq"
@@ -37,10 +37,10 @@ Pure OCaml regular expressions with:
 """
 url {
   src:
-    "https://github.com/ocaml/ocaml-re/releases/download/1.10.3/re-1.10.3.tbz"
+    "https://github.com/ocaml/ocaml-re/releases/download/1.10.4/re-1.10.4.tbz"
   checksum: [
-    "sha256=846546967f3fe31765935dd40a6460a9424337ecce7b12727fcba49480790ebb"
-    "sha512=d02103b7b8b8d8bc797341dcc933554745427f3c1b51b54b4ac9ff81badfd68c94726c57548b08e00ca99f3e09741b54b6500e97c19fc0e8fcefd6dfbe71da7f"
+    "sha256=83eb3e4300aa9b1dc7820749010f4362ea83524742130524d78c20ce99ca747c"
+    "sha512=92b05cf92c389fa8c753f2acca837b15dd05a4a2e8e2bec7a269d2e14c35b1a786d394258376648f80b4b99250ba1900cfe68230b8385aeac153149d9ce56099"
   ]
 }
-x-commit-hash: "c5d5df80e128c3d7646b7d8b1322012c5fcc35f3"
+x-commit-hash: "e9a4cecb8294c1839db18b1d0c30e755ec85ed5e"
diff --git a/esy.lock/opam/spawn.v0.15.0/opam b/esy.lock/opam/spawn.v0.15.1/opam
similarity index 79%
rename from esy.lock/opam/spawn.v0.15.0/opam
rename to esy.lock/opam/spawn.v0.15.1/opam
index d8d1578..5be3a99 100644
--- a/esy.lock/opam/spawn.v0.15.0/opam
+++ b/esy.lock/opam/spawn.v0.15.1/opam
@@ -45,12 +45,12 @@ build: [
   ]
 ]
 dev-repo: "git+https://github.com/janestreet/spawn.git"
-x-commit-hash: "b5a25cab2f53a5ee9e10a7b8a96506cc61ce1198"
+x-commit-hash: "13d279ebfa8c40d4bafe18cddfdff0de54b4eaff"
 url {
   src:
-    "https://github.com/janestreet/spawn/archive/v0.15.0.tar.gz"
+    "https://github.com/janestreet/spawn/archive/v0.15.1.tar.gz"
   checksum: [
-    "sha256=310fb2a50ac7f64c738182cbabd9d27c1aeae1a08107fe14da8d35a87cbb57c7"
-    "sha512=3a775b57a73efee6adbc30b32fa779f27d11c7008a46f90fdb9da6288533e2d83fc49dbcd770c087f2e4560c5586ff72a9a2985d8929955773cc10d83f126013"
+    "sha256=9afdee314fab6c3fcd689ab6eb5608d6b78078e6dede3953a47debde06c19d50"
+    "sha512=efdb31d5ec5ea36d0bc80224d4ee04e46ce3428d1662870e6cebece92bc313d6eebee378802c0c059dd6e0cafea515308c31b7dfaf04a098eb4566583c1e9ed4"
   ]
 }
diff --git a/esy.lock/opam/tyxml.4.5.0/opam b/esy.lock/opam/tyxml.4.5.0/opam
new file mode 100644
index 0000000..22c7760
--- /dev/null
+++ b/esy.lock/opam/tyxml.4.5.0/opam
@@ -0,0 +1,42 @@
+opam-version: "2.0"
+synopsis: "A library for building correct HTML and SVG documents"
+description:
+  "TyXML provides a set of convenient combinators that uses the OCaml type system to ensure the validity of the generated documents. TyXML can be used with any representation of HTML and SVG: the textual one, provided directly by this package, or DOM trees (`js_of_ocaml-tyxml`) virtual DOM (`virtual-dom`) and reactive or replicated trees (`eliom`). You can also create your own representation and use it to instantiate a new set of combinators."
+maintainer: ["dev@ocsigen.org"]
+authors: ["The ocsigen team"]
+license: "LGPL-2.1-only WITH OCaml-LGPL-linking-exception"
+homepage: "https://github.com/ocsigen/tyxml"
+doc: "https://ocsigen.org/tyxml/latest/manual/intro"
+bug-reports: "https://github.com/ocsigen/tyxml/issues"
+depends: [
+  "dune" {>= "2.0"}
+  "ocaml" {>= "4.02"}
+  "alcotest" {with-test}
+  "re" {>= "1.5.0"}
+  "seq"
+  "uutf" {>= "1.0.0"}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+dev-repo: "git+https://github.com/ocsigen/tyxml.git"
+x-commit-hash: "ef431a4bceaefb2d9248e79092e6c1a1a9420095"
+url {
+  src:
+    "https://github.com/ocsigen/tyxml/releases/download/4.5.0/tyxml-4.5.0.tbz"
+  checksum: [
+    "sha256=c69accef5df4dd89d38f6aa0baad01e8fda4e9e98bb7dad61bec1452c5716068"
+    "sha512=772535441b09c393d53c27152e65f404a0a541aa0cea1bda899a8d751ab64d1729237e583618c3ff33d75e3865d53503d1ea413c6bbc8c68c413347efd1709b3"
+  ]
+}
diff --git a/esy.lock/overrides/opam__s__easy_format_opam__c__1.3.3_opam_override/package.json b/esy.lock/overrides/opam__s__easy_format_opam__c__1.3.3_opam_override/package.json
new file mode 100644
index 0000000..f9bd9e0
--- /dev/null
+++ b/esy.lock/overrides/opam__s__easy_format_opam__c__1.3.3_opam_override/package.json
@@ -0,0 +1,3 @@
+{
+  "build": "dune build -p easy-format"
+}
diff --git a/flake.lock b/flake.lock
index 14acee9..ed0ef05 100644
--- a/flake.lock
+++ b/flake.lock
@@ -2,11 +2,11 @@
   "nodes": {
     "flake-utils": {
       "locked": {
-        "lastModified": 1652372896,
-        "narHash": "sha256-lURGussfF3mGrFPQT3zgW7+RC0pBhbHzco0C7I+ilow=",
+        "lastModified": 1653893745,
+        "narHash": "sha256-0jntwV3Z8//YwuOjzhV2sgJJPt+HY6KhU7VZUL0fKZQ=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "0d347c56f6f41de822a4f4c7ff5072f3382db121",
+        "rev": "1ed9fb1935d260de5fe1c2f7ee0ebaae17ed2fa1",
         "type": "github"
       },
       "original": {
@@ -17,11 +17,11 @@
     },
     "nix-filter": {
       "locked": {
-        "lastModified": 1649838635,
-        "narHash": "sha256-P1h48+l9vUvMz4JwHBgkTXiX6mE8oYR75vBVUbe6Cuc=",
+        "lastModified": 1653590866,
+        "narHash": "sha256-E4yKIrt/S//WfW5D9IhQ1dVuaAy8RE7EiCMfnbrOC78=",
         "owner": "numtide",
         "repo": "nix-filter",
-        "rev": "40a58baa248a8b335e2d66ca258a74248af9d834",
+        "rev": "3e81a637cdf9f6e9b39aeb4d6e6394d1ad158e16",
         "type": "github"
       },
       "original": {
@@ -32,11 +32,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1652231724,
-        "narHash": "sha256-MjalcXFZgcgchp4QqnF05JTkFBBGad5hbksA1EKoP98=",
+        "lastModified": 1653931853,
+        "narHash": "sha256-O3wncIouj9x7gBPntzHeK/Hkmm9M1SGlYq7JI7saTAE=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "41ff747f882914c1f8c233207ce280ac9d0c867f",
+        "rev": "f1c167688a6f81f4a51ab542e5f476c8c595e457",
         "type": "github"
       },
       "original": {
@@ -46,7 +46,7 @@
         "type": "github"
       }
     },
-    "ocaml-overlay": {
+    "ocaml-overlays": {
       "inputs": {
         "flake-utils": [
           "flake-utils"
@@ -56,11 +56,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1652354587,
-        "narHash": "sha256-4wAlDsnfdAzOEM8WGVs1HDDqB8x2tJWQd0Z/86V3q1Y=",
+        "lastModified": 1654150159,
+        "narHash": "sha256-/SbOxDGuJr+aQHtBg+V5J+3OV+/gU/cZVOlEl8/kzG4=",
         "owner": "anmonteiro",
         "repo": "nix-overlays",
-        "rev": "a5d810ae91095586c18d2cafde80381936a445ad",
+        "rev": "70165a4922ed0f4819fac34ee4879604d754af6e",
         "type": "github"
       },
       "original": {
@@ -74,7 +74,7 @@
         "flake-utils": "flake-utils",
         "nix-filter": "nix-filter",
         "nixpkgs": "nixpkgs",
-        "ocaml-overlay": "ocaml-overlay"
+        "ocaml-overlays": "ocaml-overlays"
       }
     }
   },
diff --git a/flake.nix b/flake.nix
index 3284eab..e1c7c3c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -4,19 +4,21 @@
     flake-utils.url = "github:numtide/flake-utils";
     nix-filter.url = "github:numtide/nix-filter";
 
-    ocaml-overlay.url = "github:anmonteiro/nix-overlays";
-    ocaml-overlay.inputs.nixpkgs.follows = "nixpkgs";
-    ocaml-overlay.inputs.flake-utils.follows = "flake-utils";
+    ocaml-overlays.url = "github:anmonteiro/nix-overlays";
+    ocaml-overlays.inputs = {
+      nixpkgs.follows = "nixpkgs";
+      flake-utils.follows = "flake-utils";
+    };
   };
 
-  outputs = { self, nixpkgs, flake-utils, nix-filter, ocaml-overlay }:
+  outputs = { self, nixpkgs, flake-utils, nix-filter, ocaml-overlays }:
     let
       supported_ocaml_versions = [ "ocamlPackages_4_13" "ocamlPackages_5_00" ];
       out = system:
         let
           pkgs = import nixpkgs {
             inherit system;
-            overlays = [ ocaml-overlay.overlays."${system}".default ];
+            overlays = [ ocaml-overlays.overlays."${system}".default ];
           };
           ocamlPackages_dev = pkgs.ocaml-ng.ocamlPackages_5_00;
           pollinate = (pkgs.callPackage ./nix {
diff --git a/lib/common/tqueue.ml b/lib/common/tqueue.ml
deleted file mode 100644
index f7462e9..0000000
--- a/lib/common/tqueue.ml
+++ /dev/null
@@ -1,68 +0,0 @@
-type 'a t = {
-  queue : 'a Queue.t;
-  lock : Lwt_mutex.t;
-  has_elt : unit Lwt_condition.t;
-}
-
-let create () =
-  let queue = Queue.create () in
-  let lock = Lwt_mutex.create () in
-  let has_elt = Lwt_condition.create () in
-  { queue; lock; has_elt }
-
-let add x { queue; lock; has_elt } =
-  Lwt_mutex.with_lock lock (fun () ->
-      Queue.add x queue;
-      let%lwt () =
-        if Queue.length queue = 1 then (
-          Lwt_condition.signal has_elt ();
-          Lwt.return ())
-        else
-          Lwt.return () in
-      Lwt.return ())
-
-let push = add
-
-let take { queue; lock; _ } =
-  Lwt_mutex.with_lock lock (fun () -> Lwt.return (Queue.take_opt queue))
-
-let wait_to_take { queue; lock; has_elt } =
-  Lwt_mutex.with_lock lock (fun () ->
-      let%lwt () =
-        if Queue.is_empty queue then
-          Lwt_condition.wait ~mutex:lock has_elt
-        else
-          Lwt.return () in
-      Lwt.return (Queue.take queue))
-
-let pop = take
-
-let peek { queue; lock; _ } =
-  Lwt_mutex.with_lock lock (fun () -> Lwt.return (Queue.peek_opt queue))
-
-let wait_to_peek { queue; lock; has_elt } =
-  Lwt_mutex.with_lock lock (fun () ->
-      let%lwt () =
-        if Queue.is_empty queue then
-          Lwt_condition.wait ~mutex:lock has_elt
-        else
-          Lwt.return () in
-      Lwt.return (Queue.peek queue))
-
-let top = peek
-
-let clear { queue; lock; _ } =
-  Lwt_mutex.with_lock lock (fun () -> Lwt.return (Queue.clear queue))
-
-let copy { queue; lock; _ } =
-  Lwt_mutex.with_lock lock (fun () ->
-      let queue' = queue in
-      let lock' = Lwt_mutex.create () in
-      let has_elt' = Lwt_condition.create () in
-      Lwt.return { queue = queue'; lock = lock'; has_elt = has_elt' })
-
-let is_empty { queue; lock; _ } =
-  Lwt_mutex.with_lock lock (fun () -> Lwt.return (Queue.is_empty queue))
-
-let length { queue; lock; _ } =
-  Lwt_mutex.with_lock lock (fun () -> Lwt.return (Queue.length queue))
diff --git a/lib/common/tqueue.mli b/lib/common/tqueue.mli
deleted file mode 100644
index c8b2e8f..0000000
--- a/lib/common/tqueue.mli
+++ /dev/null
@@ -1,54 +0,0 @@
-(** Thread-safe queues with the same exact interface
-as OCaml's Queue module, except any function that
-reads from or writes to a [Queue] returns a promise.
-Furthermore, there is a special take function for blocking
-the current thread until an element is available to take
-from the queue.
-Read the {{:https://ocaml.org/api/Queue.html}documentation for OCaml's Queue module}
-for more information about the functions in this module *)
-
-(** {1 Type} *)
-
-(** The type of a thread-safe queue *)
-type 'a t
-
-(** {1 API} *)
-
-(** Blocks the current thread of execution until
-an element is in the queue, then returns a promise
-containing the element. *)
-val wait_to_take : 'a t -> 'a Lwt.t
-
-(** Similar to [wait_to_take] but doesn't block
-    the current thread. *)
-val take : 'a t -> 'a option Lwt.t
-
-(** Similar to [wait_to_take], but doesn't remove
-from the queue. *)
-val wait_to_peek : 'a t -> 'a Lwt.t
-
-(** Similar to [wait_to_peek] but doesn't block
-    the current thread. *)
-val peek : 'a t -> 'a option Lwt.t
-
-(**/**)
-
-val create : unit -> 'a t
-
-val add : 'a -> 'a t -> unit Lwt.t
-
-val push : 'a -> 'a t -> unit Lwt.t
-
-val pop : 'a t -> 'a option Lwt.t
-
-val top : 'a t -> 'a option Lwt.t
-
-val clear : 'a t -> unit Lwt.t
-
-val copy : 'a t -> 'a t Lwt.t
-
-val is_empty : 'a t -> bool Lwt.t
-
-val length : 'a t -> int Lwt.t
-
-(**/**)
diff --git a/lib/common/util.ml b/lib/common/util.ml
index 8764fe2..e44cf12 100644
--- a/lib/common/util.ml
+++ b/lib/common/util.ml
@@ -45,7 +45,8 @@ end
 module Net = struct
   let create_socket port =
     let open Lwt_unix in
-    let ssock = socket ~cloexec:true PF_INET SOCK_DGRAM 0 in
+    let ssock = socket ~cloexec:false PF_INET SOCK_DGRAM 0 in
+    (* Printf.printf "Socket successfully opened on port: %d" port; *)
     let addr = ADDR_INET (Unix.inet_addr_loopback, port) in
     let%lwt () = bind ssock addr in
     return ssock
diff --git a/lib/common/util.mli b/lib/common/util.mli
index 6767ca1..c75b9b3 100644
--- a/lib/common/util.mli
+++ b/lib/common/util.mli
@@ -10,7 +10,8 @@ val ( let* ) : 'a option -> ('a -> 'b option) -> 'b option
 module Encoding : sig
   (** Defines utilities for encoding or decoding messages. *)
 
-  (** The {i int} value of the buffer size. *)
+  (** The {i int} value of the necessary buffer size for storing the size
+      header at the beginning of each Bin_prot payload. *)
   val size_header_length : int
 
   (** Reads the value of the size header prepended
diff --git a/lib/dune b/lib/dune
index f5c1898..71009f1 100644
--- a/lib/dune
+++ b/lib/dune
@@ -1,4 +1,4 @@
 (library
  (name pollinate)
  (public_name pollinate)
- (libraries pollinate.common pollinate.node))
+ (libraries pollinate.common pollinate.pnode))
diff --git a/lib/node/client.ml b/lib/node/client.ml
deleted file mode 100644
index cecfa89..0000000
--- a/lib/node/client.ml
+++ /dev/null
@@ -1,86 +0,0 @@
-open Lwt_unix
-open Common
-open Common.Util
-open Types
-
-let address_of { address; _ } = address
-
-let peer_from { address; peers; _ } =
-  Peer.
-    {
-      address;
-      status = Alive;
-      last_suspicious_status = None;
-      neighbors = peers;
-    }
-
-let add_peer node (peer : Peer.t) =
-  Base.Hashtbl.add node.peers ~key:peer.address ~data:peer
-
-let create_request node recipient payload =
-  Mutex.with_lock !node.current_request_id (fun id ->
-      id := !id + 1;
-      Lwt.return
-        Message.
-          {
-            category = Message.Request;
-            sub_category_opt = None;
-            id = !id;
-            sender = !node.address;
-            recipient;
-            payload;
-          })
-
-let create_response node request payload =
-  Message.
-    {
-      category = Message.Response;
-      sub_category_opt = None;
-      id = request.id;
-      sender = !node.address;
-      recipient = request.sender;
-      payload;
-    }
-
-let send_to node message =
-  let open Message in
-  let payload = Encoding.pack Message.bin_writer_t message in
-  let len = Bytes.length payload in
-  let addr = Address.to_sockaddr message.recipient in
-  Mutex.unsafe !node.socket (fun socket ->
-      let%lwt _ = sendto socket payload 0 len [] addr in
-      Lwt.return ())
-
-let recv_next node =
-  let open Lwt_unix in
-  let open Util in
-  (* Peek the first 8 bytes of the incoming datagram
-     to read the Bin_prot size header. *)
-  let size_buffer = Bytes.create Encoding.size_header_length in
-  let%lwt node_socket = Mutex.lock !node.socket in
-  (* Flag MSG_PEEK means: peeks at an incoming message.
-     The data is treated as unread and the next recvfrom()
-     or similar function shall still return this data.
-     Here, we only need the mg_size.
-  *)
-  let%lwt _ =
-    recvfrom node_socket size_buffer 0 Encoding.size_header_length [MSG_PEEK]
-  in
-  let msg_size =
-    Encoding.read_size_header size_buffer + Encoding.size_header_length in
-  let msg_buffer = Bytes.create msg_size in
-  (* Now that we have read the header and the message size, we can read the message *)
-  let%lwt _ = recvfrom node_socket msg_buffer 0 msg_size [] in
-  let message = Encoding.unpack Message.bin_read_t msg_buffer in
-  Mutex.unlock !node.socket;
-  Lwt.return message
-
-let request node request recipient =
-  let%lwt message = create_request node recipient request in
-  let%lwt () = send_to node message in
-  let condition_var = Lwt_condition.create () in
-  Hashtbl.add !node.request_table message.id condition_var;
-  Lwt_condition.wait condition_var
-
-let broadcast_request node req recipients =
-  List.map (request node req) recipients
diff --git a/lib/node/dune b/lib/node/dune
deleted file mode 100644
index b91407a..0000000
--- a/lib/node/dune
+++ /dev/null
@@ -1,6 +0,0 @@
-(library
- (name node)
- (public_name pollinate.node)
- (libraries bin_prot lwt lwt.unix pollinate.common)
- (preprocess
-  (pps ppx_bin_prot lwt_ppx)))
diff --git a/lib/node/inbox.ml b/lib/node/inbox.ml
deleted file mode 100644
index e83e16a..0000000
--- a/lib/node/inbox.ml
+++ /dev/null
@@ -1,31 +0,0 @@
-open Common
-type t = (Message.category, Message.t Tqueue.t) Base.Hashtbl.t
-
-let create () =
-  let inbox = Base.Hashtbl.Poly.create () in
-  let _ = Base.Hashtbl.add inbox ~key:Message.Request ~data:(Tqueue.create ()) in
-  let _ =
-    Base.Hashtbl.add inbox ~key:Message.Response ~data:(Tqueue.create ()) in
-  let _ =
-    Base.Hashtbl.add inbox ~key:Message.Uncategorized ~data:(Tqueue.create ())
-  in
-  let _ =
-    Base.Hashtbl.add inbox ~key:Message.Failure_detection
-      ~data:(Tqueue.create ()) in
-  inbox
-
-let find_or_create_category inbox category =
-  Base.Hashtbl.find_or_add inbox category ~default:(fun () -> Tqueue.create ())
-
-let next inbox ?(consume = true) category =
-  category
-  |> find_or_create_category inbox
-  |> if consume then Tqueue.take else Tqueue.peek
-
-let await_next inbox ?(consume = true) category =
-  category
-  |> find_or_create_category inbox
-  |> if consume then Tqueue.wait_to_take else Tqueue.wait_to_peek
-
-let push inbox category message =
-  category |> find_or_create_category inbox |> Tqueue.add message
diff --git a/lib/node/inbox.mli b/lib/node/inbox.mli
deleted file mode 100644
index a661d49..0000000
--- a/lib/node/inbox.mli
+++ /dev/null
@@ -1,25 +0,0 @@
-(** A Hashtbl mapping message categories to thread-safe queues
-containing messages *)
-type t
-
-(** Initializes an inbox with queues for each type of message. *)
-val create : unit -> t
-
-(** Attempts to retrieve the next message of the given category
-from the inbox, and returns None if no message is found. If consume
-is true, then the if a message is found it will be removed from the
-queue. Otherwise, it will be peeked at but not removed. Creates
-a queue for the given category if one has not been created yet. *)
-val next : t -> ?consume:bool -> Message.category -> Message.t option Lwt.t
-
-(** Blocks the current thread of execution until a message of the specified
-category is available. If consume is true, the message will be
-removed from the queue once it is available. Otherwise, it will be
-peeked at. Creates a queue for the given category if one has not
-    been created yet. *)
-val await_next : t -> ?consume:bool -> Message.category -> Message.t Lwt.t
-
-(** Pushes the given message of the given category
-to the corresponding queue. Creates a queue for the given category
-if one has not been created yet. *)
-val push : t -> Message.category -> Message.t -> unit Lwt.t
diff --git a/lib/node/message.ml b/lib/node/message.ml
deleted file mode 100644
index 961d686..0000000
--- a/lib/node/message.ml
+++ /dev/null
@@ -1,20 +0,0 @@
-open Common
-open Bin_prot.Std
-
-type category =
-  | Uncategorized
-  | Request
-  | Response
-  | Failure_detection
-  | Custom            of string
-[@@deriving bin_io]
-
-type t = {
-  category : category;
-  sub_category_opt : (string * string) option;
-  id : int;
-  sender : Address.t;
-  recipient : Address.t;
-  payload : bytes;
-}
-[@@deriving bin_io]
diff --git a/lib/node/node.mli b/lib/node/node.mli
deleted file mode 100644
index 3f425b7..0000000
--- a/lib/node/node.mli
+++ /dev/null
@@ -1,20 +0,0 @@
-open Common
-
-module Message = Message
-module Client = Client
-module Failure_detector = Failure_detector
-module Inbox = Inbox
-
-(** Initializes the node with an initial state, an optional
-routing function that the consumer can use to inspect and modify
-the incoming message as well as its metadata, and a message
-handler that acts on the current state and the Message.t representing
-the request. The message handler is used
-to initialize a server that runs asynchronously. Returns
-a reference to the node. *)
-val init :
-  ?preprocess:(Message.t -> Message.t) ->
-  msg_handler:(Message.t -> bytes) ->
-  ?init_peers:Address.t list ->
-  string * int ->
-  Types.node ref Lwt.t
diff --git a/lib/node/server.ml b/lib/node/server.ml
deleted file mode 100644
index e5dcaec..0000000
--- a/lib/node/server.ml
+++ /dev/null
@@ -1,51 +0,0 @@
-open Common.Util
-open Types
-
-let route node router msg =
-  let open Message in
-  let msg = router msg in
-  Inbox.push !node.inbox msg.category msg
-
-(** Signals a waiting request with its corresponding response
-   if it exists. Otherwise returns None. *)
-let handle_response request_table res =
-  let open Message in
-  let* res in
-  let* waiting_request = Hashtbl.find_opt request_table res.id in
-  Some (Lwt_condition.signal waiting_request res)
-
-(* Sever procedure:
-   1. Receive the next incoming message
-   2. Route the message
-   3. Grab the next response if it exists and send it to the request waiting for it
-   4. Grab the next request if it exists and send it to the message handler along with the
-     node's state
-   5. Send the encoded response from the message handler to the requester *)
-let run node router msg_handler =
-  let rec server () =
-    let%lwt message = Client.recv_next node in
-    let%lwt () = route node router message in
-
-    let%lwt () =
-      match%lwt Inbox.next !node.inbox Message.Failure_detection with
-      | Some message -> Failure_detector.handle_message node message
-      | None -> Lwt.return () in
-
-    let%lwt () = Failure_detector.suspicion_detection node in
-    let%lwt () = Failure_detector.failure_detection node in
-
-    let%lwt next_response = Inbox.next !node.inbox Message.Response in
-    let _ = handle_response !node.request_table next_response in
-
-    let%lwt request = Inbox.next !node.inbox Message.Request in
-    let%lwt () =
-      match request with
-      | Some request ->
-        let response =
-          request |> msg_handler |> Client.create_response node request in
-        let%lwt () = Client.send_to node response in
-        Lwt.return ()
-      | None -> Lwt.return () in
-
-    server () in
-  Lwt.async server
diff --git a/lib/pnode/client.ml b/lib/pnode/client.ml
new file mode 100644
index 0000000..36065db
--- /dev/null
+++ b/lib/pnode/client.ml
@@ -0,0 +1,68 @@
+open Common
+open Types
+
+let address_of { address; _ } = address
+
+let peer_from { address; peers; _ } =
+  Peer.
+    {
+      address;
+      status = Alive;
+      last_suspicious_status = None;
+      neighbors = peers;
+    }
+
+let add_peer node (peer : Peer.t) =
+  Base.Hashtbl.add node.peers ~key:peer.address ~data:peer
+
+let create_request node recipient (payload, payload_signature) =
+  Mutex.with_lock !node.current_request_id (fun id ->
+      id := !id + 1;
+      Lwt.return
+        Message.
+          {
+            category = Message.Request;
+            sub_category_opt = None;
+            id = !id;
+            timestamp = Unix.gettimeofday ();
+            sender = !node.address;
+            recipients = [recipient];
+            payload;
+            payload_signature;
+          })
+
+let create_response node request (payload, payload_signature) =
+  Message.
+    {
+      category = Message.Response;
+      sub_category_opt = None;
+      id = request.id;
+      timestamp = Unix.gettimeofday ();
+      sender = !node.address;
+      recipients = [request.sender];
+      payload;
+      payload_signature;
+    }
+
+let create_post node (payload, payload_signature) =
+  Message.
+    {
+      category = Message.Post;
+      id = -1;
+      sub_category_opt = None;
+      timestamp = Unix.gettimeofday ();
+      sender = !node.address;
+      recipients = [];
+      payload;
+      payload_signature;
+    }
+
+let request node request recipient =
+  let%lwt message = create_request node recipient request in
+  let%lwt () = Networking.send_to node message in
+  let condition_var = Lwt_condition.create () in
+  Hashtbl.add !node.request_table message.id condition_var;
+  Lwt_condition.wait condition_var
+
+let post node message =
+  !node.disseminator <- Disseminator.post !node.disseminator message
diff --git a/lib/node/client.mli b/lib/pnode/client.mli
similarity index 50%
rename from lib/node/client.mli
rename to lib/pnode/client.mli
index 1068e2d..9292de2 100644
--- a/lib/node/client.mli
+++ b/lib/pnode/client.mli
@@ -11,32 +11,26 @@ val address_of : node -> Address.t
 (** Constructs a [Peer.t] from a [Types.node]. *)
 val peer_from : node -> Peer.t
 
-(** Add a peer to the know peers. *)
+(** Add a peer to the known peers. *)
 val add_peer : node -> Peer.t -> [`Duplicate | `Ok]
 
+(** Begins disseminating an encoded message meant to be witnessed by as many
+    nodes in the network as possible. *)
+val post : node ref -> Message.t -> unit
+
 (** [create_request node recipient payload] creates a [Message.t] of the {i Request category}
 addressed to {i recipient} containing {i payload}. *)
-val create_request : node ref -> Address.t -> bytes -> Message.t Lwt.t
+val create_request :
+  node ref -> Address.t -> bytes * bytes option -> Message.t Lwt.t
 
 (** [create_response node request payload] creates a [Message.t] of the {i Response category}
 that responds to {i request} whose content is {i payload}. *)
-val create_response : node ref -> Message.t -> bytes -> Message.t
-
-(** Sends a message via datagram from the given [Types.node]
-to a specified peer within the [Message.t]. Construct a message with one of the
-[create_*] functions to then feed to this function. *)
-val send_to : node ref -> Message.t -> unit Lwt.t
-
-(** Waits for the next incoming message and returns it. *)
-val recv_next : node ref -> Message.t Lwt.t
+val create_response : node ref -> Message.t -> bytes * bytes option -> Message.t
 
 (** Sends an encoded {i request} to the specified peer and
 returns a promise holding the response from the peer. This
 function blocks the current thread of execution until a response
 arrives. *)
-val request : node ref -> bytes -> Address.t -> Message.t Lwt.t
+val request : node ref -> bytes * bytes option -> Address.t -> Message.t Lwt.t
 
-(** Broadcasts a request containing the given payload to a list
-of recipients and collects the responses in a list of [Message.t Lwt.t]. *)
-val broadcast_request :
-  node ref -> bytes -> Address.t list -> Message.t Lwt.t list
+val create_post : node ref -> bytes * bytes option -> Message.t
diff --git a/lib/pnode/disseminator.ml b/lib/pnode/disseminator.ml
new file mode 100644
index 0000000..9eb9152
--- /dev/null
+++ b/lib/pnode/disseminator.ml
@@ -0,0 +1,66 @@
+type pool_elt = {
+  message : Message.t;
+  remaining : int;
+}
+
+(** Set of md5 message hashes in hex-string form
+    for storing "seen" messages *)
+module DigestSet = Set.Make (Digest)
+
+type t = {
+  round : int;
+  pool : pool_elt list;
+  num_rounds : int;
+  epoch_length : float;
+  seen : DigestSet.t;
+}
+
+let create ~num_rounds ~epoch_length =
+  { round = 0; pool = []; num_rounds; epoch_length; seen = DigestSet.empty }
+
+(* Increments disseminator.round and decrements pool_elt.remaining for
+   each disseminator pool element. Removes messages from the pool
+   that have been disseminated num_rounds times or which are
+   older than the epoch length.*)
+let next_round disseminator =
+  let round = disseminator.round + 1 in
+  let pool =
+    disseminator.pool
+    |> List.map (fun ({ remaining; _ } as elt) ->
+           { elt with remaining = remaining - 1 })
+    |> List.filter (fun elt ->
+           elt.remaining > 0
+           && elt.message.timestamp > Unix.time () -. disseminator.epoch_length)
+  in
+
+  { disseminator with round; pool }
+
+let post disseminator message =
+  let open Message in
+  let time = Unix.time () in
+  if message.timestamp > time -. disseminator.epoch_length then
+    let pool =
+      { message; remaining = disseminator.num_rounds } :: disseminator.pool
+    in
+    let digest_of_post = Message.hash_of message in
+    let seen = DigestSet.add digest_of_post disseminator.seen in
+    { disseminator with pool; seen }
+  else
+    disseminator
+
+let broadcast_queue disseminator =
+  List.map (fun e -> e.message) disseminator.pool
+
+let seen disseminator message =
+  let open Message in
+  let time = Unix.time () in
+  if message.timestamp > time -. disseminator.epoch_length then
+    let hash = Message.hash_of message in
+    DigestSet.mem hash disseminator.seen
+  else
+    false
+
+let get_seen_messages disseminator =
+  disseminator.seen |> DigestSet.to_seq |> List.of_seq
+
+let current_round { round; _ } = round
diff --git a/lib/pnode/disseminator.mli b/lib/pnode/disseminator.mli
new file mode 100644
index 0000000..bcea15e
--- /dev/null
+++ b/lib/pnode/disseminator.mli
@@ -0,0 +1,44 @@
+(** Component responsible for gossip-style dissemination of
+    messages across the network *)
+
+(** A record containing information and state relevant to the
+    dissemination component. *)
+type t
+
+(** Creates a dissemination component that can be attached to a node
+    when given the number of "rounds" for which each new message should
+    be disseminated and an "epoch length", in seconds, which determines
+    whether a message is too old to be disseminated again by checking
+    whether the message is newer than n seconds old, where n is the
+    given epoch length. *)
+val create : num_rounds:int -> epoch_length:float -> t
+
+(** Starts the next round of dissemination, affecting the state
+    of the disseminator. In particular, this function causes the
+    current round to increase, reduces the number of rounds remaining
+    for each message being disseminated, and filters out messages with
+    no rounds remaining or a timestamp that's older than epoch_length
+    seconds. *)
+val next_round : t -> t
+
+(** Adds a new message to the dissemination pool. The message will not be
+    posted if it is older than the epoch_length. Otherwise, the message
+    will begin to be disseminated automatically as long as the disseminator
+    is running along with Networking.disseminate.*)
+val post : t -> Message.t -> t
+
+(** Returns the list of messages that need to be disseminated. For
+    exclusive use by Networking.disseminate. *)
+val broadcast_queue : t -> Message.t list
+
+(** Determines whether the dissemination component has witnessed a
+    given message before, or whether the message is too old to be
+    retained in the set of seen messages. *)
+val seen : t -> Message.t -> bool
+
+(** Returns the 7 digit hashes of all the messages
+    that the disseminator has seen. *)
+val get_seen_messages : t -> string list
+
+(** Returns the current disseminator round. *)
+val current_round : t -> int
diff --git a/lib/pnode/dune b/lib/pnode/dune
new file mode 100644
index 0000000..ed5e578
--- /dev/null
+++ b/lib/pnode/dune
@@ -0,0 +1,6 @@
+(library
+ (name pnode)
+ (public_name pollinate.pnode)
+ (libraries bin_prot lwt lwt.unix pollinate.common)
+ (preprocess
+  (pps ppx_bin_prot ppx_deriving.show lwt_ppx)))
diff --git a/lib/node/failure_detector.ml b/lib/pnode/failure_detector.ml
similarity index 80%
rename from lib/node/failure_detector.ml
rename to lib/pnode/failure_detector.ml
index 0db1061..4ce1d07 100644
--- a/lib/node/failure_detector.ml
+++ b/lib/pnode/failure_detector.ml
@@ -34,34 +34,6 @@ let wait_ack_timeout t sequence_number timeout =
        Lwt.return @@ Result.Ok "Successfully received acknowledge");
     ]
 
-(** Basic random shuffle, see https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle*)
-let knuth_shuffle known_peers =
-  let shuffled_array = Array.copy (Array.of_list known_peers) in
-  let initial_array_length = Array.length shuffled_array in
-  for i = initial_array_length - 1 downto 1 do
-    let k = Random.int (i + 1) in
-    let x = shuffled_array.(k) in
-    shuffled_array.(k) <- shuffled_array.(i);
-    shuffled_array.(i) <- x
-  done;
-  Array.to_list shuffled_array
-
-(* Regarding the SWIM protocol, if peer A cannot get ACK from peer B (timeout):
-    A sets B as `suspicious`
-    A randomly picks one (or several, should it also be randomly determined?) peer(s) from its list
-    and ask him/them to ping B.*)
-
-(** This function return the random peer, to which we will ask to ping the first peer *)
-let rec pick_random_neighbors neighbors number_of_neighbors =
-  let addresses = neighbors |> Base.Hashtbl.keys |> knuth_shuffle in
-  match addresses with
-  | [] -> failwith "pick_random_peers"
-  | elem :: _ ->
-    if number_of_neighbors = 1 then
-      [elem]
-    else
-      elem :: pick_random_neighbors neighbors (number_of_neighbors - 1)
-
 (** Updates a peer in the node's peer list with
    the given status. Returns a result that contains
    unit if the peer is found in the node's list, and
@@ -82,20 +54,22 @@ let update_peer_status node peer status =
       (Printf.sprintf "Failed to find peer with address %s:%d in node peer list"
          peer.address.address peer.address.port)
 
-let create_message node message (recipient : Peer.t) =
+let create_message node message recipient =
   Message.
     {
       category = Failure_detection;
       sub_category_opt = None;
       id = -1;
+      timestamp = Unix.gettimeofday ();
       sender = Client.address_of !node;
-      recipient = recipient.address;
+      recipients = [recipient.Peer.address];
       payload = Encoding.pack bin_writer_message message;
+      payload_signature = None;
     }
 
-let send_message message node (recipient : Peer.t) =
+let send_message message node recipient =
   let message = create_message node message recipient in
-  Client.send_to node message
+  Networking.send_to node message
 
 let send_ping_to node peer = send_message Ping node peer
 
@@ -149,7 +123,7 @@ let probe_peer t node peer_to_update =
   | Error _ -> (
     let pingers =
       t.config.helpers_size
-      |> pick_random_neighbors !node.peers
+      |> Networking.pick_random_neighbors !node.peers
       |> List.map Peer.from in
     let _ = List.map (send_ping_request_to node) pingers in
     let wait_time = t.config.protocol_period - t.config.round_trip_time in
@@ -172,8 +146,7 @@ let suspicion_detection node =
   | 0 -> Lwt.return ()
   | _ ->
     let random_peer =
-      List.map (fun p -> p.address) available_peers |> knuth_shuffle |> List.hd
-    in
+      Networking.pick_random_neighbors !node.peers 1 |> List.hd in
     let _ =
       Lwt.join
         [
diff --git a/lib/node/failure_detector.mli b/lib/pnode/failure_detector.mli
similarity index 92%
rename from lib/node/failure_detector.mli
rename to lib/pnode/failure_detector.mli
index 3ef3e48..5d1914a 100644
--- a/lib/node/failure_detector.mli
+++ b/lib/pnode/failure_detector.mli
@@ -40,10 +40,6 @@ val failure_detection : node ref -> unit Lwt.t
 
 (**/**)
 
-val knuth_shuffle : Peer.t list -> Peer.t list
-
-val pick_random_neighbors : ('a, 'b) Base.Hashtbl.t -> int -> 'a list
-
 val update_peer_status :
   Types.node ref -> Common.Peer.t -> Common.Peer.status -> (unit, string) result
 
diff --git a/lib/pnode/message.ml b/lib/pnode/message.ml
new file mode 100644
index 0000000..4fbb782
--- /dev/null
+++ b/lib/pnode/message.ml
@@ -0,0 +1,35 @@
+open Common
+open Bin_prot.Std
+
+type category =
+  | Uncategorized
+  | Request
+  | Response
+  | Post
+  | Failure_detection
+  | Custom            of string
+[@@deriving bin_io, show]
+
+type t = {
+  category : category;
+  sub_category_opt : (string * string) option;
+  id : int;
+  timestamp : float;
+  sender : Address.t;
+  recipients : Address.t list;
+  payload : bytes;
+  payload_signature : bytes option;
+}
+[@@deriving bin_io]
+
+let hash_of m =
+  [
+    m.sender.address;
+    string_of_int m.sender.port;
+    string_of_float m.timestamp;
+    Bytes.to_string m.payload;
+  ]
+  |> String.concat ""
+  |> Digest.string
+  |> Digest.to_hex
+  |> fun s -> String.sub s 0 7
diff --git a/lib/node/message.mli b/lib/pnode/message.mli
similarity index 70%
rename from lib/node/message.mli
rename to lib/pnode/message.mli
index 4068b67..50fbeb9 100644
--- a/lib/node/message.mli
+++ b/lib/pnode/message.mli
@@ -1,6 +1,6 @@
 (** Messages received by the [node], whether they are requests,
 responses, or protocol-specific messages. For consumer use
-only when implementing a routing function for the
+only when implementing a preprocessing function for the
 node. *)
 
 open Common
@@ -14,18 +14,23 @@ type category =
   | Uncategorized
   | Request
   | Response
+  | Post
   | Failure_detection
   | Custom            of string
-[@@deriving bin_io]
+[@@deriving bin_io, show]
 
 (** Messages received from [peers] which are
-stored in the node's inbox. *)
+processed by the node's message handler. *)
 type t = {
   category : category;
   sub_category_opt : (string * string) option;
   id : int;
+  timestamp : float;
   sender : Address.t;
-  recipient : Address.t;
+  recipients : Address.t list;
   payload : bytes;
+  payload_signature : bytes option;
 }
 [@@deriving bin_io]
+
+val hash_of : t -> Digest.t
diff --git a/lib/pnode/networking.ml b/lib/pnode/networking.ml
new file mode 100644
index 0000000..7937b2d
--- /dev/null
+++ b/lib/pnode/networking.ml
@@ -0,0 +1,91 @@
+open Common
+open Common.Util
+open Types
+open Lwt_unix
+
+let send_to node message =
+  let open Message in
+  (* let%lwt () = log node "Sending message\n" in *)
+  let payload = Encoding.pack Message.bin_writer_t message in
+  let len = Bytes.length payload in
+  let addrs = List.map Address.to_sockaddr message.recipients in
+  Mutex.unsafe !node.socket (fun socket ->
+      let%lwt _ =
+        Lwt_list.map_p (fun addr -> sendto socket payload 0 len [] addr) addrs
+      in
+      Lwt.return ())
+
+let recv_next node =
+  let open Lwt_unix in
+  let open Util in
+  (* Peek the first 8 bytes of the incoming datagram
+     to read the Bin_prot size header. *)
+  let size_buffer = Bytes.create Encoding.size_header_length in
+  let%lwt node_socket = Mutex.lock !node.socket in
+  (* Flag MSG_PEEK means: peeks at an incoming message.
+     The data is treated as unread and the next recvfrom()
+     or similar function shall still return this data.
+     Here, we only need the mg_size.
+  *)
+  let%lwt _ =
+    recvfrom node_socket size_buffer 0 Encoding.size_header_length [MSG_PEEK]
+  in
+  let msg_size =
+    Encoding.read_size_header size_buffer + Encoding.size_header_length in
+  let msg_buffer = Bytes.create msg_size in
+  (* Now that we have read the header and the message size, we can read the message *)
+  let%lwt _ = recvfrom node_socket msg_buffer 0 msg_size [] in
+  let message = Encoding.unpack Message.bin_read_t msg_buffer in
+  Mutex.unlock !node.socket;
+  Lwt.return message
+
+(** Basic random shuffle, see https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle*)
+let knuth_shuffle known_peers =
+  let shuffled_array = Array.copy (Array.of_list known_peers) in
+  let initial_array_length = Array.length shuffled_array in
+  for i = initial_array_length - 1 downto 1 do
+    let k = Random.int (i + 1) in
+    let x = shuffled_array.(k) in
+    shuffled_array.(k) <- shuffled_array.(i);
+    shuffled_array.(i) <- x
+  done;
+  Array.to_list shuffled_array
+
+(** This function return the random peer, to which we will ask to ping the first peer *)
+let pick_random_neighbors neighbors number_of_neighbors =
+  let rec take n l =
+    match l with
+    | [] -> []
+    | h :: t when n > 0 -> h :: take (n - 1) t
+    | _ -> [] in
+  neighbors |> Base.Hashtbl.keys |> knuth_shuffle |> take number_of_neighbors
+
+(** Injects the list of recipients into the message and sends it to
+    each recipient with a log message. *)
+let broadcast node message (recipients : Address.t list) =
+  (* let%lwt () =
+     recipients
+     |> List.map (fun Address.{ port; _ } -> string_of_int port)
+     |> String.concat " ; "
+     |> Printf.sprintf "Disseminating post %s from author %d to peers: [%s]\n"
+          (Message.hash_of message) message.sender.port
+     |> log node in *)
+  let message = Message.{ message with recipients } in
+  let%lwt () = send_to node message in
+  Lwt.return ()
+
+(** Picks random peers to broadcast each message in the dissemination
+    queue to, then sends them. This function progresses the
+    disseminator to the next round, so no other function should
+    do this. *)
+let disseminate node =
+  let dissemination_group = pick_random_neighbors !node.peers 2 in
+  let _ =
+    Disseminator.broadcast_queue !node.disseminator
+    |> List.map (fun message -> broadcast node message dissemination_group)
+  in
+  Lwt.return (!node.disseminator <- Disseminator.next_round !node.disseminator)
+
+module Testing = struct
+  let knuth_shuffle = knuth_shuffle
+end
diff --git a/lib/pnode/networking.mli b/lib/pnode/networking.mli
new file mode 100644
index 0000000..e818c96
--- /dev/null
+++ b/lib/pnode/networking.mli
@@ -0,0 +1,23 @@
+open Types
+open Common
+
+(** Sends a message via datagram from the given [Types.node]
+to a specified peer within the [Message.t]. Construct a message with one of the
+[create_*] functions to then feed to this function. *)
+val send_to : node ref -> Message.t -> unit Lwt.t
+
+(** Waits for the next incoming message and returns it. *)
+val recv_next : node ref -> Message.t Lwt.t
+
+(** Advances a node's disseminator by disseminating the messages in the queue
+    and pruning outdated messages from the queue. *)
+val disseminate : node ref -> unit Lwt.t
+
+(** Given a Base.Hashtbl of Addresses to Peers and a number n of peers to be
+    randomly chosen, returns a list of addresses corresponding to n  *)
+val pick_random_neighbors :
+  (Address.t, Peer.t) Base.Hashtbl.t -> int -> Address.t list
+
+module Testing : sig
+  val knuth_shuffle : 'a list -> 'a list
+end
diff --git a/lib/node/node.ml b/lib/pnode/pnode.ml
similarity index 53%
rename from lib/node/node.ml
rename to lib/pnode/pnode.ml
index ad939c0..7848165 100644
--- a/lib/node/node.ml
+++ b/lib/pnode/pnode.ml
@@ -3,12 +3,12 @@ open Types
 
 module Message = Message
 module Client = Client
-module Failure_detector = Failure_detector
-module Inbox = Inbox
 
-let init ?(preprocess = fun m -> m) ~msg_handler ?(init_peers = [])
-    (address, port) =
+type t = Types.node
+
+let init ?(init_peers = []) Address.{ address; port } =
   let open Util in
+  (* Printf.printf "Opening port: %d\n%!" port; *)
   let%lwt socket = Net.create_socket port in
   let peers =
     Base.Hashtbl.create ~growth_allowed:true ~size:0 (module Address) in
@@ -23,7 +23,6 @@ let init ?(preprocess = fun m -> m) ~msg_handler ?(init_peers = [])
         current_request_id = Mutex.create (ref 0);
         request_table = Hashtbl.create 20;
         socket = Mutex.create socket;
-        inbox = Inbox.create ();
         failure_detector =
           Failure_detector.make
             {
@@ -33,6 +32,19 @@ let init ?(preprocess = fun m -> m) ~msg_handler ?(init_peers = [])
               helpers_size = 3;
             };
         peers;
+        disseminator = Disseminator.create ~num_rounds:10 ~epoch_length:50.;
       } in
-  Server.run node preprocess msg_handler;
   Lwt.return node
+
+let run_server ?(preprocessor = fun m -> m) ~msg_handler node =
+  (* let _ = Printf.sprintf "I am inside run_server\n%!" in *)
+  Server.run node preprocessor msg_handler
+
+let seen node message = Disseminator.seen !node.disseminator message
+
+module Testing = struct
+  module Failure_detector = Failure_detector
+  module Networking = Networking
+  let broadcast_queue node = Disseminator.broadcast_queue !node.disseminator
+  let disseminator_round node = Disseminator.current_round !node.disseminator
+end
diff --git a/lib/pnode/pnode.mli b/lib/pnode/pnode.mli
new file mode 100644
index 0000000..a035e0c
--- /dev/null
+++ b/lib/pnode/pnode.mli
@@ -0,0 +1,29 @@
+open Common
+
+module Message = Message
+module Client = Client
+
+type t = Types.node
+
+(** Initializes the node with an initial state, an optional
+preprocessing function that the consumer can use to inspect and modify
+the incoming message as well as its metadata, and a message
+handler that acts on the current state and the incoming Message.t.
+The message handler is used to initialize a server that runs asynchronously.
+Returns reference to the newly created node. *)
+val init : ?init_peers:Address.t list -> Address.t -> t ref Lwt.t
+
+val run_server :
+  ?preprocessor:(Message.t -> Message.t) ->
+  msg_handler:(Message.t -> bytes option * bytes option) ->
+  t ref ->
+  'b Lwt.t
+
+val seen : t ref -> Message.t -> bool
+
+module Testing : sig
+  module Failure_detector = Failure_detector
+  module Networking = Networking
+  val broadcast_queue : t ref -> Message.t list
+  val disseminator_round : t ref -> int
+end
diff --git a/lib/pnode/server.ml b/lib/pnode/server.ml
new file mode 100644
index 0000000..edb6ef5
--- /dev/null
+++ b/lib/pnode/server.ml
@@ -0,0 +1,130 @@
+open Util
+open Common
+open Types
+
+(** Signals a waiting request with its corresponding response
+   if it exists. Otherwise returns None. *)
+let handle_response node res =
+  let open Message in
+  match Hashtbl.find_opt !node.request_table res.id with
+  | Some waiting_request -> Lwt_condition.signal waiting_request res
+  | None -> ()
+
+(* Preprocess a message, log some information about it, then handle it
+   based on its category. The "rules" are as follows:
+
+   Response: send the message to a "handle_response" function which wakes
+   up a sleeping request function with the response it was waiting for.
+
+   Request: run the message handler on the incoming request and, if the message
+   handler returned a response, send it to the requester.
+
+   Failure_detection: send the message to the Failure_detector.handle_message function
+
+   Post: check if the post has been seen (or if its outdated). If not, then handle the post with
+   the message handler, then disseminate it to this node's peers by reposting it.
+
+   Otherwise, we just apply the message handler and that's it.
+*)
+let process_message node preprocessor msg_handler =
+  (* let _ = Printf.sprintf "I am inside process_message\n%!" in *)
+  let open Message in
+  let%lwt message = Networking.recv_next node in
+  let message = preprocessor message in
+  (* let%lwt () =
+     log node
+       (Printf.sprintf "Processing message %s from %d...\n"
+          (Message.hash_of message) message.sender.port) in *)
+  let%lwt () =
+    match message.category with
+    | Response -> Lwt.return (handle_response node message)
+    | Request -> (
+      (* let%lwt () =
+         log node
+           (Printf.sprintf "%s:%d : Processing request from %s:%d\n"
+              !node.address.address !node.address.port message.sender.address
+              message.sender.port) in *)
+      match msg_handler message with
+      | Some payload, payload_signature ->
+        (* let _ = Printf.sprintf "I am inside msg_handler, found payload\n%!" in *)
+        (payload, payload_signature)
+        |> Client.create_response node message
+        |> Networking.send_to node
+      | None, _ -> 
+        (* let _ = Printf.sprintf "I am inside msg_handler, missing payload\n%!" in *)
+        Lwt.return ())
+    | Failure_detection -> Failure_detector.handle_message node message
+    | Post ->
+      if not (Disseminator.seen !node.disseminator message) then (
+        (* let%lwt () =
+           log node
+             (Printf.sprintf "%s:%d : Processing post %s from %s:%d\n"
+                !node.address.address !node.address.port
+                (Message.hash_of message) message.sender.address
+                message.sender.port) in *)
+        let _ = msg_handler message in
+        (* let%lwt () = log node "Adding message to broadcast queue\n" in *)
+        Client.post node message;
+        Lwt.return ())
+      else
+        (* log node
+           (Printf.sprintf "Got post %s from %s:%d but saw it already\n"
+              (Message.hash_of message) message.sender.address
+              message.sender.port) *)
+        Lwt.return ()
+    | _ ->
+      let _ = msg_handler message in
+      Lwt.return () in
+  Lwt.return ()
+
+(** Log some initial information at the beginning of a server iteration.
+    See comments for descriptions regarding what is actually being logged. *)
+let _print_logs node =
+  (* Check that the server is in fact running *)
+  let%lwt () = log node "Running server\n" in
+  (* Check which posts the node has seen so far *)
+  let%lwt () =
+    log node
+      (Printf.sprintf "Seen: %s\n"
+         (Disseminator.get_seen_messages !node.disseminator
+         |> String.concat " ; ")) in
+  (* Check who the current peers of the node are *)
+  let%lwt () =
+    !node.peers
+    |> Base.Hashtbl.keys
+    |> List.map (fun Address.{ port; _ } -> string_of_int port)
+    |> String.concat " ; "
+    |> Printf.sprintf "Peers: %s\n"
+    |> log node in
+  (* Check which posts are currently being disseminated by the node *)
+  if List.length (Disseminator.broadcast_queue !node.disseminator) > 0 then
+    let%lwt () =
+      !node.disseminator
+      |> Disseminator.broadcast_queue
+      |> List.map Message.hash_of
+      |> String.concat " "
+      |> Printf.sprintf "Broadcast Queue: %s\n"
+      |> log node in
+    Lwt.return ()
+  else
+    Lwt.return ()
+
+(* Sever procedure:
+   0. Log pertinent information about the current node.
+   1. Start a new thread for handling any incoming message.
+   2. Run the failure detector.
+   3. Run the disseminator, this includes actually sending messages to be
+      disseminated across the network.
+   4. Wait 0.001 seconds before restarting the procedure. *)
+let rec run node preprocessor msg_handler =
+  (* Step 0 *)
+  (* let%lwt () = print_logs node in *)
+  (* Step 1 *)
+  let _ = process_message node preprocessor msg_handler in
+  (* Step 2 *)
+  let%lwt () = Failure_detector.failure_detection node in
+  (* Step 3 *)
+  let%lwt () = Networking.disseminate node in
+  (* Step 4 *)
+  let%lwt () = Lwt_unix.sleep 0.001 in
+  run node preprocessor msg_handler
diff --git a/lib/pnode/server.mli b/lib/pnode/server.mli
new file mode 100644
index 0000000..17019e0
--- /dev/null
+++ b/lib/pnode/server.mli
@@ -0,0 +1,8 @@
+(** Runs the server given a reference to a node, a message preprocessor and a message handler.
+    The server is responsible for running failure detection and dissemination processes, as well
+    as issuing responses to nodes making individual requests via the message handler. *)
+val run :
+  Types.node ref ->
+  (Message.t -> Message.t) ->
+  (Message.t -> bytes option * bytes option) ->
+  'b Lwt.t
diff --git a/lib/node/types.ml b/lib/pnode/types.ml
similarity index 94%
rename from lib/node/types.ml
rename to lib/pnode/types.ml
index 934844c..b69ef6b 100644
--- a/lib/node/types.ml
+++ b/lib/pnode/types.ml
@@ -20,7 +20,7 @@ type node = {
   current_request_id : int ref Mutex.t;
   request_table : (int, Message.t Lwt_condition.t) Hashtbl.t;
   socket : file_descr Mutex.t;
-  inbox : Inbox.t;
   failure_detector : failure_detector;
   peers : (Address.t, Peer.t) Base.Hashtbl.t;
+  mutable disseminator : Disseminator.t;
 }
diff --git a/lib/node/types.mli b/lib/pnode/types.mli
similarity index 65%
rename from lib/node/types.mli
rename to lib/pnode/types.mli
index 2316105..cd3c30a 100644
--- a/lib/node/types.mli
+++ b/lib/pnode/types.mli
@@ -39,21 +39,26 @@ type failure_detector = {
 (** Represents a node with some state in a peer-to-peer network *)
 type node = {
   address : Address.t;
-      (** An ID that is incremented whenever a request is
-     made from this node. The response matching this
-     request will carry the same ID, allowing the response
-     to be identified and thus stopping the request from
-     blocking. *)
+      (* An ID that is incremented whenever a request is
+         made from this node. The response matching this
+         request will carry the same ID, allowing the response
+         to be identified and thus stopping the request from
+         blocking. *)
   current_request_id : int ref Mutex.t;
-      (** A hashtable that pairs request IDs with condition variables.
-     When a response is received by the server, it checks this table
-     for a waiting request and signals the request's condition variable
-     with the incoming response. *)
+      (* A hashtable that pairs request IDs with condition variables.
+         When a response is received by the server, it checks this table
+         for a waiting request and signals the request's condition variable
+         with the incoming response. *)
   request_table : (int, Message.t Lwt_condition.t) Hashtbl.t;
   socket : file_descr Mutex.t;
-      (** A store of incoming messages for the node. Stores
-     messages separately by category. *)
-  inbox : Inbox.t;
+  (* Failure detection component ; runs automatically with the server and is responsible
+     for automatically removing dead nodes from the peers table. *)
   failure_detector : failure_detector;
+  (* Hashtable mapping addresses to Peers with statuses according
+     to the SWIM failure-detection protocol *)
   peers : (Address.t, Peer.t) Base.Hashtbl.t;
+  (* Dissemination component ; runs automatically with the server and is responsible
+     for automatically disseminating both new Post messages and received Post messages
+     with other nodes in the network *)
+  mutable disseminator : Disseminator.t;
 }
diff --git a/lib/pnode/util.ml b/lib/pnode/util.ml
new file mode 100644
index 0000000..7ef2f62
--- /dev/null
+++ b/lib/pnode/util.ml
@@ -0,0 +1,11 @@
+open Types
+
+(** Prints a log message with information about the node it pertains to and the current time. *)
+let log node _msg =
+  let _current_time =
+    Unix.time () |> Unix.localtime |> fun tm ->
+    Printf.sprintf "%02d:%02d:%02d" tm.Unix.tm_hour tm.Unix.tm_min
+      tm.Unix.tm_sec in
+  let _addr = Printf.sprintf "%s:%d" !node.address.address !node.address.port in
+  Lwt.return ()
+  (* Lwt_io.printf "[%s @ %s] %s" addr current_time msg *)
diff --git a/lib/pollinate.ml b/lib/pollinate.ml
index 84d1900..ab4d85a 100644
--- a/lib/pollinate.ml
+++ b/lib/pollinate.ml
@@ -1,4 +1,4 @@
 module Address = Common.Address
 module Util = Common.Util
 module Peer = Common.Peer
-module Node = Node
+module PNode = Pnode
diff --git a/test/commons.ml b/test/commons.ml
index 887ebb3..4c9d7fa 100644
--- a/test/commons.ml
+++ b/test/commons.ml
@@ -1,10 +1,10 @@
 (** Utils function shared by the different tests modules *)
 module Commons = struct
-  open Pollinate.Node
+  open Pollinate.PNode
   open Pollinate.Util
   open Messages
 
-  let preprocess msg =
+  let preprocessor msg =
     let open Messages in
     match msg.Message.category with
     | Request ->
@@ -17,14 +17,18 @@ module Commons = struct
       { msg with payload = Encoding.pack bin_writer_response r }
     | _ -> msg
 
-  let msg_handler request =
+  let msg_handler message =
     let open Messages in
     let open Message in
-    let request = Encoding.unpack bin_read_request request.payload in
-    let response =
-      match request with
-      | Ping -> Pong
-      | Get -> Success "Ok"
-      | Insert _ -> Success "Successfully added value to state" in
-    Encoding.pack bin_writer_message (Response response)
+    match message.category with
+    | Request ->
+      let request = Encoding.unpack bin_read_request message.payload in
+      let response =
+        match request with
+        | Ping -> Pong
+        | Get -> Pong
+        | Insert _ -> Success "Successfully added value to state" in
+      ( Response response |> Encoding.pack bin_writer_message |> Option.some,
+        None )
+    | _ -> (None, None)
 end
diff --git a/test/disseminator_tests.ml b/test/disseminator_tests.ml
new file mode 100644
index 0000000..a7b275e
--- /dev/null
+++ b/test/disseminator_tests.ml
@@ -0,0 +1,105 @@
+open Lwt.Infix
+open Commons
+open Pollinate
+open Pollinate.PNode
+
+module Disseminator_tests = struct
+  let node =
+    Lwt_main.run
+      (let%lwt node_a =
+         PNode.init ~init_peers:[]
+           Address.{ address = "127.0.0.1"; port = 5000 } in
+       Lwt.return node_a)
+
+  let queue_insertion_test () =
+    let _server = PNode.run_server ~msg_handler:Commons.msg_handler node in
+    let payload =
+      Client.address_of !node
+      |> (fun Address.{ port; _ } -> port)
+      |> string_of_int
+      |> String.to_bytes in
+    Client.create_post node (payload, None) |> Client.post node;
+
+    Lwt.return (List.length (PNode.Testing.broadcast_queue node))
+
+  let queue_removal_test () =
+    let _server = PNode.run_server ~msg_handler:Commons.msg_handler node in
+    let payload =
+      Client.address_of !node
+      |> (fun Address.{ port; _ } -> port)
+      |> string_of_int
+      |> String.to_bytes in
+    Client.create_post node (payload, None) |> Client.post node;
+
+    let%lwt () =
+      while%lwt PNode.Testing.disseminator_round node <= 10 do
+        Lwt_unix.sleep 0.1
+      done in
+    Lwt.return (List.length (PNode.Testing.broadcast_queue node))
+
+  let seen_message_test () =
+    let _server = PNode.run_server ~msg_handler:Commons.msg_handler node in
+    let payload =
+      Client.address_of !node
+      |> (fun Address.{ port; _ } -> port)
+      |> string_of_int
+      |> String.to_bytes in
+    let message = Client.create_post node (payload, None) in
+    message |> Client.post node;
+
+    Lwt.return (PNode.seen node message)
+end
+
+(** Test for dissemination given a specific Pnode. *)
+let test_queue_removal _ () =
+  Disseminator_tests.queue_removal_test ()
+  >|= Alcotest.(check int)
+        "Length of broadcast queue is 0 10 rounds after the client posts" 0
+
+let test_queue_insertion _ () =
+  Disseminator_tests.queue_insertion_test ()
+  >|= Alcotest.(check int)
+        "Length of broadcast queue is 1 after the client posts" 1
+
+let test_seen_message _ () =
+  Disseminator_tests.seen_message_test ()
+  >|= Alcotest.(check bool)
+        "A message that's just been posted is seen by the disseminator" true
+
+let () =
+  Lwt_main.run
+  @@ Alcotest_lwt.run "Disseminator tests"
+       [
+         ( "disseminator functions",
+           [
+             Alcotest_lwt.test_case
+               "Messages are removed from queue after 10 rounds" `Quick
+               test_queue_removal;
+             Alcotest_lwt.test_case
+               "Messages are added to the queue when posted" `Quick
+               test_queue_insertion;
+             Alcotest_lwt.test_case
+               "Messages that are posted are immediately seen" `Quick
+               test_seen_message
+             (* Alcotest_lwt.test_case "Dissemination from A" `Quick
+                (test_disseminate_from Gossip_tests.node_a); *)
+             (* Alcotest_lwt.test_case "Dissemination from B" `Quick
+                  (test_disseminate_from Gossip_tests.node_b);
+                Alcotest_lwt.test_case "Dissemination from C" `Quick
+                  (test_disseminate_from Gossip_tests.node_c);
+                Alcotest_lwt.test_case "Dissemination from D" `Quick
+                  (test_disseminate_from Gossip_tests.node_d); *)
+             (* Alcotest_lwt.test_case "Dissemination from E" `Quick
+                (test_disseminate_from Gossip_tests.node_e); *)
+             (* Alcotest_lwt.test_case "Dissemination from F" `Quick
+                (test_disseminate_from Gossip_tests.node_f); *)
+             (* Alcotest_lwt.test_case "Dissemination from G" `Quick
+                (test_disseminate_from Gossip_tests.node_g); *)
+             (* Alcotest_lwt.test_case "Dissemination from H" `Quick
+                (test_disseminate_from Gossip_tests.node_h); *)
+             (* Alcotest_lwt.test_case "Dissemination from I" `Quick
+                (test_disseminate_from Gossip_tests.node_i); *)
+             (* Alcotest_lwt.test_case "Dissemination from J" `Quick
+                (test_disseminate_from Gossip_tests.node_j); ;*);
+           ] );
+       ]
diff --git a/test/dune b/test/dune
index 97f6d6d..ed3de82 100644
--- a/test/dune
+++ b/test/dune
@@ -1,19 +1,25 @@
 (tests
  (names
   node_tests
+  gossip_tests
+  disseminator_tests
   peer_prop
   address_prop
   util_prop
+  networking_prop
   failure_detector_prop
   failure_detector_tests)
  (modules
   node_tests
+  gossip_tests
+  disseminator_tests
   messages
   generators
   peer_prop
   address_prop
   commons
   util_prop
+  networking_prop
   failure_detector_prop
   failure_detector_tests)
  (libraries pollinate bin_prot lwt alcotest-lwt qcheck-core qcheck-alcotest)
diff --git a/test/failure_detector_prop.ml b/test/failure_detector_prop.ml
index fe0177b..f7fc885 100644
--- a/test/failure_detector_prop.ml
+++ b/test/failure_detector_prop.ml
@@ -1,43 +1,22 @@
 open QCheck2.Gen
 open Pollinate.Peer
-open Commons
-
-module SUT = Pollinate.Node.Failure_detector
+open Pollinate
+module SUT = Pollinate.PNode.Testing.Failure_detector
 
 let node_a =
-  Lwt_main.run
-    (Node.init ~preprocess:Commons.preprocess ~msg_handler:Commons.msg_handler
-       ("127.0.0.1", 3002))
-
-let knuth_shuffle_size =
-  QCheck2.Test.make ~count:1000
-    ~name:"Knuth_shuffle does not change the size of the list"
-    (QCheck2.Gen.list Generators.peer_gen) (fun peers ->
-      List.length (SUT.knuth_shuffle peers) == List.length peers)
+  Lwt_main.run (PNode.init Address.{ address = "127.0.0.1"; port = 3002 })
 
 let update_peer =
   QCheck2.Test.make ~count:1000
     ~name:"update_neighbor_status successfully update neighbor status"
     (pair Generators.peer_gen Generators.peer_status_gen)
     (fun (neighbor, neighbor_status) ->
-      let _ = add_neighbor (Pollinate.Node.Client.peer_from !node_a) neighbor in
+      let _ = add_neighbor (Pollinate.PNode.Client.peer_from !node_a) neighbor in
       let _ = SUT.update_peer_status node_a neighbor neighbor_status in
       neighbor.status = neighbor_status)
 
-let pick_random_neighbors =
-  QCheck2.Test.make ~count:1000
-    ~name:
-      "pick_random_neighbors on a peer with a single neighbor, returns this \
-       neighbors" (pair Generators.peer_gen Generators.peer_gen)
-    (fun (peer, neighbor) ->
-      let _ = add_neighbor peer neighbor in
-      let random_neighbor =
-        List.hd @@ SUT.pick_random_neighbors peer.neighbors 1 in
-      random_neighbor == neighbor.address)
-
 let () =
   let failure_detector_prop =
-    List.map QCheck_alcotest.to_alcotest
-      [knuth_shuffle_size; update_peer; pick_random_neighbors] in
+    List.map QCheck_alcotest.to_alcotest [update_peer] in
   Alcotest.run "Failure detector"
     [("failure_detector.ml", failure_detector_prop)]
diff --git a/test/failure_detector_tests.ml b/test/failure_detector_tests.ml
index bc82743..3fc2b95 100644
--- a/test/failure_detector_tests.ml
+++ b/test/failure_detector_tests.ml
@@ -1,17 +1,13 @@
-open Commons
-open Pollinate.Node
+open Pollinate
+open Pollinate.PNode
 open Lwt.Infix
-
-module SUT = Pollinate.Node.Failure_detector
+module SUT = Pollinate.PNode.Testing.Failure_detector
 
 let node_a =
-  Lwt_main.run
-    (Node.init ~preprocess:Commons.preprocess ~msg_handler:Commons.msg_handler
-       ("127.0.0.1", 3003))
+  Lwt_main.run (PNode.init Address.{ address = "127.0.0.1"; port = 3003 })
+
 let node_b =
-  Lwt_main.run
-    (Node.init ~preprocess:Commons.preprocess ~msg_handler:Commons.msg_handler
-       ("127.0.0.1", 3004))
+  Lwt_main.run (PNode.init Address.{ address = "127.0.0.1"; port = 3004 })
 
 let peer_b = Client.peer_from !node_b
 
@@ -19,7 +15,7 @@ let failure_detection () =
   let open Common.Peer in
   let open Client in
   let _ = add_peer !node_a peer_b in
-  let _ = Pollinate.Node.Client.peer_from !node_a in
+  let _ = Pollinate.PNode.Client.peer_from !node_a in
   let _ = SUT.update_peer_status node_a peer_b Suspicious in
   (* Need to wait for the timeout to be reached An other way to do, would be to change the `last_suspicious_status` of the peer *)
   let%lwt _ = Lwt_unix.sleep 9.1 in
@@ -28,7 +24,7 @@ let failure_detection () =
 
 let failure_detection_nothing_on_alive () =
   let open Common.Peer in
-  let _ = add_neighbor (Pollinate.Node.Client.peer_from !node_a) peer_b in
+  let _ = add_neighbor (Pollinate.PNode.Client.peer_from !node_a) peer_b in
   let _ = SUT.update_peer_status node_a peer_b Alive in
   let%lwt _ = SUT.failure_detection node_a in
   Lwt.return (Base.Hashtbl.length !node_a.peers = 1)
@@ -45,9 +41,9 @@ let () =
        [
          ( "failure_detector.ml",
            [
-             Alcotest_lwt.test_case "Remove Suspicious peer" `Quick
+             Alcotest_lwt.test_case "Remove Suspicious peer" `Slow
                test_suspicion_detection;
-             Alcotest_lwt.test_case "Do nothing on Alive peer" `Quick
+             Alcotest_lwt.test_case "Do nothing on Alive peer" `Slow
                test_failure_detection_nothing_on_alive;
            ] );
        ]
diff --git a/test/gossip_tests.ml b/test/gossip_tests.ml
new file mode 100644
index 0000000..47701c0
--- /dev/null
+++ b/test/gossip_tests.ml
@@ -0,0 +1,171 @@
+open Lwt.Infix
+open Commons
+open Pollinate
+open Pollinate.PNode
+
+module Gossip_tests = struct
+  let local_address port = Address.{ address = "127.0.0.1"; port }
+
+  (* Initializes a group of nodes connected as shown here: https://tinyurl.com/tcy8dxu8 *)
+  let ( node_a,
+        node_b,
+        node_c,
+        node_d,
+        node_e,
+        node_f,
+        node_g,
+        node_h,
+        node_i,
+        node_j ) =
+    Lwt_main.run
+      begin
+        let ( addr_a,
+              addr_b,
+              addr_c,
+              addr_d,
+              addr_e,
+              addr_f,
+              addr_g,
+              addr_h,
+              addr_i,
+              addr_j ) =
+          ( local_address 4000,
+            local_address 4001,
+            local_address 4002,
+            local_address 4003,
+            local_address 4004,
+            local_address 4005,
+            local_address 4006,
+            local_address 4007,
+            local_address 4008,
+            local_address 4009 ) in
+
+        let%lwt node_a =
+          PNode.init ~init_peers:[addr_b; addr_c; addr_e; addr_h] addr_a in
+        let%lwt node_b =
+          PNode.init ~init_peers:[addr_a; addr_d; addr_e] addr_b in
+        let%lwt node_c =
+          PNode.init ~init_peers:[addr_a; addr_f; addr_g] addr_c in
+        let%lwt node_d = PNode.init ~init_peers:[addr_b] addr_d in
+        let%lwt node_e = PNode.init ~init_peers:[addr_a; addr_b] addr_e in
+        let%lwt node_f = PNode.init ~init_peers:[addr_c] addr_f in
+        let%lwt node_g = PNode.init ~init_peers:[addr_c] addr_g in
+        let%lwt node_h =
+          PNode.init ~init_peers:[addr_a; addr_i; addr_j] addr_h in
+        let%lwt node_i = PNode.init ~init_peers:[addr_h] addr_i in
+        let%lwt node_j = PNode.init ~init_peers:[addr_h] addr_j in
+        Lwt.return
+          ( node_a,
+            node_b,
+            node_c,
+            node_d,
+            node_e,
+            node_f,
+            node_g,
+            node_h,
+            node_i,
+            node_j )
+      end
+
+  let nodes =
+    [
+      node_a;
+      node_b;
+      node_c;
+      node_d;
+      node_e;
+      node_f;
+      node_g;
+      node_h;
+      node_i;
+      node_j;
+    ]
+
+  (** Utility function for producing a list of ports from
+      the addresses of the given nodes. This provides an easy
+      way to identify nodes that are hosted on the same machine. *)
+  let node_ports nodes =
+    List.map
+      (fun n ->
+        let addr = Client.address_of !n in
+        addr.port)
+      nodes
+
+  (** Starts the server for each node and constructs a Post message
+      whose author is the specified node, then disseminates it. Waits
+      0.2 seconds for the message to disseminate fully across
+      the network. *)
+  let disseminate_from node =
+    (* Start the server for each node in a thread *)
+    let _ =
+      List.map
+        (PNode.run_server ~preprocessor:Commons.preprocessor
+           ~msg_handler:Commons.msg_handler)
+        nodes in
+    let payload =
+      Client.address_of !node
+      |> (fun Address.{ port; _ } -> port)
+      |> string_of_int
+      |> String.to_bytes in
+    let message = Client.create_post node (payload, None) in
+    Client.post node message;
+
+    (* Function to generate a list of all the nodes who have witnessed
+       the post. *)
+    let seen () =
+      nodes |> List.filter (fun n -> PNode.seen n message) |> node_ports in
+
+    (* Wait 0.2 seconds for the message to spread. *)
+    let%lwt () = Lwt_unix.sleep 0.2 in
+
+    (* Compute the list of nodes who have seen the post. *)
+    let list_of_seen = seen () in
+
+    (* Write the length of list_of_seen to a tmp log file *)
+    let%lwt () =
+      let%lwt oc =
+        Lwt_io.open_file
+          ~flags:[Unix.O_WRONLY; Unix.O_APPEND; Unix.O_CREAT]
+          ~mode:Lwt_io.Output "/tmp/log.txt" in
+      let%lwt () =
+        Lwt_io.write oc (Printf.sprintf "%d\n" (List.length list_of_seen)) in
+      Lwt_io.close oc in
+    (* End of logging code *)
+    Lwt.return list_of_seen
+end
+
+(** Test for dissemination given a specific node. *)
+let test_disseminate_from node _ () =
+  Gossip_tests.disseminate_from node
+  >|= Alcotest.(check (list int))
+        (Printf.sprintf "All nodes have seen the message %d" !node.address.port)
+        Gossip_tests.(node_ports nodes)
+
+let () =
+  Lwt_main.run
+  @@ Alcotest_lwt.run "Gossip tests"
+       [
+         ( "gossip dissemination",
+           [
+             Alcotest_lwt.test_case "Dissemination from A" `Quick
+               (test_disseminate_from Gossip_tests.node_a);
+             Alcotest_lwt.test_case "Dissemination from B" `Quick
+               (test_disseminate_from Gossip_tests.node_b);
+             Alcotest_lwt.test_case "Dissemination from C" `Quick
+               (test_disseminate_from Gossip_tests.node_c);
+             Alcotest_lwt.test_case "Dissemination from D" `Quick
+               (test_disseminate_from Gossip_tests.node_d);
+             Alcotest_lwt.test_case "Dissemination from E" `Quick
+               (test_disseminate_from Gossip_tests.node_e);
+             Alcotest_lwt.test_case "Dissemination from F" `Quick
+               (test_disseminate_from Gossip_tests.node_f);
+             Alcotest_lwt.test_case "Dissemination from G" `Quick
+               (test_disseminate_from Gossip_tests.node_g);
+             Alcotest_lwt.test_case "Dissemination from H" `Quick
+               (test_disseminate_from Gossip_tests.node_h);
+             Alcotest_lwt.test_case "Dissemination from I" `Quick
+               (test_disseminate_from Gossip_tests.node_i);
+             Alcotest_lwt.test_case "Dissemination from J" `Quick
+               (test_disseminate_from Gossip_tests.node_j);
+           ] );
+       ]
diff --git a/test/networking_prop.ml b/test/networking_prop.ml
new file mode 100644
index 0000000..b5e1115
--- /dev/null
+++ b/test/networking_prop.ml
@@ -0,0 +1,31 @@
+open QCheck2.Gen
+open Pollinate.Peer
+open Pollinate
+
+module SUT = Pollinate.PNode.Testing.Networking
+
+let node_a =
+  Lwt_main.run (PNode.init Address.{ address = "127.0.0.1"; port = 2002 })
+
+let knuth_shuffle_size =
+  QCheck2.Test.make ~count:1000
+    ~name:"Knuth_shuffle does not change the size of the list"
+    (QCheck2.Gen.list Generators.peer_gen) (fun peers ->
+      List.length (SUT.Testing.knuth_shuffle peers) == List.length peers)
+
+let pick_random_neighbors =
+  QCheck2.Test.make ~count:1000
+    ~name:
+      "pick_random_neighbors on a peer with a single neighbor, returns this \
+       neighbors" (pair Generators.peer_gen Generators.peer_gen)
+    (fun (peer, neighbor) ->
+      let _ = add_neighbor peer neighbor in
+      let random_neighbor =
+        List.hd @@ SUT.pick_random_neighbors peer.neighbors 1 in
+      random_neighbor == neighbor.address)
+
+let () =
+  let networking_prop =
+    List.map QCheck_alcotest.to_alcotest
+      [knuth_shuffle_size; pick_random_neighbors] in
+  Alcotest.run "Networking" [("networking.ml", networking_prop)]
diff --git a/test/node_tests.ml b/test/node_tests.ml
index c7e4574..f434c5e 100644
--- a/test/node_tests.ml
+++ b/test/node_tests.ml
@@ -1,22 +1,19 @@
 open Lwt.Infix
-open Pollinate.Node
-open Pollinate.Util
 open Commons
+open Pollinate
+open Pollinate.PNode
+open Pollinate.Util
 open Messages
 
 module Node_tests = struct
   (* Initializes two nodes and the related two peers *)
   let node_a =
-    Lwt_main.run
-      (Node.init ~preprocess:Commons.preprocess ~msg_handler:Commons.msg_handler
-         ("127.0.0.1", 3000))
+    Lwt_main.run (PNode.init Address.{ address = "127.0.0.1"; port = 3000 })
 
   let peer_a = Client.peer_from !node_a
 
   let node_b =
-    Lwt_main.run
-      (Node.init ~preprocess:Commons.preprocess ~msg_handler:Commons.msg_handler
-         ("127.0.0.1", 3001))
+    Lwt_main.run (PNode.init Address.{ address = "127.0.0.1"; port = 3001 })
 
   let peer_b = Client.peer_from !node_b
 
@@ -24,49 +21,39 @@ module Node_tests = struct
      of the other, returning the first element in the response of each *)
   let trade_messages () =
     let open Messages in
+    let _ =
+      Lwt_list.map_p
+        (PNode.run_server ~preprocessor:Commons.preprocessor
+           ~msg_handler:Commons.msg_handler)
+        [node_a; node_b] in
     let get = Encoding.pack bin_writer_message (Request Get) in
 
     let%lwt { payload = res_from_b; _ } =
-      Client.request node_a get peer_b.address in
+      Client.request node_a (get, None) peer_b.address in
     let res_from_b = Encoding.unpack bin_read_response res_from_b in
 
     let%lwt { payload = res_from_a; _ } =
-      Client.request node_b get peer_a.address in
+      Client.request node_b (get, None) peer_a.address in
     let res_from_a = Encoding.unpack bin_read_response res_from_a in
 
     let res_from_b, res_from_a =
       match (res_from_b, res_from_a) with
-      | Success ok1, Success ok2 -> (ok1, ok2)
+      | Pong, Pong -> ("Ok", "Ok")
       | _ -> failwith "Incorrect response" in
 
     Lwt.return (res_from_b, res_from_a)
 
-  let test_insert () =
-    let open Messages in
-    let insert_req =
-      Encoding.pack bin_writer_message (Request (Insert "something")) in
-
-    let%lwt { payload = res_a; _ } =
-      Client.request node_a insert_req peer_b.address in
-    let res_a = Encoding.unpack bin_read_response res_a in
-
-    let get = Encoding.pack bin_writer_message (Request Get) in
-    let%lwt { payload = b_state; _ } =
-      Client.request node_a get peer_b.address in
-    let b_state = Encoding.unpack bin_read_response b_state in
-
-    let res_a, b_state =
-      match (res_a, b_state) with
-      | Success ok1, Success ok2 -> (ok1, ok2)
-      | _ -> failwith "Incorrect response" in
-
-    Lwt.return (res_a, b_state)
-
   let ping_pong () =
     let open Messages in
+    let _ =
+      Lwt_list.map_p
+        (PNode.run_server ~preprocessor:Commons.preprocessor
+           ~msg_handler:Commons.msg_handler)
+        [node_a; node_b] in
     let ping = Encoding.pack bin_writer_message (Request Ping) in
 
-    let%lwt { payload = pong; _ } = Client.request node_a ping peer_b.address in
+    let%lwt { payload = pong; _ } =
+      Client.request node_a (ping, None) peer_b.address in
     let pong = Encoding.unpack bin_read_response pong in
 
     let pong =
@@ -86,20 +73,13 @@ let test_trade_messages _ () =
 let test_ping_pong _ () =
   Node_tests.ping_pong () >|= Alcotest.(check string) "Ping pong" "Pong"
 
-let test_insert_value _ () =
-  Node_tests.test_insert ()
-  >|= Alcotest.(check (pair string string))
-        "Test insert value"
-        ("Successfully added value to state", "Ok")
-
 let () =
   Lwt_main.run
   @@ Alcotest_lwt.run "Client tests"
        [
-         ( "communication",
+         ( "one-to-one communication",
            [
              Alcotest_lwt.test_case "Trading Messages" `Quick test_trade_messages;
              Alcotest_lwt.test_case "Ping pong" `Quick test_ping_pong;
-             Alcotest_lwt.test_case "Insert value" `Quick test_insert_value;
            ] );
        ]