diff --git a/pyproject.toml b/pyproject.toml
index fd67bff2..74d3afcb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -46,6 +46,7 @@ dependencies = [
   # typed IPC msging
   "msgspec>=0.19.0",
   "cffi>=1.17.1",
+  "bidict>=0.23.1",
 ]
 
 # ------ project ------
diff --git a/uv.lock b/uv.lock
index 76b22243..50a168b6 100644
--- a/uv.lock
+++ b/uv.lock
@@ -11,6 +11,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/89/aa/ab0f7891a01eeb2d2e338ae8fecbe57fcebea1a24dbb64d45801bfab481d/attrs-24.3.0-py3-none-any.whl", hash = "sha256:ac96cd038792094f438ad1f6ff80837353805ac950cd2aa0e0625ef19850c308", size = 63397 },
 ]
 
+[[package]]
+name = "bidict"
+version = "0.23.1"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/9a/6e/026678aa5a830e07cd9498a05d3e7e650a4f56a42f267a53d22bcda1bdc9/bidict-0.23.1.tar.gz", hash = "sha256:03069d763bc387bbd20e7d49914e75fc4132a41937fa3405417e1a5a2d006d71", size = 29093 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/99/37/e8730c3587a65eb5645d4aba2d27aae48e8003614d6aaf15dda67f702f1f/bidict-0.23.1-py3-none-any.whl", hash = "sha256:5dae8d4d79b552a71cbabc7deb25dfe8ce710b17ff41711e13010ead2abfc3e5", size = 32764 },
+]
+
 [[package]]
 name = "cffi"
 version = "1.17.1"
@@ -349,6 +358,7 @@ name = "tractor"
 version = "0.1.0a6.dev0"
 source = { editable = "." }
 dependencies = [
+    { name = "bidict" },
     { name = "cffi" },
     { name = "colorlog" },
     { name = "msgspec" },
@@ -371,6 +381,7 @@ dev = [
 
 [package.metadata]
 requires-dist = [
+    { name = "bidict", specifier = ">=0.23.1" },
     { name = "cffi", specifier = ">=1.17.1" },
     { name = "colorlog", specifier = ">=6.8.2,<7" },
     { name = "msgspec", specifier = ">=0.19.0" },