diff --git a/packages/squiggle-lang/__tests__/ReducerProject/ReducerProject_test.res b/packages/squiggle-lang/__tests__/ReducerProject/ReducerProject_test.res
index c6605068..466a8770 100644
--- a/packages/squiggle-lang/__tests__/ReducerProject/ReducerProject_test.res
+++ b/packages/squiggle-lang/__tests__/ReducerProject/ReducerProject_test.res
@@ -173,4 +173,3 @@ describe("project with include", () => {
     runFetchBindings(project, "main")->expect->toBe("@{common: 0,x: 1,y: 2}")
   })
 })
-
diff --git a/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject.res b/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject.res
index 8a78c795..11fa62bf 100644
--- a/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject.res
+++ b/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject.res
@@ -9,6 +9,7 @@ module InternalExpressionValue = ReducerInterface_InternalExpressionValue
 module ProjectAccessorsT = ReducerProject_ProjectAccessors_T
 module ProjectItem = ReducerProject_ProjectItem
 module T = ReducerProject_T
+module Topology = ReducerProject_Topology
 
 @genType.opaque
 type project = T.t
@@ -18,59 +19,12 @@ module Private = {
   type internalProject = T.Private.t
   type t = T.Private.t
 
-  let getSourceIds = (this: t): array<string> => Belt.Map.String.keysToArray(this["items"])
-
-  let getItem = (this: t, sourceId: string) =>
-    Belt.Map.String.getWithDefault(this["items"], sourceId, ProjectItem.emptyItem)
-
-  let getImmediateDependencies = (this: t, sourceId: string): ProjectItem.T.includesType =>
-    getItem(this, sourceId)->ProjectItem.getImmediateDependencies
-
-  type topologicalSortState = (Belt.Map.String.t<bool>, list<string>)
-  let rec topologicalSortUtil = (
-    this: t,
-    sourceId: string,
-    state: topologicalSortState,
-  ): topologicalSortState => {
-    let dependencies = getImmediateDependencies(this, sourceId)->Belt.Result.getWithDefault([])
-    let (visited, stack) = state
-    let myVisited = Belt.Map.String.set(visited, sourceId, true)
-    let (newVisited, newStack) = dependencies->Belt.Array.reduce((myVisited, stack), (
-      (currVisited, currStack),
-      dependency,
-    ) => {
-      if !Belt.Map.String.getWithDefault(currVisited, dependency, false) {
-        topologicalSortUtil(this, dependency, (currVisited, currStack))
-      } else {
-        (currVisited, currStack)
-      }
-    })
-    (newVisited, list{sourceId, ...newStack})
-  }
-
-  let getTopologicalSort = (this: t): array<string> => {
-    let (_visited, stack) = getSourceIds(this)->Belt.Array.reduce((Belt.Map.String.empty, list{}), (
-      (currVisited, currStack),
-      currId,
-    ) =>
-      if !Belt.Map.String.getWithDefault(currVisited, currId, false) {
-        topologicalSortUtil(this, currId, (currVisited, currStack))
-      } else {
-        (currVisited, currStack)
-      }
-    )
-    Belt.List.reverse(stack)->Belt.List.toArray
-  }
-
-  let getTopologicalSortFor = (this: t, sourceId) => {
-    let runOrder = getTopologicalSort(this)
-    let index = runOrder->Js.Array2.indexOf(sourceId)
-    let after = Belt.Array.sliceToEnd(runOrder, index + 1)
-    let before = Js.Array2.slice(runOrder, ~start=0, ~end_=index + 1)
-    (before, after)
-  }
-
-  let getRunOrder = getTopologicalSort
+  let getSourceIds = T.Private.getSourceIds
+  let getItem = T.Private.getItem
+  let getDependents = Topology.getDependents
+  let getDependencies = Topology.getDependencies
+  let getRunOrder = Topology.getRunOrder
+  let getRunOrderFor = Topology.getRunOrderFor
 
   let createProject = () => {
     let this: t = {
@@ -81,23 +35,6 @@ module Private = {
     this
   }
 
-  let getRunOrderFor = (this: t, sourceId: string) => {
-    let (runOrder, _) = getTopologicalSortFor(this, sourceId)
-    runOrder
-  }
-
-  let getDependencies = (this: t, sourceId: string): array<string> => {
-    let runOrder = getRunOrderFor(this, sourceId)
-
-    let _ = Js.Array2.pop(runOrder)
-    runOrder
-  }
-
-  let getDependents = (this: t, sourceId: string): array<string> => {
-    let (_, dependents) = getTopologicalSortFor(this, sourceId)
-    dependents
-  }
-
   let rec touchSource = (this: t, sourceId: string): unit => {
     let item = this->getItem(sourceId)
     let newItem = ProjectItem.touchSource(item)
@@ -245,7 +182,7 @@ module Private = {
   }
 
   let runAll = (this: t): unit => {
-    let runOrder = getTopologicalSort(this)
+    let runOrder = Topology.getRunOrder(this)
     let initialState = (Ok(InternalExpressionValue.IEvVoid), getStdLib(this))
     let _finalState = Belt.Array.reduce(runOrder, initialState, (currState, currId) =>
       tryRunWithContinuation(this, currId, currState)
@@ -253,7 +190,7 @@ module Private = {
   }
 
   let run = (this: t, sourceId: string): unit => {
-    let runOrder = getRunOrderFor(this, sourceId)
+    let runOrder = Topology.getRunOrderFor(this, sourceId)
     let initialState = (Ok(InternalExpressionValue.IEvVoid), getStdLib(this))
     let _finalState = Belt.Array.reduce(runOrder, initialState, (currState, currId) =>
       tryRunWithContinuation(this, currId, currState)
diff --git a/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_T.res b/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_T.res
index 9acaa74e..9e14c70c 100644
--- a/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_T.res
+++ b/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_T.res
@@ -22,4 +22,9 @@ module Private = {
 
   external castFromInternalProject: t => project = "%identity"
   external castToInternalProject: project => t = "%identity"
+
+  let getSourceIds = (this: t): array<string> => Belt.Map.String.keysToArray(this["items"])
+
+  let getItem = (this: t, sourceId: string) =>
+    Belt.Map.String.getWithDefault(this["items"], sourceId, ProjectItem.emptyItem)
 }
diff --git a/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_Topology.res b/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_Topology.res
new file mode 100644
index 00000000..f23c19c1
--- /dev/null
+++ b/packages/squiggle-lang/src/rescript/ReducerProject/ReducerProject_Topology.res
@@ -0,0 +1,72 @@
+module ProjectItem = ReducerProject_ProjectItem
+module T = ReducerProject_T
+type t = T.Private.t
+
+let getSourceIds = T.Private.getSourceIds
+let getItem = T.Private.getItem
+
+let getImmediateDependencies = (this: t, sourceId: string): ProjectItem.T.includesType =>
+  getItem(this, sourceId)->ProjectItem.getImmediateDependencies
+
+type topologicalSortState = (Belt.Map.String.t<bool>, list<string>)
+let rec topologicalSortUtil = (
+  this: t,
+  sourceId: string,
+  state: topologicalSortState,
+): topologicalSortState => {
+  let dependencies = getImmediateDependencies(this, sourceId)->Belt.Result.getWithDefault([])
+  let (visited, stack) = state
+  let myVisited = Belt.Map.String.set(visited, sourceId, true)
+  let (newVisited, newStack) = dependencies->Belt.Array.reduce((myVisited, stack), (
+    (currVisited, currStack),
+    dependency,
+  ) => {
+    if !Belt.Map.String.getWithDefault(currVisited, dependency, false) {
+      topologicalSortUtil(this, dependency, (currVisited, currStack))
+    } else {
+      (currVisited, currStack)
+    }
+  })
+  (newVisited, list{sourceId, ...newStack})
+}
+
+let getTopologicalSort = (this: t): array<string> => {
+  let (_visited, stack) = getSourceIds(this)->Belt.Array.reduce((Belt.Map.String.empty, list{}), (
+    (currVisited, currStack),
+    currId,
+  ) =>
+    if !Belt.Map.String.getWithDefault(currVisited, currId, false) {
+      topologicalSortUtil(this, currId, (currVisited, currStack))
+    } else {
+      (currVisited, currStack)
+    }
+  )
+  Belt.List.reverse(stack)->Belt.List.toArray
+}
+
+let getTopologicalSortFor = (this: t, sourceId) => {
+  let runOrder = getTopologicalSort(this)
+  let index = runOrder->Js.Array2.indexOf(sourceId)
+  let after = Belt.Array.sliceToEnd(runOrder, index + 1)
+  let before = Js.Array2.slice(runOrder, ~start=0, ~end_=index + 1)
+  (before, after)
+}
+
+let getRunOrder = getTopologicalSort
+
+let getRunOrderFor = (this: t, sourceId: string) => {
+  let (runOrder, _) = getTopologicalSortFor(this, sourceId)
+  runOrder
+}
+
+let getDependencies = (this: t, sourceId: string): array<string> => {
+  let runOrder = getRunOrderFor(this, sourceId)
+
+  let _ = Js.Array2.pop(runOrder)
+  runOrder
+}
+
+let getDependents = (this: t, sourceId: string): array<string> => {
+  let (_, dependents) = getTopologicalSortFor(this, sourceId)
+  dependents
+}