diff --git a/packages/squiggle-lang/__tests__/JS__Test.ts b/packages/squiggle-lang/__tests__/JS__Test.ts
index ffba5b82..67e42e55 100644
--- a/packages/squiggle-lang/__tests__/JS__Test.ts
+++ b/packages/squiggle-lang/__tests__/JS__Test.ts
@@ -1,11 +1,10 @@
-import { run, Distribution, resultMap } from "../src/js/index";
+import { run, Distribution, resultMap, squiggleExpression } from "../src/js/index";
 
-let testRun = (x: string) => {
-  let result = run(x);
-  if (result.tag == "Ok") {
-    return { tag: "Ok", value: result.value.exports };
-  } else {
-    return result;
+let testRun = (x: string): squiggleExpression => {
+  let result = run(x, {sampleCount: 100, xyPointLength: 100});
+  expect(result.tag).toEqual("Ok")
+  if(result.tag === "Ok") {
+    return result.value
   }
 };
 
@@ -16,29 +15,19 @@ function Ok<b>(x: b) {
 describe("Simple calculations and results", () => {
   test("mean(normal(5,2))", () => {
     expect(testRun("mean(normal(5,2))")).toEqual({
-      tag: "Ok",
-      value: [{ NAME: "Float", VAL: 5 }],
+      tag: "number",
+      value: 5
     });
   });
   test("10+10", () => {
     let foo = testRun("10 + 10");
-    expect(foo).toEqual({ tag: "Ok", value: [{ NAME: "Float", VAL: 20 }] });
+    expect(foo).toEqual({ tag: "number", value: 20 });
   });
 });
 describe("Log function", () => {
   test("log(1) = 0", () => {
     let foo = testRun("log(1)");
-    expect(foo).toEqual({ tag: "Ok", value: [{ NAME: "Float", VAL: 0 }] });
-  });
-});
-
-describe("Multimodal too many weights error", () => {
-  test("mm(0,0,[0,0,0])", () => {
-    let foo = testRun("mm(0,0,[0,0,0])");
-    expect(foo).toEqual({
-      tag: "Error",
-      value: "Function multimodal error: Too many weights provided",
-    });
+    expect(foo).toEqual({ tag: "number", value: 0 });
   });
 });
 
diff --git a/packages/squiggle-lang/src/js/index.ts b/packages/squiggle-lang/src/js/index.ts
index 8ff08228..923303ef 100644
--- a/packages/squiggle-lang/src/js/index.ts
+++ b/packages/squiggle-lang/src/js/index.ts
@@ -1,13 +1,10 @@
-import { runAll } from "../rescript/ProgramEvaluator.gen";
+import * as _ from 'lodash'
 import type {
-  Inputs_SamplingInputs_t as SamplingInputs,
   exportEnv,
-  exportType,
   exportDistribution,
 } from "../rescript/ProgramEvaluator.gen";
-export type { SamplingInputs, exportEnv, exportDistribution };
-export type { t as DistPlus } from "../rescript/OldInterpreter/DistPlus.gen";
-import { genericDist, env, error } from "../rescript/TypescriptInterface.gen";
+export type {  exportEnv, exportDistribution };
+import { genericDist, samplingParams, evaluate, expressionValue, errorValue, distributionError } from "../rescript/TypescriptInterface.gen";
 export { makeSampleSetDist } from "../rescript/TypescriptInterface.gen";
 import {
   Constructors_mean,
@@ -36,23 +33,16 @@ import {
   Constructors_pointwisePower,
 } from "../rescript/Distributions/DistributionOperation/DistributionOperation.gen";
 
-export let defaultSamplingInputs: SamplingInputs = {
-  sampleCount: 10000,
-  outputXYPoints: 10000,
-  pointDistLength: 1000,
+export type SamplingInputs = {
+  readonly sampleCount?: number; 
+  readonly outputXYPoints?: number; 
+  readonly kernelWidth?: number; 
+  readonly pointDistLength?: number
+};
+export let defaultSamplingInputs: samplingParams = {
+  sampleCount: 10000,
+  xyPointLength: 10000
 };
-
-export function run(
-  squiggleString: string,
-  samplingInputs?: SamplingInputs,
-  environment?: exportEnv
-): result<exportType, string> {
-  let si: SamplingInputs = samplingInputs
-    ? samplingInputs
-    : defaultSamplingInputs;
-  let env: exportEnv = environment ? environment : [];
-  return runAll(squiggleString, si, env);
-}
 
 type result<a, b> =
   | {
@@ -75,147 +65,186 @@ export function resultMap<a, b, c>(
   }
 }
 
+type tagged<a, b> = {tag: a, value: b}
+
+function tag<a,b>(x: a, y: b) : tagged<a, b>{
+  return { tag: x, value: y}
+}
+
+export type squiggleExpression = tagged<"symbol", string> | tagged<"string", string> | tagged<"array", squiggleExpression[]> | tagged<"boolean", boolean> | tagged<"distribution", Distribution> | tagged<"number", number> | tagged<"record", {[key: string]: squiggleExpression }>
+export function run(
+  squiggleString: string,
+  samplingInputs?: samplingParams,
+  _environment?: exportEnv
+): result<squiggleExpression, errorValue> {
+  let si: samplingParams = samplingInputs
+    ? samplingInputs
+    : defaultSamplingInputs;
+  let result : result<expressionValue, errorValue> = evaluate(squiggleString);
+  return resultMap(result, x => createTsExport(x, si));
+}
+
+
+function createTsExport(x: expressionValue, sampEnv: samplingParams): squiggleExpression {
+  switch (x.tag) {
+    case "EvArray":
+      return tag("array", x.value.map(x => createTsExport(x, sampEnv)));
+    case "EvBool":
+      return tag("boolean", x.value);
+    case "EvDistribution":
+      return tag("distribution", new Distribution(x.value, sampEnv));
+    case "EvNumber":
+      return tag("number", x.value);
+    case "EvRecord":
+      return tag("record", _.mapValues(x.value, x => createTsExport(x, sampEnv)))
+
+      
+      
+  }
+}
+
+
 export function resultExn<a, c>(r: result<a, c>): a | c {
   return r.value;
 }
 
 export class Distribution {
   t: genericDist;
-  env: env;
+  env: samplingParams;
 
-  constructor(t: genericDist, env: env) {
+  constructor(t: genericDist, env: samplingParams) {
     this.t = t;
     this.env = env;
     return this;
   }
 
-  mapResultDist(r: result<genericDist, error>): result<Distribution, error> {
+  mapResultDist(r: result<genericDist, distributionError>): result<Distribution, distributionError> {
     return resultMap(r, (v: genericDist) => new Distribution(v, this.env));
   }
 
-  mean(): result<number, error> {
+  mean(): result<number, distributionError> {
     return Constructors_mean({ env: this.env }, this.t);
   }
 
-  sample(): result<number, error> {
+  sample(): result<number, distributionError> {
     return Constructors_sample({ env: this.env }, this.t);
   }
 
-  pdf(n: number): result<number, error> {
+  pdf(n: number): result<number, distributionError> {
     return Constructors_pdf({ env: this.env }, this.t, n);
   }
 
-  cdf(n: number): result<number, error> {
+  cdf(n: number): result<number, distributionError> {
     return Constructors_cdf({ env: this.env }, this.t, n);
   }
 
-  inv(n: number): result<number, error> {
+  inv(n: number): result<number, distributionError> {
     return Constructors_inv({ env: this.env }, this.t, n);
   }
 
-  normalize(): result<Distribution, error> {
+  normalize(): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_normalize({ env: this.env }, this.t)
     );
   }
 
-  toPointSet(): result<Distribution, error> {
+  toPointSet(): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_toPointSet({ env: this.env }, this.t)
     );
   }
 
-  toSampleSet(n: number): result<Distribution, error> {
+  toSampleSet(n: number): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_toSampleSet({ env: this.env }, this.t, n)
     );
   }
 
-  truncate(left: number, right: number): result<Distribution, error> {
+  truncate(left: number, right: number): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_truncate({ env: this.env }, this.t, left, right)
     );
   }
 
-  inspect(): result<Distribution, error> {
+  inspect(): result<Distribution, distributionError> {
     return this.mapResultDist(Constructors_inspect({ env: this.env }, this.t));
   }
 
-  toString(): result<string, error> {
+  toString(): result<string, distributionError> {
     return Constructors_toString({ env: this.env }, this.t);
   }
 
-  toSparkline(n: number): result<string, error> {
+  toSparkline(n: number): result<string, distributionError> {
     return Constructors_toSparkline({ env: this.env }, this.t, n);
   }
 
-  algebraicAdd(d2: Distribution): result<Distribution, error> {
+  algebraicAdd(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_algebraicAdd({ env: this.env }, this.t, d2.t)
     );
   }
 
-  algebraicMultiply(d2: Distribution): result<Distribution, error> {
+  algebraicMultiply(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_algebraicMultiply({ env: this.env }, this.t, d2.t)
     );
   }
 
-  algebraicDivide(d2: Distribution): result<Distribution, error> {
+  algebraicDivide(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_algebraicDivide({ env: this.env }, this.t, d2.t)
     );
   }
 
-  algebraicSubtract(d2: Distribution): result<Distribution, error> {
+  algebraicSubtract(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_algebraicSubtract({ env: this.env }, this.t, d2.t)
     );
   }
 
-  algebraicLogarithm(d2: Distribution): result<Distribution, error> {
+  algebraicLogarithm(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_algebraicLogarithm({ env: this.env }, this.t, d2.t)
     );
   }
 
-  algebraicPower(d2: Distribution): result<Distribution, error> {
+  algebraicPower(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_algebraicPower({ env: this.env }, this.t, d2.t)
     );
   }
 
-  pointwiseAdd(d2: Distribution): result<Distribution, error> {
+  pointwiseAdd(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_pointwiseAdd({ env: this.env }, this.t, d2.t)
     );
   }
 
-  pointwiseMultiply(d2: Distribution): result<Distribution, error> {
+  pointwiseMultiply(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_pointwiseMultiply({ env: this.env }, this.t, d2.t)
     );
   }
 
-  pointwiseDivide(d2: Distribution): result<Distribution, error> {
+  pointwiseDivide(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_pointwiseDivide({ env: this.env }, this.t, d2.t)
     );
   }
 
-  pointwiseSubtract(d2: Distribution): result<Distribution, error> {
+  pointwiseSubtract(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_pointwiseSubtract({ env: this.env }, this.t, d2.t)
     );
   }
 
-  pointwiseLogarithm(d2: Distribution): result<Distribution, error> {
+  pointwiseLogarithm(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_pointwiseLogarithm({ env: this.env }, this.t, d2.t)
     );
   }
 
-  pointwisePower(d2: Distribution): result<Distribution, error> {
+  pointwisePower(d2: Distribution): result<Distribution, distributionError> {
     return this.mapResultDist(
       Constructors_pointwisePower({ env: this.env }, this.t, d2.t)
     );
diff --git a/packages/squiggle-lang/src/rescript/Reducer/Reducer.res b/packages/squiggle-lang/src/rescript/Reducer/Reducer.res
index 6e8dbdfa..7e93f367 100644
--- a/packages/squiggle-lang/src/rescript/Reducer/Reducer.res
+++ b/packages/squiggle-lang/src/rescript/Reducer/Reducer.res
@@ -5,5 +5,6 @@ module Extra = Reducer_Extra
 module Js = Reducer_Js
 module MathJs = Reducer_MathJs
 
+type expressionValue = Reducer_Expression.expressionValue
 let evaluate = Expression.eval
 let parse = Expression.parse
diff --git a/packages/squiggle-lang/src/rescript/Reducer/Reducer.resi b/packages/squiggle-lang/src/rescript/Reducer/Reducer.resi
index cf015a95..b5b811e6 100644
--- a/packages/squiggle-lang/src/rescript/Reducer/Reducer.resi
+++ b/packages/squiggle-lang/src/rescript/Reducer/Reducer.resi
@@ -6,5 +6,8 @@ module Js = Reducer_Js
 module MathJs = Reducer_MathJs
 
 @genType
-let evaluate: string => result<Expression.expressionValue, ErrorValue.errorValue>
+type expressionValue = Reducer_Expression.expressionValue
+
+@genType
+let evaluate: string => result<expressionValue, Reducer_ErrorValue.errorValue>
 let parse: string => result<Expression.expression, ErrorValue.errorValue>
diff --git a/packages/squiggle-lang/src/rescript/Reducer/Reducer_ErrorValue.res b/packages/squiggle-lang/src/rescript/Reducer/Reducer_ErrorValue.res
index 4f57bc2c..666f5476 100644
--- a/packages/squiggle-lang/src/rescript/Reducer/Reducer_ErrorValue.res
+++ b/packages/squiggle-lang/src/rescript/Reducer/Reducer_ErrorValue.res
@@ -1,3 +1,4 @@
+@genType
 type errorValue =
   | REArrayIndexNotFound(string, int)
   | REFunctionExpected(string)
diff --git a/packages/squiggle-lang/src/rescript/Reducer/Reducer_Expression/Reducer_Expression.resi b/packages/squiggle-lang/src/rescript/Reducer/Reducer_Expression/Reducer_Expression.resi
index 8b09c516..2a6db9bd 100644
--- a/packages/squiggle-lang/src/rescript/Reducer/Reducer_Expression/Reducer_Expression.resi
+++ b/packages/squiggle-lang/src/rescript/Reducer/Reducer_Expression/Reducer_Expression.resi
@@ -1,7 +1,8 @@
 module Result = Belt.Result
 module T = Reducer_Expression_T
 type expression = T.expression
-type expressionValue = ReducerInterface.ExpressionValue.expressionValue
+@genType
+type expressionValue = ReducerInterface_ExpressionValue.expressionValue
 type t = expression
 let toString: T.expression => Js.String.t
 let toStringResult: result<T.expression, 'a> => string
diff --git a/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_ExpressionValue.res b/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_ExpressionValue.res
index bfb79df1..8842ce8f 100644
--- a/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_ExpressionValue.res
+++ b/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_ExpressionValue.res
@@ -5,6 +5,7 @@
 module Extra_Array = Reducer_Extra_Array
 module ErrorValue = Reducer_ErrorValue
 
+@genType
 type rec expressionValue =
   | EvBool(bool)
   | EvNumber(float)
diff --git a/packages/squiggle-lang/src/rescript/TypescriptInterface.res b/packages/squiggle-lang/src/rescript/TypescriptInterface.res
index 6fe6f3d4..c52dd8a7 100644
--- a/packages/squiggle-lang/src/rescript/TypescriptInterface.res
+++ b/packages/squiggle-lang/src/rescript/TypescriptInterface.res
@@ -8,20 +8,31 @@ The below few seem to work fine. In the future there's definitely more work to d
 */
 
 @genType
-type env = DistributionOperation.env
+type samplingParams = DistributionOperation.env
 
 @genType
 type genericDist = GenericDist_Types.genericDist
 
 @genType
-type error = GenericDist_Types.error
+type distributionError = GenericDist_Types.error
 
 @genType
-type resultDist = result<genericDist, error>
-@genType
-type resultFloat = result<float, error>
-@genType
-type resultString = result<string, error>
+type resultDist = result<genericDist, distributionError>
 
 @genType
-let makeSampleSetDist = SampleSetDist.make
\ No newline at end of file
+type resultFloat = result<float, distributionError>
+
+@genType
+type resultString = result<string, distributionError>
+
+@genType
+let makeSampleSetDist = SampleSetDist.make
+
+@genType
+let evaluate = Reducer.evaluate
+
+@genType
+type expressionValue = Reducer_Expression.expressionValue
+
+@genType
+type errorValue = Reducer_ErrorValue.errorValue
diff --git a/packages/squiggle-lang/src/rescript/shims/Js.shim.ts b/packages/squiggle-lang/src/rescript/shims/Js.shim.ts
new file mode 100644
index 00000000..c4f41786
--- /dev/null
+++ b/packages/squiggle-lang/src/rescript/shims/Js.shim.ts
@@ -0,0 +1 @@
+export type Dict_t<T> = { [key: string]: T }