diff --git a/lib/config/builder/config.ts b/lib/config/builder/config.ts
index 110903f..905c2c7 100644
--- a/lib/config/builder/config.ts
+++ b/lib/config/builder/config.ts
@@ -5,13 +5,13 @@ import { _ } from "../../util"
 import { Effects } from "../../types"
 import { Parser, object } from "ts-matches"
 
-export type LazyBuildOptions<Manifest, ConfigType> = {
+export type LazyBuildOptions<WD, ConfigType> = {
   effects: Effects
-  utils: Utils<Manifest>
+  utils: Utils<WD>
   config: ConfigType | null
 }
-export type LazyBuild<Manifest, ConfigType, ExpectedOut> = (
-  options: LazyBuildOptions<Manifest, ConfigType>,
+export type LazyBuild<WD, ConfigType, ExpectedOut> = (
+  options: LazyBuildOptions<WD, ConfigType>,
 ) => Promise<ExpectedOut> | ExpectedOut
 
 export type MaybeLazyValues<A> = LazyBuild<any, any, A> | A
@@ -88,8 +88,8 @@ export class Config<Type extends Record<string, any>, WD, ConfigType> {
     return answer
   }
 
-  static of<Type extends Record<string, any>, Manifest, ConfigType>(spec: {
-    [K in keyof Type]: Value<Type[K], Manifest, ConfigType>
+  static of<Type extends Record<string, any>, WrapperData, ConfigType>(spec: {
+    [K in keyof Type]: Value<Type[K], WrapperData, ConfigType>
   }) {
     const validatorObj = {} as {
       [K in keyof Type]: Parser<unknown, Type[K]>
@@ -98,6 +98,16 @@ export class Config<Type extends Record<string, any>, WD, ConfigType> {
       validatorObj[key] = spec[key].validator
     }
     const validator = object(validatorObj)
-    return new Config<Type, Manifest, ConfigType>(spec, validator)
+    return new Config<Type, WrapperData, ConfigType>(spec, validator)
+  }
+
+  static withWrapperData<WrapperData>() {
+    return {
+      of<Type extends Record<string, any>>(spec: {
+        [K in keyof Type]: Value<Type[K], WrapperData, Type>
+      }) {
+        return Config.of<Type, WrapperData, Type>(spec)
+      },
+    }
   }
 }
diff --git a/lib/config/builder/value.ts b/lib/config/builder/value.ts
index a7f9e82..f84e236 100644
--- a/lib/config/builder/value.ts
+++ b/lib/config/builder/value.ts
@@ -1,4 +1,4 @@
-import { Config, LazyBuild } from "./config"
+import { Config, LazyBuild, LazyBuildOptions } from "./config"
 import { List } from "./list"
 import { Variants } from "./variants"
 import {
@@ -70,6 +70,7 @@ function asRequiredParser<
   if (testForAsRequiredParser()(input)) return parser as any
   return parser.optional() as any
 }
+
 /**
  * A value is going to be part of the form in the FE of the OS.
  * Something like a boolean, a string, a number, etc.
@@ -114,6 +115,29 @@ export class Value<Type, WD, ConfigType> {
       boolean,
     )
   }
+  static dynamicToggle<WD, CT>(
+    a: LazyBuild<
+      WD,
+      CT,
+      {
+        name: string
+        description?: string | null
+        warning?: string | null
+        default?: boolean | null
+      }
+    >,
+  ) {
+    return new Value<boolean, WD, CT>(
+      async (options) => ({
+        description: null,
+        warning: null,
+        default: null,
+        type: "toggle" as const,
+        ...(await a(options)),
+      }),
+      boolean,
+    )
+  }
   static text<Required extends RequiredDefault<DefaultString>, WD, CT>(a: {
     name: string
     description?: string | null
@@ -146,6 +170,44 @@ export class Value<Type, WD, ConfigType> {
       asRequiredParser(string, a),
     )
   }
+  static dynamicText<WD, CT>(
+    getA: LazyBuild<
+      WD,
+      CT,
+      {
+        name: string
+        description?: string | null
+        warning?: string | null
+        required: RequiredDefault<DefaultString>
+
+        /** Default = false */
+        masked?: boolean
+        placeholder?: string | null
+        minLength?: number | null
+        maxLength?: number | null
+        patterns?: Pattern[]
+        /** Default = 'text' */
+        inputmode?: ValueSpecText["inputmode"]
+      }
+    >,
+  ) {
+    return new Value<string | null | undefined, WD, CT>(async (options) => {
+      const a = await getA(options)
+      return {
+        type: "text" as const,
+        description: null,
+        warning: null,
+        masked: false,
+        placeholder: null,
+        minLength: null,
+        maxLength: null,
+        patterns: [],
+        inputmode: "text",
+        ...a,
+        ...requiredLikeToAbove(a.required),
+      }
+    }, string.optional())
+  }
   static textarea<WD, CT>(a: {
     name: string
     description?: string | null
@@ -169,6 +231,34 @@ export class Value<Type, WD, ConfigType> {
       string,
     )
   }
+  static dynamicTextarea<WD, CT>(
+    getA: LazyBuild<
+      WD,
+      CT,
+      {
+        name: string
+        description?: string | null
+        warning?: string | null
+        required: boolean
+        minLength?: number | null
+        maxLength?: number | null
+        placeholder?: string | null
+      }
+    >,
+  ) {
+    return new Value<string, WD, CT>(async (options) => {
+      const a = await getA(options)
+      return {
+        description: null,
+        warning: null,
+        minLength: null,
+        maxLength: null,
+        placeholder: null,
+        type: "textarea" as const,
+        ...a,
+      }
+    }, string)
+  }
   static number<Required extends RequiredDefault<number>, WD, CT>(a: {
     name: string
     description?: string | null
@@ -198,6 +288,41 @@ export class Value<Type, WD, ConfigType> {
       asRequiredParser(number, a),
     )
   }
+  static dynamicNumber<WD, CT>(
+    getA: LazyBuild<
+      WD,
+      CT,
+      {
+        name: string
+        description?: string | null
+        warning?: string | null
+        required: RequiredDefault<number>
+        min?: number | null
+        max?: number | null
+        /** Default = '1' */
+        step?: string | null
+        integer: boolean
+        units?: string | null
+        placeholder?: string | null
+      }
+    >,
+  ) {
+    return new Value<number | null | undefined, WD, CT>(async (options) => {
+      const a = await getA(options)
+      return {
+        type: "number" as const,
+        description: null,
+        warning: null,
+        min: null,
+        max: null,
+        step: null,
+        units: null,
+        placeholder: null,
+        ...a,
+        ...requiredLikeToAbove(a.required),
+      }
+    }, number.optional())
+  }
   static color<Required extends RequiredDefault<string>, WD, CT>(a: {
     name: string
     description?: string | null
@@ -216,6 +341,30 @@ export class Value<Type, WD, ConfigType> {
       asRequiredParser(string, a),
     )
   }
+
+  static dynamicColor<WD, CT>(
+    getA: LazyBuild<
+      WD,
+      CT,
+      {
+        name: string
+        description?: string | null
+        warning?: string | null
+        required: RequiredDefault<string>
+      }
+    >,
+  ) {
+    return new Value<string | null | undefined, WD, CT>(async (options) => {
+      const a = await getA(options)
+      return {
+        type: "color" as const,
+        description: null,
+        warning: null,
+        ...a,
+        ...requiredLikeToAbove(a.required),
+      }
+    }, string.optional())
+  }
   static datetime<Required extends RequiredDefault<string>, WD, CT>(a: {
     name: string
     description?: string | null
@@ -242,6 +391,38 @@ export class Value<Type, WD, ConfigType> {
       asRequiredParser(string, a),
     )
   }
+  static dynamicDatetime<WD, CT>(
+    getA: LazyBuild<
+      WD,
+      CT,
+      {
+        name: string
+        description?: string | null
+        warning?: string | null
+        required: RequiredDefault<string>
+        /** Default = 'datetime-local' */
+        inputmode?: ValueSpecDatetime["inputmode"]
+        min?: string | null
+        max?: string | null
+        step?: string | null
+      }
+    >,
+  ) {
+    return new Value<string | null | undefined, WD, CT>(async (options) => {
+      const a = await getA(options)
+      return {
+        type: "datetime" as const,
+        description: null,
+        warning: null,
+        inputmode: "datetime-local",
+        min: null,
+        max: null,
+        step: null,
+        ...a,
+        ...requiredLikeToAbove(a.required),
+      }
+    }, string.optional())
+  }
   static select<
     Required extends RequiredDefault<string>,
     B extends Record<string, string>,
@@ -270,6 +451,30 @@ export class Value<Type, WD, ConfigType> {
       ) as any,
     )
   }
+  static dynamicSelect<WD, CT>(
+    getA: LazyBuild<
+      WD,
+      CT,
+      {
+        name: string
+        description?: string | null
+        warning?: string | null
+        required: RequiredDefault<string>
+        values: Record<string, string>
+      }
+    >,
+  ) {
+    return new Value<string | null | undefined, WD, CT>(async (options) => {
+      const a = await getA(options)
+      return {
+        description: null,
+        warning: null,
+        type: "select" as const,
+        ...a,
+        ...requiredLikeToAbove(a.required),
+      }
+    }, string.optional())
+  }
   static multiselect<Values extends Record<string, string>, WD, CT>(a: {
     name: string
     description?: string | null
@@ -293,6 +498,33 @@ export class Value<Type, WD, ConfigType> {
       ),
     )
   }
+  static dynamicMultiselect<WD, CT>(
+    getA: LazyBuild<
+      WD,
+      CT,
+      {
+        name: string
+        description?: string | null
+        warning?: string | null
+        default: string[]
+        values: Record<string, string>
+        minLength?: number | null
+        maxLength?: number | null
+      }
+    >,
+  ) {
+    return new Value<string[], WD, CT>(async (options) => {
+      const a = await getA(options)
+      return {
+        type: "multiselect" as const,
+        minLength: null,
+        maxLength: null,
+        warning: null,
+        description: null,
+        ...a,
+      }
+    }, arrayOf(string))
+  }
   static object<Type extends Record<string, any>, WrapperData, ConfigType>(
     a: {
       name: string
@@ -339,6 +571,33 @@ export class Value<Type, WD, ConfigType> {
       asRequiredParser(aVariants.validator, a),
     )
   }
+  static filteredUnion<
+    Required extends RequiredDefault<string>,
+    Type,
+    WrapperData,
+    ConfigType,
+  >(
+    a: {
+      name: string
+      description?: string | null
+      warning?: string | null
+      required: Required
+      default?: string | null
+    },
+    aVariants: Variants<Type, WrapperData, ConfigType>,
+  ) {
+    return new Value<AsRequired<Type, Required>, WrapperData, ConfigType>(
+      async (options) => ({
+        type: "union" as const,
+        description: null,
+        warning: null,
+        ...a,
+        variants: await aVariants.build(options as any),
+        ...requiredLikeToAbove(a.required),
+      }),
+      asRequiredParser(aVariants.validator, a),
+    )
+  }
 
   static list<Type, WrapperData, ConfigType>(
     a: List<Type, WrapperData, ConfigType>,
diff --git a/lib/config/builder/variants.ts b/lib/config/builder/variants.ts
index 0aa39a5..5e5c112 100644
--- a/lib/config/builder/variants.ts
+++ b/lib/config/builder/variants.ts
@@ -103,4 +103,23 @@ export class Variants<Type, WD, ConfigType> {
       return variants
     }, validator)
   }
+
+  /** Danger, don't filter everything!! */
+  disableVariants(
+    fn: LazyBuild<
+      WD,
+      ConfigType,
+      Array<Type extends { unionSelectKey: infer B } ? B : never>
+    >,
+  ) {
+    const previousMe = this
+    return new Variants<Type, WD, ConfigType>(async (options) => {
+      const answer = { ...(await previousMe.build(options)) }
+      const filterValues = await fn(options)
+      for (const key of filterValues) {
+        delete answer[key as any]
+      }
+      return answer
+    }, this.validator)
+  }
 }
diff --git a/lib/test/configBuilder.test.ts b/lib/test/configBuilder.test.ts
index 39daf4a..d16c3d3 100644
--- a/lib/test/configBuilder.test.ts
+++ b/lib/test/configBuilder.test.ts
@@ -189,7 +189,7 @@ describe("values", () => {
     const validator = value.validator
     validator.unsafeCast("a")
     validator.unsafeCast("b")
-    expect(() => validator.unsafeCast(null)).toThrowError()
+    expect(() => validator.unsafeCast("c")).toThrowError()
     testOutput<typeof validator._TYPE, "a" | "b">()(null)
   })
   test("nullable select", async () => {
@@ -295,6 +295,280 @@ describe("values", () => {
     validator.unsafeCast([1, 2, 3])
     testOutput<typeof validator._TYPE, number[]>()(null)
   })
+
+  describe("dynamic", () => {
+    const fakeOptions = {
+      config: "config",
+      effects: "effects",
+      utils: "utils",
+    } as any
+    test("toggle", async () => {
+      const value = Value.dynamicToggle<{}, {}>(async () => ({
+        name: "Testing",
+        description: null,
+        warning: null,
+        default: null,
+      }))
+      const validator = value.validator
+      validator.unsafeCast(false)
+      expect(() => validator.unsafeCast(null)).toThrowError()
+      testOutput<typeof validator._TYPE, boolean>()(null)
+      expect(await value.build(fakeOptions)).toMatchObject({
+        name: "Testing",
+        description: null,
+        warning: null,
+        default: null,
+      })
+    })
+    test("text", async () => {
+      const value = Value.dynamicText(async () => ({
+        name: "Testing",
+        required: { default: null },
+      }))
+      const validator = value.validator
+      const rawIs = await value.build({} as any)
+      validator.unsafeCast("test text")
+      validator.unsafeCast(null)
+      testOutput<typeof validator._TYPE, string | null | undefined>()(null)
+      expect(await value.build(fakeOptions)).toMatchObject({
+        name: "Testing",
+        required: true,
+        default: null,
+      })
+    })
+    test("text", async () => {
+      const value = Value.dynamicText(async () => ({
+        name: "Testing",
+        required: { default: "null" },
+      }))
+      const validator = value.validator
+      validator.unsafeCast("test text")
+      validator.unsafeCast(null)
+      testOutput<typeof validator._TYPE, string | null | undefined>()(null)
+      expect(await value.build(fakeOptions)).toMatchObject({
+        name: "Testing",
+        required: true,
+        default: "null",
+      })
+    })
+    test("optional text", async () => {
+      const value = Value.dynamicText(async () => ({
+        name: "Testing",
+        required: false,
+      }))
+      const validator = value.validator
+      const rawIs = await value.build({} as any)
+      validator.unsafeCast("test text")
+      validator.unsafeCast(null)
+      testOutput<typeof validator._TYPE, string | null | undefined>()(null)
+      expect(await value.build(fakeOptions)).toMatchObject({
+        name: "Testing",
+        required: false,
+        default: null,
+      })
+    })
+    test("color", async () => {
+      const value = Value.dynamicColor<null, null>(async () => ({
+        name: "Testing",
+        required: false,
+        description: null,
+        warning: null,
+      }))
+      const validator = value.validator
+      validator.unsafeCast("#000000")
+      validator.unsafeCast(null)
+      testOutput<typeof validator._TYPE, string | null | undefined>()(null)
+      expect(await value.build(fakeOptions)).toMatchObject({
+        name: "Testing",
+        required: false,
+        default: null,
+        description: null,
+        warning: null,
+      })
+    })
+    test("datetime", async () => {
+      const value = Value.dynamicDatetime<{ test: "a" }, { test2: 6 }>(
+        async ({ effects, utils, config }) => {
+          ;async () => {
+            ;(await utils.getOwnWrapperData("/test").once()) satisfies "a"
+            config satisfies { test2: 6 } | null
+          }
+
+          return {
+            name: "Testing",
+            required: { default: null },
+            inputmode: "date",
+          }
+        },
+      )
+      const validator = value.validator
+      validator.unsafeCast("2021-01-01")
+      validator.unsafeCast(null)
+      testOutput<typeof validator._TYPE, string | null | undefined>()(null)
+      expect(await value.build(fakeOptions)).toMatchObject({
+        name: "Testing",
+        required: true,
+        default: null,
+        description: null,
+        warning: null,
+        inputmode: "date",
+      })
+    })
+    test("textarea", async () => {
+      const value = Value.dynamicTextarea(async () => ({
+        name: "Testing",
+        required: false,
+        description: null,
+        warning: null,
+        minLength: null,
+        maxLength: null,
+        placeholder: null,
+      }))
+      const validator = value.validator
+      validator.unsafeCast("test text")
+      expect(() => validator.unsafeCast(null)).toThrowError()
+      testOutput<typeof validator._TYPE, string>()(null)
+      expect(await value.build(fakeOptions)).toMatchObject({
+        name: "Testing",
+        required: false,
+      })
+    })
+    test("number", async () => {
+      const value = Value.dynamicNumber(() => ({
+        name: "Testing",
+        required: { default: null },
+        integer: false,
+        description: null,
+        warning: null,
+        min: null,
+        max: null,
+        step: null,
+        units: null,
+        placeholder: null,
+      }))
+      const validator = value.validator
+      validator.unsafeCast(2)
+      validator.unsafeCast(null)
+      expect(() => validator.unsafeCast("null")).toThrowError()
+      testOutput<typeof validator._TYPE, number | null | undefined>()(null)
+      expect(await value.build(fakeOptions)).toMatchObject({
+        name: "Testing",
+        required: true,
+      })
+    })
+    test("select", async () => {
+      const value = Value.dynamicSelect(() => ({
+        name: "Testing",
+        required: { default: null },
+        values: {
+          a: "A",
+          b: "B",
+        },
+        description: null,
+        warning: null,
+      }))
+      const validator = value.validator
+      validator.unsafeCast("a")
+      validator.unsafeCast("b")
+      validator.unsafeCast("c")
+      validator.unsafeCast(null)
+      testOutput<typeof validator._TYPE, string | null | undefined>()(null)
+      expect(await value.build(fakeOptions)).toMatchObject({
+        name: "Testing",
+        required: true,
+      })
+    })
+    test("multiselect", async () => {
+      const value = Value.dynamicMultiselect(() => ({
+        name: "Testing",
+        values: {
+          a: "A",
+          b: "B",
+        },
+        default: [],
+        description: null,
+        warning: null,
+        minLength: null,
+        maxLength: null,
+      }))
+      const validator = value.validator
+      validator.unsafeCast([])
+      validator.unsafeCast(["a", "b"])
+      validator.unsafeCast(["c"])
+
+      expect(() => validator.unsafeCast([4])).toThrowError()
+      expect(() => validator.unsafeCast(null)).toThrowError()
+      testOutput<typeof validator._TYPE, Array<string>>()(null)
+      expect(await value.build(fakeOptions)).toMatchObject({
+        name: "Testing",
+        default: [],
+      })
+    })
+  })
+  describe("filtering", () => {
+    test("union", async () => {
+      const value = Value.union(
+        {
+          name: "Testing",
+          required: { default: null },
+          description: null,
+          warning: null,
+          default: null,
+        },
+        Variants.of({
+          a: {
+            name: "a",
+            spec: Config.of({
+              b: Value.toggle({
+                name: "b",
+                description: null,
+                warning: null,
+                default: null,
+              }),
+            }),
+          },
+          b: {
+            name: "b",
+            spec: Config.of({
+              b: Value.toggle({
+                name: "b",
+                description: null,
+                warning: null,
+                default: null,
+              }),
+            }),
+          },
+        }).disableVariants(() => [
+          "a",
+          // @ts-expect-error
+          "c",
+        ]),
+      )
+      const validator = value.validator
+      validator.unsafeCast({ unionSelectKey: "a", unionValueKey: { b: false } })
+      type Test = typeof validator._TYPE
+      testOutput<
+        Test,
+        | { unionSelectKey: "a"; unionValueKey: { b: boolean } }
+        | { unionSelectKey: "b"; unionValueKey: { b: boolean } }
+      >()(null)
+
+      const built = await value.build({} as any)
+      expect(built).toMatchObject({
+        name: "Testing",
+        variants: {
+          b: {},
+        },
+      })
+      expect(built).not.toMatchObject({
+        name: "Testing",
+        variants: {
+          a: {},
+          b: {},
+        },
+      })
+    })
+  })
 })
 
 describe("Builder List", () => {
diff --git a/lib/types.ts b/lib/types.ts
index 916bae6..e8960e7 100644
--- a/lib/types.ts
+++ b/lib/types.ts
@@ -163,6 +163,30 @@ export type Effects = {
     toWrite: string
   }): Promise<void>
   readFile(input: { volumeId: string; path: string }): Promise<string>
+  /** Usable when not sandboxed */
+  appendFile(input: {
+    path: string
+    volumeId: string
+    toWrite: string
+  }): Promise<void>
+  /**
+   * Move file from src to dst
+   * Usable when not sandboxed */
+  moveFile(input: {
+    srcVolume: string
+    dstVolume: string
+    srcPath: string
+    dstPath: string
+  }): Promise<void>
+  /**
+   * copy from src to dst
+   * Usable when not sandboxed */
+  copyFile(input: {
+    srcVolume: string
+    dstVolume: string
+    srcPath: string
+    dstPath: string
+  }): Promise<void>
   metadata(input: { volumeId: string; path: string }): Promise<Metadata>
   /** Create a directory. Usable when not sandboxed */
   createDir(input: { volumeId: string; path: string }): Promise<string>
diff --git a/scripts/oldSpecToBuilder.ts b/scripts/oldSpecToBuilder.ts
index 0a8e1be..cdaf3a9 100644
--- a/scripts/oldSpecToBuilder.ts
+++ b/scripts/oldSpecToBuilder.ts
@@ -43,18 +43,17 @@ export default async function makeFileContentFromOld(
   const data = await inputData
 
   const namedConsts = new Set(["Config", "Value", "List"])
-  const configNameRaw = newConst("configSpecRaw", convertInputSpec(data))
+  const configName = newConst(
+    "configSpec",
+    `Config.withWrapperData<WrapperData>().of(${convertInputSpecInner(data)})`,
+  )
   const configMatcherName = newConst(
     "matchConfigSpec",
-    `${configNameRaw}.validator`,
+    `${configName}.validator`,
   )
   outputLines.push(
     `export type ConfigSpec = typeof ${configMatcherName}._TYPE;`,
   )
-  const configName = newConst(
-    "ConfigSpec",
-    `${configNameRaw} as Config<ConfigSpec, WrapperData, ConfigSpec>`,
-  )
 
   return outputLines.join("\n")
 
@@ -69,14 +68,18 @@ export default async function makeFileContentFromOld(
     if (nested) return data
     return newConst(key, data)
   }
-  function convertInputSpec(data: any) {
-    let answer = "Config.of({"
+  function convertInputSpecInner(data: any) {
+    let answer = "{"
     for (const [key, value] of Object.entries(data)) {
       const variableName = maybeNewConst(key, convertValueSpec(value))
 
       answer += `${JSON.stringify(key)}: ${variableName},`
     }
-    return `${answer}})`
+    return `${answer}}`
+  }
+
+  function convertInputSpec(data: any) {
+    return `Config.of(${convertInputSpecInner(data)})`
   }
   function convertValueSpec(value: any): string {
     switch (value.type) {