fix(core): reconcile tool repair with current v2

packages/core/src/plugin/internal.ts

@@ -88,6 +88,7 @@ import { ProviderPlugins } from "./provider.js"
 import { WebSearchPlugins } from "./websearch/index.js"
 import { SkillPlugin } from "./skill.js"
 import { VcsHgPlugin } from "./vcs/hg.js"
+import { ToolInputRepairPlugin } from "./tool-input-repair.js"
 import { OptimizePlugin } from "./optimize.js"
 import { VariantPlugin } from "./variant.js"
 import { VcsGitPlugin } from "./vcs/git.js"
@@ -193,6 +194,7 @@ export const requirements = LayerNode.group([
 export type InternalPlugin = Plugin<Requirements | Scope.Scope>
 
 const pre = [
+  ToolInputRepairPlugin.Plugin,
   BrowserPlugin,
   ConfigMcpPlugin.Plugin,
   McpCodeModeExclusionPlugin.Plugin,

packages/core/src/plugin/tool-input-repair.ts

@@ -0,0 +1,191 @@
+export * as ToolInputRepairPlugin from "./tool-input-repair.js"
+
+import { define } from "@opencode/plugin/effect/plugin"
+import type { ToolEditor } from "@opencode/plugin/effect/tool"
+import { CodeMode } from "@opencode/codemode"
+import { Effect, JsonSchema, Option, Predicate, Schema } from "effect"
+import { definition } from "../tool/runtime.js"
+
+// Repairs apply only when the input schema unambiguously supports them:
+// - Stringified root or nested object: '{"limit":"20"}' -> { limit: 20 }
+// - Closed object: { limit: "20", extra: true } -> { limit: 20 }
+// - Optional null or empty-object placeholder: { limit: null } -> {}
+// - Numeric or boolean string: { limit: "20", enabled: "false" } -> { limit: 20, enabled: false }
+// - Nullable field: { count: "2" } -> { count: 2 }
+// - Stringified array or compatible item: { tags: '["a"]', count: "2" } -> { tags: ["a"], count: [2] }
+// - Positional tuple: { pair: ["2", "false"] } -> { pair: [2, false] }
+// - Typed dictionary: { counts: { first: "2" } } -> { counts: { first: 2 } }
+// - Nested fields and local references: { items: [{ count: "2" }] } -> { items: [{ count: 2 }] }
+
+const decodeJson = Schema.decodeUnknownOption(Schema.fromJsonString(Schema.Unknown))
+const maxDepth = 6
+const executeSchema = Schema.toJsonSchemaDocument(CodeMode.Input).schema
+
+export const Plugin = define({
+  id: "opencode.tool.input.repair",
+  effect: Effect.fn(function* (ctx) {
+    let get: ToolEditor["get"] = () => undefined
+    yield* ctx.tool.transform((draft) => {
+      // The draft sees later tool transforms too; reload replaces this lookup.
+      get = draft.get
+    })
+    yield* ctx.tool.hook("execute.before", (event) =>
+      Effect.sync(() => {
+        const tool = get(event.tool)
+        // The outer Code Mode tool is synthesized by snapshots, not registered in the draft.
+        const schema = tool ? definition(tool).inputSchema : event.tool === "execute" ? executeSchema : undefined
+        if (schema?.type !== "object") return
+        event.input = repair(event.input, schema, schema, 0)
+      }),
+    )
+  }),
+})
+
+function repair(value: unknown, schema: JsonSchema.JsonSchema, root: JsonSchema.JsonSchema, depth: number): unknown {
+  if (depth > maxDepth) return value
+
+  if (typeof schema.$ref === "string") {
+    const definitions = /^#\/\$defs\/[^/]+$/.test(schema.$ref)
+      ? root.$defs
+      : /^#\/definitions\/[^/]+$/.test(schema.$ref)
+        ? root.definitions
+        : undefined
+    if (!Predicate.isObject(definitions)) return value
+    const target = Object.fromEntries(
+      Object.entries(definitions).filter((entry): entry is [string, JsonSchema.JsonSchema] =>
+        Predicate.isObject(entry[1]),
+      ),
+    )[
+      schema.$ref
+        .slice(schema.$ref.lastIndexOf("/") + 1)
+        .replaceAll("~1", "/")
+        .replaceAll("~0", "~")
+    ]
+    return target ? repair(value, target, root, depth + 1) : value
+  }
+
+  if (Array.isArray(schema.type)) {
+    if (value === null && schema.type.includes("null")) return value
+    if (schema.type.includes(typeof value)) return value
+    const types = schema.type.filter((type) => type !== "null")
+    return types.length === 1 ? repair(value, { ...schema, type: types[0] }, root, depth + 1) : value
+  }
+
+  if (schema.type === undefined) {
+    if (Array.isArray(schema.anyOf) && Array.isArray(schema.oneOf)) return value
+    const branches = Array.isArray(schema.anyOf) ? schema.anyOf : schema.oneOf
+    if (!Array.isArray(branches) || value === null) return value
+    if (branches.some((branch) => !Predicate.isObject(branch) || branch.type === typeof value)) return value
+    const candidates = branches.filter((branch) => Predicate.isObject(branch) && branch.type !== "null")
+    return candidates.length === 1 ? repair(value, candidates[0], root, depth + 1) : value
+  }
+
+  if (schema.type === "number" || schema.type === "integer") {
+    if (typeof value !== "string" || value.trim() === "") return value
+    const parsed = Number(value)
+    return Number.isFinite(parsed) && (schema.type !== "integer" || Number.isSafeInteger(parsed)) ? parsed : value
+  }
+  if (schema.type === "boolean") return value === "true" ? true : value === "false" ? false : value
+  if (schema.type === "object") return repairObject(value, schema, root, depth)
+  if (schema.type === "array") return repairArray(value, schema, root, depth)
+  return value
+}
+
+function repairObject(
+  value: unknown,
+  schema: JsonSchema.JsonSchema,
+  root: JsonSchema.JsonSchema,
+  depth: number,
+): unknown {
+  const parsed = typeof value === "string" ? Option.getOrUndefined(decodeJson(value)) : value
+  if (!Predicate.isObject(parsed)) return value
+
+  const properties = Predicate.isObject(schema.properties) ? schema.properties : {}
+  const required = Array.isArray(schema.required) ? schema.required : []
+  const patterned = Predicate.isObject(schema.patternProperties)
+  const composed = Array.isArray(schema.allOf) || Array.isArray(schema.anyOf) || Array.isArray(schema.oneOf)
+
+  return Object.keys(parsed).reduce<Record<string, unknown>>((result, key) => {
+    const current = result[key]
+    const declared = Object.hasOwn(properties, key)
+    const property = declared ? properties[key] : !patterned ? schema.additionalProperties : undefined
+
+    if (!declared && schema.additionalProperties === false && !patterned && !composed) {
+      const next = { ...result }
+      delete next[key]
+      return next
+    }
+    if (!Predicate.isObject(property)) return result
+
+    if (declared && !required.includes(key)) {
+      const branches = Array.isArray(property.anyOf)
+        ? property.anyOf
+        : Array.isArray(property.oneOf)
+          ? property.oneOf
+          : []
+      const nullable =
+        property.nullable === true ||
+        property.type === "null" ||
+        (Array.isArray(property.type) && property.type.includes("null")) ||
+        branches.some(
+          (branch) =>
+            branch === true ||
+            (Predicate.isObject(branch) &&
+              (branch.type === "null" || branch.const === null || typeof branch.$ref === "string")),
+        )
+      const placeholder =
+        Predicate.isObject(current) &&
+        Object.keys(current).length === 0 &&
+        typeof property.type === "string" &&
+        property.type !== "object" &&
+        branches.length === 0
+      if ((current === null && !nullable && (property.type !== undefined || branches.length > 0)) || placeholder) {
+        const next = { ...result }
+        delete next[key]
+        return next
+      }
+    }
+
+    const repaired = repair(current, property, root, depth + 1)
+    return repaired === current ? result : { ...result, [key]: repaired }
+  }, parsed)
+}
+
+function repairArray(
+  value: unknown,
+  schema: JsonSchema.JsonSchema,
+  root: JsonSchema.JsonSchema,
+  depth: number,
+): unknown {
+  const parsed = typeof value === "string" ? Option.getOrUndefined(decodeJson(value)) : value
+  const tuple = Array.isArray(schema.prefixItems)
+    ? schema.prefixItems
+    : Array.isArray(schema.items)
+      ? schema.items
+      : undefined
+
+  if (Array.isArray(parsed)) {
+    const repaired = parsed.map((item, index) => {
+      const member = tuple
+        ? (tuple[index] ?? (Array.isArray(schema.prefixItems) ? schema.items : schema.additionalItems))
+        : schema.items
+      return Predicate.isObject(member) ? repair(item, member, root, depth + 1) : item
+    })
+    return repaired.every((item, index) => item === parsed[index]) ? parsed : repaired
+  }
+
+  if (tuple || !Predicate.isObject(schema.items)) return value
+  const repaired = repair(value, schema.items, root, depth + 1)
+  const type = schema.items.type
+  const compatible =
+    type === "object"
+      ? Predicate.isObject(repaired)
+      : type === "array"
+        ? Array.isArray(repaired)
+        : type === "integer"
+          ? typeof repaired === "number" && Number.isSafeInteger(repaired)
+          : type === "number"
+            ? typeof repaired === "number" && Number.isFinite(repaired)
+            : (type === "string" || type === "boolean") && typeof repaired === type
+  return compatible ? [repaired] : value
+}

packages/core/test/aisdk.test.ts

@@ -702,6 +702,34 @@ it.effect("does not treat SSE comment heartbeats as model progress", () =>
   }),
 )
 
+it.effect("preserves valid stringified object tool arguments for execution hooks", () =>
+  Effect.gen(function* () {
+    const aisdk = yield* AISDK.Service
+    const input = '{"count":"2"}'
+    const raw = JSON.stringify(input)
+    yield* aisdk.hook.sdk((event) => {
+      event.sdk = {
+        languageModel: () =>
+          streamModel([
+            { type: "tool-input-start", id: "call_1", toolName: "lookup" },
+            { type: "tool-input-delta", id: "call_1", delta: raw },
+            { type: "tool-input-end", id: "call_1" },
+            { type: "tool-call", toolCallId: "call_1", toolName: "lookup", input: raw },
+            { type: "finish", finishReason: { unified: "tool-calls", raw: "tool_calls" }, usage },
+          ]),
+      }
+    })
+
+    const resolved = yield* aisdk.model(model("test-ai-sdk"))
+    const response = yield* LLMClient.generate(LLM.request({ model: resolved, prompt: "Lookup" })).pipe(
+      Effect.provide(client),
+    )
+
+    expect(response.events.find(LLMEvent.is.toolCall)).toMatchObject({ id: "call_1", name: "lookup", input })
+    expect(response.events.some(LLMEvent.is.toolInputError)).toBeFalse()
+  }),
+)
+
 it.effect("emits malformed AI SDK tool input without executing it", () =>
   Effect.gen(function* () {
     const aisdk = yield* AISDK.Service

packages/core/test/plugin/tool-input-repair-integration.test.ts

@@ -0,0 +1,114 @@
+import { expect } from "bun:test"
+import { Effect, Schema } from "effect"
+import { Agent } from "@opencode/core/agent"
+import { Plugin } from "@opencode/core/plugin"
+import { ToolInputRepairPlugin } from "@opencode/core/plugin/tool-input-repair"
+import { Session } from "@opencode/core/session"
+import { SessionMessage } from "@opencode/core/session/message"
+import { Tool } from "@opencode/core/tool"
+import { testEffect } from "../lib/effect"
+import { PluginTestLayer } from "./fixture"
+
+const it = testEffect(PluginTestLayer)
+const identity = {
+  sessionID: Session.ID.make("ses_repair"),
+  agent: Agent.ID.make("build"),
+  messageID: SessionMessage.ID.make("msg_repair"),
+}
+
+it.effect("repairs tool input before validating its original schema", () =>
+  Effect.gen(function* () {
+    const plugins = yield* Plugin.Service
+    const registry = yield* Tool.Service
+    const executed: unknown[] = []
+    yield* plugins.activate([
+      { ...ToolInputRepairPlugin.Plugin, revision: "1" },
+      {
+        id: "repairable-tool",
+        revision: "1",
+        effect: (ctx) =>
+          ctx.tool.transform((draft) =>
+            draft.add({
+              name: "repairable",
+              options: { codemode: false },
+              description: "Repairable",
+              input: Schema.Struct({ count: Schema.Int, enabled: Schema.Boolean }),
+              execute: (input) => Effect.sync(() => executed.push(input)).pipe(Effect.as({ content: "ok" })),
+            }),
+          ),
+      },
+    ])
+    const snapshot = yield* registry.snapshot()
+    yield* snapshot.execute({
+      ...identity,
+      call: {
+        type: "tool-call",
+        id: "call-repair",
+        name: "repairable",
+        input: '{"count":"2","enabled":"true","extra":true}',
+      },
+    })
+    expect(executed).toEqual([{ count: 2, enabled: true }])
+
+    yield* registry.transform((draft) => {
+      draft.update("repairable", (tool) => {
+        tool.input = Schema.Struct({ count: Schema.Boolean, enabled: Schema.Boolean })
+      })
+    })
+    const updated = yield* registry.snapshot()
+    yield* updated.execute({
+      ...identity,
+      call: {
+        type: "tool-call",
+        id: "call-updated",
+        name: "repairable",
+        input: { count: "false", enabled: "true" },
+      },
+    })
+    expect(executed).toEqual([
+      { count: 2, enabled: true },
+      { count: false, enabled: true },
+    ])
+
+    yield* registry.transform((draft) => draft.remove("repairable"))
+    const removed = yield* registry.snapshot()
+    expect(
+      (yield* removed
+        .execute({
+          ...identity,
+          call: { type: "tool-call", id: "call-removed", name: "repairable", input: {} },
+        })
+        .pipe(Effect.flip)).message,
+    ).toBe("Unknown tool: repairable")
+  }),
+)
+
+it.effect("repairs outer Code Mode input and looks up namespaced inner tool schemas", () =>
+  Effect.gen(function* () {
+    const plugins = yield* Plugin.Service
+    const registry = yield* Tool.Service
+    const executed: unknown[] = []
+    yield* plugins.activate([{ ...ToolInputRepairPlugin.Plugin, revision: "1" }])
+    yield* registry.transform((draft) =>
+      draft.add({
+        name: "count",
+        options: { namespace: "example" },
+        description: "Record a count",
+        input: Schema.Struct({ count: Schema.Int }),
+        execute: (input) => Effect.sync(() => executed.push(input)).pipe(Effect.as({ content: "ok" })),
+      }),
+    )
+
+    const snapshot = yield* registry.snapshot()
+    yield* snapshot.execute({
+      ...identity,
+      call: {
+        type: "tool-call",
+        id: "call-codemode-repair",
+        name: "execute",
+        input: JSON.stringify({ code: 'return await tools.example.count({ count: "3" })' }),
+      },
+    })
+    expect(executed).toEqual([{ count: 3 }])
+  }),
+)

packages/core/test/plugin/tool-input-repair.test.ts

@@ -0,0 +1,439 @@
+import { describe, expect } from "bun:test"
+import { Agent } from "@opencode/core/agent"
+import { ToolInputRepairPlugin } from "@opencode/core/plugin/tool-input-repair"
+import { Session } from "@opencode/core/session"
+import { SessionMessage } from "@opencode/core/session/message"
+import type { ToolHooks } from "@opencode/plugin/effect/tool"
+import { Tool } from "@opencode/schema/tool"
+import { Effect, type JsonSchema } from "effect"
+import { it } from "../lib/effect"
+import { host } from "./host"
+
+function run(input: unknown, inputSchema: JsonSchema.JsonSchema) {
+  const event: ToolHooks["execute.before"] = {
+    tool: "test",
+    input,
+    sessionID: Session.ID.make("ses_repair"),
+    agent: Agent.ID.make("build"),
+    messageID: SessionMessage.ID.make("msg_repair"),
+    id: Tool.CallID.make("call_repair"),
+  }
+  const events: ToolHooks = {
+    "execute.before": event,
+    "execute.after": { ...event, status: "error", error: new Tool.Error({ message: "unused" }) },
+  }
+  const base = host()
+  return ToolInputRepairPlugin.Plugin.effect(
+    host({
+      tool: {
+        ...base.tool,
+        transform: (callback) =>
+          Effect.sync(() => {
+            const tool = {
+              id: "test",
+              name: "test",
+              description: "Test repair",
+              input: inputSchema,
+              execute: () => Effect.succeed({ content: "unused" }),
+            }
+            callback({
+              list: () => [tool],
+              get: (id) => (id === tool.id ? tool : undefined),
+              add: () => {},
+              namespace: () => {},
+              update: () => {},
+              remove: () => {},
+            })
+            return { dispose: Effect.void }
+          }),
+        hook: (name, callback) => callback(events[name]).pipe(Effect.orDie, Effect.as({ dispose: Effect.void })),
+      },
+    }),
+  ).pipe(Effect.as(event))
+}
+
+const object = (properties: Record<string, unknown>, required?: string[]) => ({
+  type: "object" as const,
+  properties,
+  ...(required ? { required } : {}),
+})
+
+describe("tool input repair plugin", () => {
+  it.effect("preserves valid input identity, nested containers, and unknown properties", () =>
+    Effect.gen(function* () {
+      const nested = { enabled: true }
+      const items = [2, 3]
+      const input = { count: 2, nested, items, extra: "keep" }
+      const event = yield* run(
+        input,
+        object({
+          count: { type: "integer" },
+          nested: object({ enabled: { type: "boolean" } }),
+          items: { type: "array", items: { type: "number" } },
+        }),
+      )
+
+      expect(event.input).toBe(input)
+      expect((event.input as typeof input).nested).toBe(nested)
+      expect((event.input as typeof input).items).toBe(items)
+    }),
+  )
+
+  it.effect("parses root objects and repairs nested stringified containers", () =>
+    Effect.gen(function* () {
+      const schema = object({
+        count: { type: "integer" },
+        item: object({ enabled: { type: "boolean" } }),
+        list: { type: "array", items: { type: "integer" } },
+      })
+
+      expect(
+        (yield* run('{"count":"2","item":"{\\"enabled\\":\\"false\\"}","list":"[\\"3\\"]"}', schema)).input,
+      ).toEqual({
+        count: 2,
+        item: { enabled: false },
+        list: [3],
+      })
+      expect((yield* run("{broken", schema)).input).toBe("{broken")
+      expect((yield* run("[]", schema)).input).toBe("[]")
+      expect((yield* run(null, schema)).input).toBeNull()
+    }),
+  )
+
+  it.effect("removes extras only from explicitly closed objects without mutating inputs", () =>
+    Effect.gen(function* () {
+      const input = {
+        known: "2",
+        extra: true,
+        closed: { keep: "3", extra: true },
+        open: { keep: "4", extra: true },
+        items: [{ keep: "5", extra: true }],
+      }
+      const event = yield* run(input, {
+        ...object({
+          known: { type: "integer" },
+          closed: { ...object({ keep: { type: "integer" } }), additionalProperties: false },
+          open: object({ keep: { type: "integer" } }),
+          items: {
+            type: "array",
+            items: { ...object({ keep: { type: "integer" } }), additionalProperties: false },
+          },
+        }),
+        additionalProperties: false,
+      })
+
+      expect(event.input).toEqual({
+        known: 2,
+        closed: { keep: 3 },
+        open: { keep: 4, extra: true },
+        items: [{ keep: 5 }],
+      })
+      expect(input.extra).toBeTrue()
+      expect(input.closed.extra).toBeTrue()
+      expect(input.items[0]?.extra).toBeTrue()
+      expect((yield* run({ extra: true }, { ...object({}), additionalProperties: false })).input).toEqual({})
+    }),
+  )
+
+  it.effect("preserves unknown keys when patterned ownership cannot be determined", () =>
+    Effect.gen(function* () {
+      const input = { known: 1, match: "2", extra: true }
+      const event = yield* run(input, {
+        ...object({ known: { type: "integer" } }),
+        additionalProperties: false,
+        patternProperties: { "^match$": { type: "integer" } },
+      })
+
+      expect(event.input).toBe(input)
+      expect((event.input as typeof input).match).toBe("2")
+      expect((event.input as typeof input).extra).toBeTrue()
+    }),
+  )
+
+  it.effect("preserves properties that may belong to composed object schemas", () =>
+    Effect.gen(function* () {
+      const input = { name: "example", extra: true }
+
+      for (const keyword of ["allOf", "anyOf", "oneOf"]) {
+        const event = yield* run(input, {
+          type: "object",
+          [keyword]: [object({ name: { type: "string" } })],
+          additionalProperties: false,
+        })
+
+        expect(event.input).toBe(input)
+      }
+    }),
+  )
+
+  it.effect("removes only optional nonnullable nulls and non-object empty placeholders", () =>
+    Effect.gen(function* () {
+      const input = {
+        optional: null,
+        required: null,
+        nullable: null,
+        union: null,
+        constant: null,
+        permissive: null,
+        referenced: null,
+        placeholder: {},
+        array: {},
+        requiredPlaceholder: {},
+        object: {},
+        unknown: null,
+      }
+      const event = yield* run(
+        input,
+        object(
+          {
+            optional: { type: "string" },
+            required: { type: "string" },
+            nullable: { type: "string", nullable: true },
+            union: { anyOf: [{ type: "integer" }, { type: "null" }] },
+            constant: { anyOf: [{ type: "integer" }, { const: null }] },
+            permissive: { anyOf: [{ type: "integer" }, true] },
+            referenced: { anyOf: [{ type: "integer" }, { $ref: "#/$defs/nullable" }] },
+            placeholder: { type: "integer" },
+            array: { type: "array", items: { type: "string" } },
+            requiredPlaceholder: { type: "boolean" },
+            object: { type: "object" },
+            unknown: {},
+          },
+          ["required", "requiredPlaceholder"],
+        ),
+      )
+
+      expect(event.input).toEqual({
+        required: null,
+        nullable: null,
+        union: null,
+        constant: null,
+        permissive: null,
+        referenced: null,
+        requiredPlaceholder: {},
+        object: {},
+        unknown: null,
+      })
+      expect(input.optional).toBeNull()
+      expect(input.placeholder).toEqual({})
+    }),
+  )
+
+  it.effect("coerces numeric and boolean strings while preserving invalid and existing values", () =>
+    Effect.gen(function* () {
+      const input = {
+        number: "1.5",
+        integer: "42",
+        enabled: "true",
+        disabled: "false",
+        valid: 3,
+        empty: " ",
+        infinite: "Infinity",
+        fractional: "1.5",
+        unsafe: "9007199254740992",
+        uppercase: "TRUE",
+      }
+      const event = yield* run(
+        input,
+        object({
+          number: { type: "number" },
+          integer: { type: "integer" },
+          enabled: { type: "boolean" },
+          disabled: { type: "boolean" },
+          valid: { type: "integer" },
+          empty: { type: "number" },
+          infinite: { type: "number" },
+          fractional: { type: "integer" },
+          unsafe: { type: "integer" },
+          uppercase: { type: "boolean" },
+        }),
+      )
+
+      expect(event.input).toEqual({ ...input, number: 1.5, integer: 42, enabled: true, disabled: false })
+    }),
+  )
+
+  it.effect("wraps compatible scalars after repairing array items", () =>
+    Effect.gen(function* () {
+      const event = yield* run(
+        {
+          text: "one",
+          integer: "42",
+          boolean: "false",
+          item: '{"count":"2"}',
+          incompatible: 2,
+          fractional: 1.5,
+          unconstrained: "4",
+        },
+        object({
+          text: { type: "array", items: { type: "string" } },
+          integer: { type: "array", items: { type: "integer" } },
+          boolean: { type: "array", items: { type: "boolean" } },
+          item: { type: "array", items: object({ count: { type: "integer" } }) },
+          incompatible: { type: "array", items: { type: "string" } },
+          fractional: { type: "array", items: { type: "integer" } },
+          unconstrained: { type: "array" },
+        }),
+      )
+
+      expect(event.input).toEqual({
+        text: ["one"],
+        integer: [42],
+        boolean: [false],
+        item: [{ count: 2 }],
+        incompatible: 2,
+        fractional: 1.5,
+        unconstrained: "4",
+      })
+    }),
+  )
+
+  it.effect("repairs nested question-like inputs without mutating original containers", () =>
+    Effect.gen(function* () {
+      const question = { question: "Pick one", multiple: "false", options: { label: "First", description: null } }
+      const input = { questions: [question] }
+      const event = yield* run(
+        input,
+        object({
+          questions: {
+            type: "array",
+            items: object({
+              question: { type: "string" },
+              multiple: { type: "boolean" },
+              options: {
+                type: "array",
+                items: object({ label: { type: "string" }, description: { type: "string" } }, ["label"]),
+              },
+            }),
+          },
+        }),
+      )
+
+      expect(event.input).toEqual({
+        questions: [{ question: "Pick one", multiple: false, options: [{ label: "First" }] }],
+      })
+      expect(input).toEqual({ questions: [question] })
+      expect(question.options.description).toBeNull()
+    }),
+  )
+
+  it.effect("repairs unique nullable alternatives while preserving accepted union values", () =>
+    Effect.gen(function* () {
+      const input = {
+        number: "2",
+        boolean: "false",
+        nullable: null,
+        typed: "3",
+        typedBoolean: "true",
+        accepted: "4",
+        valid: 5,
+      }
+      const event = yield* run(
+        input,
+        object({
+          number: { anyOf: [{ type: "number" }, { type: "null" }] },
+          boolean: { oneOf: [{ type: "boolean" }, { type: "null" }] },
+          nullable: { anyOf: [{ type: "number" }, { type: "null" }] },
+          typed: { type: ["integer", "null"] },
+          typedBoolean: { type: ["boolean", "null"] },
+          accepted: { anyOf: [{ type: "string" }, { type: "number" }] },
+          valid: { type: ["number", "null"] },
+        }),
+      )
+
+      expect(event.input).toEqual({ ...input, number: 2, boolean: false, typed: 3, typedBoolean: true })
+    }),
+  )
+
+  it.effect("repairs tuple positions and rest items while preserving valid array identity", () =>
+    Effect.gen(function* () {
+      const valid = [2, false]
+      const input = { prefix: ["2", "false", "3"], draft: '["4","true"]', valid, scalar: "5" }
+      const event = yield* run(
+        input,
+        object({
+          prefix: {
+            type: "array",
+            prefixItems: [{ type: "integer" }, { type: "boolean" }],
+            items: { type: "number" },
+          },
+          draft: { type: "array", items: [{ type: "integer" }, { type: "boolean" }] },
+          valid: { type: "array", prefixItems: [{ type: "integer" }, { type: "boolean" }] },
+          scalar: { type: "array", prefixItems: [{ type: "integer" }] },
+        }),
+      )
+
+      expect(event.input).toEqual({ prefix: [2, false, 3], draft: [4, true], valid, scalar: "5" })
+      expect((event.input as typeof input).valid).toBe(valid)
+      expect(input.prefix).toEqual(["2", "false", "3"])
+    }),
+  )
+
+  it.effect("repairs typed dictionaries and straightforward local references", () =>
+    Effect.gen(function* () {
+      const input = {
+        modern: "2",
+        legacy: "false",
+        nested: { count: "3" },
+        dictionary: { first: "4" },
+        missing: "5",
+        pointer: "6",
+        escaped: "7",
+      }
+      const event = yield* run(input, {
+        ...object({
+          modern: { $ref: "#/$defs/integer" },
+          legacy: { $ref: "#/definitions/boolean" },
+          nested: { $ref: "#/$defs/nested" },
+          dictionary: { type: "object", additionalProperties: { $ref: "#/$defs/integer" } },
+          missing: { $ref: "#/$defs/missing" },
+          pointer: { $ref: "#/$defs/nested/properties/count" },
+          escaped: { $ref: "#/$defs/a~1b~0c" },
+        }),
+        $defs: {
+          integer: { type: "integer" },
+          "a/b~c": { type: "integer" },
+          nested: object({ count: { $ref: "#/$defs/integer" } }),
+        },
+        definitions: { boolean: { type: "boolean" } },
+      })
+
+      expect(event.input).toEqual({
+        modern: 2,
+        legacy: false,
+        nested: { count: 3 },
+        dictionary: { first: 4 },
+        missing: "5",
+        pointer: "6",
+        escaped: 7,
+      })
+      expect(input.nested.count).toBe("3")
+      expect(input.dictionary.first).toBe("4")
+    }),
+  )
+
+  it.effect("leaves ambiguous unions, compositions, and unsupported roots unchanged", () =>
+    Effect.gen(function* () {
+      const input = { numeric: "2", objects: { value: "3" }, both: "4", composed: "5", unknown: "6" }
+      const event = yield* run(
+        input,
+        object({
+          numeric: { anyOf: [{ type: "number" }, { type: "integer" }] },
+          objects: {
+            oneOf: [
+              object({ value: { type: "integer" } }, ["value"]),
+              object({ value: { type: "number" } }, ["value"]),
+            ],
+          },
+          both: { anyOf: [{ type: "integer" }], oneOf: [{ type: "integer" }] },
+          composed: { allOf: [{ type: "integer" }] },
+          unknown: {},
+        }),
+      )
+
+      expect(event.input).toBe(input)
+      expect((yield* run(input, { properties: { numeric: { type: "integer" } } })).input).toBe(input)
+      expect((yield* run(input, { allOf: [object({ numeric: { type: "integer" } })] })).input).toBe(input)
+    }),
+  )
+})