fix(vscode): allow removing provider reasoning (#11238)

* fix(vscode): allow removing provider reasoning

* style(vscode): format provider regression test

---------

Co-authored-by: Christiaan Arnoldus <christiaan.arnoldus@outlook.com>

.changeset/calm-models-forget.md

@@ -0,0 +1,5 @@
+---
+"kilo-code": patch
+---
+
+Allow reasoning to be removed from custom provider models after it has been enabled.

packages/kilo-vscode/src/shared/custom-provider.ts

@@ -149,13 +149,23 @@ export function sanitizeCustomProviderConfig(provider: unknown): { value: Saniti
 }
 
 type AnyRecord = Record<string, unknown>
+type ProviderPatch = Omit<SanitizedProviderConfig, "models"> & {
+  models: Record<
+    string,
+    null | {
+      name: string
+      reasoning?: true | null
+      variants?: Record<string, VariantConfig | null>
+    }
+  >
+}
 
 function isRecord(v: unknown): v is AnyRecord {
   return !!v && typeof v === "object" && !Array.isArray(v)
 }
 
 /**
- * Build a provider patch that includes null sentinels for models and variants
+ * Build a provider patch that includes null sentinels for model properties
  * that existed in the previous config but are absent from the new one. The CLI
  * `config.update` endpoint deep-merges the payload with the existing config;
  * without explicit nulls, removed entries would persist on disk.
@@ -163,7 +173,7 @@ function isRecord(v: unknown): v is AnyRecord {
 export function withCustomProviderDeletions(existing: unknown, next: SanitizedProviderConfig): SanitizedProviderConfig {
   if (!isRecord(existing)) return next
   const oldModels = isRecord(existing.models) ? existing.models : {}
-  const patched: AnyRecord = { ...next.models }
+  const patched: ProviderPatch["models"] = { ...next.models }
 
   for (const id of Object.keys(oldModels)) {
     if (!(id in patched)) {
@@ -171,15 +181,21 @@ export function withCustomProviderDeletions(existing: unknown, next: SanitizedPr
       continue
     }
     const oldModel = oldModels[id]
-    const oldVariants = isRecord(oldModel) && isRecord(oldModel.variants) ? oldModel.variants : {}
     const newModel = patched[id]
-    if (!isRecord(newModel)) continue
+    if (!isRecord(oldModel) || !isRecord(newModel)) continue
+    const oldVariants = isRecord(oldModel.variants) ? oldModel.variants : {}
     const newVariants = isRecord(newModel.variants) ? newModel.variants : {}
-    const removedVariants = Object.keys(oldVariants).filter((v) => !(v in newVariants))
-    if (removedVariants.length === 0) continue
-    const nulls = Object.fromEntries(removedVariants.map((v) => [v, null]))
-    patched[id] = { ...newModel, variants: { ...newVariants, ...nulls } }
+    const removed = Object.keys(oldVariants).filter((variant) => !(variant in newVariants))
+    const variants =
+      removed.length > 0
+        ? { ...newVariants, ...Object.fromEntries(removed.map((variant) => [variant, null])) }
+        : newModel.variants
+    patched[id] = {
+      ...newModel,
+      ...(variants ? { variants } : {}),
+      ...(oldModel.reasoning !== undefined && newModel.reasoning === undefined ? { reasoning: null } : {}),
+    }
   }
 
-  return { ...next, models: patched as SanitizedProviderConfig["models"] }
+  return { ...next, models: patched } as SanitizedProviderConfig
 }

packages/kilo-vscode/tests/unit/custom-provider.test.ts

@@ -166,11 +166,12 @@ describe("withCustomProviderDeletions", () => {
     expect(models.gone).toBeNull()
   })
 
-  it("emits null for variants removed from a surviving model", () => {
+  it("emits null for reasoning and variants removed from a surviving model", () => {
     const existing = {
       models: {
         keep: {
           name: "Keep",
+          reasoning: true,
           variants: { high: { reasoningEffort: "high" }, low: { reasoningEffort: "low" } },
         },
       },
@@ -182,9 +183,11 @@ describe("withCustomProviderDeletions", () => {
       },
     } as typeof baseNext
     const result = withCustomProviderDeletions(existing, next)
-    const model = (result.models as Record<string, { variants: Record<string, unknown> }>).keep
-    expect(model.variants.high).toEqual({ reasoningEffort: "high" })
-    expect(model.variants.low).toBeNull()
+    const model = (result.models as Record<string, { reasoning?: boolean | null; variants?: Record<string, unknown> }>)
+      .keep
+    expect(model.reasoning).toBeNull()
+    expect(model.variants?.high).toEqual({ reasoningEffort: "high" })
+    expect(model.variants?.low).toBeNull()
   })
 
   it("does not touch variants on a model that is being deleted", () => {

packages/kilo-vscode/tests/unit/provider-actions-save.test.ts

@@ -243,7 +243,7 @@ describe("saveCustomProvider", () => {
     expect(payload.myprovider.models["model-gone"]).toBeNull()
   })
 
-  it("emits null sentinels for variants removed from a model that still exists", async () => {
+  it("emits null sentinels when reasoning and variants are removed from a model", async () => {
     const existing = {
       disabled_providers: [],
       provider: {
@@ -270,11 +270,7 @@ describe("saveCustomProvider", () => {
       name: "My Provider",
       options: { baseURL: "https://example.com/v1" },
       models: {
-        "model-1": {
-          name: "Model One",
-          reasoning: true,
-          variants: { high: { reasoningEffort: "high" } },
-        },
+        "model-1": { name: "Model One" },
       },
     }
     await saveCustomProvider(ctx, "req", "myprovider", next, undefined, false, null, setCachedConfig)
@@ -283,11 +279,11 @@ describe("saveCustomProvider", () => {
     const model = (
       calls.config[0].config.provider as Record<
         string,
-        { models: Record<string, { variants?: Record<string, unknown> }> }
+        { models: Record<string, { reasoning?: boolean | null; variants?: Record<string, unknown> }> }
       >
     ).myprovider.models["model-1"]
-    expect(model.variants).toBeDefined()
-    expect(model.variants?.high).toBeDefined()
+    expect(model.reasoning).toBeNull()
+    expect(model.variants?.high).toBeNull()
     expect(model.variants?.low).toBeNull()
   })
 

packages/opencode/src/config/provider.ts

@@ -12,7 +12,7 @@ export const Model = Schema.Struct({
   ai_sdk_provider: Schema.optional(Schema.Literals(AI_SDK_PROVIDERS)), // kilocode_change
   release_date: Schema.optional(Schema.String),
   attachment: Schema.optional(Schema.Boolean),
-  reasoning: Schema.optional(Schema.Boolean),
+  reasoning: Schema.optional(Schema.NullOr(Schema.Boolean)), // kilocode_change - allow null so reasoning can be removed via stripNulls on save
   temperature: Schema.optional(Schema.Boolean),
   tool_call: Schema.optional(Schema.Boolean),
   interleaved: Schema.optional(

packages/opencode/test/kilocode/config/config.test.ts

@@ -234,6 +234,61 @@ describe("kilocode indexing config", () => {
   })
 })
 
+describe("custom provider model config", () => {
+  test("persists and removes reasoning across a global config reload", async () => {
+    await using globalTmp = await tmpdir()
+    const file = path.join(globalTmp.path, "kilo.json")
+    const prev = Global.Path.config
+    ;(Global.Path as { config: string }).config = globalTmp.path
+    await clear()
+    await disposeAllInstances()
+
+    try {
+      await writeConfig(globalTmp.path, {
+        provider: {
+          custom: {
+            name: "Custom",
+            models: { model: { name: "Model" } },
+          },
+        },
+      })
+      await saveGlobal(
+        decode({
+          provider: {
+            custom: {
+              models: { model: { reasoning: true } },
+            },
+          },
+        }),
+      )
+      const added = JSON.parse(await Bun.file(file).text())
+      expect(added.provider.custom.models.model.reasoning).toBe(true)
+
+      await saveGlobal(
+        decode({
+          provider: {
+            custom: {
+              models: { model: { reasoning: null } },
+            },
+          },
+        }),
+      )
+      const written = JSON.parse(await Bun.file(file).text())
+      expect(written.provider.custom.models.model).not.toHaveProperty("reasoning")
+
+      await clear()
+      const reloaded = await Effect.runPromise(
+        Config.Service.use((svc) => svc.getGlobal()).pipe(Effect.scoped, Effect.provide(layer)),
+      )
+      expect(reloaded.provider?.custom?.models?.model?.reasoning).toBeUndefined()
+    } finally {
+      ;(Global.Path as { config: string }).config = prev
+      await clear()
+      await disposeAllInstances()
+    }
+  })
+})
+
 describe("subagent variant overrides", () => {
   test("removes one model override without removing sibling models", () => {
     const patch = decode({