fix(opencode): preserve external pricing contracts

packages/opencode/src/provider/provider.ts

@@ -1094,6 +1094,21 @@ export const ConfigProvidersResult = Schema.Struct({
 export type ConfigProvidersResult = Types.DeepMutable<Schema.Schema.Type<typeof ConfigProvidersResult>>
 
 export function toPublicInfo(provider: Info): Info {
+  const result = cloneInfo(provider)
+  for (const model of Object.values(result.models)) {
+    if (model.cost.experimentalOver200K) continue
+    if (model.cost.tiers?.length !== 1) continue
+    const [tier] = model.cost.tiers
+    model.cost.experimentalOver200K = {
+      input: tier.input,
+      output: tier.output,
+      cache: { ...tier.cache },
+    }
+  }
+  return result
+}
+
+function cloneInfo(provider: Info): Info {
   return JSON.parse(
     JSON.stringify(
       {
@@ -1202,8 +1217,8 @@ function cost(c: ModelsDev.Model["cost"]): Model["cost"] {
       write: c?.cache_write ?? 0,
     },
   }
-  if (c?.tiers) {
-    result.tiers = c.tiers.map((item) => ({
+  const tiers =
+    c?.tiers?.map((item) => ({
       input: item.input,
       output: item.output,
       cache: {
@@ -1211,18 +1226,19 @@ function cost(c: ModelsDev.Model["cost"]): Model["cost"] {
         write: item.cache_write ?? 0,
       },
       tier: item.tier,
-    }))
-  }
-  if (c?.context_over_200k) {
-    result.experimentalOver200K = {
+    })) ?? []
+  const legacy = c?.context_over_200k
+  if (legacy && tiers.length === 0)
+    tiers.push({
+      input: legacy.input,
+      output: legacy.output,
       cache: {
-        read: c.context_over_200k.cache_read ?? 0,
-        write: c.context_over_200k.cache_write ?? 0,
+        read: legacy.cache_read ?? 0,
+        write: legacy.cache_write ?? 0,
       },
-      input: c.context_over_200k.input,
-      output: c.context_over_200k.output,
-    }
-  }
+      tier: { type: "context", size: 200_000 },
+    })
+  if (tiers.length > 0) result.tiers = tiers
   return result
 }
 
@@ -1378,7 +1394,7 @@ const layer = Layer.effect(
         const cfg = yield* config.get()
         const modelsDev = yield* modelsDevSvc.get()
         const catalog = mapValues(modelsDev, fromModelsDevProvider)
-        const database = mapValues(catalog, toPublicInfo)
+        const database = mapValues(catalog, cloneInfo)
 
         const providers: Record<ProviderV2.ID, Info> = {} as Record<ProviderV2.ID, Info>
         const languages = new Map<string, LanguageModelV3>()
@@ -1482,6 +1498,20 @@ const layer = Layer.effect(
               if (model.id && model.id !== modelID) return modelID
               return existingModel?.name ?? modelID
             })
+            const legacy = existingModel?.cost.tiers?.length ? undefined : model.cost?.context_over_200k
+            const tiers = legacy
+              ? [
+                  ...(existingModel?.cost.tiers?.filter(
+                    (item) => item.tier.type !== "context" || item.tier.size !== 200_000,
+                  ) ?? []),
+                  {
+                    input: legacy.input,
+                    output: legacy.output,
+                    cache: { read: legacy.cache_read ?? 0, write: legacy.cache_write ?? 0 },
+                    tier: { type: "context" as const, size: 200_000 },
+                  },
+                ]
+              : existingModel?.cost.tiers
             const parsedModel: Model = {
               id: ModelV2.ID.make(modelID),
               api: {
@@ -1528,6 +1558,7 @@ const layer = Layer.effect(
                   read: model?.cost?.cache_read ?? existingModel?.cost?.cache.read ?? 0,
                   write: model?.cost?.cache_write ?? existingModel?.cost?.cache.write ?? 0,
                 },
+                tiers,
               },
               options: mergeDeep(existingModel?.options ?? {}, model.options ?? {}),
               limit: {

packages/opencode/src/session/session.ts

@@ -380,10 +380,7 @@ export const getUsage = (input: { model: Provider.Model; usage: Usage; metadata?
   const costInfo =
     input.model.cost?.tiers
       ?.filter((item) => item.tier.type === "context" && contextTokens > item.tier.size)
-      .sort((a, b) => b.tier.size - a.tier.size)[0] ??
-    (input.model.cost?.experimentalOver200K && contextTokens > 200_000
-      ? input.model.cost.experimentalOver200K
-      : input.model.cost)
+      .sort((a, b) => b.tier.size - a.tier.size)[0] ?? input.model.cost
   const totalNanoAiu = input.metadata?.["copilot"]?.["totalNanoAiu"]
   return {
     cost:

packages/opencode/test/provider/provider.test.ts

@@ -566,6 +566,81 @@ it.instance(
   },
 )
 
+it.instance(
+  "model config preserves catalog cost tiers",
+  Effect.gen(function* () {
+    yield* set("REQUESTY_API_KEY", "test-api-key")
+    const providers = yield* list
+    const provider = providers[ProviderV2.ID.make("requesty")]
+    const model = provider.models["google/gemini-2.5-pro"]
+    expect(model.cost.tiers).toEqual([
+      {
+        input: 2.5,
+        output: 15,
+        cache: { read: 0.25, write: 0 },
+        tier: { type: "context", size: 200_000 },
+      },
+    ])
+    expect(model.cost.experimentalOver200K).toBeUndefined()
+    expect(Provider.toPublicInfo(provider).models["google/gemini-2.5-pro"].cost.experimentalOver200K).toEqual({
+      input: 2.5,
+      output: 15,
+      cache: { read: 0.25, write: 0 },
+    })
+  }),
+  {
+    config: {
+      provider: {
+        requesty: {
+          models: {
+            "google/gemini-2.5-pro": {
+              cost: {
+                input: 1.25,
+                output: 10,
+                context_over_200k: { input: 4, output: 16, cache_read: 0.4 },
+              },
+            },
+          },
+        },
+      },
+    },
+  },
+)
+
+it.instance(
+  "legacy model config pricing is normalized into a context tier",
+  Effect.gen(function* () {
+    const providers = yield* list
+    expect(providers[ProviderV2.ID.make("legacy")].models.legacy.cost.tiers).toEqual([
+      {
+        input: 4,
+        output: 16,
+        cache: { read: 0.4, write: 0 },
+        tier: { type: "context", size: 200_000 },
+      },
+    ])
+  }),
+  {
+    config: {
+      provider: {
+        legacy: {
+          npm: "@ai-sdk/openai-compatible",
+          options: { apiKey: "test-api-key" },
+          models: {
+            legacy: {
+              cost: {
+                input: 1.25,
+                output: 10,
+                context_over_200k: { input: 4, output: 16, cache_read: 0.4 },
+              },
+            },
+          },
+        },
+      },
+    },
+  },
+)
+
 it.instance(
   "model config preserves explicitly empty models.dev variants",
   Effect.gen(function* () {
@@ -1401,10 +1476,18 @@ test("mode options and cost are derived from the base model", () => {
           input: 2.5,
           output: 15,
           cache_read: 0.25,
+          tiers: [
+            {
+              input: 5,
+              output: 22.5,
+              cache_read: 0.5,
+              tier: { type: "context", size: 272_000 },
+            },
+          ],
           context_over_200k: {
-            input: 5,
-            output: 22.5,
-            cache_read: 0.5,
+            input: 4,
+            output: 20,
+            cache_read: 0.4,
           },
         },
         limit: {
@@ -1449,11 +1532,49 @@ test("mode options and cost are derived from the base model", () => {
   const pro = Provider.fromModelsDevProvider(provider).models["gpt-5.6-sol-pro"]
   expect(pro.api.id).toEqual("gpt-5.6-sol")
   expect(pro.options).toEqual({ reasoningMode: "pro", serviceTier: "priority" })
-  expect(model.cost.experimentalOver200K).toEqual({
-    input: 5,
-    output: 22.5,
-    cache: { read: 0.5, write: 0 },
-  })
+  expect(model.cost.tiers).toEqual([
+    {
+      input: 5,
+      output: 22.5,
+      cache: { read: 0.5, write: 0 },
+      tier: { type: "context", size: 272_000 },
+    },
+  ])
+})
+
+test("legacy models.dev pricing is normalized into a context tier", () => {
+  const provider = {
+    id: "legacy",
+    name: "Legacy",
+    env: [],
+    npm: "@ai-sdk/openai-compatible",
+    models: {
+      legacy: {
+        id: "legacy",
+        name: "Legacy",
+        release_date: "2026-01-01",
+        attachment: false,
+        reasoning: false,
+        temperature: true,
+        tool_call: true,
+        cost: {
+          input: 1,
+          output: 2,
+          context_over_200k: { input: 3, output: 4, cache_read: 0.3 },
+        },
+        limit: { context: 1_000_000, output: 32_000 },
+      },
+    },
+  } as unknown as ModelsDev.Provider
+
+  expect(Provider.fromModelsDevProvider(provider).models.legacy.cost.tiers).toEqual([
+    {
+      input: 3,
+      output: 4,
+      cache: { read: 0.3, write: 0 },
+      tier: { type: "context", size: 200_000 },
+    },
+  ])
 })
 
 test("models.dev normalization fills required response fields", () => {

packages/opencode/test/session/compaction.test.ts

@@ -1830,7 +1830,7 @@ describe("SessionNs.getUsage", () => {
     expect(result.cost).toBe(0.04473525)
   })
 
-  test("uses matching context cost tier before over-200k fallback", () => {
+  test("uses the matching context cost tier", () => {
     const model = createModel({
       context: 1_000_000,
       output: 32_000,
@@ -1852,11 +1852,6 @@ describe("SessionNs.getUsage", () => {
             tier: { type: "context", size: 500_000 },
           },
         ],
-        experimentalOver200K: {
-          input: 100,
-          output: 100,
-          cache: { read: 100, write: 100 },
-        },
       },
     })
     const result = SessionNs.getUsage({
@@ -1873,7 +1868,7 @@ describe("SessionNs.getUsage", () => {
     expect(result.cost).toBe(2.75 + 0.6 + 0.05)
   })
 
-  test("falls back to over-200k pricing when no cost tier matches", () => {
+  test("uses base pricing when no context cost tier matches", () => {
     const model = createModel({
       context: 1_000_000,
       output: 32_000,
@@ -1889,11 +1884,6 @@ describe("SessionNs.getUsage", () => {
             tier: { type: "context", size: 500_000 },
           },
         ],
-        experimentalOver200K: {
-          input: 3,
-          output: 4,
-          cache: { read: 0.3, write: 1.5 },
-        },
       },
     })
     const result = SessionNs.getUsage({
@@ -1901,7 +1891,7 @@ describe("SessionNs.getUsage", () => {
       usage: usage({ inputTokens: 300_000, outputTokens: 100_000, totalTokens: 400_000 }),
     })
 
-    expect(result.cost).toBe(0.9 + 0.4)
+    expect(result.cost).toBe(0.3 + 0.2)
   })
 
   test.each(["@ai-sdk/anthropic", "@ai-sdk/amazon-bedrock", "@ai-sdk/google-vertex/anthropic"])(