fix(provider): default custom models to image input

packages/core/src/config/plugin/provider.ts

@@ -63,16 +63,22 @@ export const Plugin = define({
             const providerPackage = providerApi?.type === "aisdk" ? providerApi.package : undefined
 
             for (const [id, config] of Object.entries(item.models ?? {})) {
+              const existing = catalog.model.get(providerID, id)
               catalog.model.update(providerID, id, (model) => {
                 if (config.family !== undefined) model.family = config.family
                 if (config.name !== undefined) model.name = config.name
                 if (config.api !== undefined) model.api = { ...model.api, ...config.api }
                 const packageName = model.api.type === "aisdk" ? model.api.package : providerPackage
+                // TODO: Move these defaults to a dedicated configured-model constructor when one exists.
+                if (existing === undefined) {
+                  model.capabilities.input = ["text", "image"]
+                  model.capabilities.output = ["text"]
+                }
                 if (config.capabilities !== undefined) {
                   model.capabilities = {
-                    tools: config.capabilities.tools,
-                    input: [...config.capabilities.input],
-                    output: [...config.capabilities.output],
+                    tools: config.capabilities.tools ?? model.capabilities.tools,
+                    input: [...(config.capabilities.input ?? model.capabilities.input)],
+                    output: [...(config.capabilities.output ?? model.capabilities.output)],
                   }
                 }
                 if (config.request !== undefined) {

packages/core/src/config/provider.ts

@@ -44,11 +44,17 @@ const ModelApi = Schema.Union([
   }),
 ])
 
+class Capabilities extends Schema.Class<Capabilities>("ConfigV2.Model.Capabilities")({
+  tools: ModelV2.Capabilities.fields.tools.pipe(Schema.optional),
+  input: ModelV2.Capabilities.fields.input.pipe(Schema.optional),
+  output: ModelV2.Capabilities.fields.output.pipe(Schema.optional),
+}) {}
+
 class Model extends Schema.Class<Model>("ConfigV2.Model")({
   family: ModelV2.Family.pipe(Schema.optional),
   name: Schema.String.pipe(Schema.optional),
   api: ModelApi.pipe(Schema.optional),
-  capabilities: ModelV2.Capabilities.pipe(Schema.optional),
+  capabilities: Capabilities.pipe(Schema.optional),
   request: Schema.Struct({
     ...Request.fields,
     variant: Schema.String.pipe(Schema.optional),

packages/core/src/v1/config/migrate.ts

@@ -215,8 +215,23 @@ function migrateModel(info: typeof ConfigProviderV1.Model.Type, packageName?: st
       : []),
   ]
   const capabilities =
-    info.tool_call !== undefined || info.modalities?.input !== undefined || info.modalities?.output !== undefined
-      ? { tools: info.tool_call ?? false, input: info.modalities?.input ?? [], output: info.modalities?.output ?? [] }
+    info.attachment !== undefined ||
+    info.tool_call !== undefined ||
+    info.modalities?.input !== undefined ||
+    info.modalities?.output !== undefined
+      ? {
+          ...(info.tool_call === undefined ? {} : { tools: info.tool_call }),
+          ...(info.modalities?.input !== undefined
+            ? { input: info.modalities.input }
+            : info.attachment !== undefined
+              ? { input: info.attachment ? ["text", "image"] : ["text"] }
+              : {}),
+          ...(info.modalities?.output !== undefined
+            ? { output: info.modalities.output }
+            : info.attachment !== undefined
+              ? { output: ["text"] }
+              : {}),
+        }
       : undefined
   return {
     family: info.family,

packages/core/test/config/config.test.ts

@@ -116,6 +116,34 @@ describe("Config", () => {
     }),
   )
 
+  it.effect("migrates v1 custom model capability overrides without replacing unspecified fields", () =>
+    Effect.sync(() => {
+      const migrated = ConfigMigrateV1.migrate({
+        provider: {
+          custom: {
+            models: {
+              default: { tool_call: true },
+              text: { attachment: false },
+              explicit: { modalities: { input: ["audio"], output: ["audio"] } },
+            },
+          },
+        },
+      })
+
+      expect(migrated.providers?.custom?.models?.default?.capabilities).toEqual({
+        tools: true,
+      })
+      expect(migrated.providers?.custom?.models?.text?.capabilities).toEqual({
+        input: ["text"],
+        output: ["text"],
+      })
+      expect(migrated.providers?.custom?.models?.explicit?.capabilities).toEqual({
+        input: ["audio"],
+        output: ["audio"],
+      })
+    }),
+  )
+
   it.effect("migrates v1 command configuration", () =>
     Effect.sync(() => {
       expect(

packages/core/test/config/provider.test.ts

@@ -3,6 +3,7 @@ import { Effect, Schema } from "effect"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { Config } from "@opencode-ai/core/config"
 import { ConfigProviderPlugin } from "@opencode-ai/core/config/plugin/provider"
+import { ConfigMigrateV1 } from "@opencode-ai/core/v1/config/migrate"
 import { Integration } from "@opencode-ai/core/integration"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
@@ -244,7 +245,9 @@ describe("ConfigProviderPlugin.Plugin", () => {
 
         const provider = required(yield* catalog.provider.get(providerID))
         const model = required(yield* catalog.model.get(providerID, modelID))
-        expect((yield* catalog.model.default())?.id).toBe(ModelV2.ID.make("default"))
+        const defaultModel = required(yield* catalog.model.default())
+        expect(defaultModel.id).toBe(ModelV2.ID.make("default"))
+        expect(defaultModel.capabilities).toEqual({ tools: false, input: ["text", "image"], output: ["text"] })
         expect(provider.name).toBe("Renamed")
         expect((yield* integrations.get(Integration.ID.make("custom")))?.methods).toContainEqual({
           type: "env",
@@ -271,4 +274,67 @@ describe("ConfigProviderPlugin.Plugin", () => {
       }),
     ),
   )
+
+  it.effect("lowers a migrated attachment override into modalities", () =>
+    Effect.gen(function* () {
+      const catalog = yield* Catalog.Service
+      const providerID = ProviderV2.ID.make("custom")
+      const modelID = ModelV2.ID.make("chat")
+      yield* catalog.transform((catalog) =>
+        catalog.model.update(providerID, modelID, (model) => {
+          model.capabilities = { tools: true, input: ["text", "image", "audio"], output: ["text", "audio"] }
+        }),
+      )
+      const config = Config.Service.of({
+        entries: () =>
+          Effect.succeed([
+            new Config.Document({
+              type: "document",
+              info: decode(
+                ConfigMigrateV1.migrate({
+                  provider: { custom: { models: { chat: { attachment: false } } } },
+                }),
+              ),
+            }),
+          ]),
+      })
+
+      yield* addPlugin(config)
+
+      expect(required(yield* catalog.model.get(providerID, modelID)).capabilities).toEqual({
+        tools: true,
+        input: ["text"],
+        output: ["text"],
+      })
+    }),
+  )
+
+  it.effect("defaults a migrated custom model with attachment disabled to text only", () =>
+    Effect.gen(function* () {
+      const catalog = yield* Catalog.Service
+      const providerID = ProviderV2.ID.make("custom")
+      const modelID = ModelV2.ID.make("chat")
+      const config = Config.Service.of({
+        entries: () =>
+          Effect.succeed([
+            new Config.Document({
+              type: "document",
+              info: decode(
+                ConfigMigrateV1.migrate({
+                  provider: { custom: { models: { chat: { attachment: false } } } },
+                }),
+              ),
+            }),
+          ]),
+      })
+
+      yield* addPlugin(config)
+
+      expect(required(yield* catalog.model.get(providerID, modelID)).capabilities).toEqual({
+        tools: false,
+        input: ["text"],
+        output: ["text"],
+      })
+    }),
+  )
 })

packages/core/test/model.test.ts

@@ -21,3 +21,11 @@ describe("ModelV2.Ref", () => {
     })
   })
 })
+
+describe("ModelV2.Info", () => {
+  test("creates an empty model without modalities", () => {
+    const model = ModelV2.Info.empty(ProviderV2.ID.make("custom"), ModelV2.ID.make("model"))
+
+    expect(model.capabilities).toEqual({ tools: false, input: [], output: [] })
+  })
+})

packages/opencode/src/provider/provider.ts

@@ -1413,12 +1413,15 @@ export const layer = Layer.effect(
               capabilities: {
                 temperature: model.temperature ?? existingModel?.capabilities.temperature ?? false,
                 reasoning: model.reasoning ?? existingModel?.capabilities.reasoning ?? false,
-                attachment: model.attachment ?? existingModel?.capabilities.attachment ?? false,
+                attachment: model.attachment ?? existingModel?.capabilities.attachment ?? true,
                 toolcall: model.tool_call ?? existingModel?.capabilities.toolcall ?? true,
                 input: {
                   text: model.modalities?.input?.includes("text") ?? existingModel?.capabilities.input.text ?? true,
                   audio: model.modalities?.input?.includes("audio") ?? existingModel?.capabilities.input.audio ?? false,
-                  image: model.modalities?.input?.includes("image") ?? existingModel?.capabilities.input.image ?? false,
+                  image:
+                    model.modalities?.input?.includes("image") ??
+                    existingModel?.capabilities.input.image ??
+                    model.attachment !== false,
                   video: model.modalities?.input?.includes("video") ?? existingModel?.capabilities.input.video ?? false,
                   pdf: model.modalities?.input?.includes("pdf") ?? existingModel?.capabilities.input.pdf ?? false,
                 },

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

@@ -544,6 +544,46 @@ it.instance(
   },
 )
 
+it.instance(
+  "inherited modalities take precedence over attachment false",
+  Effect.gen(function* () {
+    yield* set("ANTHROPIC_API_KEY", "test-api-key")
+    const providers = yield* list
+    const model = providers[ProviderV2.ID.anthropic].models["claude-sonnet-4-20250514"]
+    expect(model.capabilities.attachment).toBe(false)
+    expect(model.capabilities.input.text).toBe(true)
+    expect(model.capabilities.input.image).toBe(true)
+    expect(model.capabilities.output.text).toBe(true)
+  }),
+  {
+    config: {
+      provider: { anthropic: { models: { "claude-sonnet-4-20250514": { attachment: false } } } },
+    },
+  },
+)
+
+it.instance(
+  "inherited modalities take precedence over attachment true",
+  Effect.gen(function* () {
+    const providers = yield* list
+    const model = providers[ProviderV2.ID.make("perplexity")].models.sonar
+    expect(model.capabilities.attachment).toBe(true)
+    expect(model.capabilities.input.text).toBe(true)
+    expect(model.capabilities.input.image).toBe(false)
+    expect(model.capabilities.output.text).toBe(true)
+  }),
+  {
+    config: {
+      provider: {
+        perplexity: {
+          env: [],
+          models: { sonar: { attachment: true } },
+        },
+      },
+    },
+  },
+)
+
 it.instance(
   "disabled_providers prevents loading even with env var",
   Effect.gen(function* () {
@@ -589,11 +629,13 @@ it.instance(
 )
 
 it.instance(
-  "model modalities default correctly",
+  "custom model media capabilities default correctly",
   Effect.gen(function* () {
     const providers = yield* list
     const model = providers[ProviderV2.ID.make("test-provider")].models["test-model"]
+    expect(model.capabilities.attachment).toBe(true)
     expect(model.capabilities.input.text).toBe(true)
+    expect(model.capabilities.input.image).toBe(true)
     expect(model.capabilities.output.text).toBe(true)
   }),
   {
@@ -611,6 +653,65 @@ it.instance(
   },
 )
 
+it.instance(
+  "custom model media capabilities can be disabled explicitly",
+  Effect.gen(function* () {
+    const providers = yield* list
+    const model = providers[ProviderV2.ID.make("test-provider")].models["test-model"]
+    expect(model.capabilities.attachment).toBe(false)
+    expect(model.capabilities.input.text).toBe(true)
+    expect(model.capabilities.input.image).toBe(false)
+  }),
+  {
+    config: {
+      provider: {
+        "test-provider": {
+          name: "Test",
+          npm: "@ai-sdk/openai-compatible",
+          env: [],
+          models: {
+            "test-model": {
+              name: "Test Model",
+              attachment: false,
+            },
+          },
+        },
+      },
+    },
+  },
+)
+
+it.instance(
+  "custom model explicit modalities override media defaults",
+  Effect.gen(function* () {
+    const providers = yield* list
+    const provider = providers[ProviderV2.ID.make("test-provider")]
+    const audio = provider.models.audio
+    expect(audio.capabilities.input.text).toBe(false)
+    expect(audio.capabilities.input.audio).toBe(true)
+    expect(audio.capabilities.input.image).toBe(false)
+    expect(audio.capabilities.output.audio).toBe(true)
+    const empty = provider.models.empty
+    expect(Object.values(empty.capabilities.input).some(Boolean)).toBe(false)
+    expect(Object.values(empty.capabilities.output).some(Boolean)).toBe(false)
+  }),
+  {
+    config: {
+      provider: {
+        "test-provider": {
+          name: "Test",
+          npm: "@ai-sdk/openai-compatible",
+          env: [],
+          models: {
+            audio: { modalities: { input: ["audio"], output: ["audio"] } },
+            empty: { modalities: { input: [], output: [] } },
+          },
+        },
+      },
+    },
+  },
+)
+
 it.instance(
   "model with custom cost values",
   Effect.gen(function* () {