chore(ai-openrouter): clarify changeset, tidy image error check, document common options

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: tombeckenham

.changeset/giant-garlics-crash.md

@@ -7,7 +7,7 @@
 - Derive `text-provider-options` types from the SDK's `ChatRequest` so provider options stay in lockstep with the SDK surface
 - Drop `topK` / `topA` / `minP` / `repetitionPenalty` / `includeReasoning` / `verbosity` / `webSearchOptions` from `OpenRouterBaseOptions` now that the SDK narrows `ChatRequest` to OpenAI-compatible fields — callers passing these previously saw them silently stripped at runtime, and now get a TypeScript error instead
 - Add those same keys to `excludedParams` in the model-catalog generator so future syncs don't reintroduce them
-- Add native structured output support using JSON Schema response formats
+- Switch `structuredOutput` to the SDK's native `responseFormat: { type: 'json_schema' }` instead of coercing the model via a forced `structured_output` tool call — the schema now flows straight to the provider, yielding cleaner responses and dropping the dummy-tool round-trip
 - Refactor options passthrough to use camelCase naming convention
 - Refresh the model catalog with the latest OpenRouter models (Opus 4.6, Sonnet 4.6, Gemini 3.1 Pro, etc.) and remove the deprecated `openrouter/auto` model
 - Unify the outbound request payload envelope

packages/typescript/ai-openrouter/src/adapters/image.ts

@@ -98,12 +98,13 @@ export class OpenRouterImageAdapter<
         },
       })
 
-      const maybeError = (response as { error?: unknown }).error
-      if (maybeError) {
+      // Check for error in response
+      if ('error' in response && response.error) {
+        const { error } = response
         const errorMsg =
-          typeof maybeError === 'object' && 'message' in maybeError
-            ? String((maybeError as { message: unknown }).message)
-            : String(maybeError)
+          typeof error === 'object' && 'message' in error
+            ? String(error.message)
+            : String(error)
         throw new Error(`Image generation failed: ${errorMsg}`)
       }
 

packages/typescript/ai-openrouter/src/text/text-provider-options.ts

@@ -57,7 +57,14 @@ export type OpenRouterCommonOptions = Pick<
   | 'parallelToolCalls'
   | 'modalities'
 > & {
+  /**
+   * A list of model IDs to use as fallbacks if the primary model is unavailable.
+   */
   models?: Array<OpenRouterChatModel>
+  /**
+   * The model variant to use, if supported by the model.
+   * Will be appended to the model ID.
+   */
   variant?: 'free' | 'nitro' | 'online' | 'exacto' | 'extended' | 'thinking'
 }