Merge pull request #2606 from RaviTharuma/fix/clamp-variant-on-non-opus-fallback

fix: clamp unsupported max variant for non-Opus Claude models

src/plugin/chat-params.test.ts

@@ -35,4 +35,37 @@ describe("createChatParamsHandler", () => {
     //#then
     expect(called).toBe(true)
   })
+
+  test("passes the original mutable message object to chat.params hooks", async () => {
+    //#given
+    const handler = createChatParamsHandler({
+      anthropicEffort: {
+        "chat.params": async (input) => {
+          input.message.variant = "high"
+        },
+      },
+    })
+
+    const message = { variant: "max" }
+    const input = {
+      sessionID: "ses_chat_params",
+      agent: { name: "sisyphus" },
+      model: { providerID: "opencode", modelID: "claude-sonnet-4-6" },
+      provider: { id: "opencode" },
+      message,
+    }
+
+    const output = {
+      temperature: 0.1,
+      topP: 1,
+      topK: 1,
+      options: {},
+    }
+
+    //#when
+    await handler(input, output)
+
+    //#then
+    expect(message.variant).toBe("high")
+  })
 })

src/plugin/chat-params.ts

@@ -6,6 +6,10 @@ export type ChatParamsInput = {
   message: { variant?: string }
 }
 
+type ChatParamsHookInput = ChatParamsInput & {
+  rawMessage?: Record<string, unknown>
+}
+
 export type ChatParamsOutput = {
   temperature?: number
   topP?: number
@@ -17,7 +21,7 @@ function isRecord(value: unknown): value is Record<string, unknown> {
   return typeof value === "object" && value !== null
 }
 
-function buildChatParamsInput(raw: unknown): ChatParamsInput | null {
+function buildChatParamsInput(raw: unknown): ChatParamsHookInput | null {
   if (!isRecord(raw)) return null
 
   const sessionID = raw.sessionID
@@ -56,7 +60,9 @@ function buildChatParamsInput(raw: unknown): ChatParamsInput | null {
     agent: { name: agentName },
     model: { providerID, modelID },
     provider: { id: providerId },
-    message: typeof variant === "string" ? { variant } : {},
+    message,
+    rawMessage: message,
+    ...(typeof variant === "string" ? {} : {}),
   }
 }
 
@@ -69,7 +75,7 @@ function isChatParamsOutput(raw: unknown): raw is ChatParamsOutput {
 }
 
 export function createChatParamsHandler(args: {
-  anthropicEffort: { "chat.params"?: (input: ChatParamsInput, output: ChatParamsOutput) => Promise<void> } | null
+  anthropicEffort: { "chat.params"?: (input: ChatParamsHookInput, output: ChatParamsOutput) => Promise<void> } | null
 }): (input: unknown, output: unknown) => Promise<void> {
   return async (input, output): Promise<void> => {
     const normalizedInput = buildChatParamsInput(input)