fix(provider): send Anthropic's dashed native slug through the AI Gateway (#44281)

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>

packages/opencode/src/provider/provider.ts

@@ -844,7 +844,12 @@ function custom(dep: CustomDep): Record<string, CustomLoader> {
           // The passthrough wrappers inject a CF_TEMP_TOKEN sentinel that the gateway strips before
           // dispatch, so upstream billing stays on the gateway (Unified Billing / stored BYOK).
           if (modelID.startsWith("openai/")) return aigateway(createOpenAI()(modelID.slice("openai/".length)))
-          if (modelID.startsWith("anthropic/")) return aigateway(createAnthropic()(modelID.slice("anthropic/".length)))
+          // models.dev lists Anthropic ids with dotted versions (claude-haiku-4.5); Anthropic's
+          // Messages API expects dashed native slugs (claude-haiku-4-5), so translate before passing.
+          // No native Anthropic slug contains a dot, so the blanket replacement is lossless here -
+          // unlike OpenAI above, whose native ids (e.g. gpt-4.1) keep their dots and must not be touched.
+          if (modelID.startsWith("anthropic/"))
+            return aigateway(createAnthropic()(modelID.slice("anthropic/".length).replaceAll(".", "-")))
           // Workers AI is the only first-party provider whose upstream is Cloudflare itself, so it is
           // the only one that should receive the Cloudflare token as its upstream Authorization header.
           // The Unified API addresses Workers AI both with the explicit "workers-ai/" prefix and as

packages/opencode/test/provider/cf-ai-gateway-e2e.test.ts

@@ -165,7 +165,8 @@ function extractUpstreamHeaders(body: unknown): Record<string, unknown> | undefi
 function gatewayModel(apiId: string, gatewayToken = "test") {
   const aigateway = createAiGateway({ accountId: "test", gateway: "test", apiKey: gatewayToken })
   if (apiId.startsWith("openai/")) return aigateway(createOpenAI()(apiId.slice("openai/".length)))
-  if (apiId.startsWith("anthropic/")) return aigateway(createAnthropic()(apiId.slice("anthropic/".length)))
+  if (apiId.startsWith("anthropic/"))
+    return aigateway(createAnthropic()(apiId.slice("anthropic/".length).replaceAll(".", "-")))
   const isWorkersAi = apiId.startsWith("workers-ai/") || apiId.startsWith("@cf/")
   const unified = createUnified(isWorkersAi ? { apiKey: gatewayToken } : {})
   return aigateway(unified(apiId))
@@ -195,6 +196,17 @@ describe("cf-ai-gateway routing", () => {
     expect(upstream?.model).toBe("claude-sonnet-4-6")
   })
 
+  test("anthropic/* with a dotted models.dev id reaches Anthropic as a dashed native slug", async () => {
+    // models.dev ids are dotted (claude-haiku-4.5); Anthropic's Messages API 404s unless the
+    // version is dashed (claude-haiku-4-5). Regression guard for the dotted-id translation.
+    await callThroughGateway("anthropic/claude-haiku-4.5", {})
+    const step = firstStep(captured?.outerBody)
+    expect(step?.provider).toBe("anthropic")
+    expect(step?.endpoint).toBe("v1/messages")
+    const upstream = extractUpstreamQuery(captured?.outerBody)
+    expect(upstream?.model).toBe("claude-haiku-4-5")
+  })
+
   test("workers-ai models stay on the unified /compat route", async () => {
     await callThroughGateway("workers-ai/@cf/moonshotai/kimi-k2.6", {})
     const step = firstStep(captured?.outerBody)