From 53248a05961c2c0faa5518bdb54eaa95a94c5295 Mon Sep 17 00:00:00 2001
From: Giorgos Giakoumettis <giorgos@yiakoumettis.gr>
Date: Tue, 22 Sep 2026 21:36:16 +0300
Subject: [PATCH 1/8] feat(providers): add Claude Opus 5.5 support

Register claude-opus-5-5 on the Anthropic API, Claude OAuth, Bedrock
(anthropic.claude-opus-5-5) and Vertex catalogs with native 1M context,
128K output and the five effort tiers. The model spec marks it
adaptive-only, rejecting disabled thinking and forced tool_choice, so the
existing normalizers strip thinking.type:"disabled", collapse manual
budgets and relax any/tool choices before dispatch.

Adds $4/$20 pricing (cache read $0.20, write $5), Opus 5 family
fallback, Fast Mode defaults, static discovery, and native-1M
recognition so the context-1m beta is never forwarded for it.
---
 config/quality/eslint-suppressions.json       |   5 -
 .../config/claudeCodeCompatibleIdentity.ts    |   2 +-
 .../providers/registry/anthropic/index.ts     |  11 ++
 .../providers/registry/bedrock/index.ts       |  11 ++
 .../config/providers/registry/claude/index.ts |  11 ++
 .../config/providers/registry/vertex/index.ts |   1 +
 .../registry/vertex/partner/index.ts          |   1 +
 open-sse/services/modelFamilyFallback.ts      |   1 +
 open-sse/services/providerCostData.ts         |   1 +
 src/lib/db/settings.ts                        |   1 +
 src/lib/providers/claudeFastMode.ts           |   1 +
 src/lib/providers/staticModels.ts             |   1 +
 src/shared/constants/modelSpecs.ts            |  15 ++
 src/shared/constants/pricing/frontier-labs.ts |   2 +
 .../constants/pricing/oauth-subscriptions.ts  |   2 +
 src/shared/constants/pricing/shared-tiers.ts  |   8 +
 tests/unit/claude-opus-5-5.test.ts            | 155 ++++++++++++++++++
 tests/unit/pricing-fallback.test.ts           |   2 +-
 18 files changed, 224 insertions(+), 7 deletions(-)
 create mode 100644 tests/unit/claude-opus-5-5.test.ts

diff --git a/config/quality/eslint-suppressions.json b/config/quality/eslint-suppressions.json
index 83a2feda4850..0bd67fd7dcef 100644
--- a/config/quality/eslint-suppressions.json
+++ b/config/quality/eslint-suppressions.json
@@ -24,11 +24,6 @@
       "count": 6
     }
   },
-  "open-sse/config/providers/registry/vertex/index.ts": {
-    "@typescript-eslint/no-unused-vars": {
-      "count": 1
-    }
-  },
   "open-sse/config/providers/shared.ts": {
     "@typescript-eslint/no-unused-vars": {
       "count": 1
diff --git a/open-sse/config/claudeCodeCompatibleIdentity.ts b/open-sse/config/claudeCodeCompatibleIdentity.ts
index 29f996278c2e..2b1bec402272 100644
--- a/open-sse/config/claudeCodeCompatibleIdentity.ts
+++ b/open-sse/config/claudeCodeCompatibleIdentity.ts
@@ -15,7 +15,7 @@ export const CLAUDE_CODE_COMPATIBLE_USER_AGENT = getClaudeCodeUserAgent("sdk-cli
 export { getClaudeCodeUserAgent };
 export const CLAUDE_CODE_COMPATIBLE_STAINLESS_PACKAGE_VERSION = CLAUDE_CODE_SDK_PACKAGE_VERSION;
 export const CLAUDE_CODE_COMPATIBLE_STAINLESS_RUNTIME_VERSION = CLAUDE_CODE_RUNTIME_VERSION;
-const CONTEXT_1M_NATIVE_MODELS = ["claude-fable-5-1", "claude-opus-5"];
+const CONTEXT_1M_NATIVE_MODELS = ["claude-fable-5-1", "claude-opus-5-5", "claude-opus-5"];
 
 export function modelHasNativeContext1m(model: string | null | undefined): boolean {
   const normalizedModel = String(model || "")
diff --git a/open-sse/config/providers/registry/anthropic/index.ts b/open-sse/config/providers/registry/anthropic/index.ts
index 2845296b15fa..e463aeb9e472 100644
--- a/open-sse/config/providers/registry/anthropic/index.ts
+++ b/open-sse/config/providers/registry/anthropic/index.ts
@@ -33,6 +33,17 @@ export const anthropicProvider: RegistryEntry = {
       contextLength: 1048576,
       unsupportedParams: ["temperature", "top_p", "top_k"],
     },
+    {
+      id: "claude-opus-5-5",
+      name: "Claude Opus 5.5",
+      contextLength: 1000000,
+      maxOutputTokens: 128000,
+      supportsReasoning: true,
+      supportedThinkingEfforts: ["low", "medium", "high", "xhigh", "max"],
+      supportsXHighEffort: true,
+      supportsVision: true,
+      unsupportedParams: ["temperature", "top_p", "top_k"],
+    },
     {
       id: "claude-opus-5",
       name: "Claude Opus 5",
diff --git a/open-sse/config/providers/registry/bedrock/index.ts b/open-sse/config/providers/registry/bedrock/index.ts
index ce70091a2776..c9dae4d55b5e 100644
--- a/open-sse/config/providers/registry/bedrock/index.ts
+++ b/open-sse/config/providers/registry/bedrock/index.ts
@@ -20,6 +20,17 @@ export const bedrockProvider: RegistryEntry = {
       contextLength: 1000000,
       maxOutputTokens: 128000,
     },
+    {
+      id: "anthropic.claude-opus-5-5",
+      name: "Claude Opus 5.5 (Bedrock)",
+      toolCalling: true,
+      supportsReasoning: true,
+      supportedThinkingEfforts: ["low", "medium", "high", "xhigh", "max"],
+      supportsXHighEffort: true,
+      supportsVision: true,
+      contextLength: 1000000,
+      maxOutputTokens: 128000,
+    },
     {
       id: "anthropic.claude-sonnet-4-6",
       name: "Claude Sonnet 4.6 (Bedrock)",
diff --git a/open-sse/config/providers/registry/claude/index.ts b/open-sse/config/providers/registry/claude/index.ts
index 83888123003b..8ff530bc5b75 100644
--- a/open-sse/config/providers/registry/claude/index.ts
+++ b/open-sse/config/providers/registry/claude/index.ts
@@ -47,6 +47,17 @@ export const claudeProvider: RegistryEntry = {
       // is fixed; reasoning is steered by output_config.effort). Strip them before dispatch.
       unsupportedParams: ["temperature", "top_p", "top_k"],
     },
+    {
+      id: "claude-opus-5-5",
+      name: "Claude Opus 5.5",
+      contextLength: 1000000,
+      maxOutputTokens: 128000,
+      supportsReasoning: true,
+      supportedThinkingEfforts: ["low", "medium", "high", "xhigh", "max"],
+      supportsXHighEffort: true,
+      supportsVision: true,
+      unsupportedParams: ["temperature", "top_p", "top_k"],
+    },
     {
       id: "claude-opus-5",
       name: "Claude Opus 5",
diff --git a/open-sse/config/providers/registry/vertex/index.ts b/open-sse/config/providers/registry/vertex/index.ts
index 1a8975e2e307..d896b94f8ebd 100644
--- a/open-sse/config/providers/registry/vertex/index.ts
+++ b/open-sse/config/providers/registry/vertex/index.ts
@@ -49,6 +49,7 @@ export const vertexProvider: RegistryEntry = {
     ...VERTEX_XAI_MODELS,
     { id: "claude-fable-5-1", name: "Claude Fable 5.1 (Vertex)", targetFormat: "claude" },
     { id: "claude-fable-5", name: "Claude Fable 5 (Vertex)", targetFormat: "claude" },
+    { id: "claude-opus-5-5", name: "Claude Opus 5.5 (Vertex)", targetFormat: "claude" },
     { id: "claude-opus-5", name: "Claude Opus 5 (Vertex)", targetFormat: "claude" },
     { id: "claude-sonnet-5", name: "Claude Sonnet 5 (Vertex)", targetFormat: "claude" },
     { id: "claude-opus-4-8", name: "Claude Opus 4.8 (Vertex)", targetFormat: "claude" },
diff --git a/open-sse/config/providers/registry/vertex/partner/index.ts b/open-sse/config/providers/registry/vertex/partner/index.ts
index 0ce2be94ac6c..e33ebaaf4ddf 100644
--- a/open-sse/config/providers/registry/vertex/partner/index.ts
+++ b/open-sse/config/providers/registry/vertex/partner/index.ts
@@ -21,6 +21,7 @@ export const vertex_partnerProvider: RegistryEntry = {
     ...VERTEX_XAI_MODELS,
     { id: "claude-fable-5-1", name: "Claude Fable 5.1", targetFormat: "claude" },
     { id: "claude-fable-5", name: "Claude Fable 5", targetFormat: "claude" },
+    { id: "claude-opus-5-5", name: "Claude Opus 5.5", targetFormat: "claude" },
     { id: "claude-opus-5", name: "Claude Opus 5", targetFormat: "claude" },
     { id: "claude-sonnet-5", name: "Claude Sonnet 5", targetFormat: "claude" },
     { id: "claude-opus-4-8", name: "Claude Opus 4.8", targetFormat: "claude" },
diff --git a/open-sse/services/modelFamilyFallback.ts b/open-sse/services/modelFamilyFallback.ts
index 6226c1217b04..d362485146ef 100644
--- a/open-sse/services/modelFamilyFallback.ts
+++ b/open-sse/services/modelFamilyFallback.ts
@@ -84,6 +84,7 @@ const FAMILY_FALLBACK_TEMPLATES: Record<string, readonly string[]> = {
   "claude-fable-5": ["claude-opus-4-8", "claude-opus-4-7", "claude-sonnet-5"],
 
   // Claude Opus family
+  "claude-opus-5-5": ["claude-opus-5", "claude-opus-4-8", "claude-sonnet-5"],
   "claude-opus-5": ["claude-opus-4-8", "claude-opus-4-7", "claude-sonnet-5"],
   "claude-opus-4-8": ["claude-opus-4-7", "claude-opus-4-6", "claude-sonnet-5"],
   "claude-opus-4-7": ["claude-opus-4-6", "claude-opus-4-5-20251101", "claude-sonnet-5"],
diff --git a/open-sse/services/providerCostData.ts b/open-sse/services/providerCostData.ts
index 675514d816eb..24e54bdd41f8 100644
--- a/open-sse/services/providerCostData.ts
+++ b/open-sse/services/providerCostData.ts
@@ -14,6 +14,7 @@ export const KNOWN_MODEL_PRICING: Record<string, ModelPricing> = {
   "gpt-4o-mini": { inputCostPer1M: 0.15, outputCostPer1M: 0.6, isFree: false },
   "claude-fable-5-1": { inputCostPer1M: 10.0, outputCostPer1M: 50.0, isFree: false },
   "claude-fable-5": { inputCostPer1M: 15.0, outputCostPer1M: 75.0, isFree: false },
+  "claude-opus-5-5": { inputCostPer1M: 4.0, outputCostPer1M: 20.0, isFree: false },
   "claude-opus-5": { inputCostPer1M: 5.0, outputCostPer1M: 25.0, isFree: false },
   "claude-opus-4-8": { inputCostPer1M: 15.0, outputCostPer1M: 75.0, isFree: false },
   "claude-opus-4-7": { inputCostPer1M: 15.0, outputCostPer1M: 75.0, isFree: false },
diff --git a/src/lib/db/settings.ts b/src/lib/db/settings.ts
index 448c38e6d7a9..1e1cca9168ee 100644
--- a/src/lib/db/settings.ts
+++ b/src/lib/db/settings.ts
@@ -210,6 +210,7 @@ export async function getSettings() {
       enabled: false,
       supportedModels: [
         "claude-fable-5",
+        "claude-opus-5-5",
         "claude-opus-5",
         "claude-opus-4-8",
         "claude-opus-4-7",
diff --git a/src/lib/providers/claudeFastMode.ts b/src/lib/providers/claudeFastMode.ts
index a007b2fee4f6..1f93be3ef23d 100644
--- a/src/lib/providers/claudeFastMode.ts
+++ b/src/lib/providers/claudeFastMode.ts
@@ -8,6 +8,7 @@ type JsonRecord = Record<string, unknown>;
  */
 export const CLAUDE_FAST_MODE_DEFAULT_MODELS = [
   "claude-fable-5",
+  "claude-opus-5-5",
   "claude-opus-5",
   "claude-opus-4-8",
   "claude-opus-4-7",
diff --git a/src/lib/providers/staticModels.ts b/src/lib/providers/staticModels.ts
index 5bb6598db5df..5d1e0fb83e2b 100644
--- a/src/lib/providers/staticModels.ts
+++ b/src/lib/providers/staticModels.ts
@@ -37,6 +37,7 @@ const STATIC_MODEL_PROVIDERS: Record<string, () => Array<{ id: string; name: str
   claude: () => [
     { id: "claude-fable-5-1", name: "Claude Fable 5.1" },
     { id: "claude-fable-5", name: "Claude Fable 5" },
+    { id: "claude-opus-5-5", name: "Claude Opus 5.5" },
     { id: "claude-opus-5", name: "Claude Opus 5" },
     { id: "claude-opus-4-8", name: "Claude Opus 4.8" },
     { id: "claude-opus-4-7", name: "Claude Opus 4.7" },
diff --git a/src/shared/constants/modelSpecs.ts b/src/shared/constants/modelSpecs.ts
index 3f84b77ef469..0b776a44673f 100644
--- a/src/shared/constants/modelSpecs.ts
+++ b/src/shared/constants/modelSpecs.ts
@@ -468,6 +468,21 @@ export const MODEL_SPECS: Record<string, ModelSpec> = {
     aliases: BEDROCK_CLAUDE_ALIASES("claude-fable-5"),
   },
 
+  // ── Claude Opus 5.5 ─────────────────────────────────────────────
+  "claude-opus-5-5": {
+    maxOutputTokens: 128000,
+    contextWindow: 1000000,
+    defaultThinkingBudget: 32000,
+    thinkingBudgetCap: 120000,
+    supportsThinking: true,
+    supportsTools: true,
+    supportsVision: true,
+    rejectsThinkingDisabled: true,
+    adaptiveThinkingOnly: true,
+    rejectsForcedToolChoice: true,
+    aliases: BEDROCK_CLAUDE_ALIASES("claude-opus-5-5"),
+  },
+
   // ── Claude Opus 5 ───────────────────────────────────────────────
   "claude-opus-5": {
     maxOutputTokens: 128000,
diff --git a/src/shared/constants/pricing/frontier-labs.ts b/src/shared/constants/pricing/frontier-labs.ts
index 0d6e0ce8878d..60608c515089 100644
--- a/src/shared/constants/pricing/frontier-labs.ts
+++ b/src/shared/constants/pricing/frontier-labs.ts
@@ -11,6 +11,7 @@ import {
   GPT_5_6_TERRA_PRICING,
   CLAUDE_FABLE_5_1_PRICING,
   CLAUDE_FABLE_5_PRICING,
+  CLAUDE_OPUS_5_5_PRICING,
   CLAUDE_OPUS_5_PRICING,
   CLAUDE_OPUS_4_PRICING,
   CLAUDE_SONNET_4_PRICING,
@@ -218,6 +219,7 @@ export const DEFAULT_PRICING_FRONTIER = {
     // to cover hyphen-notation IDs (claude-opus-4-6) used by some clients
     "claude-fable-5-1": CLAUDE_FABLE_5_1_PRICING,
     "claude-fable-5": CLAUDE_FABLE_5_PRICING,
+    "claude-opus-5-5": CLAUDE_OPUS_5_5_PRICING,
     "claude-opus-5": CLAUDE_OPUS_5_PRICING,
     "claude-sonnet-5": CLAUDE_SONNET_5_PRICING,
     "claude-opus-4.8": CLAUDE_OPUS_4_PRICING,
diff --git a/src/shared/constants/pricing/oauth-subscriptions.ts b/src/shared/constants/pricing/oauth-subscriptions.ts
index a6e68896ba3d..2a36c66eb80d 100644
--- a/src/shared/constants/pricing/oauth-subscriptions.ts
+++ b/src/shared/constants/pricing/oauth-subscriptions.ts
@@ -5,6 +5,7 @@
 import {
   GPT_6_ASTRA_PRICING,
   CLAUDE_FABLE_5_1_PRICING,
+  CLAUDE_OPUS_5_5_PRICING,
   CLAUDE_OPUS_5_PRICING,
   GEMINI_3_7_FLASH_PROMO_PRICING,
   GPT_5_3_CODEX_PRICING,
@@ -34,6 +35,7 @@ export const DEFAULT_PRICING_OAUTH = {
       reasoning: 50.0,
       cache_creation: 12.5,
     },
+    "claude-opus-5-5": CLAUDE_OPUS_5_5_PRICING,
     "claude-opus-5": CLAUDE_OPUS_5_PRICING,
     "claude-opus-4-8": {
       input: 5.0,
diff --git a/src/shared/constants/pricing/shared-tiers.ts b/src/shared/constants/pricing/shared-tiers.ts
index f6c0382ee4cc..f8f2f2aeaca0 100644
--- a/src/shared/constants/pricing/shared-tiers.ts
+++ b/src/shared/constants/pricing/shared-tiers.ts
@@ -78,6 +78,14 @@ export const CLAUDE_FABLE_5_1_PRICING = {
   cache_creation: 12.5,
 };
 
+export const CLAUDE_OPUS_5_5_PRICING = {
+  input: 4.0,
+  output: 20.0,
+  cached: 0.2,
+  reasoning: 20.0,
+  cache_creation: 5.0,
+};
+
 export const CLAUDE_OPUS_5_PRICING = {
   input: 5.0,
   output: 25.0,
diff --git a/tests/unit/claude-opus-5-5.test.ts b/tests/unit/claude-opus-5-5.test.ts
new file mode 100644
index 000000000000..d5ff4ffc0482
--- /dev/null
+++ b/tests/unit/claude-opus-5-5.test.ts
@@ -0,0 +1,155 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import {
+  getModelTargetFormat,
+  getModelsByProviderId,
+  supportsClaudeMaxEffort,
+  supportsXHighEffort,
+} from "../../open-sse/config/providerModels.ts";
+import {
+  getClaudeCodeDefaultModels,
+  getUnsupportedParams,
+} from "../../open-sse/config/providerRegistry.ts";
+import { modelHasNativeContext1m } from "../../open-sse/config/claudeCodeCompatibleIdentity.ts";
+import { modelSupportsContext1mBeta } from "../../open-sse/config/context1m.ts";
+import { normalizeClaudeAdaptiveThinking } from "../../open-sse/services/claudeAdaptiveThinking.ts";
+import { getNextFamilyFallback } from "../../open-sse/services/modelFamilyFallback.ts";
+import { getModelPricing } from "../../open-sse/services/providerCostData.ts";
+import { CLAUDE_FAST_MODE_DEFAULT_MODELS } from "../../src/lib/providers/claudeFastMode.ts";
+import { getStaticModelsForProvider } from "../../src/lib/providers/staticModels.ts";
+import { getDefaultPricing } from "../../src/shared/constants/pricing.ts";
+import {
+  getModelSpec,
+  normalizeForcedToolChoiceForModel,
+  normalizeThinkingForModel,
+} from "../../src/shared/constants/modelSpecs.ts";
+
+const MODEL_ID = "claude-opus-5-5";
+const BEDROCK_MODEL_ID = "anthropic.claude-opus-5-5";
+const EFFORTS = ["low", "medium", "high", "xhigh", "max"];
+
+test("Claude Opus 5.5 is registered only on verified launch surfaces", () => {
+  for (const [providerId, modelId] of [
+    ["anthropic", MODEL_ID],
+    ["claude", MODEL_ID],
+    ["bedrock", BEDROCK_MODEL_ID],
+    ["vertex", MODEL_ID],
+    ["vertex-partner", MODEL_ID],
+  ] as const) {
+    const model = getModelsByProviderId(providerId).find((entry) => entry.id === modelId);
+    assert.ok(model, `${providerId} must expose ${modelId}`);
+    if (providerId === "vertex" || providerId === "vertex-partner") {
+      assert.equal(model.targetFormat, "claude", `${providerId} wire format`);
+    } else {
+      assert.equal(model.contextLength, 1_000_000, `${providerId} context window`);
+      assert.equal(model.maxOutputTokens, 128_000, `${providerId} max output`);
+      assert.deepEqual(model.supportedThinkingEfforts, EFFORTS, `${providerId} effort levels`);
+    }
+  }
+
+  assert.equal(getModelTargetFormat("vertex", MODEL_ID), "claude");
+  assert.equal(getModelTargetFormat("vertex-partner", MODEL_ID), "claude");
+
+  for (const providerId of ["claude-web", "github", "ghe-copilot", "kiro", "cursor"]) {
+    const ids = new Set(getModelsByProviderId(providerId).map((entry) => entry.id));
+    assert.equal(ids.has(MODEL_ID), false, `${providerId} availability is not verified`);
+  }
+
+  assert.ok(
+    getStaticModelsForProvider("claude")?.some((entry) => entry.id === MODEL_ID),
+    "Claude OAuth static discovery must expose Opus 5.5"
+  );
+  assert.equal(getClaudeCodeDefaultModels().opus, MODEL_ID);
+  assert.equal(
+    getNextFamilyFallback(`claude/${MODEL_ID}`, new Set([`claude/${MODEL_ID}`])),
+    "claude/claude-opus-5"
+  );
+});
+
+test("Claude Opus 5.5 has native 1M context and always-on adaptive thinking", () => {
+  assert.equal(modelHasNativeContext1m(MODEL_ID), true);
+  assert.equal(modelHasNativeContext1m(BEDROCK_MODEL_ID), true);
+  assert.equal(modelSupportsContext1mBeta(MODEL_ID), false);
+
+  const spec = getModelSpec(MODEL_ID);
+  assert.notEqual(spec, getModelSpec("claude-opus-5"), "must not inherit the Opus 5 spec");
+  assert.equal(spec?.contextWindow, 1_000_000);
+  assert.equal(spec?.maxOutputTokens, 128_000);
+  assert.equal(spec?.supportsThinking, true);
+  assert.equal(spec?.supportsTools, true);
+  assert.equal(spec?.supportsVision, true);
+  assert.equal(spec?.adaptiveThinkingOnly, true);
+  assert.equal(spec?.rejectsThinkingDisabled, true);
+  assert.equal(spec?.rejectsForcedToolChoice, true);
+  assert.equal(spec?.maxEffortWhenThinkingDisabled, undefined);
+
+  assert.equal(getModelSpec(`global.${BEDROCK_MODEL_ID}`), spec);
+  assert.equal(supportsXHighEffort("claude", MODEL_ID), true);
+  assert.equal(supportsClaudeMaxEffort(MODEL_ID), true);
+});
+
+test("Claude Opus 5.5 strips unsupported sampling parameters", () => {
+  for (const providerId of ["anthropic", "claude"] as const) {
+    const unsupported = getUnsupportedParams(providerId, MODEL_ID);
+    for (const param of ["temperature", "top_p", "top_k"]) {
+      assert.ok(unsupported.includes(param), `${providerId}/${MODEL_ID} must strip ${param}`);
+    }
+  }
+});
+
+test("Claude Opus 5.5 drops disabled thinking and collapses manual budgets to adaptive", () => {
+  const withoutDisabled = normalizeThinkingForModel(
+    { model: MODEL_ID, thinking: { type: "disabled" }, output_config: { effort: "low" } },
+    MODEL_ID
+  );
+  assert.equal("thinking" in withoutDisabled, false);
+  assert.deepEqual(withoutDisabled.output_config, { effort: "low" });
+
+  const adaptive = normalizeClaudeAdaptiveThinking(
+    { model: MODEL_ID, thinking: { type: "enabled", budget_tokens: 64_000 } },
+    MODEL_ID
+  );
+  assert.deepEqual(adaptive.thinking, { type: "adaptive" });
+});
+
+test("Claude Opus 5.5 relaxes forced tool choices without removing tools", () => {
+  for (const toolChoice of [
+    "required",
+    { type: "any" },
+    { type: "tool", name: "read_file" },
+    { type: "function", function: { name: "read_file" } },
+  ]) {
+    const tools = [{ name: "read_file", input_schema: { type: "object" } }];
+    const result = normalizeForcedToolChoiceForModel(
+      { model: MODEL_ID, tools, tool_choice: toolChoice },
+      MODEL_ID
+    );
+    assert.equal("tool_choice" in result, false);
+    assert.equal(result.tools, tools);
+  }
+
+  const opus5 = { model: "claude-opus-5", tool_choice: { type: "tool", name: "read_file" } };
+  assert.equal(normalizeForcedToolChoiceForModel(opus5, "claude-opus-5"), opus5);
+});
+
+test("Claude Opus 5.5 is a Fast Mode default model", () => {
+  assert.ok((CLAUDE_FAST_MODE_DEFAULT_MODELS as readonly string[]).includes(MODEL_ID));
+});
+
+test("Claude Opus 5.5 pricing matches Anthropic's published rates", () => {
+  for (const providerId of ["anthropic", "cc"] as const) {
+    const price = getDefaultPricing()[providerId][MODEL_ID];
+    assert.equal(price.input, 4);
+    assert.equal(price.output, 20);
+    assert.equal(price.cached, 0.2);
+    assert.equal(price.reasoning, 20);
+    assert.equal(price.cache_creation, 5);
+  }
+
+  assert.deepEqual(getModelPricing("anthropic", MODEL_ID), {
+    inputCostPer1M: 4,
+    outputCostPer1M: 20,
+    isFree: false,
+  });
+});
diff --git a/tests/unit/pricing-fallback.test.ts b/tests/unit/pricing-fallback.test.ts
index 13e2f4fffca5..dce4790c7663 100644
--- a/tests/unit/pricing-fallback.test.ts
+++ b/tests/unit/pricing-fallback.test.ts
@@ -27,7 +27,7 @@ test("off-table paid model keeps the conservative fallback", () => {
 });
 
 test("table hits are untouched", () => {
-  assert.equal(Object.keys(KNOWN_MODEL_PRICING).length, 21);
+  assert.equal(Object.keys(KNOWN_MODEL_PRICING).length, 22);
   assert.deepEqual(getModelPricing("openai", "gpt-4o"), KNOWN_MODEL_PRICING["gpt-4o"]);
   assert.deepEqual(getModelPricing("longcat", "LongCat-2.0"), KNOWN_MODEL_PRICING["longcat-2.0"]);
 });

From 5f0ef1c30fb637967ed751a6ce1085307e43eca1 Mon Sep 17 00:00:00 2001
From: Giorgos Giakoumettis <giorgos@yiakoumettis.gr>
Date: Tue, 22 Sep 2026 21:37:50 +0300
Subject: [PATCH 2/8] docs(changelog): add Claude Opus 5.5 fragment

---
 changelog.d/features/14546-claude-opus-5-5.md | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/features/14546-claude-opus-5-5.md

diff --git a/changelog.d/features/14546-claude-opus-5-5.md b/changelog.d/features/14546-claude-opus-5-5.md
new file mode 100644
index 000000000000..f182293bfd0b
--- /dev/null
+++ b/changelog.d/features/14546-claude-opus-5-5.md
@@ -0,0 +1 @@
+- **feat(providers):** add Claude Opus 5.5 (`claude-opus-5-5`) to the Anthropic API, Claude OAuth, Bedrock and Vertex catalogs — native 1M context, 128K output, five effort tiers, $4/$20 pricing, Fast Mode, Opus 5 fallback; disabled thinking, manual budgets and forced `tool_choice` are normalized before dispatch since Opus 5.5 rejects them ([#14546](https://github.com/diegosouzapw/OmniRoute/pull/14546)).

From f76f1059e068cf961e1bb230ac02741883916803 Mon Sep 17 00:00:00 2001
From: Giorgos Giakoumettis <giorgos@yiakoumettis.gr>
Date: Tue, 22 Sep 2026 21:53:03 +0300
Subject: [PATCH 3/8] fix(providers): strip sampling params on Bedrock Opus 5.5
 and resolve claude-opus-5.5

Bedrock anthropic.claude-opus-5-5 now declares temperature/top_p/top_k as
unsupported, so the Converse translator no longer forwards them into a 400.
The Opus 5.5 spec gains a claude-opus-5.5 alias so dot-notation ids stop
prefix-matching the Opus 5 spec (which skipped the disabled-thinking and
forced tool_choice normalizers), and modelHasNativeContext1m folds dotted
versions before matching. The fast-mode test now asserts behavior instead
of list membership.
---
 .../config/claudeCodeCompatibleIdentity.ts    |  1 +
 .../providers/registry/bedrock/index.ts       |  1 +
 src/shared/constants/modelSpecs.ts            |  2 +-
 tests/unit/claude-opus-5-5.test.ts            | 36 +++++++++++++++----
 4 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/open-sse/config/claudeCodeCompatibleIdentity.ts b/open-sse/config/claudeCodeCompatibleIdentity.ts
index 2b1bec402272..757583d8cfda 100644
--- a/open-sse/config/claudeCodeCompatibleIdentity.ts
+++ b/open-sse/config/claudeCodeCompatibleIdentity.ts
@@ -22,6 +22,7 @@ export function modelHasNativeContext1m(model: string | null | undefined): boole
     .trim()
     .toLowerCase()
     .replace(/^.*?(?=claude-)/, "")
+    .replace(/(\d)\.(\d)/g, "$1-$2")
     .replace(/-\d{8}$/, "");
 
   return CONTEXT_1M_NATIVE_MODELS.some(
diff --git a/open-sse/config/providers/registry/bedrock/index.ts b/open-sse/config/providers/registry/bedrock/index.ts
index c9dae4d55b5e..6657bd994912 100644
--- a/open-sse/config/providers/registry/bedrock/index.ts
+++ b/open-sse/config/providers/registry/bedrock/index.ts
@@ -30,6 +30,7 @@ export const bedrockProvider: RegistryEntry = {
       supportsVision: true,
       contextLength: 1000000,
       maxOutputTokens: 128000,
+      unsupportedParams: ["temperature", "top_p", "top_k"],
     },
     {
       id: "anthropic.claude-sonnet-4-6",
diff --git a/src/shared/constants/modelSpecs.ts b/src/shared/constants/modelSpecs.ts
index 0b776a44673f..eb6175550d66 100644
--- a/src/shared/constants/modelSpecs.ts
+++ b/src/shared/constants/modelSpecs.ts
@@ -480,7 +480,7 @@ export const MODEL_SPECS: Record<string, ModelSpec> = {
     rejectsThinkingDisabled: true,
     adaptiveThinkingOnly: true,
     rejectsForcedToolChoice: true,
-    aliases: BEDROCK_CLAUDE_ALIASES("claude-opus-5-5"),
+    aliases: BEDROCK_CLAUDE_ALIASES("claude-opus-5-5", "claude-opus-5.5"),
   },
 
   // ── Claude Opus 5 ───────────────────────────────────────────────
diff --git a/tests/unit/claude-opus-5-5.test.ts b/tests/unit/claude-opus-5-5.test.ts
index d5ff4ffc0482..cd94195cfc5d 100644
--- a/tests/unit/claude-opus-5-5.test.ts
+++ b/tests/unit/claude-opus-5-5.test.ts
@@ -16,7 +16,7 @@ import { modelSupportsContext1mBeta } from "../../open-sse/config/context1m.ts";
 import { normalizeClaudeAdaptiveThinking } from "../../open-sse/services/claudeAdaptiveThinking.ts";
 import { getNextFamilyFallback } from "../../open-sse/services/modelFamilyFallback.ts";
 import { getModelPricing } from "../../open-sse/services/providerCostData.ts";
-import { CLAUDE_FAST_MODE_DEFAULT_MODELS } from "../../src/lib/providers/claudeFastMode.ts";
+import { shouldRequestClaudeFastMode } from "../../src/lib/providers/claudeFastMode.ts";
 import { getStaticModelsForProvider } from "../../src/lib/providers/staticModels.ts";
 import { getDefaultPricing } from "../../src/shared/constants/pricing.ts";
 import {
@@ -27,6 +27,7 @@ import {
 
 const MODEL_ID = "claude-opus-5-5";
 const BEDROCK_MODEL_ID = "anthropic.claude-opus-5-5";
+const DOT_MODEL_ID = "claude-opus-5.5";
 const EFFORTS = ["low", "medium", "high", "xhigh", "max"];
 
 test("Claude Opus 5.5 is registered only on verified launch surfaces", () => {
@@ -70,6 +71,7 @@ test("Claude Opus 5.5 is registered only on verified launch surfaces", () => {
 test("Claude Opus 5.5 has native 1M context and always-on adaptive thinking", () => {
   assert.equal(modelHasNativeContext1m(MODEL_ID), true);
   assert.equal(modelHasNativeContext1m(BEDROCK_MODEL_ID), true);
+  assert.equal(modelHasNativeContext1m(DOT_MODEL_ID), true);
   assert.equal(modelSupportsContext1mBeta(MODEL_ID), false);
 
   const spec = getModelSpec(MODEL_ID);
@@ -85,15 +87,20 @@ test("Claude Opus 5.5 has native 1M context and always-on adaptive thinking", ()
   assert.equal(spec?.maxEffortWhenThinkingDisabled, undefined);
 
   assert.equal(getModelSpec(`global.${BEDROCK_MODEL_ID}`), spec);
+  assert.equal(getModelSpec(DOT_MODEL_ID), spec, "dot notation must not prefix-match Opus 5");
   assert.equal(supportsXHighEffort("claude", MODEL_ID), true);
   assert.equal(supportsClaudeMaxEffort(MODEL_ID), true);
 });
 
 test("Claude Opus 5.5 strips unsupported sampling parameters", () => {
-  for (const providerId of ["anthropic", "claude"] as const) {
-    const unsupported = getUnsupportedParams(providerId, MODEL_ID);
+  for (const [providerId, modelId] of [
+    ["anthropic", MODEL_ID],
+    ["claude", MODEL_ID],
+    ["bedrock", BEDROCK_MODEL_ID],
+  ] as const) {
+    const unsupported = getUnsupportedParams(providerId, modelId);
     for (const param of ["temperature", "top_p", "top_k"]) {
-      assert.ok(unsupported.includes(param), `${providerId}/${MODEL_ID} must strip ${param}`);
+      assert.ok(unsupported.includes(param), `${providerId}/${modelId} must strip ${param}`);
     }
   }
 });
@@ -106,6 +113,12 @@ test("Claude Opus 5.5 drops disabled thinking and collapses manual budgets to ad
   assert.equal("thinking" in withoutDisabled, false);
   assert.deepEqual(withoutDisabled.output_config, { effort: "low" });
 
+  const dotWithoutDisabled = normalizeThinkingForModel(
+    { model: DOT_MODEL_ID, thinking: { type: "disabled" } },
+    DOT_MODEL_ID
+  );
+  assert.equal("thinking" in dotWithoutDisabled, false);
+
   const adaptive = normalizeClaudeAdaptiveThinking(
     { model: MODEL_ID, thinking: { type: "enabled", budget_tokens: 64_000 } },
     MODEL_ID
@@ -133,8 +146,19 @@ test("Claude Opus 5.5 relaxes forced tool choices without removing tools", () =>
   assert.equal(normalizeForcedToolChoiceForModel(opus5, "claude-opus-5"), opus5);
 });
 
-test("Claude Opus 5.5 is a Fast Mode default model", () => {
-  assert.ok((CLAUDE_FAST_MODE_DEFAULT_MODELS as readonly string[]).includes(MODEL_ID));
+test("Claude Opus 5.5 requests Fast Mode when the toggle is on", () => {
+  assert.equal(shouldRequestClaudeFastMode({ claudeFastMode: { enabled: true } }, MODEL_ID), true);
+  assert.equal(
+    shouldRequestClaudeFastMode({ claudeFastMode: { enabled: false } }, MODEL_ID),
+    false
+  );
+  assert.equal(
+    shouldRequestClaudeFastMode(
+      { claudeFastMode: { enabled: true, supportedModels: [MODEL_ID] } },
+      "claude-opus-5"
+    ),
+    false
+  );
 });
 
 test("Claude Opus 5.5 pricing matches Anthropic's published rates", () => {

From 785b5ce261ef95333210c62ca20095b401ddac41 Mon Sep 17 00:00:00 2001
From: Giorgos Giakoumettis <giorgos@yiakoumettis.gr>
Date: Tue, 22 Sep 2026 22:46:31 +0300
Subject: [PATCH 4/8] fix(providers): bump Claude Code wire identity to 2.1.280
 for Opus 5.5

Anthropic's OAuth endpoint rejects claude-opus-5-5 with
"Claude Code 2.1.258 does not support this model; version 2.1.280 or
newer is required". Values were captured from the real 2.1.280 CLI via a
loopback listener: the version and billing revision (d7b) change; the
Stainless package (0.112.1) and runtime (v26.3.0) are unchanged. The Devin
bridge image pin stays at 2.1.258 until it is live-validated.
---
 .env.example                                  |  2 +-
 .../maintenance/14546-claude-code-2-1-280.md  |  1 +
 docs/providers/AGENTROUTER.md                 |  2 +-
 docs/reference/ENVIRONMENT.md                 |  4 ++--
 docs/security/STEALTH_GUIDE.md                |  4 ++--
 src/shared/constants/claudeCodeClient.ts      |  9 +++++---
 tests/snapshots/provider/translate-path.json  | 12 +++++-----
 .../unit/anthropic-cache-fingerprint.test.ts  |  2 +-
 tests/unit/cc-bridge-transforms.test.ts       |  2 +-
 ...claude-codex-identity-version-sync.test.ts | 22 +++++++------------
 .../unit/cli-client-version-env-12417.test.ts |  4 ++--
 tests/unit/client-identity-profiles.test.ts   |  6 ++---
 tests/unit/executor-default-base.test.ts      |  2 +-
 tests/unit/glm-executor.test.ts               |  2 +-
 tests/unit/system-transforms.test.ts          |  2 +-
 15 files changed, 37 insertions(+), 39 deletions(-)
 create mode 100644 changelog.d/maintenance/14546-claude-code-2-1-280.md

diff --git a/.env.example b/.env.example
index 5f52deb964ec..39ad41fbe319 100644
--- a/.env.example
+++ b/.env.example
@@ -1442,7 +1442,7 @@ GITHUB_OAUTH_CLIENT_ID=Iv1.b507a08c87ecfe98
 # Used by: open-sse/executors/base.ts — buildHeaders() dynamic lookup.
 # Update these when providers release new CLI versions to avoid blocks.
 
-CLAUDE_USER_AGENT="claude-cli/2.1.258 (external, cli)"
+CLAUDE_USER_AGENT="claude-cli/2.1.280 (external, cli)"
 
 # Disable the deterministic tool-name cloak applied on both Anthropic-bound paths
 # (executors/base.ts native OAuth + executors/cliproxyapi.ts CLIProxyAPI) —
diff --git a/changelog.d/maintenance/14546-claude-code-2-1-280.md b/changelog.d/maintenance/14546-claude-code-2-1-280.md
new file mode 100644
index 000000000000..b07e55ce456b
--- /dev/null
+++ b/changelog.d/maintenance/14546-claude-code-2-1-280.md
@@ -0,0 +1 @@
+- **chore(providers):** bump the Claude Code wire identity from `2.1.258` to `2.1.280` (billing revision `d7b`, captured from the real CLI) — Anthropic gates Claude Opus 5.5 behind Claude Code `>= 2.1.280` on the OAuth path ([#14546](https://github.com/diegosouzapw/OmniRoute/pull/14546))
diff --git a/docs/providers/AGENTROUTER.md b/docs/providers/AGENTROUTER.md
index ea375f43c936..2561e35b0201 100644
--- a/docs/providers/AGENTROUTER.md
+++ b/docs/providers/AGENTROUTER.md
@@ -130,7 +130,7 @@ request (see `open-sse/services/claudeCodeCompatible.ts`):
 | Header                                      | Value                                                                                                   |
 | ------------------------------------------- | ------------------------------------------------------------------------------------------------------- |
 | `Authorization`                             | `Bearer <api-key>`                                                                                      |
-| `User-Agent`                                | `claude-cli/2.1.258 (external, sdk-cli)`                                                                |
+| `User-Agent`                                | `claude-cli/2.1.280 (external, sdk-cli)`                                                                |
 | `anthropic-version`                         | `2023-06-01`                                                                                            |
 | `anthropic-beta`                            | `claude-code-20250219,interleaved-thinking-2025-05-14,effort-2025-11-24`                                |
 | Per-connection redact-thinking beta toggle  | Adds `redact-thinking-2026-02-12` for upstreams that specifically require redacted thinking streams     |
diff --git a/docs/reference/ENVIRONMENT.md b/docs/reference/ENVIRONMENT.md
index 931fda33c22b..9c73ae478e88 100644
--- a/docs/reference/ENVIRONMENT.md
+++ b/docs/reference/ENVIRONMENT.md
@@ -656,11 +656,11 @@ process.env[`${PROVIDER_ID}_USER_AGENT`]
 
 | Variable                         | Default Value                                 | When to Update                                                                                   |
 | -------------------------------- | --------------------------------------------- | ------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
-| `CLAUDE_USER_AGENT`              | `claude-cli/2.1.258 (external, cli)`          | When Anthropic releases a new CLI version                                                        |
+| `CLAUDE_USER_AGENT`              | `claude-cli/2.1.280 (external, cli)`          | When Anthropic releases a new CLI version                                                        |
 | `CLAUDE_DISABLE_TOOL_NAME_CLOAK` | `false`                                       | `executors/base.ts` + `executors/cliproxyapi.ts`                                                 | Set to `1`/`true` to forward third-party harness tool names verbatim to Anthropic on both Anthropic-bound paths (native OAuth and CLIProxyAPI). By default the executor deterministically aliases non-Claude-Code tool names (Claude Code canonical mapping where one exists, otherwise PascalCase) and reverses them on the response via `_toolNameMap`, so harnesses with snake_case tools are not refused as fingerprinted third-party clients. Debugging only. |
 | `CODEX_USER_AGENT`               | `codex-cli/0.155.0 (Windows 10.0.26200; x64)` | When OpenAI updates the Codex CLI                                                                |
 | `CODEX_CLIENT_VERSION`           | `0.155.0`                                     | Override Codex client version independently of full UA string                                    |
-| `CLAUDE_CODE_CLIENT_VERSION`     | `2.1.258`                                     | Override advertised Claude Code version independently of `CLAUDE_USER_AGENT`. Anthropic gates some models on this value (#12417). |
+| `CLAUDE_CODE_CLIENT_VERSION`     | `2.1.280`                                     | Override advertised Claude Code version independently of `CLAUDE_USER_AGENT`. Anthropic gates some models on this value (#12417). |
 | `GITHUB_COPILOT_CLI_VERSION`     | `1.0.81-6`                                    | Override advertised Copilot CLI version independently of `GITHUB_USER_AGENT`                     |
 | `GITHUB_USER_AGENT`              | `GitHubCopilotChat/0.54.0`                    | When GitHub Copilot Chat updates                                                                 |
 | `ANTIGRAVITY_USER_AGENT`         | `antigravity/2.0.1 darwin/arm64`              | When Antigravity IDE updates                                                                     |
diff --git a/docs/security/STEALTH_GUIDE.md b/docs/security/STEALTH_GUIDE.md
index 93aef78aba61..419e6568cb55 100644
--- a/docs/security/STEALTH_GUIDE.md
+++ b/docs/security/STEALTH_GUIDE.md
@@ -124,7 +124,7 @@ Applied to: `system` blocks, all `messages[].content`, and `tools[].description`
 
 For third-party Anthropic relays that only accept "real Claude Code" traffic:
 
-- `CLAUDE_CODE_COMPATIBLE_USER_AGENT = "claude-cli/2.1.258 (external, sdk-cli)"`
+- `CLAUDE_CODE_COMPATIBLE_USER_AGENT = "claude-cli/2.1.280 (external, sdk-cli)"`
 - `CLAUDE_CODE_COMPATIBLE_STAINLESS_PACKAGE_VERSION = "0.112.1"`
 - `CLAUDE_CODE_COMPATIBLE_STAINLESS_RUNTIME_VERSION = "v26.3.0"`
 - `anthropic-beta = "claude-code-20250219,interleaved-thinking-2025-05-14,effort-2025-11-24"` by default
@@ -248,7 +248,7 @@ All MITM endpoints require management auth (`requireCliToolsAuth`). The sudo pas
 
 | Variable                 | Default                                                         |
 | ------------------------ | --------------------------------------------------------------- |
-| `CLAUDE_USER_AGENT`      | `claude-cli/2.1.258 (external, cli)`                            |
+| `CLAUDE_USER_AGENT`      | `claude-cli/2.1.280 (external, cli)`                            |
 | `CODEX_USER_AGENT`       | `codex-cli/0.155.0 (Windows 10.0.26200; x64)`                   |
 | `GITHUB_USER_AGENT`      | `GitHubCopilotChat/0.54.0`                                      |
 | `ANTIGRAVITY_USER_AGENT` | `antigravity/2.0.1 linux/arm64 google-api-nodejs-client/10.3.0` |
diff --git a/src/shared/constants/claudeCodeClient.ts b/src/shared/constants/claudeCodeClient.ts
index 50be40b7404c..52b1854e1996 100644
--- a/src/shared/constants/claudeCodeClient.ts
+++ b/src/shared/constants/claudeCodeClient.ts
@@ -8,8 +8,8 @@
  * advertise the version on the wire must go through getClaudeCodeClientVersion()
  * so operators can bump past Anthropic's model gate without a rebuild (#12417).
  */
-export const CLAUDE_CODE_CLIENT_VERSION = "2.1.258";
-export const CLAUDE_CODE_CLIENT_BUILD_REVISION = "1e2";
+export const CLAUDE_CODE_CLIENT_VERSION = "2.1.280";
+export const CLAUDE_CODE_CLIENT_BUILD_REVISION = "d7b";
 export const CLAUDE_CODE_CLIENT_BILLING_VERSION = `${CLAUDE_CODE_CLIENT_VERSION}.${CLAUDE_CODE_CLIENT_BUILD_REVISION}`;
 export const CLAUDE_CODE_SDK_PACKAGE_VERSION = "0.112.1";
 export const CLAUDE_CODE_RUNTIME_VERSION = "v26.3.0";
@@ -30,7 +30,10 @@ function getSafeEnvValue(name: string, pattern: RegExp): string | null {
 }
 
 export function getClaudeCodeClientVersion(): string {
-  return getSafeEnvValue(CLAUDE_VERSION_OVERRIDE_ENV, SAFE_HEADER_TOKEN_PATTERN) || CLAUDE_CODE_CLIENT_VERSION;
+  return (
+    getSafeEnvValue(CLAUDE_VERSION_OVERRIDE_ENV, SAFE_HEADER_TOKEN_PATTERN) ||
+    CLAUDE_CODE_CLIENT_VERSION
+  );
 }
 
 export function getClaudeCodeClientBillingVersion(): string {
diff --git a/tests/snapshots/provider/translate-path.json b/tests/snapshots/provider/translate-path.json
index 217ee8166f5b..c84a90b65a06 100644
--- a/tests/snapshots/provider/translate-path.json
+++ b/tests/snapshots/provider/translate-path.json
@@ -28,7 +28,7 @@
       "apiKey": {
         "Accept": "text/event-stream",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.258 (external, sdk-cli)",
+        "User-Agent": "claude-cli/2.1.280 (external, sdk-cli)",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Lang": "js",
         "X-Stainless-OS": "MacOS",
@@ -47,7 +47,7 @@
       "nonStream": {
         "Accept": "application/json",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.258 (external, sdk-cli)",
+        "User-Agent": "claude-cli/2.1.280 (external, sdk-cli)",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Lang": "js",
         "X-Stainless-OS": "MacOS",
@@ -66,7 +66,7 @@
       "oauth": {
         "Accept": "text/event-stream",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.258 (external, sdk-cli)",
+        "User-Agent": "claude-cli/2.1.280 (external, sdk-cli)",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Lang": "js",
         "X-Stainless-OS": "MacOS",
@@ -1012,7 +1012,7 @@
         "Anthropic-Dangerous-Direct-Browser-Access": "true",
         "Anthropic-Version": "2023-06-01",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.258 (external, cli)",
+        "User-Agent": "claude-cli/2.1.280 (external, cli)",
         "X-App": "cli",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Helper-Method": "stream",
@@ -1030,7 +1030,7 @@
         "Anthropic-Dangerous-Direct-Browser-Access": "true",
         "Anthropic-Version": "2023-06-01",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.258 (external, cli)",
+        "User-Agent": "claude-cli/2.1.280 (external, cli)",
         "X-App": "cli",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Helper-Method": "stream",
@@ -1049,7 +1049,7 @@
         "Anthropic-Dangerous-Direct-Browser-Access": "true",
         "Anthropic-Version": "2023-06-01",
         "Content-Type": "application/json",
-        "User-Agent": "claude-cli/2.1.258 (external, cli)",
+        "User-Agent": "claude-cli/2.1.280 (external, cli)",
         "X-App": "cli",
         "X-Stainless-Arch": "<ARCH>",
         "X-Stainless-Helper-Method": "stream",
diff --git a/tests/unit/anthropic-cache-fingerprint.test.ts b/tests/unit/anthropic-cache-fingerprint.test.ts
index 59c736a63c50..743710d98dac 100644
--- a/tests/unit/anthropic-cache-fingerprint.test.ts
+++ b/tests/unit/anthropic-cache-fingerprint.test.ts
@@ -5,6 +5,6 @@ import { CLAUDE_CODE_CLIENT_BILLING_VERSION } from "../../src/shared/constants/c
 
 describe("Anthropic billing header fingerprint (#1638)", () => {
   it("uses the immutable build revision captured from the signed CLI", () => {
-    assert.equal(CLAUDE_CODE_CLIENT_BILLING_VERSION, "2.1.258.1e2");
+    assert.equal(CLAUDE_CODE_CLIENT_BILLING_VERSION, "2.1.280.d7b");
   });
 });
diff --git a/tests/unit/cc-bridge-transforms.test.ts b/tests/unit/cc-bridge-transforms.test.ts
index cbaf19c50af1..2d3136b118d3 100644
--- a/tests/unit/cc-bridge-transforms.test.ts
+++ b/tests/unit/cc-bridge-transforms.test.ts
@@ -52,7 +52,7 @@ test("DEFAULT_CC_BRIDGE_PIPELINE places billing header at [0] and identity at [1
     DEFAULT_CC_BRIDGE_PIPELINE
   );
   const blocks = result.body.system as any[];
-  assert.ok(blocks[0].text.startsWith("x-anthropic-billing-header: cc_version=2.1.258.1e2;"));
+  assert.ok(blocks[0].text.startsWith("x-anthropic-billing-header: cc_version=2.1.280.d7b;"));
   assert.equal(blocks[1].text, CLAUDE_AGENT_SDK_IDENTITY);
 });
 
diff --git a/tests/unit/claude-codex-identity-version-sync.test.ts b/tests/unit/claude-codex-identity-version-sync.test.ts
index b59f90a01c37..ed0b13fc2e0f 100644
--- a/tests/unit/claude-codex-identity-version-sync.test.ts
+++ b/tests/unit/claude-codex-identity-version-sync.test.ts
@@ -40,10 +40,10 @@ test("Claude CLI version constants are in lockstep across all 4 sources", () =>
   );
 });
 
-test("Claude CLI wire versions match the captured 2.1.258 binary", () => {
-  assert.equal(canonical.CLAUDE_CODE_CLIENT_VERSION, "2.1.258");
-  assert.equal(canonical.CLAUDE_CODE_CLIENT_BUILD_REVISION, "1e2");
-  assert.equal(canonical.CLAUDE_CODE_CLIENT_BILLING_VERSION, "2.1.258.1e2");
+test("Claude CLI wire versions match the captured 2.1.280 binary", () => {
+  assert.equal(canonical.CLAUDE_CODE_CLIENT_VERSION, "2.1.280");
+  assert.equal(canonical.CLAUDE_CODE_CLIENT_BUILD_REVISION, "d7b");
+  assert.equal(canonical.CLAUDE_CODE_CLIENT_BILLING_VERSION, "2.1.280.d7b");
   assert.equal(canonical.CLAUDE_CODE_SDK_PACKAGE_VERSION, "0.112.1");
   assert.equal(canonical.CLAUDE_CODE_RUNTIME_VERSION, "v26.3.0");
   assert.equal(
@@ -94,10 +94,7 @@ test("Codex client version locksteps Dockerfile @openai/codex", () => {
   assert.equal(codexCfg.DEFAULT_CODEX_CLIENT_VERSION, pinned);
   assert.equal(codexCfg.getCodexClientVersion(), pinned);
   assert.equal(codexCfg.getCodexDefaultHeaders().Version, pinned);
-  assert.equal(
-    codexCfg.getCodexCliRsHeaders()["User-Agent"],
-    `codex_cli_rs/${pinned}`,
-  );
+  assert.equal(codexCfg.getCodexCliRsHeaders()["User-Agent"], `codex_cli_rs/${pinned}`);
 });
 
 test("Codex client version env override still wins", async () => {
@@ -110,7 +107,7 @@ test("Codex client version env override still wins", async () => {
 test("test 7: live-empty GitHub catalog path does not call persist", () => {
   const src = fs.readFileSync(
     path.join(process.cwd(), "src/app/api/providers/[id]/models/route.ts"),
-    "utf8",
+    "utf8"
   );
   // The githubCatalogModels fallback must use buildResponse, not buildApiDiscoveryResponse.
   const idx = src.indexOf("Codex live catalog unavailable — using GitHub model catalog");
@@ -137,16 +134,13 @@ test("Codex client version locksteps Dockerfile @openai/codex and env override",
   assert.equal(codexCfg.DEFAULT_CODEX_CLIENT_VERSION, pinned);
   assert.equal(codexCfg.getCodexClientVersion(), pinned);
   assert.equal(codexCfg.getCodexDefaultHeaders().Version, pinned);
-  assert.equal(
-    codexCfg.getCodexCliRsHeaders()["User-Agent"],
-    `codex_cli_rs/${pinned}`,
-  );
+  assert.equal(codexCfg.getCodexCliRsHeaders()["User-Agent"], `codex_cli_rs/${pinned}`);
 });
 
 test("test 7: live-empty GitHub catalog path does not call persist", () => {
   const src = fs.readFileSync(
     path.join(process.cwd(), "src/app/api/providers/[id]/models/route.ts"),
-    "utf8",
+    "utf8"
   );
   // The githubCatalogModels fallback must use buildResponse, not buildApiDiscoveryResponse.
   const idx = src.indexOf("Codex live catalog unavailable — using GitHub model catalog");
diff --git a/tests/unit/cli-client-version-env-12417.test.ts b/tests/unit/cli-client-version-env-12417.test.ts
index bc28100be934..3a4a424af4fb 100644
--- a/tests/unit/cli-client-version-env-12417.test.ts
+++ b/tests/unit/cli-client-version-env-12417.test.ts
@@ -40,8 +40,8 @@ async function withEnv<T>(
   }
 }
 
-test("#12417 Claude pin stays the captured 2.1.258 binary", () => {
-  assert.equal(canonical.CLAUDE_CODE_CLIENT_VERSION, "2.1.258");
+test("#12417 Claude pin stays the captured 2.1.280 binary", () => {
+  assert.equal(canonical.CLAUDE_CODE_CLIENT_VERSION, "2.1.280");
 });
 
 test("#12417 getClaudeCodeClientVersion falls back to the captured pin", async () => {
diff --git a/tests/unit/client-identity-profiles.test.ts b/tests/unit/client-identity-profiles.test.ts
index 698b6d60ea0e..07470cf682b9 100644
--- a/tests/unit/client-identity-profiles.test.ts
+++ b/tests/unit/client-identity-profiles.test.ts
@@ -40,7 +40,7 @@ test("getClientIdentityProfileHeaders: unknown profile id falls back to no heade
 
 test("getClientIdentityProfileHeaders: known CLI profiles expose their preset headers", () => {
   const claudeCli = getClientIdentityProfileHeaders("claude-cli");
-  assert.equal(claudeCli["User-Agent"], "claude-cli/2.1.258 (external, cli)");
+  assert.equal(claudeCli["User-Agent"], "claude-cli/2.1.280 (external, cli)");
   assert.equal(claudeCli["X-App"], "cli");
 
   const codexCli = getClientIdentityProfileHeaders("codex-cli");
@@ -56,7 +56,7 @@ test("getClientIdentityProfileHeaders: returns a fresh mutable copy (catalog sta
   headers["User-Agent"] = "tampered";
   assert.equal(
     CLIENT_IDENTITY_PROFILES["claude-cli"].headers["User-Agent"],
-    "claude-cli/2.1.258 (external, cli)"
+    "claude-cli/2.1.280 (external, cli)"
   );
 });
 
@@ -104,7 +104,7 @@ test("profile headers merged into customHeaders survive applyCustomHeaders sanit
     true
   ) as Record<string, string>;
 
-  assert.equal(headers["User-Agent"], "claude-cli/2.1.258 (external, cli)");
+  assert.equal(headers["User-Agent"], "claude-cli/2.1.280 (external, cli)");
   assert.equal(headers["X-App"], "cli");
   assert.equal(headers["Authorization"], "Bearer test-key");
 });
diff --git a/tests/unit/executor-default-base.test.ts b/tests/unit/executor-default-base.test.ts
index 25d5a8bda2b6..b5ae57ef30c3 100644
--- a/tests/unit/executor-default-base.test.ts
+++ b/tests/unit/executor-default-base.test.ts
@@ -1575,7 +1575,7 @@ test("DefaultExecutor.execute does not produce duplicate anthropic-version heade
   const sentBody = JSON.parse(capturedBody) as { system?: Array<{ text?: string }> };
   assert.match(
     sentBody.system?.[0]?.text ?? "",
-    /^x-anthropic-billing-header: cc_version=2\.1\.258\.1e2; cc_entrypoint=cli; cch=[0-9a-f]{5};$/
+    /^x-anthropic-billing-header: cc_version=2\.1\.280\.d7b; cc_entrypoint=cli; cch=[0-9a-f]{5};$/
   );
 });
 
diff --git a/tests/unit/glm-executor.test.ts b/tests/unit/glm-executor.test.ts
index 26ef4f8526ba..a34b698ccef8 100644
--- a/tests/unit/glm-executor.test.ts
+++ b/tests/unit/glm-executor.test.ts
@@ -183,7 +183,7 @@ test("GlmExecutor separates OpenAI-compatible coding headers from Anthropic head
   assert.equal(anthropicHeaders["anthropic-version"], "2023-06-01");
   assert.match(anthropicHeaders["anthropic-beta"], /claude-code-20250219/);
   assert.equal(anthropicHeaders["anthropic-dangerous-direct-browser-access"], "true");
-  assert.match(anthropicHeaders["User-Agent"], /^claude-cli\/2\.1\.258 \(external, sdk-cli\)$/);
+  assert.match(anthropicHeaders["User-Agent"], /^claude-cli\/2\.1\.280 \(external, sdk-cli\)$/);
   assert.equal(anthropicHeaders["X-Stainless-Lang"], "js");
   assert.equal(anthropicHeaders["X-Stainless-Runtime"], "node");
 });
diff --git a/tests/unit/system-transforms.test.ts b/tests/unit/system-transforms.test.ts
index e5683766eb96..c9eba1e0da7e 100644
--- a/tests/unit/system-transforms.test.ts
+++ b/tests/unit/system-transforms.test.ts
@@ -559,7 +559,7 @@ const UI_DEFAULTS_SNAPSHOT = {
           entrypoint: "sdk-cli",
           versionFormat: "ex-machina",
           cchAlgo: "sha256-first-user",
-          buildRevision: "1e2",
+          buildRevision: "d7b",
         },
       ],
     },

From ded7b4406cb98fa6406ef36e52d66e0d65f198ee Mon Sep 17 00:00:00 2001
From: Giorgos Giakoumettis <giorgos@yiakoumettis.gr>
Date: Wed, 23 Sep 2026 20:25:33 +0300
Subject: [PATCH 5/8] fix(providers): keep claude-opus-5 as the cc/ Opus
 default

Connections whose authoritative live catalog was synced before the launch
reject claude-opus-5-5 with model_not_found until refreshed, so listing
Opus 5.5 first made ANTHROPIC_DEFAULT_OPUS_MODEL point at a model those
catalogs refuse. List it after Opus 5 until catalogs catch up.

Refs #14612
---
 .../config/providers/registry/claude/index.ts     | 15 ++++++++-------
 tests/unit/claude-opus-5-5.test.ts                | 10 +++++++++-
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/open-sse/config/providers/registry/claude/index.ts b/open-sse/config/providers/registry/claude/index.ts
index 8ff530bc5b75..6a10b926eed1 100644
--- a/open-sse/config/providers/registry/claude/index.ts
+++ b/open-sse/config/providers/registry/claude/index.ts
@@ -48,22 +48,23 @@ export const claudeProvider: RegistryEntry = {
       unsupportedParams: ["temperature", "top_p", "top_k"],
     },
     {
-      id: "claude-opus-5-5",
-      name: "Claude Opus 5.5",
+      id: "claude-opus-5",
+      name: "Claude Opus 5",
       contextLength: 1000000,
       maxOutputTokens: 128000,
-      supportsReasoning: true,
-      supportedThinkingEfforts: ["low", "medium", "high", "xhigh", "max"],
       supportsXHighEffort: true,
-      supportsVision: true,
       unsupportedParams: ["temperature", "top_p", "top_k"],
     },
+    // Listed after Opus 5 so the cc/ Opus default stays on a model stale live catalogs still accept (#14612).
     {
-      id: "claude-opus-5",
-      name: "Claude Opus 5",
+      id: "claude-opus-5-5",
+      name: "Claude Opus 5.5",
       contextLength: 1000000,
       maxOutputTokens: 128000,
+      supportsReasoning: true,
+      supportedThinkingEfforts: ["low", "medium", "high", "xhigh", "max"],
       supportsXHighEffort: true,
+      supportsVision: true,
       unsupportedParams: ["temperature", "top_p", "top_k"],
     },
     {
diff --git a/tests/unit/claude-opus-5-5.test.ts b/tests/unit/claude-opus-5-5.test.ts
index cd94195cfc5d..bf10752efb90 100644
--- a/tests/unit/claude-opus-5-5.test.ts
+++ b/tests/unit/claude-opus-5-5.test.ts
@@ -61,13 +61,21 @@ test("Claude Opus 5.5 is registered only on verified launch surfaces", () => {
     getStaticModelsForProvider("claude")?.some((entry) => entry.id === MODEL_ID),
     "Claude OAuth static discovery must expose Opus 5.5"
   );
-  assert.equal(getClaudeCodeDefaultModels().opus, MODEL_ID);
   assert.equal(
     getNextFamilyFallback(`claude/${MODEL_ID}`, new Set([`claude/${MODEL_ID}`])),
     "claude/claude-opus-5"
   );
 });
 
+test("Claude Code CLI keeps Opus 5 as the cc/ Opus default until live catalogs refresh", () => {
+  // Given a claude connection synced before the launch, whose live catalog lacks Opus 5.5 (#14612)
+  // When the Claude Code CLI defaults are derived from the registry
+  const { opus } = getClaudeCodeDefaultModels();
+
+  // Then ANTHROPIC_DEFAULT_OPUS_MODEL keeps pointing at a model that catalog still accepts
+  assert.equal(opus, "claude-opus-5");
+});
+
 test("Claude Opus 5.5 has native 1M context and always-on adaptive thinking", () => {
   assert.equal(modelHasNativeContext1m(MODEL_ID), true);
   assert.equal(modelHasNativeContext1m(BEDROCK_MODEL_ID), true);

From 52d175b6da901046f21042182ee08e0f6afebe97 Mon Sep 17 00:00:00 2001
From: Giorgos Giakoumettis <giorgos@yiakoumettis.gr>
Date: Wed, 23 Sep 2026 20:25:55 +0300
Subject: [PATCH 6/8] test(providers): assert the Claude CLI pin clears the
 Opus 5.5 gate

Ported from #14557: guards against a future pin regressing below the
2.1.280 floor Anthropic enforces for claude-opus-5-5.

Co-authored-by: PixmaNTS <maxime@maxime-pointet.fr>
---
 tests/unit/claude-codex-identity-version-sync.test.ts | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tests/unit/claude-codex-identity-version-sync.test.ts b/tests/unit/claude-codex-identity-version-sync.test.ts
index ed0b13fc2e0f..6332148f751f 100644
--- a/tests/unit/claude-codex-identity-version-sync.test.ts
+++ b/tests/unit/claude-codex-identity-version-sync.test.ts
@@ -40,6 +40,15 @@ test("Claude CLI version constants are in lockstep across all 4 sources", () =>
   );
 });
 
+test("Claude CLI pin clears Anthropic's Opus 5.5 model gate (>= 2.1.280)", () => {
+  const [major, minor, patch] = canonical.CLAUDE_CODE_CLIENT_VERSION.split(".").map(Number);
+  const meetsGate = major > 2 || (major === 2 && (minor > 1 || (minor === 1 && patch >= 280)));
+  assert.ok(
+    meetsGate,
+    `claude-cli pin ${canonical.CLAUDE_CODE_CLIENT_VERSION} < 2.1.280 — Anthropic rejects claude-opus-5-5 with 400 "Claude Code ${canonical.CLAUDE_CODE_CLIENT_VERSION} does not support this model"`
+  );
+});
+
 test("Claude CLI wire versions match the captured 2.1.280 binary", () => {
   assert.equal(canonical.CLAUDE_CODE_CLIENT_VERSION, "2.1.280");
   assert.equal(canonical.CLAUDE_CODE_CLIENT_BUILD_REVISION, "d7b");

From 31318a8e3e3a245c7ad75e5f7fe8c4a858d26668 Mon Sep 17 00:00:00 2001
From: Giorgos Giakoumettis <giorgos@yiakoumettis.gr>
Date: Wed, 23 Sep 2026 20:35:10 +0300
Subject: [PATCH 7/8] feat(providers): default Claude Opus 5.5 reasoning effort
 to medium

Ported from #14548: requests without an explicit effort get
reasoning_effort=medium; a client-chosen effort still wins.

Co-authored-by: Minxi Hou <houminxi@gmail.com>
---
 src/shared/constants/modelSpecs.ts |  1 +
 tests/unit/claude-opus-5-5.test.ts | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/src/shared/constants/modelSpecs.ts b/src/shared/constants/modelSpecs.ts
index eb6175550d66..eabf885fccde 100644
--- a/src/shared/constants/modelSpecs.ts
+++ b/src/shared/constants/modelSpecs.ts
@@ -480,6 +480,7 @@ export const MODEL_SPECS: Record<string, ModelSpec> = {
     rejectsThinkingDisabled: true,
     adaptiveThinkingOnly: true,
     rejectsForcedToolChoice: true,
+    defaultReasoningEffort: "medium",
     aliases: BEDROCK_CLAUDE_ALIASES("claude-opus-5-5", "claude-opus-5.5"),
   },
 
diff --git a/tests/unit/claude-opus-5-5.test.ts b/tests/unit/claude-opus-5-5.test.ts
index bf10752efb90..cee315a8bceb 100644
--- a/tests/unit/claude-opus-5-5.test.ts
+++ b/tests/unit/claude-opus-5-5.test.ts
@@ -100,6 +100,22 @@ test("Claude Opus 5.5 has native 1M context and always-on adaptive thinking", ()
   assert.equal(supportsClaudeMaxEffort(MODEL_ID), true);
 });
 
+test("Claude Opus 5.5 defaults reasoning effort to medium without overriding the client", async () => {
+  const { applyDefaultReasoningEffort } =
+    await import("../../open-sse/services/defaultReasoningEffort.ts");
+  assert.equal(getModelSpec(MODEL_ID)?.defaultReasoningEffort, "medium");
+
+  const bare: Record<string, unknown> = { model: MODEL_ID, messages: [] };
+  assert.equal(applyDefaultReasoningEffort(bare, MODEL_ID).reasoning_effort, "medium");
+
+  const chosen: Record<string, unknown> = {
+    model: MODEL_ID,
+    messages: [],
+    reasoning_effort: "max",
+  };
+  assert.equal(applyDefaultReasoningEffort(chosen, MODEL_ID).reasoning_effort, "max");
+});
+
 test("Claude Opus 5.5 strips unsupported sampling parameters", () => {
   for (const [providerId, modelId] of [
     ["anthropic", MODEL_ID],

From 7f2eecceb3642a3eceff61c506ee8a3c211d747e Mon Sep 17 00:00:00 2001
From: Giorgos Giakoumettis <giorgos@yiakoumettis.gr>
Date: Wed, 23 Sep 2026 20:35:25 +0300
Subject: [PATCH 8/8] docs(changelog): note Opus 5.5 effort default and cc/
 Opus default

Co-authored-by: Minxi Hou <houminxi@gmail.com>
---
 changelog.d/features/14546-claude-opus-5-5.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/changelog.d/features/14546-claude-opus-5-5.md b/changelog.d/features/14546-claude-opus-5-5.md
index f182293bfd0b..51e5e46a1b8c 100644
--- a/changelog.d/features/14546-claude-opus-5-5.md
+++ b/changelog.d/features/14546-claude-opus-5-5.md
@@ -1 +1 @@
-- **feat(providers):** add Claude Opus 5.5 (`claude-opus-5-5`) to the Anthropic API, Claude OAuth, Bedrock and Vertex catalogs — native 1M context, 128K output, five effort tiers, $4/$20 pricing, Fast Mode, Opus 5 fallback; disabled thinking, manual budgets and forced `tool_choice` are normalized before dispatch since Opus 5.5 rejects them ([#14546](https://github.com/diegosouzapw/OmniRoute/pull/14546)).
+- **feat(providers):** add Claude Opus 5.5 (`claude-opus-5-5`) to the Anthropic API, Claude OAuth, Bedrock and Vertex catalogs — native 1M context, 128K output, five effort tiers (default `medium`), $4/$20 pricing, Fast Mode, Opus 5 fallback; disabled thinking, manual budgets and forced `tool_choice` are normalized before dispatch since Opus 5.5 rejects them. The `cc/` Opus CLI default stays `claude-opus-5`, because `claude`/`anthropic` connections synced before the launch reject Opus 5.5 until their model list is refreshed (Refs #14612) ([#14546](https://github.com/diegosouzapw/OmniRoute/pull/14546)).