fix claude oauth and cc-compatible regressions

open-sse/executors/github.ts

@@ -76,7 +76,12 @@ export class GithubExecutor extends BaseExecutor {
     if (!result || !result.response?.body) return result;
 
     const isStreaming = input.stream === true;
-    if (isStreaming) {
+    const contentType = (result.response.headers.get("content-type") || "").toLowerCase();
+    if (isStreaming && result.response.ok && contentType.includes("text/event-stream")) {
+      // Preserve the original response body for downstream error handling.
+      const sourceResponse = result.response.clone();
+      if (!sourceResponse.body) return result;
+
       const decoder = new TextDecoder();
       const transformStream = new TransformStream({
         transform(chunk, controller) {
@@ -88,10 +93,10 @@ export class GithubExecutor extends BaseExecutor {
         },
       });
 
-      const newResponse = new Response(result.response.body.pipeThrough(transformStream), {
-        status: result.response.status,
-        statusText: result.response.statusText,
-        headers: result.response.headers, // Headers class carries over correctly
+      const newResponse = new Response(sourceResponse.body.pipeThrough(transformStream), {
+        status: sourceResponse.status,
+        statusText: sourceResponse.statusText,
+        headers: new Headers(sourceResponse.headers),
       });
       result.response = newResponse;
     }

open-sse/handlers/chatCore.ts

@@ -794,11 +794,13 @@ export async function handleChatCore({
       translatedBody = buildClaudeCodeCompatibleRequest({
         sourceBody: body,
         normalizedBody: normalizedForCc,
+        claudeBody: sourceFormat === FORMATS.CLAUDE ? body : null,
         model,
         stream: upstreamStream,
         sessionId: ccSessionId,
         cwd: process.cwd(),
         now: new Date(),
+        preserveCacheControl,
       });
       log?.debug?.("FORMAT", "claude-code-compatible bridge enabled");
     } else if (isClaudePassthrough && preserveCacheControl) {

open-sse/services/claudeCodeCompatible.ts

@@ -1,5 +1,7 @@
 import { createHash, randomUUID } from "node:crypto";
 
+import { prepareClaudeRequest } from "../translator/helpers/claudeHelper.ts";
+
 export const CLAUDE_CODE_COMPATIBLE_PREFIX = "anthropic-compatible-cc-";
 export const CLAUDE_CODE_COMPATIBLE_DEFAULT_CHAT_PATH = "/v1/messages?beta=true";
 export const CLAUDE_CODE_COMPATIBLE_DEFAULT_MODELS_PATH = "/models";
@@ -26,11 +28,13 @@ type MessageLike = {
 type BuildRequestOptions = {
   sourceBody?: Record<string, unknown> | null;
   normalizedBody?: Record<string, unknown> | null;
+  claudeBody?: Record<string, unknown> | null;
   model: string;
   stream?: boolean;
   cwd?: string;
   now?: Date;
   sessionId?: string | null;
+  preserveCacheControl?: boolean;
 };
 
 export function isClaudeCodeCompatibleProvider(provider: string | null | undefined): boolean {
@@ -137,25 +141,38 @@ export function resolveClaudeCodeCompatibleSessionId(headers?: HeaderLike): stri
 export function buildClaudeCodeCompatibleRequest({
   sourceBody,
   normalizedBody,
+  claudeBody,
   model,
   stream = false,
   cwd = process.cwd(),
   now = new Date(),
   sessionId,
+  preserveCacheControl = false,
 }: BuildRequestOptions) {
   const normalized = normalizedBody || {};
-  const messages = Array.isArray(normalized.messages)
-    ? buildClaudeCodeCompatibleMessages(normalized.messages as MessageLike[])
-    : [];
-  const system = buildClaudeCodeCompatibleSystemBlocks(
-    normalized.messages as MessageLike[],
+  const preparedClaudeBody = claudeBody
+    ? prepareClaudeCodeCompatibleBody(claudeBody, preserveCacheControl)
+    : null;
+  const messages = preparedClaudeBody
+    ? buildClaudeCodeCompatibleMessagesFromClaude(
+        preparedClaudeBody.messages as MessageLike[],
+        preserveCacheControl
+      )
+    : Array.isArray(normalized.messages)
+      ? buildClaudeCodeCompatibleMessages(normalized.messages as MessageLike[])
+      : [];
+  const system = buildClaudeCodeCompatibleSystemBlocks({
+    messages: normalized.messages as MessageLike[],
+    systemBlocks: preparedClaudeBody?.system as Record<string, unknown>[] | undefined,
     cwd,
-    now
-  );
+    now,
+  });
   const resolvedSessionId = sessionId || randomUUID();
   const effort = resolveClaudeCodeCompatibleEffort(sourceBody, normalizedBody, model);
   const maxTokens = resolveClaudeCodeCompatibleMaxTokens(sourceBody, normalizedBody);
-  const tools = buildClaudeCodeCompatibleTools(normalizedBody, sourceBody);
+  const tools = preparedClaudeBody?.tools
+    ? (preparedClaudeBody.tools as Record<string, unknown>[])
+    : buildClaudeCodeCompatibleTools(normalizedBody, sourceBody);
   const toolChoice =
     tools.length > 0
       ? buildClaudeCodeCompatibleToolChoice(
@@ -295,32 +312,83 @@ function buildClaudeCodeCompatibleMessages(messages: MessageLike[]) {
     }
   }
 
-  for (let i = merged.length - 1; i >= 0; i--) {
-    if (merged[i].role !== "user") continue;
-    const lastBlock = merged[i].content[merged[i].content.length - 1];
-    if (lastBlock) {
-      lastBlock.cache_control = { type: "ephemeral" };
+  applyClaudeCodeCompatibleMessageCacheStrategy(merged);
+
+  return merged;
+}
+
+function buildClaudeCodeCompatibleMessagesFromClaude(
+  messages: MessageLike[] | undefined,
+  preserveCacheControl: boolean
+) {
+  const converted = Array.isArray(messages)
+    ? messages
+        .map((message) => convertClaudeCodeCompatibleClaudeMessage(message, preserveCacheControl))
+        .filter(
+          (
+            message
+          ): message is { role: "user" | "assistant"; content: Array<Record<string, unknown>> } =>
+            !!message && message.content.length > 0
+        )
+    : [];
+
+  const merged: Array<{ role: "user" | "assistant"; content: Array<Record<string, unknown>> }> = [];
+
+  for (const message of converted) {
+    const last = merged[merged.length - 1];
+    if (last && last.role === message.role) {
+      last.content.push(...message.content);
+      continue;
+    }
+    merged.push({ role: message.role, content: [...message.content] });
+  }
+
+  while (merged.length > 0 && merged[merged.length - 1].role === "assistant") {
+    merged.pop();
+  }
+
+  if (!preserveCacheControl) {
+    for (const message of merged) {
+      stripCacheControlFromContentBlocks(message.content);
+    }
+    applyClaudeCodeCompatibleMessageCacheStrategy(merged);
+  }
+
+  if (merged.length === 0) {
+    const fallbackText = converted
+      .flatMap((message) => message.content)
+      .map((block) => contentToText(block))
+      .filter(Boolean)
+      .join("\n")
+      .trim();
+    if (fallbackText) {
+      return [
+        {
+          role: "user" as const,
+          content: [{ type: "text", text: fallbackText, cache_control: { type: "ephemeral" } }],
+        },
+      ];
     }
-    break;
   }
 
   return merged;
 }
 
-function buildClaudeCodeCompatibleSystemBlocks(
-  messages: MessageLike[] | undefined,
-  cwd: string,
-  now: Date
-) {
-  const customSystemBlocks = Array.isArray(messages)
-    ? messages
-        .filter((message) => {
-          const role = String(message?.role || "").toLowerCase();
-          return role === "system" || role === "developer";
-        })
-        .map((message) => contentToText(message?.content))
-        .filter(Boolean)
-    : [];
+function buildClaudeCodeCompatibleSystemBlocks({
+  messages,
+  systemBlocks,
+  cwd,
+  now,
+}: {
+  messages: MessageLike[] | undefined;
+  systemBlocks?: Array<Record<string, unknown>> | undefined;
+  cwd: string;
+  now: Date;
+}) {
+  const customSystemBlocks =
+    Array.isArray(systemBlocks) && systemBlocks.length > 0
+      ? systemBlocks
+      : extractCustomSystemBlocks(messages);
 
   const dateText = formatDate(now);
   const blocks: Array<Record<string, unknown>> = [
@@ -340,12 +408,8 @@ function buildClaudeCodeCompatibleSystemBlocks(
     },
   ];
 
-  for (const systemText of customSystemBlocks) {
-    blocks.push({
-      type: "text",
-      text: systemText,
-      cache_control: { type: "ephemeral" },
-    });
+  for (const systemBlock of customSystemBlocks) {
+    blocks.push(systemBlock);
   }
 
   return blocks;
@@ -383,7 +447,14 @@ function buildClaudeCodeCompatibleTools(
 
   return rawTools
     .map((tool) => convertClaudeCodeCompatibleTool(tool))
-    .filter((tool): tool is Record<string, unknown> => !!tool);
+    .filter((tool): tool is Record<string, unknown> => !!tool)
+    .map((tool, index, tools) => {
+      if (index !== findLastCacheableToolIndex(tools)) return tool;
+      return {
+        ...tool,
+        cache_control: { type: "ephemeral", ttl: "1h" },
+      };
+    });
 }
 
 function convertClaudeCodeCompatibleTool(tool: unknown) {
@@ -444,6 +515,190 @@ function buildClaudeCodeCompatibleToolChoice(choice: unknown) {
   return null;
 }
 
+function prepareClaudeCodeCompatibleBody(
+  claudeBody: Record<string, unknown>,
+  preserveCacheControl: boolean
+) {
+  const prepared = prepareClaudeRequest(
+    {
+      system: normalizeClaudeSystemInput(claudeBody.system),
+      messages: normalizeClaudeMessageInput(claudeBody.messages),
+      tools: normalizeClaudeToolInput(claudeBody.tools),
+      thinking: readRecord(claudeBody.thinking) || claudeBody.thinking,
+    },
+    CLAUDE_CODE_COMPATIBLE_PREFIX,
+    preserveCacheControl
+  );
+
+  return readRecord(prepared);
+}
+
+function normalizeClaudeSystemInput(system: unknown) {
+  if (typeof system === "string") {
+    const text = system.trim();
+    return text ? [{ type: "text", text }] : [];
+  }
+
+  if (!Array.isArray(system)) return [];
+  return system
+    .map((block) => normalizeClaudeContentBlock(block))
+    .filter((block): block is Record<string, unknown> => !!block);
+}
+
+function normalizeClaudeMessageInput(messages: unknown) {
+  if (!Array.isArray(messages)) return [];
+  return messages
+    .map((message) => {
+      const record = readRecord(message);
+      if (!record) return null;
+
+      return {
+        ...record,
+        content: normalizeClaudeContentInput(record.content),
+      };
+    })
+    .filter((message): message is Record<string, unknown> => !!message);
+}
+
+function normalizeClaudeToolInput(tools: unknown) {
+  if (!Array.isArray(tools)) return [];
+  return tools
+    .map((tool) => readRecord(cloneValue(tool)))
+    .filter((tool): tool is Record<string, unknown> => !!tool);
+}
+
+function normalizeClaudeContentInput(content: unknown) {
+  const blocks = normalizeClaudeContentBlocks(content);
+  return blocks.length > 0 ? blocks : content;
+}
+
+function normalizeClaudeContentBlocks(content: unknown) {
+  if (typeof content === "string") {
+    const text = content.trim();
+    return text ? [{ type: "text", text }] : [];
+  }
+
+  if (!Array.isArray(content)) {
+    const block = normalizeClaudeContentBlock(content);
+    return block ? [block] : [];
+  }
+
+  return content
+    .map((block) => normalizeClaudeContentBlock(block))
+    .filter((block): block is Record<string, unknown> => !!block);
+}
+
+function normalizeClaudeContentBlock(block: unknown) {
+  const record = readRecord(cloneValue(block));
+  if (!record) return null;
+
+  if (
+    record.type === "text" ||
+    (typeof record.type !== "string" && typeof record.text === "string")
+  ) {
+    const text = toNonEmptyString(record.text);
+    if (!text) return null;
+    return {
+      ...record,
+      type: "text",
+      text,
+    };
+  }
+
+  return record;
+}
+
+function convertClaudeCodeCompatibleClaudeMessage(
+  message: MessageLike | null | undefined,
+  preserveCacheControl: boolean
+) {
+  const rawRole = String(message?.role || "").toLowerCase();
+  const role = rawRole === "user" ? "user" : rawRole === "assistant" ? "assistant" : null;
+
+  if (!role) return null;
+
+  const content = normalizeClaudeContentBlocks(message?.content).map((block) => {
+    if (preserveCacheControl) return block;
+    const { cache_control, ...rest } = block;
+    return rest;
+  });
+  if (content.length === 0) return null;
+
+  return {
+    role,
+    content,
+  };
+}
+
+function extractCustomSystemBlocks(messages: MessageLike[] | undefined) {
+  if (!Array.isArray(messages)) return [];
+
+  return messages
+    .filter((message) => {
+      const role = String(message?.role || "").toLowerCase();
+      return role === "system" || role === "developer";
+    })
+    .map((message) => contentToText(message?.content))
+    .filter(Boolean)
+    .map((text) => ({
+      type: "text",
+      text,
+      cache_control: { type: "ephemeral" },
+    }));
+}
+
+function applyClaudeCodeCompatibleMessageCacheStrategy(
+  messages: Array<{ role: "user" | "assistant"; content: Array<Record<string, unknown>> }>
+) {
+  const userIndexes = messages.reduce((indexes, message, index) => {
+    if (message.role === "user") indexes.push(index);
+    return indexes;
+  }, [] as number[]);
+  const hasAssistant = messages.some((message) => message.role === "assistant");
+  const secondToLastUserIndex = userIndexes.length >= 2 ? userIndexes[userIndexes.length - 2] : -1;
+
+  if (secondToLastUserIndex >= 0) {
+    markLastContentCacheControl(messages[secondToLastUserIndex].content);
+  } else if (!hasAssistant && userIndexes.length > 0) {
+    markLastContentCacheControl(messages[userIndexes[userIndexes.length - 1]].content);
+  }
+
+  for (let i = messages.length - 1; i >= 0; i--) {
+    if (messages[i].role !== "assistant") continue;
+    if (markLastContentCacheControl(messages[i].content)) break;
+  }
+}
+
+function stripCacheControlFromContentBlocks(content: Array<Record<string, unknown>>) {
+  for (const block of content) {
+    delete block.cache_control;
+  }
+}
+
+function markLastContentCacheControl(content: Array<Record<string, unknown>>, ttl?: string) {
+  if (!Array.isArray(content) || content.length === 0) return false;
+  const lastBlock = content[content.length - 1];
+  if (!lastBlock) return false;
+  lastBlock.cache_control = ttl ? { type: "ephemeral", ttl } : { type: "ephemeral" };
+  return true;
+}
+
+function findLastCacheableToolIndex(tools: Array<Record<string, unknown>>) {
+  for (let i = tools.length - 1; i >= 0; i--) {
+    if (!tools[i].defer_loading) {
+      return i;
+    }
+  }
+  return -1;
+}
+
+function cloneValue<T>(value: T): T {
+  if (typeof structuredClone === "function") {
+    return structuredClone(value);
+  }
+  return JSON.parse(JSON.stringify(value)) as T;
+}
+
 function contentToText(content: unknown): string {
   if (typeof content === "string") {
     return content.trim();

src/app/api/v1/models/catalog.ts

@@ -18,6 +18,7 @@ import { getAllModerationModels } from "@omniroute/open-sse/config/moderationReg
 import { getAllVideoModels } from "@omniroute/open-sse/config/videoRegistry.ts";
 import { getAllMusicModels } from "@omniroute/open-sse/config/musicRegistry.ts";
 import { REGISTRY } from "@omniroute/open-sse/config/providerRegistry.ts";
+import { getCompatibleFallbackModels } from "@/lib/providers/managedAvailableModels";
 
 const FALLBACK_ALIAS_TO_PROVIDER = {
   ag: "antigravity",
@@ -485,6 +486,45 @@ export async function getUnifiedModelsResponse(
       console.log("Could not fetch custom models");
     }
 
+    // Add managed fallback models for compatible providers that don't import a model list.
+    for (const conn of connections) {
+      const providerId = typeof conn.provider === "string" ? conn.provider : null;
+      if (!providerId) continue;
+      if (blockedProviders.has(providerId)) continue;
+
+      const fallbackModels = getCompatibleFallbackModels(providerId);
+      if (!Array.isArray(fallbackModels) || fallbackModels.length === 0) continue;
+
+      const prefix = providerIdToPrefix[providerId];
+      const alias = prefix || providerIdToAlias[providerId] || providerId;
+
+      for (const model of fallbackModels) {
+        const modelId = typeof model.id === "string" ? model.id : null;
+        if (!modelId) continue;
+        if (getModelIsHidden(providerId, modelId)) continue;
+
+        const aliasId = `${alias}/${modelId}`;
+        if (models.some((m) => m.id === aliasId)) continue;
+
+        const visionFields =
+          getVisionCapabilityFields(aliasId) || getVisionCapabilityFields(modelId);
+        const contextLength =
+          typeof model.contextLength === "number" ? model.contextLength : undefined;
+
+        models.push({
+          id: aliasId,
+          object: "model",
+          created: timestamp,
+          owned_by: providerId,
+          permission: [],
+          root: modelId,
+          parent: null,
+          ...(contextLength ? { context_length: contextLength } : {}),
+          ...(visionFields || {}),
+        });
+      }
+    }
+
     // Filter by API key permissions if requested
     const authHeader = request.headers.get("authorization");
     let finalModels = models;

src/lib/oauth/providers/claude.ts

@@ -3,12 +3,12 @@ import { CLAUDE_CONFIG } from "../constants/oauth";
 export const claude = {
   config: CLAUDE_CONFIG,
   flowType: "authorization_code_pkce",
-  buildAuthUrl: (config, _redirectUri, state, codeChallenge) => {
+  buildAuthUrl: (config, redirectUri, state, codeChallenge) => {
     const params = new URLSearchParams({
       code: "true",
       client_id: config.clientId,
       response_type: "code",
-      redirect_uri: config.redirectUri,
+      redirect_uri: redirectUri,
       scope: config.scopes.join(" "),
       code_challenge: codeChallenge,
       code_challenge_method: config.codeChallengeMethod,
@@ -16,7 +16,7 @@ export const claude = {
     });
     return `${config.authorizeUrl}?${params.toString()}`;
   },
-  exchangeToken: async (config, code, _redirectUri, codeVerifier, state) => {
+  exchangeToken: async (config, code, redirectUri, codeVerifier, state) => {
     let authCode = code;
     let codeState = "";
     if (authCode.includes("#")) {
@@ -36,7 +36,7 @@ export const claude = {
         state: codeState || state,
         grant_type: "authorization_code",
         client_id: config.clientId,
-        redirect_uri: config.redirectUri,
+        redirect_uri: redirectUri,
         code_verifier: codeVerifier,
       }),
     });

src/shared/components/ModelSelectModal.tsx

@@ -4,6 +4,7 @@ import { useState, useMemo, useEffect } from "react";
 import PropTypes from "prop-types";
 import Modal from "./Modal";
 import { getModelsByProviderId, PROVIDER_ID_TO_ALIAS } from "@/shared/constants/models";
+import { getCompatibleFallbackModels } from "@/lib/providers/managedAvailableModels";
 import {
   OAUTH_PROVIDERS,
   FREE_PROVIDERS,
@@ -160,9 +161,24 @@ export default function ModelSelectModal({
             value: `${nodePrefix}/${fullModel.replace(`${providerId}/`, "")}`,
           }));
 
+        const fallbackEntries = (
+          getCompatibleFallbackModels(providerId, providerCustomModels) || []
+        )
+          .filter((fm) => !nodeModels.some((nm) => nm.id === fm.id))
+          .map((fm) => ({
+            id: fm.id,
+            name: fm.name || fm.id,
+            value: `${nodePrefix}/${fm.id}`,
+            isFallback: true,
+          }));
+
         // Merge custom models for custom providers
         const customEntries = providerCustomModels
-          .filter((cm) => !nodeModels.some((nm) => nm.id === cm.id))
+          .filter(
+            (cm) =>
+              !nodeModels.some((nm) => nm.id === cm.id) &&
+              !fallbackEntries.some((fm) => fm.id === cm.id)
+          )
           .map((cm) => ({
             id: cm.id,
             name: cm.name || cm.id,
@@ -170,7 +186,7 @@ export default function ModelSelectModal({
             isCustom: true,
           }));
 
-        const allModels = [...nodeModels, ...customEntries];
+        const allModels = [...nodeModels, ...fallbackEntries, ...customEntries];
 
         if (allModels.length > 0) {
           groups[providerId] = {

tests/unit/cc-compatible-model-catalog.test.mjs

@@ -0,0 +1,67 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-cc-models-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const providersDb = await import("../../src/lib/db/providers.ts");
+const v1ModelsCatalog = await import("../../src/app/api/v1/models/catalog.ts");
+
+async function resetStorage() {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+}
+
+test.afterEach(async () => {
+  await resetStorage();
+});
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+test("v1 models exposes CC-compatible fallback models under the provider node prefix", async () => {
+  await providersDb.createProviderNode({
+    id: "anthropic-compatible-cc-cm",
+    type: "anthropic-compatible",
+    name: "Claude Max",
+    prefix: "cm",
+    baseUrl: "https://proxy.example.com",
+    chatPath: "/v1/messages?beta=true",
+    modelsPath: "/v1/models",
+  });
+
+  await providersDb.createProviderConnection({
+    provider: "anthropic-compatible-cc-cm",
+    authType: "apikey",
+    name: "cm-main",
+    apiKey: "sk-test",
+    isActive: true,
+    providerSpecificData: {
+      baseUrl: "https://proxy.example.com",
+      chatPath: "/v1/messages?beta=true",
+      modelsPath: "/v1/models",
+    },
+  });
+
+  const response = await v1ModelsCatalog.getUnifiedModelsResponse(
+    new Request("http://localhost/api/v1/models", { method: "GET" })
+  );
+
+  assert.equal(response.status, 200);
+  const body = await response.json();
+  const ids = new Set(body.data.map((item) => item.id));
+
+  assert.ok(ids.has("cm/claude-opus-4-6"));
+  assert.ok(ids.has("cm/claude-sonnet-4-6"));
+  assert.equal(
+    [...ids].some((id) => id.startsWith("anthropic-compatible-cc-cm/")),
+    false
+  );
+});

tests/unit/cc-compatible-provider.test.mjs

@@ -104,11 +104,14 @@ test("buildClaudeCodeCompatibleRequest keeps prior role history while dropping t
       { role: "user", text: "u2" },
     ]
   );
-  assert.deepEqual(payload.messages.at(-1).content.at(-1).cache_control, { type: "ephemeral" });
+  assert.deepEqual(payload.messages[0].content.at(-1).cache_control, { type: "ephemeral" });
+  assert.deepEqual(payload.messages[1].content.at(-1).cache_control, { type: "ephemeral" });
+  assert.equal(payload.messages[2].content.at(-1).cache_control, undefined);
   assert.equal(payload.system.length, 4);
   assert.equal(payload.system.at(-1).text, "sys");
   assert.equal(payload.tools.length, 1);
-  assert.deepEqual(payload.tools[0], {
+  const { cache_control, ...toolWithoutCacheControl } = payload.tools[0];
+  assert.deepEqual(toolWithoutCacheControl, {
     name: "lookup_weather",
     description: "Fetch weather",
     input_schema: {
@@ -119,11 +122,70 @@ test("buildClaudeCodeCompatibleRequest keeps prior role history while dropping t
       required: ["city"],
     },
   });
+  assert.deepEqual(payload.tools[0].cache_control, { type: "ephemeral", ttl: "1h" });
   assert.deepEqual(payload.tool_choice, { type: "any" });
   assert.equal(payload.context_management.edits[0].type, "clear_thinking_20251015");
   assert.equal(JSON.parse(payload.metadata.user_id).session_id, "session-1");
 });
 
+test("buildClaudeCodeCompatibleRequest preserves Claude cache markers when requested", () => {
+  const payload = buildClaudeCodeCompatibleRequest({
+    sourceBody: {
+      max_tokens: 64,
+    },
+    normalizedBody: {
+      max_tokens: 64,
+      messages: [{ role: "user", content: "fallback" }],
+    },
+    claudeBody: {
+      system: [{ type: "text", text: "sys", cache_control: { type: "ephemeral", ttl: "5m" } }],
+      messages: [
+        {
+          role: "user",
+          content: [{ type: "text", text: "u1", cache_control: { type: "ephemeral" } }],
+        },
+        {
+          role: "assistant",
+          content: [
+            {
+              type: "text",
+              text: "a1",
+              cache_control: { type: "ephemeral", ttl: "10m" },
+            },
+          ],
+        },
+        { role: "user", content: [{ type: "text", text: "u2" }] },
+      ],
+      tools: [
+        {
+          name: "lookup_weather",
+          description: "Fetch weather",
+          input_schema: {
+            type: "object",
+            properties: {
+              city: { type: "string" },
+            },
+            required: ["city"],
+          },
+          cache_control: { type: "ephemeral", ttl: "30m" },
+        },
+      ],
+    },
+    model: "claude-sonnet-4-6",
+    sessionId: "session-preserve",
+    preserveCacheControl: true,
+  });
+
+  assert.deepEqual(payload.system.at(-1).cache_control, { type: "ephemeral", ttl: "5m" });
+  assert.deepEqual(payload.messages[0].content[0].cache_control, { type: "ephemeral" });
+  assert.deepEqual(payload.messages[1].content[0].cache_control, {
+    type: "ephemeral",
+    ttl: "10m",
+  });
+  assert.equal(payload.messages[2].content[0].cache_control, undefined);
+  assert.deepEqual(payload.tools[0].cache_control, { type: "ephemeral", ttl: "30m" });
+});
+
 test("buildClaudeCodeCompatibleRequest falls back to a user turn when the source only has assistant/model text", () => {
   const payload = buildClaudeCodeCompatibleRequest({
     sourceBody: {
@@ -181,6 +243,7 @@ test("buildClaudeCodeCompatibleRequest omits auto tool_choice while preserving t
   });
 
   assert.equal(payload.tools.length, 1);
+  assert.deepEqual(payload.tools[0].cache_control, { type: "ephemeral", ttl: "1h" });
   assert.equal(payload.tool_choice, undefined);
 });
 
@@ -356,6 +419,126 @@ test("handleChatCore forces upstream streaming for CC compatible while returning
   assert.equal(payload.usage.completion_tokens, 5);
 });
 
+test("handleChatCore preserves Claude cache_control when CC-compatible requests originate from Claude", async () => {
+  const calls = [];
+  globalThis.fetch = async (url, init = {}) => {
+    calls.push({
+      url: String(url),
+      method: init.method || "GET",
+      headers: init.headers,
+      body: init.body ? JSON.parse(String(init.body)) : null,
+    });
+
+    return new Response(
+      [
+        "event: message_start",
+        'data: {"type":"message_start","message":{"id":"msg_2","type":"message","role":"assistant","model":"claude-sonnet-4-6","usage":{"input_tokens":12,"output_tokens":0}}}',
+        "",
+        "event: content_block_start",
+        'data: {"type":"content_block_start","index":0,"content_block":{"type":"text","text":""}}',
+        "",
+        "event: content_block_delta",
+        'data: {"type":"content_block_delta","index":0,"delta":{"type":"text_delta","text":"Preserved"}}',
+        "",
+        "event: message_delta",
+        'data: {"type":"message_delta","delta":{"stop_reason":"end_turn"},"usage":{"output_tokens":3}}',
+        "",
+        "event: message_stop",
+        'data: {"type":"message_stop"}',
+        "",
+      ].join("\n"),
+      {
+        status: 200,
+        headers: {
+          "content-type": "text/event-stream",
+        },
+      }
+    );
+  };
+
+  const claudeBody = {
+    model: "claude-sonnet-4-6",
+    max_tokens: 64,
+    system: [{ type: "text", text: "system", cache_control: { type: "ephemeral", ttl: "5m" } }],
+    messages: [
+      {
+        role: "user",
+        content: [{ type: "text", text: "u1", cache_control: { type: "ephemeral" } }],
+      },
+      {
+        role: "assistant",
+        content: [
+          {
+            type: "text",
+            text: "a1",
+            cache_control: { type: "ephemeral", ttl: "10m" },
+          },
+        ],
+      },
+      { role: "user", content: [{ type: "text", text: "u2" }] },
+    ],
+    tools: [
+      {
+        name: "lookup_weather",
+        description: "Fetch weather",
+        input_schema: {
+          type: "object",
+          properties: {
+            city: { type: "string" },
+          },
+        },
+        cache_control: { type: "ephemeral", ttl: "30m" },
+      },
+    ],
+  };
+
+  const result = await handleChatCore({
+    body: claudeBody,
+    modelInfo: {
+      provider: "anthropic-compatible-cc-test",
+      model: "claude-sonnet-4-6",
+      extendedContext: false,
+    },
+    credentials: {
+      apiKey: "sk-test",
+      providerSpecificData: {
+        baseUrl: "https://proxy.example.com",
+        chatPath: CLAUDE_CODE_COMPATIBLE_DEFAULT_CHAT_PATH,
+      },
+    },
+    clientRawRequest: {
+      endpoint: "/v1/messages",
+      body: claudeBody,
+      headers: new Headers({ accept: "application/json" }),
+    },
+    userAgent: "Claude-Code/1.0.0",
+    log: {
+      debug() {},
+      info() {},
+      warn() {},
+      error() {},
+    },
+  });
+
+  assert.equal(result.success, true);
+  assert.equal(calls.length, 1);
+  assert.deepEqual(calls[0].body.system.at(-1).cache_control, {
+    type: "ephemeral",
+    ttl: "5m",
+  });
+  assert.deepEqual(calls[0].body.messages[0].content[0].cache_control, {
+    type: "ephemeral",
+  });
+  assert.deepEqual(calls[0].body.messages[1].content[0].cache_control, {
+    type: "ephemeral",
+    ttl: "10m",
+  });
+  assert.deepEqual(calls[0].body.tools[0].cache_control, {
+    type: "ephemeral",
+    ttl: "30m",
+  });
+});
+
 test("provider-nodes create route rejects CC mode when feature flag is disabled", async () => {
   delete process.env.ENABLE_CC_COMPATIBLE_PROVIDER;
 

tests/unit/claude-oauth-provider.test.mjs

@@ -0,0 +1,55 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { claude } from "../../src/lib/oauth/providers/claude.ts";
+import { CLAUDE_CONFIG } from "../../src/lib/oauth/constants/oauth.ts";
+
+const originalFetch = globalThis.fetch;
+
+test.afterEach(() => {
+  globalThis.fetch = originalFetch;
+});
+
+test("Claude OAuth provider uses the runtime redirectUri when building the auth URL", () => {
+  const redirectUri = "http://localhost:43121/callback";
+  const authUrl = claude.buildAuthUrl(CLAUDE_CONFIG, redirectUri, "state-123", "challenge-456");
+  const parsed = new URL(authUrl);
+
+  assert.equal(parsed.searchParams.get("redirect_uri"), redirectUri);
+  assert.equal(parsed.searchParams.get("state"), "state-123");
+  assert.equal(parsed.searchParams.get("code_challenge"), "challenge-456");
+});
+
+test("Claude OAuth provider uses the runtime redirectUri during token exchange", async () => {
+  let captured = null;
+
+  globalThis.fetch = async (url, init = {}) => {
+    captured = {
+      url: String(url),
+      method: init.method,
+      headers: init.headers,
+      body: JSON.parse(String(init.body)),
+    };
+
+    return new Response(JSON.stringify({ access_token: "token-1" }), {
+      status: 200,
+      headers: { "Content-Type": "application/json" },
+    });
+  };
+
+  const redirectUri = "http://localhost:43121/callback";
+  await claude.exchangeToken(
+    CLAUDE_CONFIG,
+    "auth-code#state-from-fragment",
+    redirectUri,
+    "verifier-123",
+    "state-from-request"
+  );
+
+  assert.equal(captured.url, CLAUDE_CONFIG.tokenUrl);
+  assert.equal(captured.method, "POST");
+  assert.equal(captured.body.redirect_uri, redirectUri);
+  assert.equal(captured.body.code, "auth-code");
+  assert.equal(captured.body.state, "state-from-fragment");
+  assert.equal(captured.body.code_verifier, "verifier-123");
+});

tests/unit/t27-github-copilot-response-format.test.mjs

@@ -82,3 +82,30 @@ test("T27: SSE [DONE] guard applies only in streaming mode", async () => {
     BaseExecutor.prototype.execute = originalExecute;
   }
 });
+
+test("T27: streaming error responses keep their original body readable", async () => {
+  const executor = new GithubExecutor();
+  const originalExecute = BaseExecutor.prototype.execute;
+
+  BaseExecutor.prototype.execute = async () => ({
+    response: new Response("IDE token expired: unauthorized: token expired\n", {
+      status: 401,
+      headers: { "content-type": "text/plain; charset=utf-8" },
+    }),
+    url: "https://api.githubcopilot.com/chat/completions",
+  });
+
+  try {
+    const result = await executor.execute({
+      model: "claude-sonnet-4.5",
+      body: { messages: [] },
+      stream: true,
+      credentials: { accessToken: "token" },
+    });
+
+    assert.equal(result.response.status, 401);
+    assert.equal(await result.response.text(), "IDE token expired: unauthorized: token expired\n");
+  } finally {
+    BaseExecutor.prototype.execute = originalExecute;
+  }
+});