diff --git a/src/engine/tools/claude.ts b/src/engine/tools/claude.ts
index b39f58a..548d2d5 100644
--- a/src/engine/tools/claude.ts
+++ b/src/engine/tools/claude.ts
@@ -3,11 +3,21 @@ import { PROVIDER_NAME, type ZroModel } from "../constants.js";
 import { jsonSerializer } from "../serializers.js";
 import type { ToolModule } from "../types.js";
 
+// Claude Code hands backgrounded sessions to a daemon whose workers do not
+// inherit this launch's environment, and a respawned worker re-reads these
+// files long after the launching process exits. Both therefore live at a
+// stable path rather than the per-launch temp dir.
+export function claudeConfigDir(homeDir: string, env: NodeJS.ProcessEnv): string {
+  return path.join(env.XDG_CACHE_HOME || path.join(homeDir, ".cache"), "zro", "claude");
+}
+
 export const claudeTool: ToolModule = {
   id: "claude",
   label: "Claude Code",
   async launch(ctx) {
-    const mcpConfigPath = path.join(ctx.tempDir, "claude", "mcp.json");
+    const configDir = claudeConfigDir(ctx.homeDir, ctx.env);
+    const mcpConfigPath = path.join(configDir, "mcp.json");
+    const settingsPath = path.join(configDir, "settings.json");
     if (!ctx.models.some((model) => model.id === ctx.model)) {
       ctx.stderr.write(
         `Warning: model "${ctx.model}" is not in the Zro catalog; Claude Code will assume a 200k context window.\n`
@@ -27,6 +37,8 @@ export const claudeTool: ToolModule = {
         "--managed-settings",
         buildClaudeManagedSettingsArg(ctx.models, aliasPlan),
         ...(ctx.noAuth ? [] : ["--mcp-config", mcpConfigPath]),
+        "--settings",
+        settingsPath,
         ...ctx.extraArgs
       ],
       env: {
@@ -44,18 +56,31 @@ export const claudeTool: ToolModule = {
         CLAUDE_CODE_DISABLE_FEEDBACK_SURVEY: "1",
         DO_NOT_TRACK: "1"
       },
-      files: ctx.noAuth ? [] : [{
-        path: mcpConfigPath,
-        contents: jsonSerializer.stringify({
-          mcpServers: {
-            zro: {
-              type: "http",
-              url: ctx.mcpUrl,
-              headers: { Authorization: `Bearer ${ctx.apiKey}` }
+      files: [
+        ...(ctx.noAuth ? [] : [{
+          path: mcpConfigPath,
+          contents: jsonSerializer.stringify({
+            mcpServers: {
+              zro: {
+                type: "http",
+                url: ctx.mcpUrl,
+                headers: { Authorization: `Bearer ${ctx.apiKey}` }
+              }
             }
-          }
-        })
-      }],
+          }),
+          persistent: true
+        }]),
+        {
+          path: settingsPath,
+          contents: jsonSerializer.stringify({
+            env: {
+              ANTHROPIC_BASE_URL: ctx.inferenceRoot,
+              ANTHROPIC_AUTH_TOKEN: ctx.apiKey
+            }
+          }),
+          persistent: true
+        }
+      ],
       message: "Launch Claude Code with Zro"
     };
   }
diff --git a/src/run.ts b/src/run.ts
index a6591b2..09350e8 100644
--- a/src/run.ts
+++ b/src/run.ts
@@ -18,7 +18,7 @@ import {
   resolveApiKey,
   writeStoredApiKey
 } from "./engine/key.js";
-import { CLAUDE_MODEL_ALIAS_SLOTS, claudeTool } from "./engine/tools/claude.js";
+import { CLAUDE_MODEL_ALIAS_SLOTS, claudeConfigDir, claudeTool } from "./engine/tools/claude.js";
 import {
   codexAppCredentialFilePath,
   codexAppTool,
@@ -598,6 +598,8 @@ async function logout(
     deleteStoredApiKey({ homeDir: io.homeDir, env }),
     deleteOptionalFile(codexAppCredentialFilePath(io.homeDir)),
     invalidateModelCatalog({ homeDir: io.homeDir, env }),
+    fs.rm(claudeConfigDir(io.homeDir, env), { recursive: true, force: true })
+      .catch(() => undefined),
   ]);
   const removed = storedKeyRemoved || codexAppKeyRemoved;
   io.stdout.write(output === "json"
diff --git a/tests/run.test.ts b/tests/run.test.ts
index 66711b2..085feec 100644
--- a/tests/run.test.ts
+++ b/tests/run.test.ts
@@ -7,6 +7,7 @@ import path from "node:path";
 import { PassThrough } from "node:stream";
 import { describe, expect, it } from "vitest";
 import { CLAUDE_MODEL_ALIAS_SLOTS, claudeTool } from "../src/engine/tools/claude.js";
+import { ENDPOINT_ROOT } from "../src/engine/constants.js";
 import { TEST_CATALOG_RESPONSE, TIER_MODELS } from "./fixtures.js";
 import type { SpawnOptions, SpawnProcess } from "../src/engine/types.js";
 import { run } from "../src/run.js";
@@ -337,6 +338,50 @@ describe("zro experience", () => {
     expect(plan.env!.ANTHROPIC_CUSTOM_MODEL_OPTION).toBe("anthropic.injected");
   });
 
+  it("launches claude with persistent config files for background sessions", async () => {
+    const stderr = new PassThrough();
+    const plan = await claudeTool.launch({
+      apiKey: "sk-stable-secret",
+      apiKeySource: "env",
+      inferenceRoot: "https://zro.moonmath.ai",
+      inferenceBaseUrl: "https://zro.moonmath.ai/v1",
+      mcpUrl: "https://zro.moonmath.ai/mcp/zro",
+      noAuth: false,
+      env: {},
+      model: "kimi-k3",
+      models: TIER_MODELS,
+      extraArgs: [],
+      homeDir: "/tmp/zro-stable-home",
+      cwd: "/tmp",
+      tempDir: "/tmp/zro-stable-session",
+      stdin: new PassThrough(),
+      stdout: new PassThrough(),
+      stderr
+    });
+
+    const settingsPath = plan.args![plan.args!.indexOf("--settings") + 1];
+    expect(settingsPath).toBe(
+      path.join("/tmp/zro-stable-home", ".cache", "zro", "claude", "settings.json")
+    );
+    expect(plan.args![plan.args!.indexOf("--mcp-config") + 1]).toBe(
+      path.join("/tmp/zro-stable-home", ".cache", "zro", "claude", "mcp.json")
+    );
+
+    const settings = plan.files!.find((file) => file.path === settingsPath)!;
+    expect(settings.persistent).toBe(true);
+    expect(JSON.parse(settings.contents)).toEqual({
+      env: {
+        ANTHROPIC_BASE_URL: ENDPOINT_ROOT,
+        ANTHROPIC_AUTH_TOKEN: "sk-stable-secret"
+      }
+    });
+
+    const mcp = plan.files!.find((file) => file.path.endsWith("mcp.json"))!;
+    expect(mcp.persistent).toBe(true);
+    expect(JSON.parse(mcp.contents).mcpServers.zro.headers.Authorization)
+      .toBe("Bearer sk-stable-secret");
+  });
+
   it("forwards --alias overrides through zro again", async () => {
     const home = await fs.mkdtemp(path.join(os.tmpdir(), "zro-again-alias-"));
     const stdout = new PassThrough();
@@ -670,6 +715,11 @@ describe("zro experience", () => {
     const catalogPath = path.join(home, ".cache", "zro", "model-catalog.json");
     await fs.mkdir(path.dirname(catalogPath), { recursive: true });
     await fs.writeFile(catalogPath, JSON.stringify(dynamicCatalogResponse()));
+    const claudeConfigDir = path.join(home, ".cache", "zro", "claude");
+    await fs.mkdir(claudeConfigDir, { recursive: true });
+    await fs.writeFile(path.join(claudeConfigDir, "settings.json"),
+      JSON.stringify({ env: { ANTHROPIC_AUTH_TOKEN: "sk-stored" } }));
+    await fs.writeFile(path.join(claudeConfigDir, "mcp.json"), "{}");
     const stdout = new PassThrough();
 
     const code = await run(["logout", "--json"], io(home, stdout));
@@ -687,6 +737,10 @@ describe("zro experience", () => {
     await expect(fs.stat(catalogPath)).rejects.toMatchObject({ code: "ENOENT" });
     await expect(fs.readFile(path.join(codexAppDir, "config.toml"), "utf8"))
       .resolves.toBe("model = \"glm-5.3\"\n");
+    await expect(fs.stat(path.join(claudeConfigDir, "settings.json")))
+      .rejects.toMatchObject({ code: "ENOENT" });
+    await expect(fs.stat(path.join(claudeConfigDir, "mcp.json")))
+      .rejects.toMatchObject({ code: "ENOENT" });
   });
 
   it("removes the Codex App key when it is the only stored credential", async () => {