fix(devin-cli): honor platform path semantics in credential discovery

src/oauth/devin-cli.ts

@@ -18,7 +18,7 @@
  */
 import { existsSync, readFileSync } from "node:fs";
 import { homedir } from "node:os";
-import { join } from "node:path";
+import { posix, win32 } from "node:path";
 import { DEVIN_CLI_INSTALL_HINT } from "../adapters/devin-cli/binary";
 import { identityFromApiKey } from "./devin";
 import { resolveDevinApiBaseUrl } from "./devin/api-base";
@@ -58,12 +58,13 @@ export function devinCliCredentialsPath(
   // Absolute only. A relative override would resolve against whatever directory
   // the proxy happens to be running in, which is not a location a user can mean.
   if (override && (override.startsWith("/") || /^[A-Za-z]:[\\/]/.test(override))) return override;
+  const paths = platform === "win32" ? win32 : posix;
   if (platform === "win32") {
-    const appData = env.APPDATA ?? join(homedir(), "AppData", "Roaming");
-    return join(appData, "devin", "credentials.toml");
+    const appData = env.APPDATA ?? paths.join(homedir(), "AppData", "Roaming");
+    return paths.join(appData, "devin", "credentials.toml");
   }
-  const dataHome = env.XDG_DATA_HOME ?? join(homedir(), ".local", "share");
-  return join(dataHome, "devin", "credentials.toml");
+  const dataHome = env.XDG_DATA_HOME ?? paths.join(homedir(), ".local", "share");
+  return paths.join(dataHome, "devin", "credentials.toml");
 }
 
 export interface DevinCliCredentialFile {

structure/providers/xai-grok.md

@@ -65,3 +65,5 @@ see [Combo editor routing quota](../gui-and-management-api.md#combo-editor-routi
 
 Claude replay carries [Go conversation affinity](../data-planes/inbound-compat.md#claude-affinity-at-final-go-dispatch)
 privately to final dispatch; preliminary route selection does not inject Go-only headers.
+
+Devin CLI credential path composition in `src/oauth/devin-cli.ts` follows the selected platform: Windows uses Win32 APPDATA paths, other platforms use POSIX XDG-data paths. The explicit absolute override remains verbatim; credential parsing and login behavior are unchanged.

structure/runtime.md

@@ -233,3 +233,5 @@ Cline CLI joins the existing export/client integration registries. Explicit CLI
 Config JSON preserves the boolean; only literal true activates the role-changing transform.
 
 The lightweight top-level CLI help counts Cline CLI among the fifteen registered export clients; registry parity remains covered by the client help and integration tests.
+
+Devin CLI credential path composition in `src/oauth/devin-cli.ts` follows the selected platform: Windows uses Win32 APPDATA paths, other platforms use POSIX XDG-data paths. The explicit absolute override remains verbatim; credential parsing and login behavior are unchanged.

structure/transports/inventory.md

@@ -70,3 +70,5 @@ see [Combo editor routing quota](../gui-and-management-api.md#combo-editor-routi
 
 Claude replay carries [Go conversation affinity](../data-planes/inbound-compat.md#claude-affinity-at-final-go-dispatch)
 privately to final dispatch; preliminary route selection does not inject Go-only headers.
+
+Devin CLI credential path composition in `src/oauth/devin-cli.ts` follows the selected platform: Windows uses Win32 APPDATA paths, other platforms use POSIX XDG-data paths. The explicit absolute override remains verbatim; credential parsing and login behavior are unchanged.

tests/providers/devin-cli-adapter.test.ts

@@ -1,3 +1,4 @@
+import { join } from "node:path";
 import { describe, expect, test } from "bun:test";
 import {
   ACP_SESSION_NEW_ID,
@@ -213,13 +214,20 @@ describe("devin cli discovery", () => {
 
   test("known install paths are preferred over a shadowed PATH entry, and absence is undefined", () => {
     const previous = process.env[DEVIN_CLI_BIN_ENV];
+    const previousPath = process.env.PATH;
     delete process.env[DEVIN_CLI_BIN_ENV];
+    process.env.PATH = join("/shadow", "bin");
     try {
-      const only = (p: string) => p === "/home/u/.local/bin/devin";
-      expect(resolveDevinCliBinary({ exists: only, home: "/home/u", useCache: false })).toBe("/home/u/.local/bin/devin");
+      const expected = join("/home/u", ".local", "bin", "devin");
+      const shadowed = join("/shadow", "bin", "devin");
+      const exists = (p: string) => p === expected || p === shadowed;
+      expect(resolveDevinCliBinary({ exists, home: "/home/u", useCache: false })).toBe(expected);
+      expect(resolveDevinCliBinary({ exists: p => p === shadowed, home: "/home/u", useCache: false })).toBe(shadowed);
       expect(resolveDevinCliBinary({ exists: () => false, home: "/home/u", useCache: false })).toBeUndefined();
     } finally {
       if (previous !== undefined) process.env[DEVIN_CLI_BIN_ENV] = previous;
+      if (previousPath === undefined) delete process.env.PATH;
+      else process.env.PATH = previousPath;
     }
   });
 });

tests/providers/devin-cli-login.test.ts

@@ -46,7 +46,7 @@ describe("devin-cli credentials path", () => {
 
   test("Windows uses APPDATA", () => {
     expect(devinCliCredentialsPath({ APPDATA: "C:\\Users\\u\\AppData\\Roaming" }, "win32"))
-      .toContain("devin");
+      .toBe("C:\\Users\\u\\AppData\\Roaming\\devin\\credentials.toml");
   });
 
   test("the override must be absolute", () => {