diff --git a/CHANGELOG.md b/CHANGELOG.md
index b9c9c4a7f0..44b4802e86 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -26,6 +26,8 @@
 
 ### 🔧 Bug Fixes
 
+- **oauth (Zed "Unknown provider" crash):** adding **Zed** from the providers dashboard threw an unhandled `OAuth GET error: Unknown provider: zed` (500) ([#6041](https://github.com/diegosouzapw/OmniRoute/issues/6041)). Zed is a **keychain-import-only** provider — it's listed in the OAuth catalog so the UI shows it, but has no OAuth handler, so the generic `/api/oauth/[provider]/[action]` route hit `getProvider("zed")` and crashed. The route now recognizes keychain-import-only providers and returns a clear **400** pointing users at the **Import** button (for both GET and POST OAuth actions), instead of a 500. Regression guard: `tests/unit/oauth-keychain-import-only-6041.test.ts`. (thanks @imblowsnow)
+
 - **fix(providers):** disable the unsupported `thinking` param for `minimax-m2.7` on NVIDIA NIM (the upstream rejects it). Regression guard: `tests/unit/nvidia-minimax-thinking-strip.test.ts`. (thanks @anki1kr)
 
 - **fix(mitm):** add an in-process guard so concurrent MITM server starts no longer race — a second start while one is already in flight is short-circuited instead of double-binding the listener. Regression guard: `tests/unit/mitm-start-guard.test.ts`. (thanks @anki1kr)
diff --git a/src/app/api/oauth/[provider]/[action]/route.ts b/src/app/api/oauth/[provider]/[action]/route.ts
index 4bf2a1ba24..373f572b01 100755
--- a/src/app/api/oauth/[provider]/[action]/route.ts
+++ b/src/app/api/oauth/[provider]/[action]/route.ts
@@ -68,6 +68,40 @@ const RETIRED_PKCE_PROVIDERS = new Set(["windsurf", "devin-cli"]);
 /** Providers that allow direct import of a raw API token (no OAuth exchange). */
 const IMPORT_TOKEN_PROVIDERS = new Set(["windsurf", "devin-cli", "grok-cli"]);
 
+/**
+ * Providers that have NO browser OAuth flow at all — their credentials are read
+ * from the OS keychain via a dedicated Import button, not an OAuth
+ * authorize/exchange. They are listed in the OAuth provider *catalog*
+ * (so the dashboard shows them) but have no entry in the OAuth provider
+ * *handler* registry, so hitting the generic OAuth route for them threw an
+ * unhandled `Unknown provider: <id>` 500 (#6041). Return a clear, actionable
+ * response pointing at the Import flow instead.
+ */
+const KEYCHAIN_IMPORT_ONLY_PROVIDERS = new Set(["zed"]);
+
+/** GET/POST OAuth actions that don't apply to keychain-import-only providers. */
+const OAUTH_FLOW_ACTIONS = new Set([
+  "authorize",
+  "device-code",
+  "start-callback-server",
+  "poll-callback",
+  "exchange",
+  "poll",
+  "device-complete",
+]);
+
+function keychainImportOnlyResponse(provider: string) {
+  return NextResponse.json(
+    {
+      error:
+        `${provider} has no browser OAuth flow — it imports LLM credentials from the ` +
+        `OS keychain. Use the "Import" button on the ${provider} provider card in the ` +
+        `dashboard to discover and import them automatically.`,
+    },
+    { status: 400 }
+  );
+}
+
 /**
  * Constant-time string comparison to prevent timing-oracle attacks (CWE-208).
  * Handles null/undefined safely and different-length strings.
@@ -136,6 +170,14 @@ export async function GET(
         { status: 410 }
       );
     }
+    // Keychain-import-only providers (e.g. zed) have no OAuth flow — return a
+    // clear 400 pointing at the Import button instead of a 500 (#6041).
+    if (
+      KEYCHAIN_IMPORT_ONLY_PROVIDERS.has(earlyParams.provider) &&
+      OAUTH_FLOW_ACTIONS.has(earlyParams.action)
+    ) {
+      return keychainImportOnlyResponse(earlyParams.provider);
+    }
   } catch {
     /* fall through to normal handling */
   }
@@ -356,6 +398,13 @@ export async function POST(
         { status: 410 }
       );
     }
+    // Keychain-import-only providers (e.g. zed) have no OAuth flow (#6041).
+    if (
+      KEYCHAIN_IMPORT_ONLY_PROVIDERS.has(earlyParams.provider) &&
+      OAUTH_FLOW_ACTIONS.has(earlyParams.action)
+    ) {
+      return keychainImportOnlyResponse(earlyParams.provider);
+    }
   } catch {
     /* fall through to normal handling */
   }
diff --git a/tests/unit/oauth-keychain-import-only-6041.test.ts b/tests/unit/oauth-keychain-import-only-6041.test.ts
new file mode 100644
index 0000000000..d2363ea225
--- /dev/null
+++ b/tests/unit/oauth-keychain-import-only-6041.test.ts
@@ -0,0 +1,71 @@
+// Regression guard for #6041 — the generic OAuth route threw an unhandled
+// `Unknown provider: zed` 500 when the dashboard hit /api/oauth/zed/authorize.
+// Zed is a keychain-import-only provider (listed in the OAuth catalog so the UI
+// shows it, but with no OAuth handler), so the route now returns a clear 400
+// pointing at the Import flow instead of crashing.
+//
+// DB handles released in test.after (CLAUDE.md learning: unreleased SQLite
+// handles hang node:test).
+
+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-oauth-6041-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const settingsDb = await import("../../src/lib/db/settings.ts");
+const route = await import("../../src/app/api/oauth/[provider]/[action]/route.ts");
+
+test.before(async () => {
+  // The guard runs BEFORE the auth check, but disable login so any fall-through
+  // path is exercised without a 401 masking the result.
+  await settingsDb.updateSettings({ requireLogin: false });
+});
+
+test.after(async () => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+function get(provider: string, action: string) {
+  const request = new Request(`http://localhost:20128/api/oauth/${provider}/${action}`);
+  return route.GET(request, { params: Promise.resolve({ provider, action }) });
+}
+
+test("#6041 GET /oauth/zed/authorize returns a graceful 400, not a 500 'Unknown provider'", async () => {
+  const res = await get("zed", "authorize");
+  assert.equal(res.status, 400, "must be a clean 400, not a 500 crash");
+  const body = await res.json();
+  assert.ok(body.error, "error message present");
+  assert.match(body.error, /Import/i, "must point the user at the Import flow");
+  assert.doesNotMatch(body.error, /Unknown provider/i, "must not leak the raw 'Unknown provider' error");
+  // Never leak a stack trace (ERROR_SANITIZATION).
+  assert.doesNotMatch(body.error, /at \//, "must not leak a stack trace");
+});
+
+test("#6041 other keychain OAuth actions for zed are also handled gracefully", async () => {
+  for (const action of ["device-code", "exchange", "poll"]) {
+    const res = await get("zed", action);
+    assert.equal(res.status, 400, `zed/${action} must be a clean 400`);
+    const body = await res.json();
+    assert.match(body.error, /Import/i, `zed/${action} points at Import`);
+  }
+});
+
+test("#6041 POST /oauth/zed/exchange is also guarded (no 500)", async () => {
+  const request = new Request("http://localhost:20128/api/oauth/zed/exchange", {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify({}),
+  });
+  const res = await route.POST(request, {
+    params: Promise.resolve({ provider: "zed", action: "exchange" }),
+  });
+  assert.equal(res.status, 400);
+  const body = await res.json();
+  assert.match(body.error, /Import/i);
+});