diff --git a/.env.example b/.env.example
index 3335784a6c..26d6ee99e7 100644
--- a/.env.example
+++ b/.env.example
@@ -598,6 +598,11 @@ PROVIDER_LIMITS_SYNC_SPACING_MS=1500
 # Used by: scripts/postinstall.mjs.
 #OMNIROUTE_SKIP_POSTINSTALL=0
 
+# Operator-supplied JSON credentials for the offline compression-eval CLI
+# (parsed with JSON.parse; leave unset for a dry run). Developer tooling only.
+# Used by: scripts/compression-eval/index.ts.  Default: {} (empty).
+#OMNIROUTE_EVAL_CREDENTIALS={}
+
 # Skip the DB healthcheck entirely on startup (useful for short-lived tasks / tests).
 # Used by: src/lib/db/core.ts, src/lib/db/healthCheck.ts.  Set to 1 to disable.  Default: 0.
 #OMNIROUTE_SKIP_DB_HEALTHCHECK=0
diff --git a/docs/reference/ENVIRONMENT.md b/docs/reference/ENVIRONMENT.md
index ffebb7a27d..ad9a789b52 100644
--- a/docs/reference/ENVIRONMENT.md
+++ b/docs/reference/ENVIRONMENT.md
@@ -1082,3 +1082,12 @@ is developer tooling only.
 | `OMNIROUTE_URL`    | `http://localhost:20128` | `scripts/ad-hoc/regen-opencode-config.ts` | Base URL of the OmniRoute instance to query for `/v1/models`.                                                             |
 | `OMNIROUTE_KEY`    | _(unset)_                | `scripts/ad-hoc/regen-opencode-config.ts` | API key to authenticate against the OmniRoute `/v1/models` endpoint. Falls back to `OPENCODE_API_KEY` when unset.         |
 | `OPENCODE_API_KEY` | _(unset)_                | `scripts/ad-hoc/regen-opencode-config.ts` | OpenCode-style API key (`sk-...`) written into the regenerated `opencode.json`. Falls back to `OMNIROUTE_KEY` when unset. |
+
+### Compression offline-eval harness (ad-hoc tooling)
+
+Used by `scripts/compression-eval/index.ts`, the offline compression evaluation CLI.
+Not required for normal operation — developer tooling only.
+
+| Variable                    | Default      | Source File                       | Description                                                                                                                                              |
+| --------------------------- | ------------ | --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `OMNIROUTE_EVAL_CREDENTIALS` | `{}` (empty) | `scripts/compression-eval/index.ts` | Operator-supplied JSON credentials for the provider exercised by the offline compression-eval CLI (parsed with `JSON.parse`). Leave unset for a dry run. |
diff --git a/src/app/api/settings/compression/run-telemetry/route.ts b/src/app/api/settings/compression/run-telemetry/route.ts
index 04288d713c..d5e797a75f 100644
--- a/src/app/api/settings/compression/run-telemetry/route.ts
+++ b/src/app/api/settings/compression/run-telemetry/route.ts
@@ -1,9 +1,14 @@
-import { NextResponse } from "next/server";
+import { NextRequest, NextResponse } from "next/server";
+import { isAuthenticated } from "@/shared/utils/apiAuth";
 import { getCompressionRunTelemetrySummary } from "@/lib/db/compressionRunTelemetry";
 
 export const dynamic = "force-dynamic";
 
-export async function GET() {
+export async function GET(request: NextRequest) {
+  if (!(await isAuthenticated(request))) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
   try {
     const summary = getCompressionRunTelemetrySummary();
     return NextResponse.json(summary);
diff --git a/tests/unit/compression-run-telemetry-auth.test.ts b/tests/unit/compression-run-telemetry-auth.test.ts
new file mode 100644
index 0000000000..cabfb66384
--- /dev/null
+++ b/tests/unit/compression-run-telemetry-auth.test.ts
@@ -0,0 +1,45 @@
+/**
+ * Security regression (#4694 sibling-path gate parity): the compression
+ * run-telemetry route MUST authenticate before disclosing telemetry, mirroring
+ * its sibling `settings/compression/route.ts`. A behavioral 401 test would need
+ * full DB/settings bootstrap (isAuthenticated reads settings), so this is a
+ * source guard that fails if the auth gate is removed or reordered after the
+ * data call — the same wiring-guard pattern used elsewhere in the suite.
+ */
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import { dirname, join } from "node:path";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const ROUTE = join(
+  __dirname,
+  "../../src/app/api/settings/compression/run-telemetry/route.ts"
+);
+
+test("run-telemetry GET imports isAuthenticated from the shared auth util", () => {
+  const src = readFileSync(ROUTE, "utf8");
+  assert.match(src, /import\s*\{[^}]*\bisAuthenticated\b[^}]*\}\s*from\s*["']@\/shared\/utils\/apiAuth["']/);
+});
+
+test("run-telemetry GET gates on auth and returns 401 before reading telemetry", () => {
+  const src = readFileSync(ROUTE, "utf8");
+
+  const authIdx = src.indexOf("isAuthenticated(request)");
+  const unauthorizedIdx = src.search(/status:\s*401/);
+  const dataIdx = src.indexOf("getCompressionRunTelemetrySummary(");
+
+  assert.ok(authIdx > 0, "must call isAuthenticated(request)");
+  assert.ok(unauthorizedIdx > 0, "must return a 401 on failed auth");
+  assert.ok(dataIdx > 0, "must call getCompressionRunTelemetrySummary");
+
+  // The auth check and its 401 must come BEFORE the telemetry read.
+  assert.ok(authIdx < dataIdx, "auth check must precede the telemetry read");
+  assert.ok(unauthorizedIdx < dataIdx, "401 response must precede the telemetry read");
+});
+
+test("run-telemetry GET receives the request object (so auth can read it)", () => {
+  const src = readFileSync(ROUTE, "utf8");
+  assert.match(src, /export\s+async\s+function\s+GET\s*\(\s*request\s*:/);
+});