sgl-router: experimental Rust HTTP router for SGLang worker pools (#25851)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

experimental/sgl-router/tests/e2e/test_tokenize_smoke.py

@@ -0,0 +1,37 @@
+"""
+Smoke test for /v1/tokenize and /v1/detokenize round-trip.
+"""
+
+from __future__ import annotations
+
+import httpx
+
+MODEL = "Qwen/Qwen3-0.6B"
+TEXT = "Hello, world!"
+
+
+def test_tokenize_round_trip(router: str) -> None:
+    """POST /v1/tokenize then /v1/detokenize must recover the original text."""
+    # Tokenize
+    tok_resp = httpx.post(
+        f"{router}/v1/tokenize",
+        json={"model": MODEL, "prompt": TEXT},
+        timeout=30,
+    )
+    assert tok_resp.status_code == 200, tok_resp.text
+    tokens = tok_resp.json()["tokens"]
+    assert (
+        isinstance(tokens, list) and len(tokens) > 0
+    ), f"Expected non-empty token list, got: {tokens}"
+
+    # Detokenize
+    detok_resp = httpx.post(
+        f"{router}/v1/detokenize",
+        json={"model": MODEL, "tokens": tokens},
+        timeout=30,
+    )
+    assert detok_resp.status_code == 200, detok_resp.text
+    recovered = detok_resp.json()["text"]
+    assert (
+        TEXT in recovered or recovered in TEXT
+    ), f"Round-trip mismatch: original={TEXT!r}, recovered={recovered!r}"