config: one control-plane log for the process (#35028)

.claude/skills/sglang-runtime-context/SKILL.md

@@ -54,6 +54,32 @@ resolved configuration lives in the namespace bags.**
   There is **no write-through** to the `ServerArgs` instance — it stays pristine.
   There is no in-place mutation entry on the instance at all: it is read-only after
   resolution.
+- **Reading a leaf when the caller holds the field *name*** (a readback endpoint,
+  a control-plane handler): `get_context().config_leaf(name)` — the read side of
+  `override`. It resolves the flat name through the same `NS` map the write side
+  uses and raises on a name that is not a config leaf. Code that knows its field
+  when it is written reads the bag leaf directly; `config_leaf` is for
+  name-driven code, not a way around the seed ratchet.
+- **Post-startup control-plane changes** — a weight update, a HiCache mirror
+  attach, a parser resolved from the chat template — go through
+  `TokenizerManager.record_config_updates(source, **fields)`, a named wrapper
+  over `get_context().override`. One process keeps one log: the request dumps
+  ship `get_context().overrides_log()`, and `config_value(name)` /
+  `resolved_config_dict(base)` answer from the bags. The exposure ratchet
+  resolves the wrapper, so a field recorded through it joins the post-publish
+  override surface exactly like a direct `override` and needs the same ordering
+  judgment against any supplied-instance read of it
+  (`test_supplied_instance_exposure_ratchet.py`).
+- **`model_path` and `served_model_name` are answered off the manager.** Both are
+  `NS` leaves and `override` accepts them, but the tokenizer-side weight reload
+  records only `load_format` and writes the two path fields as `TokenizerManager`
+  attributes (`_MANAGER_OWNED_FIELDS`); `config_value` and `resolved_config_dict`
+  overlay them on top of the bags. Bags do not cross a process boundary (above),
+  so recording those two in the tokenizer process would leave every other
+  process's bag on the old path while the log claimed a process-wide change. The
+  scheduler rewrites its own copy where the reload happens —
+  `ModelRunner.update_model_fields` overrides `model_path` / `load_format` for
+  the target runner.
 - **Late launcher-stage resolution (pre-publish)**: a few rules cannot run inside
   `__post_init__` — LoRA normalization, and the auto-parser detection that needs a
   tokenizer/chat-template load. They are resolution, not mutation, and they write
@@ -143,6 +169,51 @@ bag to override at all.
   named `server_args`), and a factory whose contract is "build X from the record
   you are handed" (`create_kt_config_from_server_args`, `DllmConfig.from_server_args`).
 
+### Four ways a config sweep breaks something no test runs
+
+Each of these shipped in a review round and cost a real defect; each now has a
+guard, named here so the next sweep checks the same four things by hand first.
+
+1. **The other implementations of an interface.** Dropping a parameter means
+   auditing implementers, not just callers: `CustomSpecAlgo` is the plugin
+   base for speculative algorithms, and the dispatch calls it with the
+   built-in's argument list. Nothing in the tree implements it, so only a
+   plugin user hits the `TypeError`.
+   Guard: `test_plugin_hook_signatures.py`.
+2. **Publish order inside a process entry, not per file.** A file containing a
+   `publish` says nothing about whether a given read runs before it. Spawned
+   workers (`MMEncoder` for encoder DP/TP, the Ray scheduler actor) start with
+   an empty context, so a bag read above the publish raises only there.
+   Guard: `test_publish_precedes_bag_reads.py`.
+3. **The role namespace a process publishes under.** `ROLE_NAMESPACE_SETS`
+   narrows what each role may read; the DP controller is audited for `exec`
+   alone. A helper that reaches for another namespace passes every default-mode
+   test and aborts startup under `SGLANG_ROLE_NAMESPACES=enforce`. Prefer
+   answering from the caller's own namespaces over widening the set.
+4. **Sibling surfaces of a readback.** Changing what one entry point reports
+   means enumerating the others: HTTP, gRPC and in-process `Engine` each have
+   their own server-info and model-info, and each passes its own tests while
+   its users lose the field.
+   Guard: `test_effective_state_surfaces.py`.
+
+A fifth, from the same rounds: the accessor **name itself**. Called as an
+object member (`manager.get_disagg()`), or shadowed by a same-named import
+(`from model_loader import get_model` next to the model bag, where the later
+import silently wins and the loader call gets a zero-argument bag), it imports
+fine and fails only when that path runs. The invariant is one line: the name
+means the process-wide bag, takes no arguments, and is bound once per module.
+`ruff --select F811` catches the import collision; the member-call shapes are an
+`AttributeError` at call time only because `RuntimeContext` has no bag-named
+member and no `__getattr__` -- a delegating `__getattr__` would make them
+silent, and that is when this needs a guard again rather than a rule.
+
+Write these guards over a **derived** set, never a hand-kept list: an entry
+naming a function that no longer exists, or a field list missing the one field
+nobody migrated, passes green forever. Both happened here -- a `_ENTRY_POINTS`
+row for a method the Ray actor does not have, and an effective-field set
+without `load_format` -- and both were invisible because the assertion had
+slack (`>= len(...) - 1`) or compared key names instead of value sources.
+
 ### `get_parallel()`: config leaves vs live topology
 
 Config leaves (`nccl_port`, `enable_dp_attention`, `dp_size`, `ep_size`,
@@ -182,6 +253,9 @@ this).
   parallel bag's own leaf — are what see post-publish overrides. Only the
   instance-derived accessors (the ones with no leaf to read) answer from the
   startup record and therefore do not.
+- **a leaf the caller names at runtime** (a readback reporting a list of fields)
+  → `get_context().config_leaf(name)`; it resolves the name through `NS` and
+  raises on a non-leaf. A call site that knows its field reads the bag leaf.
 - **the live topology** → `get_parallel()`.
 - **a value derived from published leaves** → an accessor in `runtime_context` that
   derives it *from the bags*: `mamba_extra_buffer_enabled()` /

python/sglang/srt/managers/tokenizer_manager.py

@@ -122,6 +122,7 @@ from sglang.srt.observability.request_metrics_exporter import (
 )
 from sglang.srt.observability.trace import SpanAttributes, extract_trace_headers
 from sglang.srt.runtime_context import (
+    get_context,
     get_device,
     get_disagg,
     get_exec,
@@ -379,8 +380,6 @@ class InputFormat(Enum):
     CROSS_ENCODER_PAIRS = 3  # Cross-encoder pairs like [["query", "document"]]
 
 
-_SERVER_ARGS_FIELDS = frozenset(f.name for f in dataclasses.fields(ServerArgs))
-
 _MANAGER_OWNED_FIELDS = ("model_path", "served_model_name")
 
 
@@ -410,7 +409,6 @@ class TokenizerManager(TokenizerControlMixin, TokenizerManagerScoreMixin):
         # the in-process path re-projects the object the launcher published.
         set_global_server_args_for_tokenizer(server_args)
         self.startup_time: Optional[Dict[str, Any]] = None
-        self._config_updates: List[Tuple[str, Dict[str, Any]]] = []
         self.elastic_worker_count = get_parallel().dp_size
         self.elastic_pending_ep_size = None
         self.elastic_scale_phase = "idle"
@@ -2065,31 +2063,19 @@ class TokenizerManager(TokenizerControlMixin, TokenizerManagerScoreMixin):
         return success, message, num_paused_requests
 
     def record_config_updates(self, source: str, **fields) -> None:
-        """Record a control-plane config change for this engine.
+        """Record a control-plane config change: a weight update, a parser
+        resolved from the chat template, a HiCache mirror attach.
 
-        These are post-startup facts the config bags do not model (weight
+        These land in the config bags like every other post-publish change, so
-        version, model path, the tokenizer's HiCache mirror); the readback
+        one log carries the provenance for the whole process.
-        endpoints overlay them onto the startup config. The process-global
-        sibling is ``RuntimeContext.override`` / ``resolved_server_args_dict``,
-        which writes the config bags.
         """
-        unknown = sorted(f for f in fields if f not in _SERVER_ARGS_FIELDS)
+        get_context().override(source, **fields)
-        if unknown:
-            raise ValueError(
-                f"{unknown} are not ServerArgs fields; the readback endpoints "
-                "overlay these onto a serialized ServerArgs, so an unknown key "
-                "would surface as a phantom config entry."
-            )
-        self._config_updates.append((source, dict(fields)))
 
     def config_value(self, name: str):
-        """The value in effect for one config field, control-plane updates first."""
+        """The value in effect for one config field."""
         if name in _MANAGER_OWNED_FIELDS:
             return getattr(self, name)
-        for _source, fields in reversed(self._config_updates):
+        return get_context().config_leaf(name)
-            if name in fields:
-                return fields[name]
-        return getattr(self.server_args, name)
 
     def _dump_config_snapshot(self) -> Optional[Dict[str, Any]]:
         """The config in effect, or None when it cannot be serialized.
@@ -2104,18 +2090,18 @@ class TokenizerManager(TokenizerControlMixin, TokenizerManagerScoreMixin):
             return None
 
     def resolved_config_dict(self, base: Dict[str, Any]) -> Dict[str, Any]:
-        """``base`` (a serialized ``ServerArgs``) with the control-plane updates on top."""
+        """``base`` (a serialized ``ServerArgs``) with the control-plane changes on top."""
-        resolved = dict(base)
+        resolved = get_context().resolved_server_args_dict(base)
-        for _source, fields in self._config_updates:
-            resolved.update(fields)
         for name in _MANAGER_OWNED_FIELDS:
             resolved[name] = getattr(self, name)
         return resolved
 
     def _update_model_path_info(self, model_path: str, load_format: str):
+        # These two stay on the manager: the readback reads them from here,
+        # and a bag write would not reach the other processes anyway.
         self.served_model_name = model_path
-        self.record_config_updates("tokenizer.update_weights", load_format=load_format)
         self.model_path = model_path
+        self.record_config_updates("tokenizer.update_weights", load_format=load_format)
 
     async def _wait_for_model_update_from_disk(
         self, obj: UpdateWeightFromDiskReqInput
@@ -2986,7 +2972,7 @@ class TokenizerManager(TokenizerControlMixin, TokenizerManagerScoreMixin):
         logger.info(log_message)
         to_dump_with_server_args = {
             "server_args": self.server_args,
-            "config_updates": list(self._config_updates),
+            "config_updates": get_context().overrides_log(),
             "resolved_config": self._dump_config_snapshot(),
             "requests": data_list.copy(),
         }
@@ -3071,7 +3057,7 @@ class TokenizerManager(TokenizerControlMixin, TokenizerManagerScoreMixin):
                 # Write the data to the file
                 data_to_dump_with_server_args = {
                     "server_args": self.server_args,
-                    "config_updates": list(self._config_updates),
+                    "config_updates": get_context().overrides_log(),
                     "resolved_config": self._dump_config_snapshot(),
                     "requests": data_to_dump,
                     "launch_command": " ".join(sys.argv),

python/sglang/srt/runtime_context.py

@@ -903,6 +903,29 @@ class RuntimeContext:
             bag._set(name, value)
         self._overrides_log.append((source, dict(fields)))
 
+    def config_leaf(self, name: str):
+        """One resolved config leaf by field name — the read side of ``override``.
+
+        Callers that hold a field name rather than a namespace (a readback
+        endpoint, a control-plane handler) would otherwise have to know which
+        bag it lives in.
+        """
+        bags = self._config_bags
+        if bags is None:
+            raise ValueError("config not published; cannot read a config leaf")
+        from sglang.srt.arg_groups.arg_utils import namespace_of
+
+        path = namespace_of(type(self._server_args)).get(name)
+        if path is None:
+            raise ValueError(f"{name!r} is not a config leaf (no NS namespace)")
+        parts = path.split(".")
+        bag = self.config_bag(parts[0])
+        for seg in parts[1:]:
+            bag = object.__getattribute__(bag, "_subs").get(seg)
+            if bag is None:
+                raise ValueError(f"subgroup {seg!r} missing under {path!r}")
+        return getattr(bag, name)
+
     def overrides_log(self) -> list:
         """Provenance of post-publish ``override`` calls: ``[(source, {field: value})]``.
 
@@ -925,12 +948,14 @@ class RuntimeContext:
         ``ServerArgs`` field names, so overlaying them onto the top level of
         either base is exact.
 
-        This covers the process-global bags only. Control-plane facts the bags
+        The log is per process: it carries what *this* process overrode. A
-        do not model (weight version, model path, the tokenizer's HiCache
+        weight reload records ``model_path`` and ``load_format`` from the
-        mirror) live on the tokenizer manager, and
+        scheduler process (``ModelRunner.update_model_fields``); the tokenizer
-        ``TokenizerManager.resolved_config_dict`` overlays those for the
+        process records only ``load_format`` and keeps ``model_path`` /
-        top-level ``/server_info`` body. The two are separate logs, not one
+        ``served_model_name`` as ``TokenizerManager`` attributes, which
-        merged dict.
+        ``TokenizerManager.resolved_config_dict`` overlays on top of this dump.
+        The top-level ``/server_info`` fields are the startup record, not this
+        dump.
         """
         d = dict(vars(self.server_args)) if base is None else dict(base)
         for _source, fields in self._overrides_log:

test/registered/unit/entrypoints/openai/test_serving_chat.py

@@ -75,7 +75,9 @@ class _MockTokenizerManager:
         self.model_path = self.server_args.model_path
         # The manager tracks the served name itself; a weight update rewrites it.
         self.served_model_name = "test-model"
-        self._config_updates = []
+        # Stands in for the context's resolved leaves: an override replaces the
+        # field's one live value, the seed stays on server_args.
+        self._config_overrides = {}
 
         # Mock hf_config for _resolve_chat_encoding_spec check
         mock_hf_config = Mock()
@@ -114,10 +116,9 @@ class _MockTokenizerManager:
         self.request_logger = Mock(log_requests=False, log_requests_level=0)
 
     def config_value(self, name: str):
-        """The manager's overlay accessor: no control-plane update recorded."""
+        """The value in effect for one config field."""
-        for _source, fields in reversed(self._config_updates):
+        if name in self._config_overrides:
-            if name in fields:
+            return self._config_overrides[name]
-                return fields[name]
         return getattr(self.server_args, name)
 
 
@@ -160,15 +161,12 @@ class ServingChatTestCase(unittest.TestCase):
         self.fastapi_request.headers = {}
 
     def test_parsers_follow_the_control_plane_overlay(self):
-        """Template detection records the parsers on the manager, not on its
+        """Template detection records the parsers through `override`, so they
-        ServerArgs — the instance keeps what the launcher passed."""
+        answer from the bags; `ServerArgs` keeps the launcher's seed."""
         self.tm.server_args.tool_call_parser = "auto"
         self.tm.server_args.reasoning_parser = "auto"
-        self.tm._config_updates.append(
+        self.tm._config_overrides.update(
-            (
+            {"tool_call_parser": "qwen25", "reasoning_parser": None}
-                "template-detection",
-                {"tool_call_parser": "qwen25", "reasoning_parser": None},
-            )
         )
 
         chat = OpenAIServingChat(self.tm, self.template_manager)
@@ -180,9 +178,7 @@ class ServingChatTestCase(unittest.TestCase):
     def test_the_xgrammar_gate_follows_the_overlay(self):
         """A detected `reasoning_parser` must gate xgrammar, not the seed's "auto"."""
         self.tm.server_args.reasoning_parser = "auto"
-        self.tm._config_updates.append(
+        self.tm._config_overrides["reasoning_parser"] = "qwen3"
-            ("template-detection", {"reasoning_parser": "qwen3"})
-        )
         chat = OpenAIServingChat(self.tm, self.template_manager)
         self.assertEqual(chat.reasoning_parser, "qwen3")
         # the gate reads the same value the parser was built from

test/registered/unit/entrypoints/openai/utils.py

@@ -54,7 +54,9 @@ class MockTokenizerManager:
             tool_call_parser=None,
             incremental_streaming_output=False,
         )
-        self._config_updates = []
+        # Stands in for the context's resolved leaves: an override replaces the
+        # field's one live value, the seed stays on server_args.
+        self._config_overrides = {}
         self.tokenizer = Mock()
         self.tokenizer.encode.return_value = [1, 2, 3]
         self.tokenizer.chat_template = None
@@ -64,10 +66,9 @@ class MockTokenizerManager:
         self.create_abort_task = Mock()
 
     def config_value(self, name: str):
-        """The manager's overlay accessor: no control-plane update recorded."""
+        """The value in effect for one config field."""
-        for _source, fields in reversed(self._config_updates):
+        if name in self._config_overrides:
-            if name in fields:
+            return self._config_overrides[name]
-                return fields[name]
         return getattr(self.server_args, name)
 
 

test/registered/unit/entrypoints/test_server_info.py

@@ -43,15 +43,13 @@ def _stub_tokenizer_manager(
     """A manager carrying the state `/server_info` and its writers read.
 
     `__new__` skips `__init__`, which would open the ZMQ sockets and start
-    the handle loop; `_config_updates` is the log `record_config_updates`
+    the handle loop.
-    appends to.
     """
     tokenizer_manager = TokenizerManager.__new__(TokenizerManager)
     tokenizer_manager.server_args = server_args
     tokenizer_manager.model_path = server_args.model_path
     tokenizer_manager.served_model_name = server_args.served_model_name
     tokenizer_manager.startup_time = None
-    tokenizer_manager._config_updates = []
     tokenizer_manager.get_internal_state = get_internal_state
     return tokenizer_manager
 

test/registered/unit/managers/test_tokenizer_config_updates.py

@@ -1,9 +1,9 @@
-"""Control-plane config updates stay on the tokenizer manager.
+"""Control-plane config updates go into the process log, not onto the record.
 
 Regression: runtime updates (weight version, model path, HiCache attach) were
 written onto the manager's ServerArgs instance so that the readback endpoints
-would show them. The record stays pristine; the updates live in a separate log
+would show them. The record stays pristine; the update lands in the runtime
-that the endpoints overlay on top of it.
+context, which is where a reader of any field asks for the value in effect.
 """
 
 import re
@@ -12,6 +12,7 @@ from pathlib import Path
 
 import sglang
 from sglang.srt.managers.tokenizer_manager import TokenizerManager
+from sglang.srt.runtime_context import get_context, publish, reset_context
 from sglang.srt.server_args import ServerArgs
 from sglang.test.ci.ci_register import register_cpu_ci
 from sglang.test.test_utils import CustomTestCase
@@ -19,28 +20,31 @@ from sglang.test.test_utils import CustomTestCase
 register_cpu_ci(est_time=5, suite="base-a-test-cpu")
 
 
-def _manager(**fields):
+def _manager(case, **fields):
+    """A manager over a published config: the updates it records go to the bags."""
+    server_args = ServerArgs(model_path="dummy", **fields)
+    publish(server_args, role="tokenizer")
+    case.addCleanup(reset_context)
     manager = TokenizerManager.__new__(TokenizerManager)
-    manager.server_args = ServerArgs(model_path="dummy", **fields)
+    manager.server_args = server_args
-    manager._config_updates = []
     return manager
 
 
 class TestTokenizerConfigUpdates(CustomTestCase):
     def test_startup_config_shows_through_until_something_updates_it(self):
-        manager = _manager(weight_version="v1")
+        manager = _manager(self, weight_version="v1")
         self.assertEqual(manager.config_value("weight_version"), "v1")
 
         manager.record_config_updates("test", weight_version="v2")
         self.assertEqual(manager.config_value("weight_version"), "v2")
 
     def test_the_serverargs_instance_is_not_written(self):
-        manager = _manager(weight_version="v1")
+        manager = _manager(self, weight_version="v1")
         manager.record_config_updates("test", weight_version="v2")
         self.assertEqual(manager.server_args.weight_version, "v1")
 
     def test_the_readback_dict_carries_the_updates(self):
-        manager = _manager(hicache_storage_backend=None)
+        manager = _manager(self, hicache_storage_backend=None)
         manager.record_config_updates(
             "test", hicache_storage_backend="file", hicache_write_policy="write_through"
         )
@@ -54,7 +58,7 @@ class TestTokenizerConfigUpdates(CustomTestCase):
         self.assertEqual(resolved["model_path"], "dummy")
 
     def test_detach_reports_the_backend_as_gone(self):
-        manager = _manager(hicache_storage_backend="file")
+        manager = _manager(self, hicache_storage_backend="file")
         manager.record_config_updates(
             "test",
             hicache_storage_backend=None,
@@ -63,22 +67,27 @@ class TestTokenizerConfigUpdates(CustomTestCase):
         self.assertIsNone(manager.config_value("hicache_storage_backend"))
 
     def test_an_unknown_field_is_refused(self):
-        manager = _manager()
+        manager = _manager(self)
-        with self.assertRaisesRegex(ValueError, "not ServerArgs fields"):
+        with self.assertRaisesRegex(ValueError, "not a resolved config leaf"):
             manager.record_config_updates("test", waight_version="v2")
 
+    def test_a_name_that_is_not_a_config_leaf_is_refused(self):
+        manager = _manager(self)
+        with self.assertRaisesRegex(ValueError, "not a config leaf"):
+            manager.config_value("waight_version")
+
     def test_the_source_is_kept_for_provenance(self):
-        manager = _manager(weight_version="v1")
+        manager = _manager(self, weight_version="v1")
         manager.record_config_updates("http.update_weight_version", weight_version="v2")
         self.assertEqual(
-            manager._config_updates,
+            get_context().overrides_log(),
             [("http.update_weight_version", {"weight_version": "v2"})],
         )
 
     def test_the_dump_snapshot_identifies_the_running_checkpoint(self):
         import dataclasses
 
-        manager = _manager(load_format="auto")
+        manager = _manager(self, load_format="auto")
         manager.model_path = "at-startup"
         manager.served_model_name = "at-startup"
         manager._update_model_path_info("after-reload", "dummy")
@@ -87,6 +96,10 @@ class TestTokenizerConfigUpdates(CustomTestCase):
         self.assertEqual(snapshot["model_path"], "after-reload")
         self.assertEqual(snapshot["served_model_name"], "after-reload")
         self.assertEqual(snapshot["load_format"], "dummy")
+        self.assertEqual(
+            get_context().overrides_log(),
+            [("tokenizer.update_weights", {"load_format": "dummy"})],
+        )
         self.assertEqual(manager.server_args.model_path, "dummy")
 
     def test_an_unsnapshotable_config_does_not_lose_the_dump(self):
@@ -94,7 +107,7 @@ class TestTokenizerConfigUpdates(CustomTestCase):
             def __deepcopy__(self, memo):
                 raise RuntimeError("refuses to be copied")
 
-        manager = _manager()
+        manager = _manager(self)
         manager.model_path = "dummy"
         manager.served_model_name = "dummy"
         manager.server_args.custom_sigquit_handler = Hostile()
@@ -105,7 +118,7 @@ class TestTokenizerConfigUpdates(CustomTestCase):
         import dataclasses
         import pickle
 
-        manager = _manager()
+        manager = _manager(self)
         manager.model_path = "dummy"
         manager.served_model_name = "dummy"
         # What --custom-sigquit-handler leaves on a real ServerArgs.
@@ -113,7 +126,7 @@ class TestTokenizerConfigUpdates(CustomTestCase):
 
         payload = {
             "server_args": manager.server_args,
-            "config_updates": list(manager._config_updates),
+            "config_updates": get_context().overrides_log(),
             "resolved_config": manager.resolved_config_dict(
                 dataclasses.asdict(manager.server_args)
             ),
@@ -128,7 +141,7 @@ class TestTokenizerConfigUpdates(CustomTestCase):
         self.assertTrue(pickle.dumps(payload))
 
     def test_the_model_path_readback_follows_the_manager(self):
-        manager = _manager()
+        manager = _manager(self)
         manager.model_path = "after-update"
         manager.served_model_name = "after-update"
         resolved = manager.resolved_config_dict({"model_path": "at-startup"})
@@ -200,8 +213,9 @@ class TestControlPlaneFieldsAreNotReadFromTheInstance(CustomTestCase):
         self.assertEqual(
             stale,
             [],
-            "control-plane fields change at runtime and the update lives on the "
+            "control-plane fields change at runtime and the update lands in "
-            "TokenizerManager; read them with config_value() / "
+            "the process bags (model_path / served_model_name stay manager "
+            "attributes); read them with config_value() / "
             "resolved_config_dict() so the readback reflects the change:\n"
             + "\n".join(stale),
         )

test/registered/unit/test_supplied_instance_exposure_ratchet.py

@@ -367,6 +367,8 @@ _EXPOSED_CUDA_ONLY: frozenset = frozenset()
 # some code overrides post-publish. Each needs an ordering judgment, not a blanket
 # conversion; the list exists so a new one is a decision made when it is written.
 _OVERRIDDEN_AND_READ = {
+    ("entrypoints/engine.py", "reasoning_parser"),
+    ("entrypoints/engine.py", "tool_call_parser"),
     ("configs/model_config.py", "dtype"),
     ("configs/model_config.py", "model_path"),
     ("disaggregation/decode_kvcache_offload_manager.py", "hicache_storage_backend"),
@@ -442,11 +444,53 @@ def _expanded_override_keys(rel, tree, call, kw) -> set:
         ):
             return set()
 
+    def loop_variable_values(name: str) -> set:
+        """The values a `for name, ... in (<literal tuples>)` loop binds.
+
+        A handler that records one field per loop iteration spells the field
+        names in the loop's own literal, so they are still static.
+        """
+        values = set()
+        for node in ast.walk(tree):
+            if not isinstance(node, ast.For):
+                continue
+            target = node.target
+            names = (
+                [target]
+                if isinstance(target, ast.Name)
+                else list(getattr(target, "elts", []))
+            )
+            if not names or not isinstance(names[0], ast.Name) or names[0].id != name:
+                continue
+            if not (node.lineno <= call.lineno <= (node.end_lineno or node.lineno)):
+                continue
+            for item in getattr(node.iter, "elts", []):
+                first = (
+                    item.elts[0] if isinstance(item, ast.Tuple) and item.elts else item
+                )
+                if isinstance(first, ast.Constant) and isinstance(first.value, str):
+                    values.add(first.value)
+        return values
+
     def dict_keys(node) -> set:
-        assert isinstance(node, ast.Dict) and all(
+        assert isinstance(
-            isinstance(key, ast.Constant) for key in node.keys
+            node, ast.Dict
         ), f"non-literal dict in override expansion at {rel}:{call.lineno}"
-        return {key.value for key in node.keys}
+        keys = set()
+        for key in node.keys:
+            if isinstance(key, ast.Constant):
+                keys.add(key.value)
+                continue
+            assert isinstance(
+                key, ast.Name
+            ), f"non-literal dict key in override expansion at {rel}:{call.lineno}"
+            bound = loop_variable_values(key.id)
+            assert bound, (
+                f"dict key {key.id!r} at {rel}:{call.lineno} is not bound by a "
+                "literal loop; extend the resolver"
+            )
+            keys |= bound
+        return keys
 
     if isinstance(kw.value, ast.Dict):
         return dict_keys(kw.value)
@@ -941,17 +985,29 @@ class TestSuppliedInstanceExposure(CustomTestCase):
                 raise AssertionError(f"unparsable module in the census: {rel}")
             for node in ast.walk(tree):
                 if not (
-                    isinstance(node, ast.Call)
+                    isinstance(node, ast.Call) and isinstance(node.func, ast.Attribute)
-                    and isinstance(node.func, ast.Attribute)
-                    and node.func.attr == "override"
                 ):
                     continue
                 base = node.func.value
-                if (
+                is_override = node.func.attr == "override" and (
                     isinstance(base, ast.Call)
                     and isinstance(base.func, ast.Name)
                     and base.func.id == "get_context"
-                ):
+                )
+                # `record_config_updates` is a named wrapper over override, so
+                # its call sites are override sites. Its body forwards **kwargs
+                # and names no field, so skip the forwarding call itself.
+                is_wrapper = node.func.attr == "record_config_updates"
+                if not (is_override or is_wrapper):
+                    continue
+                inside_wrapper = any(
+                    isinstance(fn, (ast.FunctionDef, ast.AsyncFunctionDef))
+                    and fn.name == "record_config_updates"
+                    and fn.lineno <= node.lineno <= (fn.end_lineno or fn.lineno)
+                    for fn in ast.walk(tree)
+                )
+                if inside_wrapper:
+                    continue
                 for kw in node.keywords:
                     if kw.arg == "source":
                         # Override metadata, not a config field.