config: ServerArgs holds the raw input (#36255)

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

@@ -22,12 +22,18 @@ flags/resources/forward tiers.
 
 ## Config: publish + namespace bags
 
-**`ServerArgs` is a pristine seed. Business code never reads it for decisions —
-resolved configuration lives in the namespace bags.**
+**`ServerArgs` holds the raw input and nothing else. Resolution writes no field:
+it declares, and the declarations are what the namespace bags are projected from.
+Business code never reads the record for a decision — and after this cut, a field
+read there answers with what the operator typed, not with what resolution
+decided.**
 
 - Every publishing process entry calls `publish(server_args, role=...)`
   (`run_scheduler_process`, the Ray `SchedulerActor`, the DP controller, tokenizer,
-  detokenizer, encoder, weight-cache daemon, ...); the roles are enumerated once,
+  detokenizer, encoder, weight-cache daemon, the multi-tokenizer worker, the
+  spawned encoder TP/DP workers, the benchmark work functions, ...); constructors
+  do not publish — `ModelRunner`, `TokenizerManager` and `MMEncoder` call
+  `assert_published` and fail loudly if an entry forgot. The roles are enumerated once,
   as the keys of `ROLE_NAMESPACE_SETS` — there is no `launcher` role, the launch
   path publishes as `tokenizer`. The remaining non-publisher is
   `run_multi_detokenizer_router_process`: it *is* handed a `ServerArgs`, and uses
@@ -82,13 +88,15 @@ resolved configuration lives in the namespace bags.**
   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
-  **in place** via `arg_groups.overrides.declare_late_resolution(server_args,
-  source, **fields)`, which refuses the published instance. In place is the point:
-  every holder of that object must see the resolved value — the HTTP server, the
-  multi-tokenizer workers it is serialized for, the schedulers it forks. Returning a
-  variant here is a bug: the launcher rebinds its local and everyone else keeps the
-  unresolved object.
+  tokenizer/chat-template load. They are resolution, not mutation, and they
+  **declare** via `arg_groups.overrides.declare_late_resolution(server_args,
+  source, **fields)`, which refuses the published instance. The declaration lands
+  in the stash on that very object, so every holder of it carries the decision —
+  the HTTP server, the multi-tokenizer workers it is serialized for, the
+  schedulers it forks — and each of them publishes bags projected from it. The
+  fields stay the operator's input; `resolution_result(sa, field)` and the bags
+  are what answer for the decision. Returning a variant here is a bug: the
+  launcher rebinds its local and everyone else keeps the unresolved object.
 - **A value another runner / worker owns is a constructor argument, not a config
   copy.** The draft worker's `context_length`, load format and attention backend
   travel as arguments to `TpModelWorker` / `ModelRunner` and live on the runner
@@ -99,8 +107,8 @@ resolved configuration lives in the namespace bags.**
 
 **Why a bag override cannot stand in for late resolution or per-runner
 construction.** The bags are projected at
-publish *from the instance's fields*, so anything the runtime must read has to be on
-the instance before publish — an override afterwards puts instance and bags back out
+publish *from the declarations over the instance's raw fields*, so anything the
+runtime must read has to be declared before publish — an override afterwards puts instance and bags back out
 of agreement, and whole-object readers (`ModelConfig.from_server_args`,
 `build_load_config`, `MMEncoder`'s own `self.server_args.X`) never see it. And bags do
 not cross a process boundary: a child publishes from the object it receives and
@@ -114,7 +122,8 @@ bag to override at all.
 - **Per-runner values** — there is no per-runner `ServerArgs` any more. The
   draft-worker config copy is gone: every worker (`TpModelWorker`, the draft
   workers in `speculative/`) is handed the *same* instance the process published,
-  so `self.server_args.X` and the bag leaf agree **at publish** — a
+  so a bag leaf is the decision and `self.server_args.X` is the operator's
+  input — a
   post-publish `override` moves only the bag, which is exactly why a field that
   is process-wide config (`attention_backend`, `skip_tokenizer_init`,
   `kv_cache_dtype`) reads from the bags like any other, and why a residual
@@ -320,9 +329,9 @@ what sits beside it is residue, not a family — and not for one single reason:
   without publishing has to keep patching the factory (or publish itself);
 - `MMEncoder` publishes the very instance it is handed (`publish(server_args,
   role="encoder")`) and takes its per-worker device as a separate `gpu_id`
-  argument, so its `self.server_args` reads and the bag agree today. They are on
-  this list as a construction-path convention rather than a semantic exception —
-  and the residual is real: a post-publish `override` would not reach them.
+  argument. Its `self.server_args` reads are on this list as a construction-path
+  convention, and the residual is real: they answer with the raw input, so a leaf
+  resolution decided and a post-publish `override` both pass them by.
 
 Their tests are not one story: a `GrammarManager` built standalone turns the
 factory's bag read into "config namespace not published" unless the test patches
@@ -357,14 +366,30 @@ if you do it, say so in the test.
 
 ### Mid-resolution reads (inside the pipeline only)
 
-Resolution itself still runs in `__post_init__`: handlers and hooks read the
-in-flight state through `resolved_view(server_args)` / `self._resolved()`, fields are
-read-only during resolution, and declarations materialize once at the very end of
-`__post_init__` (gate order, last writer wins) — *then* `publish` snapshots the
-resolved values into the bags. `resolved_view` is pipeline-internal
-(`server_args.py` / `arg_groups/`, plus helpers the pipeline itself invokes
-mid-resolution, e.g. `adaptive_spec_params`); do not introduce new
-out-of-pipeline call sites.
+Resolution runs in `__post_init__` and **writes nothing onto the record**: a
+handler declares (`self._declare` / `declare_resolution`), the declaration goes
+into the stash, and the fields keep what the caller passed. So a mid-resolution
+read of a field answers with the *raw input* — every reader in the pipeline goes
+through a view instead:
+
+- `resolving_view(server_args)` / `self._resolved()` — the live view (walks the
+  stash per read). This is what handlers and hooks bind, conventionally as
+  `cfg = resolving_view(self)` at the top of the handler.
+- `resolved_view(server_args)` — snapshots the overlay when built, which is what
+  a post-process pass wants: it reads the state at *its* slot.
+
+`test_resolution_reads_the_declarations` pins direct field reads at zero over the
+two scopes it can derive exactly (every `arg_groups` function taking a config,
+every `ServerArgs` handler the dispatcher reaches). Readers the pipeline calls
+from elsewhere (`ModelConfig`, the platform defaults, the spec-algo hook) have
+moved to the view as well — a field read there is the same bug, just one the
+derivation cannot enumerate.
+
+One consequence worth knowing: because the fields are the raw input, resolving a
+bare `dataclasses.replace` copy lands in the same place as the parent — the
+pipeline reads only its own input. `replace_resolved` is the way to copy a
+resolved record (it carries the declarations and the `model_config` memo, so the
+copy does not re-resolve at all).
 
 ### Adding a model-specific config adjustment
 
@@ -473,8 +498,12 @@ ONE thread — do not design for TBO threads that don't exist.
   them explicitly on the mock; `MagicMock(spec=...)` raises on attributes that only
   exist post-`__init__`, which is the fastest way to find a missed stub.
 - `reset_context()` in teardown when a test publishes outside a scoped override.
-- `ServerArgs(model_path="dummy")` early-returns `__post_init__` (no materialization, no
+- `ServerArgs(model_path="dummy")` early-returns the pipeline (few declarations, no
   strict guard) — fine for lightweight fixtures.
+- **Asserting what resolution decided reads `resolution_result(sa, "field")`**, not
+  `sa.field`: the field is the raw input. Assert the field only when the point of
+  the case *is* that the record stayed pristine (the FA4 page-size and waterfill
+  cases do exactly that, and say so).
 - **Run changed test files per-file** (own process), the way CI does: a monolithic local
   pytest run lets a context published by an earlier file mask a missing-publish bug in a
   later one.

examples/runtime/engine/save_remote_state.py

@@ -23,6 +23,7 @@ from argparse import ArgumentParser
 from pathlib import Path
 
 from sglang import Engine, ServerArgs
+from sglang.srt.arg_groups.overrides import resolution_result
 
 parser = ArgumentParser()
 ServerArgs.add_cli_args(parser)
@@ -44,7 +45,7 @@ parser.add_argument(
 def main(args):
     engine_args = ServerArgs.from_cli_args(args)
     engine_args.resolve_once()
-    model_path = engine_args.model_path
+    model_path = resolution_result(engine_args, "model_path")
     if not Path(model_path).is_dir():
         raise ValueError("model path must be a local directory")
     # Create LLM instance from arguments

examples/runtime/engine/save_sharded_state.py

@@ -28,6 +28,7 @@ from argparse import ArgumentParser
 from pathlib import Path
 
 from sglang import Engine, ServerArgs
+from sglang.srt.arg_groups.overrides import resolution_result
 
 parser = ArgumentParser()
 ServerArgs.add_cli_args(parser)
@@ -49,7 +50,7 @@ parser.add_argument(
 def main(args):
     engine_args = ServerArgs.from_cli_args(args)
     engine_args.resolve_once()
-    model_path = engine_args.model_path
+    model_path = resolution_result(engine_args, "model_path")
     if not Path(model_path).is_dir():
         raise ValueError("model path must be a local directory")
     # Create LLM instance from arguments

examples/runtime/token_in_token_out/token_in_token_out_vlm_engine.py

@@ -5,6 +5,7 @@ from transformers import AutoProcessor
 
 from sglang import Engine
 from sglang.lang.chat_template import get_chat_template_by_model_path
+from sglang.srt.arg_groups.overrides import resolving_view
 from sglang.srt.configs.model_config import ModelConfig
 from sglang.srt.server_args import ServerArgs
 from sglang.test.test_utils import DEFAULT_IMAGE_URL
@@ -36,12 +37,13 @@ def get_input_ids(
 def token_in_out_example(
     server_args: ServerArgs,
 ):
+    cfg = resolving_view(server_args)
     input_ids, image_data = get_input_ids(
         server_args,
         ModelConfig(
-            server_args.model_path,
-            trust_remote_code=server_args.trust_remote_code,
-            model_override_args=server_args.json_model_override_args,
+            cfg.model_path,
+            trust_remote_code=cfg.trust_remote_code,
+            model_override_args=cfg.json_model_override_args,
         ),
     )
     backend = Engine(server_args=server_args)

python/sglang/benchmark/one_batch.py

@@ -1005,7 +1005,7 @@ def main(server_args, bench_args):
     # The decode phase has to capture the batch sizes this run benchmarks, and
     # the per-phase convenience knob loses to an explicit --cuda-graph-config
     # JSON (resolution applies that last), so the size is merged into that JSON.
-    if getattr(server_args, "_declarations_materialized", False):
+    if getattr(server_args, "_resolution_finished", False):
         # A record the caller already resolved: nothing will parse a raw dict
         # again, so the declaration has to be the finished typed config.
         merged = resolution_result(server_args, "cuda_graph_config")

python/sglang/srt/arg_groups/arg_utils.py

@@ -75,10 +75,10 @@ class Arg:
     # When True, this field is skipped by add_cli_args_from_dataclass.
     # Use for fields that have no CLI surface (e.g. injected via Python only).
     no_cli: bool = False
-    # When True, this field may be written by config resolution (model
-    # overrides and post-process passes): it is part of the whitelist accepted
-    # by the declaration stash, and its resolved value materializes onto the
-    # field at the end of __post_init__.
+    # When True, config resolution (model overrides and post-process passes)
+    # may decide this field: the declaration stash accepts the name, and
+    # `resolution_result` and the config bags answer with the decision. The
+    # field keeps what the operator passed.
     resolvable: bool = False
 
 

python/sglang/srt/arg_groups/overrides.py

@@ -14,9 +14,13 @@
 """Declarative model-override registry.
 
 Model-identity adjustments to the server configuration are DECLARED here and
-materialized onto ``server_args`` at the end of ``__post_init__`` (gate
-order, last writer wins) — model code never mutates ``ServerArgs`` fields
-imperatively.
+appended to the record's declaration stash (gate order, last writer wins).
+Nothing here writes back onto ``ServerArgs``: the record holds the user's raw
+input, and a decision is read through ``resolution_result`` or the published
+config bags — model code never mutates ``ServerArgs`` fields imperatively. The
+one channel that still leaves a field changed is ``declare_direct_writes``,
+which does not perform the write: it captures one an out-of-tree plugin already
+made, and undoing it would surprise the plugin's own reads.
 
 Two declaration forms, keyed on ``hf_config.architectures[0]``:
 
@@ -206,10 +210,8 @@ def register_post_process(fn: Callable[..., dict]) -> Callable[..., dict]:
 def _declaration_overlay(server_args: Any) -> Dict[str, Any]:
     """What the declarations say so far, last writer wins.
 
-    Passes declare without touching the fields until
-    ``materialize_declarations``, so a mid-resolution reader needs this to see
-    them; handlers and hooks write as they declare, and for those the overlay
-    repeats what the field already holds."""
+    Nothing writes the fields, so a mid-resolution reader needs this to see a
+    decision at all; the fields keep what the caller supplied."""
     overlay: Dict[str, Any] = {}
     for _source, declared in getattr(server_args, "_resolved_overrides", None) or ():
         overlay.update(declared)
@@ -222,9 +224,9 @@ def run_post_process_pass(server_args: Any, fn: Callable[..., dict]) -> None:
     Evaluates the pass on the resolving state (a read-only view with the
     accumulated declarations overlaid from the stash) and appends its
     declaration to the stash. During ``__post_init__`` the fields stay
-    untouched — ``materialize_declarations`` applies the whole stash once at
-    the end of resolution; a pass invoked after materialization (a post-init
-    slot) writes through immediately.
+    untouched: the stash is what the config bags are projected from. A pass
+    invoked after resolution finished (a post-init slot) writes through
+    immediately, because there is no later projection to pick it up.
     """
     declared = fn(ResolvedView(server_args, overlay=_declaration_overlay(server_args)))
     if not isinstance(declared, dict):
@@ -244,7 +246,7 @@ def run_post_process_pass(server_args: Any, fn: Callable[..., dict]) -> None:
             stash = server_args._resolved_overrides = []
         stash.append(entry)
         validate_declarations(server_args, [entry])
-        if getattr(server_args, "_declarations_materialized", False):
+        if getattr(server_args, "_resolution_finished", False):
             _apply_fields(server_args, declared)
 
 
@@ -260,29 +262,17 @@ def _apply_fields(server_args: Any, fields: Dict[str, Any]) -> None:
 
 
 def declare_resolution(server_args: Any, source: str, **fields: Any) -> None:
-    """Record a resolution write in the declaration stash, and apply it now.
+    """Record a resolution write in the declaration stash.
 
-    The stash is what the projection reads, so a resolver that only assigns
-    the field leaves that write invisible to it. The immediate write keeps the
-    resolver's successors seeing the value where they read the field directly.
+    The stash *is* the resolution result: the bags are projected from it,
+    `resolution_result` answers from it, and no field is written. A resolver
+    reading a field another resolver may have decided must read `resolving_view`
+    (or `ServerArgs._resolved()`), which
+    `test_resolution_reads_the_declarations` pins.
 
-    What it does change is which writer wins. A declaration is appended and
-    replayed last, so a resolver that declares a field a *deferred* writer (a
-    post-process pass, a registry entry) also decides now beats it, where its
-    bare assignment used to be overwritten by that writer's declaration. A
-    resolver that gates on such a field has to read the resolving view rather
-    than the raw field, or it decides from a value that is already stale.
-
-    For resolvers inside ``__post_init__``: the handlers on ``ServerArgs``
-    (through ``self._declare``) and the ``arg_groups`` hooks and hardware
-    defaults they call. Resolution that has to wait for the launcher stage
-    goes through ``declare_late_resolution`` instead.
-
-    Names arrive as keyword arguments, which accept anything; a misspelled one
-    would otherwise become a new attribute that nothing ever reads, so it is
-    rejected here. This is not the model-override whitelist: that one limits
-    which fields a *registry entry* may reach, while a resolver writing the
-    field it owns is the pipeline resolving by construction.
+    For resolvers inside ``__post_init__``; launcher-stage resolution goes
+    through ``declare_late_resolution``. A name that is not a field is rejected
+    here rather than becoming an attribute nothing reads.
     """
     if dataclasses.is_dataclass(type(server_args)):
         unknown = sorted(set(fields) - field_names(type(server_args)))
@@ -293,8 +283,6 @@ def declare_resolution(server_args: Any, source: str, **fields: Any) -> None:
         stash = []
         object.__setattr__(server_args, "_resolved_overrides", stash)
     stash.append((source, dict(fields)))
-    for name, value in fields.items():
-        setattr(server_args, name, value)
 
 
 def declare_late_resolution(server_args: Any, source: str, **fields: Any) -> None:
@@ -304,10 +292,10 @@ def declare_late_resolution(server_args: Any, source: str, **fields: Any) -> Non
     normalization and the auto-parser detection need the launcher's validation
     stage (and, for the parsers, a tokenizer / chat-template load). They still
     belong to the resolution pipeline — they decide what the process will run
-    with — so they write the fields in place, before anything publishes the
-    object. Writing in place is the point: every holder of that instance (the
-    HTTP server, the multi-tokenizer workers it serializes for, the schedulers
-    it forks) must see the resolved value.
+    with — so their decision goes to the stash like any other, and the record
+    keeps what the caller passed. Every holder of that instance reads the
+    decision the same way the rest of the pipeline does: the bags it publishes,
+    or ``resolution_result``, both of which survive the pickle to a child.
 
     Refuses to touch the published instance: after publish the bags exist and a
     field write would desync them, which is what ``get_context().override`` is
@@ -334,7 +322,6 @@ def declare_late_resolution(server_args: Any, source: str, **fields: Any) -> Non
         stash = []
         object.__setattr__(server_args, "_resolved_overrides", stash)
     stash.append((source, dict(fields)))
-    _apply_fields(server_args, fields)
 
 
 def declare_direct_writes(
@@ -348,7 +335,10 @@ def declare_direct_writes(
     Out-of-tree platform plugins are handed the record and set fields on it.
     Their implementations live outside this tree, so they cannot be converted
     by editing the resolver; and the raw snapshot is taken before the pipeline
-    starts, so a plugin's default is neither declared nor raw.
+    starts, so a plugin's default is neither declared nor raw. The write itself
+    stays: this captures it into the stash so the projection and the bags carry
+    it, but reverting the field would break the plugin's own reads of what it
+    just set. It is the only field a record still carries from resolution.
 
     Rebinding is what the diff sees, and rebinding is all it needs to see: a
     plugin that mutates a value in place reaches the projection anyway, because
@@ -384,24 +374,12 @@ def declare_direct_writes(
     return result
 
 
-def materialize_declarations(server_args: Any) -> None:
-    """Apply the accumulated declarations onto ``server_args`` once, at the
-    end of ``__post_init__`` (gate order: last writer wins). After this the
-    fields carry the resolved configuration — every post-init reader, in any
-    process, reads them directly; ``resolved_view`` remains an internal
-    helper for mid-resolution code only."""
-    for _source, declared in getattr(server_args, "_resolved_overrides", None) or ():
-        for field, value in declared.items():
-            setattr(server_args, field, value)
-    server_args._declarations_materialized = True
-
-
 def resolution_result(server_args: Any, field: str, default: Any = None) -> Any:
     """What resolution decided for ``field``: the declaration if there is one,
     otherwise what the caller supplied.
 
     This is what the config projection reads. Reading the field instead would
-    work only for as long as declarations materialize onto the record -- and
+    work whatever the caller passed onto the record -- and
     the point of declaring is that they will not, so the projection must not
     depend on it. A config that never ran the pipeline (a mock, a partial
     fixture) carries no raw snapshot; its fields are all it has.
@@ -422,9 +400,8 @@ def resolution_projection(server_args: Any) -> Dict[str, Any]:
 
     The whole-object shape of ``resolution_result``, for the exits that hand out
     the entire configuration (``/server_info``, the gRPC and engine readbacks).
-    They used ``dataclasses.asdict``, which reads the fields -- correct only for
-    as long as declarations materialize onto the record, and the point of
-    declaring is that they will not. Field values only: the private resolution
+    They used ``dataclasses.asdict``, which reads the fields -- the operator's
+    input, not what resolution decided. Field values only: the private resolution
     bookkeeping and the ``model_config`` memo that a ``vars()`` dump carried into
     the readback are not configuration.
     """
@@ -453,10 +430,14 @@ def _plain(value: Any) -> Any:
 
 
 def resolved_view(server_args: Any) -> ResolvedView:
-    """Read-only view of the resolving configuration for mid-resolution code
-    that is not a pass (``__post_init__`` handlers and hooks). Internal to
-    the resolution pipeline: after ``materialize_declarations`` runs, the
-    fields themselves carry the resolved values — read them directly."""
+    """Read-only view of the resolving configuration: the declarations
+    overlaid on the fields, snapshotted per call.
+
+    For mid-resolution code that is not a pass (``__post_init__`` handlers and
+    hooks), and for the record's own members that must answer with what
+    resolution decided -- a declaration-only resolver (a model-specific
+    override, a registry entry) never writes the field, so a field read there
+    answers with the raw input."""
     return ResolvedView(server_args, overlay=_declaration_overlay(server_args))
 
 

python/sglang/srt/entrypoints/engine.py

@@ -251,7 +251,7 @@ class Engine(EngineScoreMixin, EngineBase):
                 kwargs["log_level"] = "error"
             server_args = self.server_args_class(**kwargs)
         self.server_args = server_args
-        logger.info(f"{server_args=}")
+        logger.info(f"server_args={server_args.resolved_dict()}")
 
         # Rust Server is not supported with the offline Engine API
         if envs.SGLANG_RUST_SERVER.get():
@@ -1076,7 +1076,7 @@ class Engine(EngineScoreMixin, EngineBase):
             # Allocate ports for inter-process communications
             if port_args is None:
                 port_args = PortArgs.init_new(server_args)
-            logger.info(f"{server_args=}")
+            logger.info(f"server_args={server_args.resolved_dict()}")
 
             # Start the engine info bootstrap server if per-rank info is needed.
             engine_info_bootstrap_server = None

python/sglang/srt/entrypoints/http_server.py

@@ -803,8 +803,8 @@ async def get_server_info():
 async def server_info():
     """The startup configuration, plus live scheduler state.
 
-    The `ServerArgs` fields here are the record: what the launcher was given,
-    with resolution written back into it. Fields the control plane changes
+    The values here are the resolution result: what the launcher was given,
+    with every decision resolution made applied over it. Fields the control plane changes
     after publication -- the model a weight update swapped in, its load format,
     an operator-set weight version -- are reported by `/model_info`, and the
     HiCache mirror by `GET /hicache/storage-backend`.

python/sglang/srt/layers/attention/minimax_sparse_backend.py

@@ -247,11 +247,10 @@ class MiniMaxSparseAttnBackend(AttentionBackend):
             Phase,
             check_cuda_graph_backend,
         )
+        from sglang.srt.runtime_context import get_spec
 
-        _sa = getattr(runner, "server_args", None)
-        self.speculative_num_draft_tokens = getattr(
-            _sa, "speculative_num_draft_tokens", None
-        )
+        spec = get_spec()
+        self.speculative_num_draft_tokens = spec.speculative_num_draft_tokens
         _decode_cuda_graph = not check_cuda_graph_backend(
             Phase.DECODE, Backend.DISABLED
         )
@@ -264,7 +263,7 @@ class MiniMaxSparseAttnBackend(AttentionBackend):
         if (
             self.use_msa
             and _decode_cuda_graph
-            and getattr(_sa, "speculative_algorithm", None) is not None
+            and spec.speculative_algorithm is not None
         ):
             raise NotImplementedError(
                 "MiniMax-M3 MSA attention does not support speculative decoding under "

python/sglang/srt/layers/moe/utils.py

@@ -315,8 +315,8 @@ def initialize_moe_config():
     """Seed the MoE runtime flags from the published configuration.
 
     Reads the bags: `moe_a2a_backend` and its siblings are resolution's
-    answers, and the record carries them only while declarations materialize
-    onto it. Called once per process after publish
+    answers, and the record carries the operator's input. Called once per
+    process after publish
     (scheduler init, the benchmark work functions).
     """
     exec_moe = get_exec().moe

python/sglang/srt/managers/scheduler.py

@@ -39,7 +39,6 @@ from sglang.srt.runtime_context import (
     get_observability,
     get_parallel,
     get_schedule,
-    get_server_args,
     get_serving,
     get_spec,
 )
@@ -4412,7 +4411,7 @@ class Scheduler(
         # Resolved config (pristine server_args + post-publish overrides) so a
         # readback reflects values changed via /set_internal_state, not startup.
         ret = get_context().resolved_server_args_dict()
-        ret["world_size"] = compute_world_size(get_server_args())
+        ret["world_size"] = compute_world_size(get_parallel().config)
         ret["last_gen_throughput"] = self.metrics_reporter.last_gen_throughput
         draft_graph_memory_usage = (
             None if self.draft_worker is None else self.draft_worker.graph_memory_usage

python/sglang/srt/mem_cache/kv_cache_configurator.py

@@ -1380,7 +1380,7 @@ class KVCacheConfigurator:
         """
         full_pool_class = DSATokenToKVPool if is_dsa_model else MLATokenToKVPool
         common = {
-            "page_size": self.server_args.page_size,
+            "page_size": get_schedule().page_size,
             "device": self.device,
             "enable_memory_saver": False,
         }
@@ -1401,7 +1401,7 @@ class KVCacheConfigurator:
         return SWAKVPool(
             size=full_max_total_num_tokens,
             size_swa=swa_max_total_num_tokens,
-            page_size=self.server_args.page_size,
+            page_size=get_schedule().page_size,
             dtype=self.kv_cache_dtype,
             head_num=0,
             head_dim=0,

python/sglang/srt/parser/template_detection.py

@@ -702,12 +702,13 @@ def _architecture_auto_parsers(server_args, needs: Tuple[str, ...]) -> Dict[str,
 
 def resolve_auto_parsers(server_args) -> None:
     """Resolve ``--reasoning-parser=auto`` / ``--tool-call-parser=auto`` from the
-    chat template, in place, before anything publishes ``server_args``.
+    chat template, before anything publishes ``server_args``.
 
-    Performs a lightweight tokenizer load, so it runs once in engine init. In
-    place because everyone who holds this instance must see the resolved value:
-    the schedulers it forks, the HTTP server, and the tokenizer workers it is
-    serialized for.
+    Performs a lightweight tokenizer load, so it runs once in engine init. The
+    decision goes to this instance's declaration stash, so every holder of it
+    carries it -- the schedulers it forks, the HTTP server, the tokenizer
+    workers it is serialized for -- and each publishes bags projected from it.
+    The fields stay what the operator passed.
     """
     cfg = resolving_view(server_args)
     needs = tuple(

python/sglang/srt/ray/engine.py

@@ -35,7 +35,7 @@ from sglang.srt.ray.scheduler_actor import SchedulerActor
 from sglang.srt.runtime_context import (
     get_parallel,
 )
-from sglang.srt.server_args import PortArgs, ServerArgs
+from sglang.srt.server_args import PortArgs, ServerArgs, compute_world_size
 
 logger = logging.getLogger(__name__)
 
@@ -108,14 +108,10 @@ def _get_bundle_node_ip(placement_group: PlacementGroup, bundle_idx: int) -> str
 def _compute_world_size() -> int:
     """Compute world_size (total number of scheduler actors/GPUs needed).
 
-    Normal: dp_size * tp_size * pp_size; DP attention: tp_size * pp_size.
     Reads the published parallel leaves: the driver is sizing the actors that
     will hold the process groups, so there is nothing live to ask.
     """
-    parallel = get_parallel().config
-    if parallel.enable_dp_attention:
-        return parallel.tp_size * parallel.pp_size
-    return parallel.dp_size * parallel.tp_size * parallel.pp_size
+    return compute_world_size(get_parallel().config)
 
 
 def _resolve_bundle_indices(pg: PlacementGroup, world_size: int) -> List[int]:

python/sglang/srt/runtime_context.py

@@ -24,9 +24,10 @@ getters. The resolved parallel **configuration** is the same object's ``config``
 hop (``get_parallel().config.tp_size``), which reads the published ``parallel``
 bag: bare is the live group, ``config`` is what was configured.
 
-``get_server_args()`` returns the process-wide ``ServerArgs``. This is the pristine / resolved-at-startup **read-only** record kept
-for debug and reproduction; business code reads resolved config from the
-namespace bags below, not from this object. The context owns the storage:
+``get_server_args()`` returns the process-wide ``ServerArgs``. This is the
+user's raw input, kept **read-only** for debug and reproduction; what
+resolution decided lives in the declarations (``resolution_result``) and, for
+business code, in the namespace bags below -- never on this object's fields. The context owns the storage:
 publishing goes through ``RuntimeContext.set_server_args`` (the legacy
 ``set_global_server_args_for_scheduler`` / ``get_global_server_args`` are thin
 shims over this slot).
@@ -440,8 +441,8 @@ class DpFlags(_FlagGroupBase):
 class Flags(_FlagGroupBase):
     """Root of the runtime-flags tier.
 
-    Resolved configuration lives on ``server_args`` fields (materialized at
-    the end of ``__post_init__``) — this tier only carries genuine runtime
+    Resolved configuration lives in the config bags below (projected from the
+    declarations at publish) — this tier only carries genuine runtime
     state whose value is not a function of the configuration alone, grouped
     by lifecycle (``capture``) or subsystem (``moe`` / ``dp``).
     """
@@ -700,8 +701,7 @@ def _build_config_bags(server_args: Any) -> dict:
     """Snapshot the resolution result into the namespace bag tree, driven by
     the ``NS(...)`` metadata on the dataclass fields. Each leaf comes from
     ``resolution_result`` -- the declaration if resolution made one, else what
-    the caller supplied -- rather than from the field, which carries the same
-    value only while declarations still materialize. Returns
+    the caller supplied. Returns
     ``{top_level_name: _ConfigBag}``, arbitrarily nested (``exec.moe.eplb.…``).
     Only dataclass fields carry ``NS`` markers, so derived properties/methods are
     naturally excluded (they stay on the bag). A name used as both a leaf and a
@@ -783,7 +783,13 @@ class RuntimeContext:
         if stream is None:
             import torch
 
-            device = self._server_args.device if self._server_args else "cuda"
+            from sglang.srt.arg_groups.overrides import resolution_result
+
+            device = (
+                resolution_result(self._server_args, "device")
+                if self._server_args
+                else "cuda"
+            )
             stream = torch.get_device_module(device).Stream()
             self.resources.streams[name] = stream
         return stream
@@ -819,8 +825,8 @@ class RuntimeContext:
         Overwrite-allowed: a re-publish replaces the slot (test kits re-publish
         per test; production ordering discipline lives at the call-sites, e.g.
         the draft-worker guard in ``ModelRunner.__init__``). The published
-        object already carries the resolved configuration (declarations
-        materialize at the end of ``__post_init__``).
+        object is the raw input; the resolution it carries is its declaration
+        stash, which is what the bags are projected from.
         """
         # Seed the capture tier for the new lifecycle (defaults for sentinel
         # and mock publishes, which carry no config).
@@ -1078,10 +1084,11 @@ class _ServerArgsOverride:
         }
         if declared:
             declare_late_resolution(server_args, "override_server_args", **declared)
-        _apply_fields(
-            server_args,
-            {name: value for name, value in self._fields.items() if name[0] == "_"},
-        )
+        # This hook stands in for a launch: the caller's values are both what
+        # the operator passed and what resolution decided, so they go on the
+        # record as well as into the stash. Production late resolution declares
+        # only -- there the record stays the operator's input.
+        _apply_fields(server_args, self._fields)
         ctx.set_server_args(server_args)
         self._installed = True
         return server_args

python/sglang/srt/server_args.py

@@ -3709,7 +3709,7 @@ class ServerArgs:
         arrived by pickle and brought its declarations along, so the child has
         nothing left to derive and projects what the parent decided.
         """
-        if getattr(self, "_declarations_materialized", False):
+        if getattr(self, "_resolution_finished", False):
             return
         if getattr(self, "_resolution_failed", False):
             raise RuntimeError(
@@ -3721,23 +3721,22 @@ class ServerArgs:
         try:
             self._run_resolution_pipeline()
         except BaseException:
-            # The handlers that ran already wrote to the record, and they are
-            # not idempotent over their own output.
+            # The handlers that ran already declared, and they are not
+            # idempotent over their own output.
             object.__setattr__(self, "_resolution_failed", True)
             raise
         # Set here too, because the dummy/absent-model path returns before the
-        # materialization that normally sets it: the gate is about whether the
-        # handlers ran, not how far they got.
-        self._declarations_materialized = True
+        # end of the pipeline that normally sets it: the gate is about whether
+        # the handlers ran, not how far they got.
+        self._resolution_finished = True
 
     def resolved_dict(self) -> Dict[str, Any]:
         """This configuration as a plain dict of resolved field values.
 
         What the whole-object readbacks report (`/server_info` and its gRPC and
         in-process twins). `dataclasses.asdict(self)` reads the fields, which
-        carry resolution's result only while declarations materialize onto the
-        record; this reads the declarations, so it keeps answering with what
-        resolution decided once they stop. Nested dataclass fields are expanded
+        carry the raw input; this reads the declarations, so it answers with what
+        resolution decided. Nested dataclass fields are expanded
         the way `asdict` expands them; the private resolution bookkeeping and the
         `model_config` memo are not fields and do not appear.
         """
@@ -3750,12 +3749,11 @@ class ServerArgs:
 
         `dataclasses.replace` builds a new instance, so the copy carries none of
         what makes a record resolved: no raw snapshot, no declarations, no
-        materialization. The next publish therefore finds an unmaterialized
-        record and runs the pipeline over values it already decided -- DP
-        attention halves `chunked_prefill_size` a second time (8192 -> 4096 ->
-        2048) and the schedule conservativeness is scaled again (0.3 -> 0.09).
-        The Ray paths replace `dist_init_addr` on a resolved record, which is
-        how they hit it.
+        finished flag. The next publish therefore resolves it again, which
+        drops every decision the stash held -- the late ones (the auto-detected
+        parsers) and the direct ones alike -- and re-runs the device probes in
+        whatever process opened the copy. The Ray paths replace
+        `dist_init_addr` on a resolved record, which is how they reach this.
 
         The change is appended to the stash rather than left on the field: the
         projection reads the raw snapshot plus the declarations, so a field the
@@ -3770,7 +3768,7 @@ class ServerArgs:
         copy's deep structure in-process mutates the parent's too.
         """
         replacement = dataclasses.replace(self, **changes)
-        if not getattr(self, "_declarations_materialized", False):
+        if not getattr(self, "_resolution_finished", False):
             # Not resolved yet: the copy goes through the gate itself.
             return replacement
 
@@ -3780,7 +3778,7 @@ class ServerArgs:
         # (the read-only guard refuses the write).
         field_names = {field.name for field in dataclasses.fields(self)}
         for name, value in vars(self).items():
-            if name in field_names or name == "_declarations_materialized":
+            if name in field_names or name == "_resolution_finished":
                 continue
             if isinstance(value, (dict, list, set)):
                 value = copy.copy(value)
@@ -3791,7 +3789,7 @@ class ServerArgs:
             object.__setattr__(replacement, "_resolved_overrides", stash)
         if changes:
             stash.append((source, dict(changes)))
-        object.__setattr__(replacement, "_declarations_materialized", True)
+        object.__setattr__(replacement, "_resolution_finished", True)
         return replacement
 
     def _declare(self, source: str, **fields: Any) -> None:
@@ -4022,13 +4020,7 @@ class ServerArgs:
         # time; last declarations of the resolution, mirroring that order.
         self._handle_model_capability_adjustments()
 
-        # End of resolution: apply the accumulated declarations onto the
-        # fields once (gate order). From here on server_args carries the
-        # resolved configuration — post-init readers, in any process, read
-        # the fields directly.
-        from sglang.srt.arg_groups.overrides import materialize_declarations
-
-        materialize_declarations(self)
+        self._resolution_finished = True
 
     def _handle_return_hidden_states_mode(self):
         cfg = resolving_view(self)
@@ -9794,22 +9786,22 @@ class ServerArgs:
     def _late_resolution(self, source: str, **fields) -> None:
         """Resolve fields at the launcher's validation stage (pre-publish).
 
-        See ``arg_groups.overrides.declare_late_resolution``: in place, because
-        every holder of this instance must see the resolved value, and refused
-        outright once the config is published.
+        See ``arg_groups.overrides.declare_late_resolution``: the decision goes
+        to this instance's declaration stash, so every holder of it carries the
+        decision and publishes bags that answer with it. Refused outright once
+        the config is published.
         """
         from sglang.srt.arg_groups.overrides import declare_late_resolution
 
         declare_late_resolution(self, source, **fields)
 
     def __setattr__(self, name, value):
-        # After materialization the fields are the resolved startup
-        # configuration -- the pristine, READ-ONLY record that the config bags
-        # were projected from. Resolved config changes go to the bags via
+        # Once resolution has finished the record is the READ-ONLY raw input
+        # the config bags were projected from. Resolved config changes go to the bags via
         # get_context().override(source, ...); a value one runner or worker
         # owns travels as a constructor argument to it.
         if (
-            getattr(self, "_declarations_materialized", False)
+            getattr(self, "_resolution_finished", False)
             and not getattr(self, "_internal_write", False)
             and name not in _CACHE_SLOTS
             and (not name.startswith("_") or name in _underscore_field_names())
@@ -9832,7 +9824,13 @@ class ServerArgs:
         return attention_backends_of(resolved_view(self))
 
     def get_attention_backends(self):
-        return attention_backends_of(self)
+        """The (prefill, decode) pair resolution decided.
+
+        Reads through the declaration stash, not the fields: the model-specific
+        overrides declare into the stash without writing the fields, so a field
+        read answers with what the operator typed.
+        """
+        return attention_backends_of(resolved_view(self))
 
     def use_mla_backend(self):
         from sglang.srt.configs.model_config import AttentionArch
@@ -9884,7 +9882,7 @@ class ServerArgs:
             # state needs steps + 1 draft-token slots. Revisit this if topk>1
             # is supported.
             result = max(candidate_steps) + 1
-        if getattr(self, "_declarations_materialized", False):
+        if getattr(self, "_resolution_finished", False):
             object.__setattr__(self, "_max_speculative_num_draft_tokens", result)
         return result
 
@@ -9913,7 +9911,7 @@ class ServerArgs:
             assert (
                 max(chunk_size, page_size) % min(chunk_size, page_size) == 0
             ), f"For SSM models, either chunk_size or page_size must be divisible by the other, got {chunk_size=}, {page_size=}"
-            if not getattr(self, "_declarations_materialized", False):
+            if not getattr(self, "_resolution_finished", False):
                 return max(chunk_size, page_size)
             self._mamba_cache_chunk_size = max(chunk_size, page_size)
         return self._mamba_cache_chunk_size
@@ -10574,8 +10572,8 @@ class ServerArgs:
             "endpoint_host": host,
             "endpoint_port_base": port,
             "topic": cfg.topic,
-            "block_size": self.kv_event_block_size,
-            "dp_size": self.dp_size,
+            "block_size": resolved.kv_event_block_size,
+            "dp_size": resolved.dp_size,
         }
 
     def should_report_expert_balancedness(self) -> bool:
@@ -10593,12 +10591,19 @@ class ServerArgs:
         return cfg.expert_balancedness_report_mode in ("prometheus", "both")
 
 
-def compute_world_size(server_args: ServerArgs) -> int:
-    """Return the total GPU count across all data-parallel replicas."""
+def compute_world_size(config) -> int:
+    """Return the total GPU count across all data-parallel replicas.
+
+    Takes the resolved topology -- the published `parallel` bag, or a view over
+    the declarations. `enable_dp_attention` and `dp_size` are both resolution's
+    answers (`_handle_dwdp` fills the pair, DeepSeek MLA context parallelism
+    turns DP attention on), so a raw-record read would size the world from what
+    the operator typed.
+    """
     return (
-        (1 if server_args.enable_dp_attention else server_args.dp_size)
-        * server_args.tp_size
-        * server_args.pp_size
+        (1 if config.enable_dp_attention else config.dp_size)
+        * config.tp_size
+        * config.pp_size
     )
 
 

scripts/playground/bench_speculative.py

@@ -22,6 +22,7 @@ from transformers import AutoTokenizer
 from sglang.bench_serving import benchmark, set_global_args
 from sglang.benchmark.datasets import DatasetRow
 from sglang.benchmark.datasets.mmmu import sample_mmmu_requests
+from sglang.srt.arg_groups.overrides import resolution_projection
 from sglang.srt.server_args import ServerArgs
 from sglang.test.test_utils import (
     DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
@@ -135,6 +136,9 @@ def send_one_batch(base_url, num_prompts, batch_size, processor, is_multimodal):
 
 
 def main(args, server_args):
+    from sglang.srt.arg_groups.overrides import resolution_projection
+
+    server_args = SimpleNamespace(**resolution_projection(server_args))
     base_url = "http://127.0.0.1:20000"
 
     configs = []

sgl-model-gateway/bindings/python/src/sglang_router/launch_server.py

@@ -87,18 +87,21 @@ def launch_server_process(
     server_args: ServerArgs, worker_port: int, dp_id: int
 ) -> mp.Process:
     """Launch a single server process with the given args and port."""
-    # This binding is installed against a released sglang, so it cannot call
-    # into helpers newer than that wheel. Copy first, then write through the
-    # sanctioned channel if the record is resolved (a resolved record refuses
-    # plain assignment), else assign.
-    worker_args = copy.deepcopy(server_args)
     changes = {
         "port": worker_port,
         "base_gpu_id": dp_id * server_args.tp_size,
         "dp_size": 1,
     }
+    # Three channels, newest first. A wheel that has the read-only record but not
+    # `replace_resolved` still has `_late_resolution`, and plain assignment there
+    # raises; only a wheel with neither accepts `setattr`.
+    replace_resolved = getattr(server_args, "replace_resolved", None)
+    if replace_resolved is not None:
+        worker_args = replace_resolved("sglang_router.launch_server_process", **changes)
+    else:
+        worker_args = copy.deepcopy(server_args)
         late = getattr(worker_args, "_late_resolution", None)
-    if late is not None and getattr(worker_args, "_declarations_materialized", False):
+        if late is not None:
             late("sglang_router.launch_server_process", **changes)
         else:
             for field, value in changes.items():
@@ -188,7 +191,11 @@ def main():
         server_args.resolve_once()
     router_args = RouterArgs.from_cli_args(args, use_router_prefix=True)
 
-    # Find available ports for workers
+    # Find available ports for workers. The count is the operator's requested
+    # replica count, which is the raw field on purpose: `--dwdp-size` makes
+    # resolution declare a `dp_size` that describes one multi-rank server's
+    # internal topology, and spawning that many single-rank children would ask
+    # for dp_size^2 GPUs.
     worker_ports = find_available_ports(
         args.router_dp_worker_base_port, server_args.dp_size
     )

sgl-model-gateway/bindings/python/tests/test_startup_sequence.py

@@ -856,6 +856,62 @@ def test_launch_server_process_and_cleanup(monkeypatch):
     assert (p1.pid, _sig.SIGTERM) in calls and (p2.pid, _sig.SIGTERM) in calls
     assert (p2.pid, _sig.SIGKILL) in calls
 
+
+def test_launch_server_process_declares_on_a_resolved_record(monkeypatch):
+    """A record that carries its resolution takes the declaration channel.
+
+    The stub above has no `replace_resolved`, so it exercises the older wheels'
+    path. A current `ServerArgs` refuses plain assignment once resolution has
+    finished; the per-worker values reach the child as a declaration on a copy,
+    and the parent keeps what the operator passed.
+    """
+    _install_sglang_stubs(monkeypatch)
+    import importlib
+
+    ls = importlib.import_module("sglang_router.launch_server")
+
+    created = {}
+
+    class FakeProcess:
+        def __init__(self, target, args):
+            created["target"] = target
+            created["args"] = args
+            self.pid = 4243
+
+        def start(self):
+            created["started"] = True
+
+    monkeypatch.setattr(ls.mp, "Process", FakeProcess)
+
+    calls = []
+
+    class ResolvedServerArgs:
+        def __init__(self, **fields):
+            self.port = fields.get("port", 30000)
+            self.base_gpu_id = fields.get("base_gpu_id", 0)
+            self.dp_size = fields.get("dp_size", 4)
+            self.tp_size = fields.get("tp_size", 2)
+
+        def replace_resolved(self, source, **changes):
+            calls.append((source, dict(changes)))
+            fields = dict(vars(self))
+            fields.update(changes)
+            return ResolvedServerArgs(**fields)
+
+    parent = ResolvedServerArgs()
+    proc = ls.launch_server_process(parent, worker_port=31002, dp_id=3)
+
+    assert created.get("started") is True
+    assert proc.pid == 4243
+    assert len(calls) == 1
+    source, changes = calls[0]
+    assert source == "sglang_router.launch_server_process"
+    assert changes == {"port": 31002, "base_gpu_id": 6, "dp_size": 1}
+
+    worker = created["args"][0]
+    assert (worker.port, worker.base_gpu_id, worker.dp_size) == (31002, 6, 1)
+    assert (parent.port, parent.base_gpu_id, parent.dp_size) == (30000, 0, 4)
+
     def test_validation_error_handling(self):
         """Test error handling when validation fails."""
         args = RouterArgs(

sgl-model-gateway/src/policies/cache_aware.rs

@@ -679,7 +679,7 @@ mod tests {
         let mut workers: Vec<Arc<dyn Worker>> = Vec::new();
         for j in 0..num_workers {
             workers.push(Arc::new(
-                BasicWorkerBuilder::new(&format!("http://w{}:8000", j))
+                BasicWorkerBuilder::new(format!("http://w{}:8000", j))
                     .worker_type(WorkerType::Regular)
                     .build(),
             ));
@@ -738,7 +738,7 @@ mod tests {
         let mut workers: Vec<Arc<dyn Worker>> = Vec::new();
         for j in 0..num_workers {
             workers.push(Arc::new(
-                BasicWorkerBuilder::new(&format!("http://w{}:8000", j))
+                BasicWorkerBuilder::new(format!("http://w{}:8000", j))
                     .worker_type(WorkerType::Regular)
                     .build(),
             ));

test/registered/cpu/test_server_args_backend.py

@@ -4,6 +4,7 @@ import tempfile
 import unittest
 from unittest.mock import patch
 
+from sglang.srt.arg_groups.overrides import resolution_result
 from sglang.srt.server_args import ServerArgs
 from sglang.test.ci.ci_register import register_cpu_ci
 
@@ -25,8 +26,10 @@ class TestServerArgsCPUBackend(unittest.TestCase):
 
         ServerArgs._handle_cpu_backends(server_args)
 
-        self.assertEqual(server_args.attention_backend, "torch_native")
-        self.assertEqual(server_args.sampling_backend, "pytorch")
+        self.assertEqual(
+            resolution_result(server_args, "attention_backend"), "torch_native"
+        )
+        self.assertEqual(resolution_result(server_args, "sampling_backend"), "pytorch")
 
     @patch("sglang.srt.server_args.is_host_cpu_arm64", return_value=False)
     def test_x86_cpu_defaults_to_intel_amx(self, _mock_is_arm64):
@@ -34,8 +37,10 @@ class TestServerArgsCPUBackend(unittest.TestCase):
 
         ServerArgs._handle_cpu_backends(server_args)
 
-        self.assertEqual(server_args.attention_backend, "intel_amx")
-        self.assertEqual(server_args.sampling_backend, "pytorch")
+        self.assertEqual(
+            resolution_result(server_args, "attention_backend"), "intel_amx"
+        )
+        self.assertEqual(resolution_result(server_args, "sampling_backend"), "pytorch")
 
 
 class TestServerArgsIBDeviceValidation(unittest.TestCase):

test/registered/unit/managers/test_scheduler_internal_state_env_vars.py

@@ -48,10 +48,11 @@ class TestSchedulerInternalStateEnvVars(unittest.TestCase):
         ), patch(
             "sglang.srt.managers.scheduler.get_exec",
             return_value=SimpleNamespace(moe=SimpleNamespace(elastic_ep_backend=None)),
-        ), patch(
-            "sglang.srt.managers.scheduler.get_server_args", return_value=None
         ), patch(
             "sglang.srt.managers.scheduler.compute_world_size", return_value=1
+        ), patch(
+            "sglang.srt.managers.scheduler.get_parallel",
+            return_value=SimpleNamespace(config=SimpleNamespace()),
         ):
             output = scheduler.get_internal_state(recv_req=GetInternalStateReq())
 

test/registered/unit/managers/test_scheduler_internal_state_world_size.py

@@ -9,16 +9,16 @@ maybe_stub_sgl_kernel()
 
 from sglang.srt.managers.io_struct import GetInternalStateReq
 from sglang.srt.managers.scheduler import Scheduler
-from sglang.srt.server_args import ServerArgs, compute_world_size
+from sglang.srt.server_args import compute_world_size
 
 register_cpu_ci(est_time=5, suite="base-a-test-cpu")
 
 
-def _make_server_args(
+def _make_parallel_config(
     *, tp_size: int, pp_size: int, dp_size: int, enable_dp_attention: bool
-) -> ServerArgs:
-    return ServerArgs(
-        model_path="dummy",
+) -> SimpleNamespace:
+    """The four `parallel` leaves the world size is computed from."""
+    return SimpleNamespace(
         tp_size=tp_size,
         pp_size=pp_size,
         dp_size=dp_size,
@@ -29,39 +29,39 @@ def _make_server_args(
 class TestComputeWorldSize(unittest.TestCase):
     def test_a_single_gpu_server_holds_one_gpu(self):
         """The default shape has to come out as one, or every consumer is off by a factor."""
-        server_args = _make_server_args(
+        config = _make_parallel_config(
             tp_size=1, pp_size=1, dp_size=1, enable_dp_attention=False
         )
 
-        self.assertEqual(compute_world_size(server_args), 1)
+        self.assertEqual(compute_world_size(config), 1)
 
     def test_tensor_and_pipeline_stages_multiply(self):
         """Each (pp_rank, tp_rank) pair is its own scheduler process on its own gpu."""
-        server_args = _make_server_args(
+        config = _make_parallel_config(
             tp_size=2, pp_size=3, dp_size=1, enable_dp_attention=False
         )
 
-        self.assertEqual(compute_world_size(server_args), 6)
+        self.assertEqual(compute_world_size(config), 6)
 
     def test_plain_data_parallel_replicas_each_hold_their_own_gpus(self):
         """Without dp attention every replica launches a full tensor-parallel group of its own."""
-        server_args = _make_server_args(
+        config = _make_parallel_config(
             tp_size=2, pp_size=1, dp_size=2, enable_dp_attention=False
         )
 
-        self.assertEqual(compute_world_size(server_args), 4)
+        self.assertEqual(compute_world_size(config), 4)
 
     def test_data_parallel_attention_shares_the_tensor_parallel_gpus(self):
         """With dp attention the dp ranks live inside the tensor-parallel world, not beside it."""
-        server_args = _make_server_args(
+        config = _make_parallel_config(
             tp_size=4, pp_size=1, dp_size=2, enable_dp_attention=True
         )
 
-        self.assertEqual(compute_world_size(server_args), 4)
+        self.assertEqual(compute_world_size(config), 4)
 
 
 class TestSchedulerInternalStateWorldSize(unittest.TestCase):
-    def _get_internal_state(self, server_args: ServerArgs) -> dict:
+    def _get_internal_state(self, config: SimpleNamespace) -> dict:
         scheduler = Scheduler.__new__(Scheduler)
         scheduler.metrics_reporter = SimpleNamespace(
             last_gen_throughput=1.0,
@@ -94,8 +94,8 @@ class TestSchedulerInternalStateWorldSize(unittest.TestCase):
             "sglang.srt.managers.scheduler.get_exec",
             return_value=SimpleNamespace(moe=SimpleNamespace(elastic_ep_backend=None)),
         ), patch(
-            "sglang.srt.managers.scheduler.get_server_args",
-            return_value=server_args,
+            "sglang.srt.managers.scheduler.get_parallel",
+            return_value=SimpleNamespace(config=config),
         ):
             output = scheduler.get_internal_state(recv_req=GetInternalStateReq())
 
@@ -103,24 +103,24 @@ class TestSchedulerInternalStateWorldSize(unittest.TestCase):
 
     def test_the_internal_state_reports_the_whole_server(self):
         """A consumer sizing an external fleet reads the gpus the server occupies, not the declared sizes."""
-        server_args = _make_server_args(
+        config = _make_parallel_config(
             tp_size=2, pp_size=1, dp_size=2, enable_dp_attention=False
         )
 
-        internal_state = self._get_internal_state(server_args)
+        internal_state = self._get_internal_state(config)
 
         self.assertEqual(internal_state["world_size"], 4)
 
     def test_the_reported_size_is_not_one_replica_of_a_data_parallel_server(self):
         """Each plain dp replica has its own process group, so no scheduler can report the whole server from it."""
-        server_args = _make_server_args(
+        config = _make_parallel_config(
             tp_size=2, pp_size=1, dp_size=2, enable_dp_attention=False
         )
 
-        internal_state = self._get_internal_state(server_args)
+        internal_state = self._get_internal_state(config)
 
         self.assertNotEqual(
-            internal_state["world_size"], server_args.tp_size * server_args.pp_size
+            internal_state["world_size"], config.tp_size * config.pp_size
         )
 
 

test/registered/unit/parser/test_template_manager.py

@@ -765,6 +765,18 @@ class TestToolCallParserDetection(unittest.TestCase):
         self.assertEqual(result, "minicpm5")
 
 
+def _declared(server_args, field):
+    """What late resolution decided for `field` on this record.
+
+    `resolve_auto_parsers` declares; the field keeps what the operator passed,
+    so the decision is read through the resolution result -- the same surface
+    the config bags are projected from.
+    """
+    from sglang.srt.arg_groups.overrides import resolution_result
+
+    return resolution_result(server_args, field)
+
+
 class TestResolveAutoParsers(unittest.TestCase):
     """Tests for resolve_auto_parsers()."""
 
@@ -790,8 +802,8 @@ class TestResolveAutoParsers(unittest.TestCase):
         with _patch_hf_transformers_utils(Mock(return_value=tokenizer)):
             resolve_auto_parsers(args)
 
-        self.assertEqual(args.reasoning_parser, "qwen3")
-        self.assertEqual(args.tool_call_parser, "qwen")
+        self.assertEqual(_declared(args, "reasoning_parser"), "qwen3")
+        self.assertEqual(_declared(args, "tool_call_parser"), "qwen")
 
     def test_resolves_reasoning_parser_only(self):
         args = self._make_server_args(reasoning_parser="auto", tool_call_parser=None)
@@ -800,8 +812,8 @@ class TestResolveAutoParsers(unittest.TestCase):
         with _patch_hf_transformers_utils(Mock(return_value=tokenizer)):
             resolve_auto_parsers(args)
 
-        self.assertEqual(args.reasoning_parser, "qwen3")
-        self.assertIsNone(args.tool_call_parser)
+        self.assertEqual(_declared(args, "reasoning_parser"), "qwen3")
+        self.assertIsNone(_declared(args, "tool_call_parser"))
 
     def test_resolves_tool_call_parser_only(self):
         args = self._make_server_args(reasoning_parser="qwen3", tool_call_parser="auto")
@@ -810,14 +822,14 @@ class TestResolveAutoParsers(unittest.TestCase):
         with _patch_hf_transformers_utils(Mock(return_value=tokenizer)):
             resolve_auto_parsers(args)
 
-        self.assertEqual(args.reasoning_parser, "qwen3")
-        self.assertEqual(args.tool_call_parser, "qwen")
+        self.assertEqual(_declared(args, "reasoning_parser"), "qwen3")
+        self.assertEqual(_declared(args, "tool_call_parser"), "qwen")
 
     def test_neither_auto_is_noop(self):
         args = self._make_server_args(reasoning_parser="qwen3", tool_call_parser="qwen")
         resolve_auto_parsers(args)
-        self.assertEqual(args.reasoning_parser, "qwen3")
-        self.assertEqual(args.tool_call_parser, "qwen")
+        self.assertEqual(_declared(args, "reasoning_parser"), "qwen3")
+        self.assertEqual(_declared(args, "tool_call_parser"), "qwen")
 
     def test_nonexistent_model_disables_both_parsers(self):
         args = self._make_server_args(reasoning_parser="auto", tool_call_parser="auto")
@@ -832,8 +844,8 @@ class TestResolveAutoParsers(unittest.TestCase):
         ):
             resolve_auto_parsers(args)
 
-        self.assertIsNone(args.reasoning_parser)
-        self.assertIsNone(args.tool_call_parser)
+        self.assertIsNone(_declared(args, "reasoning_parser"))
+        self.assertIsNone(_declared(args, "tool_call_parser"))
 
     def test_none_chat_template_disables_both_parsers(self):
         args = self._make_server_args(reasoning_parser="auto", tool_call_parser="auto")
@@ -842,8 +854,8 @@ class TestResolveAutoParsers(unittest.TestCase):
         with _patch_hf_transformers_utils(Mock(return_value=tokenizer)):
             resolve_auto_parsers(args)
 
-        self.assertIsNone(args.reasoning_parser)
-        self.assertIsNone(args.tool_call_parser)
+        self.assertIsNone(_declared(args, "reasoning_parser"))
+        self.assertIsNone(_declared(args, "tool_call_parser"))
 
     def test_deepseek_v32_arch_without_chat_template_uses_custom_encoder(self):
         args = self._make_server_args(reasoning_parser="auto", tool_call_parser="auto")
@@ -855,8 +867,8 @@ class TestResolveAutoParsers(unittest.TestCase):
         ):
             resolve_auto_parsers(args)
 
-        self.assertEqual(args.reasoning_parser, "deepseek-v3")
-        self.assertEqual(args.tool_call_parser, "deepseekv32")
+        self.assertEqual(_declared(args, "reasoning_parser"), "deepseek-v3")
+        self.assertEqual(_declared(args, "tool_call_parser"), "deepseekv32")
 
     def test_deepseek_v4_arch_without_chat_template_uses_custom_encoder(self):
         args = self._make_server_args(reasoning_parser="auto", tool_call_parser="auto")
@@ -868,8 +880,8 @@ class TestResolveAutoParsers(unittest.TestCase):
         ):
             resolve_auto_parsers(args)
 
-        self.assertEqual(args.reasoning_parser, "deepseek-v4")
-        self.assertEqual(args.tool_call_parser, "deepseekv4")
+        self.assertEqual(_declared(args, "reasoning_parser"), "deepseek-v4")
+        self.assertEqual(_declared(args, "tool_call_parser"), "deepseekv4")
 
     def test_kimi_k3_arch_without_chat_template_uses_custom_encoder(self):
         args = self._make_server_args(reasoning_parser="auto", tool_call_parser="auto")
@@ -883,8 +895,8 @@ class TestResolveAutoParsers(unittest.TestCase):
         ):
             resolve_auto_parsers(args)
 
-        self.assertEqual(args.reasoning_parser, "kimi_k3")
-        self.assertEqual(args.tool_call_parser, "kimi_k3")
+        self.assertEqual(_declared(args, "reasoning_parser"), "kimi_k3")
+        self.assertEqual(_declared(args, "tool_call_parser"), "kimi_k3")
 
     def test_kimi_k3_model_type_without_architecture_uses_custom_encoder(self):
         args = self._make_server_args(reasoning_parser="auto", tool_call_parser="auto")
@@ -896,8 +908,8 @@ class TestResolveAutoParsers(unittest.TestCase):
         ):
             resolve_auto_parsers(args)
 
-        self.assertEqual(args.reasoning_parser, "kimi_k3")
-        self.assertEqual(args.tool_call_parser, "kimi_k3")
+        self.assertEqual(_declared(args, "reasoning_parser"), "kimi_k3")
+        self.assertEqual(_declared(args, "tool_call_parser"), "kimi_k3")
 
     def test_deepseek_arch_fallback_runs_when_tokenizer_load_fails(self):
         args = self._make_server_args(reasoning_parser="auto", tool_call_parser="auto")
@@ -909,8 +921,8 @@ class TestResolveAutoParsers(unittest.TestCase):
         ):
             resolve_auto_parsers(args)
 
-        self.assertEqual(args.reasoning_parser, "deepseek-v3")
-        self.assertEqual(args.tool_call_parser, "deepseekv32")
+        self.assertEqual(_declared(args, "reasoning_parser"), "deepseek-v3")
+        self.assertEqual(_declared(args, "tool_call_parser"), "deepseekv32")
 
     def test_explicit_non_jinja_template_skips_architecture_fallback(self):
         args = self._make_server_args(
@@ -926,8 +938,8 @@ class TestResolveAutoParsers(unittest.TestCase):
             resolve_auto_parsers(args)
 
         get_config.assert_not_called()
-        self.assertIsNone(args.reasoning_parser)
-        self.assertIsNone(args.tool_call_parser)
+        self.assertIsNone(_declared(args, "reasoning_parser"))
+        self.assertIsNone(_declared(args, "tool_call_parser"))
 
     def test_explicit_jinja_template_takes_precedence(self):
         tokenizer = _DummyTokenizer([], chat_template=None)
@@ -947,8 +959,8 @@ class TestResolveAutoParsers(unittest.TestCase):
             with _patch_hf_transformers_utils(Mock(return_value=tokenizer)):
                 resolve_auto_parsers(args)
 
-        self.assertEqual(args.reasoning_parser, "deepseek-v3")
-        self.assertEqual(args.tool_call_parser, "deepseekv32")
+        self.assertEqual(_declared(args, "reasoning_parser"), "deepseek-v3")
+        self.assertEqual(_declared(args, "tool_call_parser"), "deepseekv32")
 
 
 if __name__ == "__main__":

test/registered/unit/server_args/test_model_config_reads_resolved_input.py

@@ -26,8 +26,8 @@ register_cpu_ci(est_time=5, suite="base-a-test-cpu")
 _SRT = pathlib.Path(sglang.__file__).resolve().parent / "srt"
 
 # Read for what the caller asked for: the constructor passes it through and
-# never stores it, while resolution later overwrites the field with the value
-# the architecture implies. Two quantities sharing one name.
+# never stores it, while resolution declares the value the architecture implies.
+# Two quantities sharing one name.
 _READ_BEFORE_RESOLUTION = frozenset({"is_embedding"})
 
 # Declared after the first `get_model_config()`, so the cached configuration

test/registered/unit/server_args/test_resolution_declarations.py

@@ -5,13 +5,11 @@ so a resolution write that only assigns the field is invisible to it. Every
 resolver declares now -- the record's handlers through `self._declare`, the
 hooks and hardware defaults through `declare_resolution` -- and that is pinned
 two ways: no bare assignment to a field survives anywhere a ServerArgs instance
-is in reach, and after resolution every declared field agrees with what the
-stash says. The second check is the one that keeps the transition honest --
-while a declaration still writes the field immediately, a stash entry and a
-field can only disagree if something assigned the field behind the stash's
-back. A third check runs the other way: every field resolution moved has to
-be explained by the stash, which covers the spellings a source scan cannot
-see.
+is in reach, and after resolution `resolution_result` answers for every declared
+field with what the stash holds. The second check is what the stash is measured
+against: the two can disagree only if something wrote behind the stash's back. A
+third check runs the other way -- every field resolution moved has to be
+explained by the stash, which covers the spellings a source scan cannot see.
 """
 
 import ast
@@ -233,6 +231,11 @@ def _bare_assignments():
     return sorted(found)
 
 
+def shape_key(shape):
+    """A shape rendered short enough for a failure message."""
+    return ",".join(f"{k}={v}" for k, v in sorted(shape.items())) or "defaults"
+
+
 def _stash_overlay(server_args):
     """What the declarations say, last writer wins -- the projection's input."""
     overlay = {}
@@ -345,35 +348,43 @@ class TestResolutionDeclarations(CustomTestCase):
             + "\n  ".join(unexplained),
         )
 
-    def test_the_projection_input_is_the_resolved_configuration(self):
-        """What the bags are built from equals what the record ends up holding.
+    def test_a_declaration_only_resolver_leaves_the_field_alone(self):
+        """The direction of travel: resolution decides, the record does not move.
 
-        The projection reads `raw input + declarations` rather than the
-        fields, so that it keeps working when the declarations stop
-        materializing. While they still do, the two have to agree leaf for
-        leaf -- a difference means the projection would publish something the
-        record does not say, which is the failure this whole transition is
-        meant to avoid.
+        A resolver that only declares -- a model-specific override, a registry
+        entry -- writes nothing onto the record. The projection carries its
+        answer and the field still holds what the caller passed.
         """
         from sglang.srt.arg_groups.arg_utils import namespace_of
         from sglang.srt.arg_groups.overrides import resolution_result
 
-        differences = []
+        found = []
         for shape in _SHAPES:
             server_args = self._resolve(shape)
+            raw = getattr(server_args, "_raw_input", None) or {}
             for field in namespace_of(type(server_args)):
-                projected = resolution_result(server_args, field)
+                if field not in raw:
+                    continue
+                decided = resolution_result(server_args, field)
                 on_record = getattr(server_args, field)
-                if projected != on_record:
-                    differences.append(
-                        f"{shape} -> {field}: projection={projected!r} "
-                        f"record={on_record!r}"
-                    )
+                if decided == on_record:
+                    continue
+                # It moved away from the record's value, so the record must
+                # still hold exactly what the caller passed.
                 self.assertEqual(
-            differences,
+                    on_record,
+                    raw[field],
+                    f"{shape} -> {field}: the record holds {on_record!r}, which "
+                    f"is neither the raw input {raw[field]!r} nor what "
+                    f"resolution decided ({decided!r})",
+                )
+                found.append((shape_key(shape), field))
+        self.assertNotEqual(
+            found,
             [],
-            "the projection and the record disagree about a config leaf:\n  "
-            + "\n  ".join(differences),
+            "no field is resolved by declaration alone any more, so this check "
+            "no longer covers anything -- either the shapes stopped reaching "
+            "one or the declarations are writing the fields again",
         )
 
     def test_the_whole_object_readback_carries_only_fields(self):
@@ -561,10 +572,9 @@ class TestResolutionDeclarations(CustomTestCase):
 
         The parser detection and the LoRA normalization run at launcher stage --
         they need a tokenizer, a chat template, an adapter directory -- and they
-        write through `declare_late_resolution`. If those writes only reached
-        the fields, the bags would describe the *unresolved* value: a server
-        launched with `--reasoning-parser auto` would advertise and apply
-        `auto` after detection had already replaced it.
+        declare through `declare_late_resolution`. The declaration is the only
+        home for what they decide: the record keeps `--reasoning-parser auto`,
+        and the bags a process publishes carry the detected parser.
 
         A real model path, not the dummy one: a dummy record never materializes,
         so its `resolve_once` re-runs and re-snapshots the raw input from
@@ -586,15 +596,22 @@ class TestResolutionDeclarations(CustomTestCase):
         )
         publish(server_args, role="tokenizer")
         self.assertEqual(get_serving().reasoning_parser, "qwen3")
-        self.assertEqual(server_args.reasoning_parser, get_serving().reasoning_parser)
+        self.assertEqual(
+            server_args.reasoning_parser,
+            "auto",
+            "the record is the operator's input; late resolution declares, it "
+            "does not write back",
+        )
 
     def test_validation_can_still_resolve_before_the_record_is_published(self):
-        """The LoRA checks normalize in place, so they must precede publish.
+        """The LoRA checks resolve, so they must precede publish.
 
         `check_server_args` is not read-only: it infers `enable_lora`, parses
         adapter paths and normalizes target modules through late resolution,
         which a published record refuses. The launcher order is what keeps this
-        legal, and this is the assertion that notices if it moves.
+        legal, and this is the assertion that notices if it moves. What those
+        declarations decide reaches the bags; the record keeps the raw form the
+        operator passed.
         """
         from sglang.srt.runtime_context import get_lora, publish, reset_context
 
@@ -608,9 +625,17 @@ class TestResolutionDeclarations(CustomTestCase):
         self.addCleanup(reset_context)
         server_args.check_server_args()
         publish(server_args, role="tokenizer")
-        self.assertEqual(get_lora().enable_lora, server_args.enable_lora)
         self.assertEqual(
-            get_lora().lora_target_modules, server_args.lora_target_modules
+            get_lora().enable_lora, resolution_result(server_args, "enable_lora")
+        )
+        self.assertEqual(
+            get_lora().lora_target_modules,
+            resolution_result(server_args, "lora_target_modules"),
+        )
+        self.assertEqual(
+            server_args.lora_target_modules,
+            ["q_proj"],
+            "normalization is a declaration; the record keeps what was passed",
         )
 
     def test_the_launcher_finishes_resolving_before_it_publishes(self):
@@ -661,24 +686,37 @@ class TestResolutionDeclarations(CustomTestCase):
             f"written:\n  " + "\n  ".join(too_late),
         )
 
-    def test_the_stash_agrees_with_the_fields_it_declared(self):
-        mismatches = []
+    def test_an_undeclared_field_still_holds_the_raw_input(self):
+        """Nothing writes a field behind the stash's back.
+
+        Comparing the stash against `resolution_result` would agree by
+        construction -- both are the same last-writer-wins walk over
+        `_resolved_overrides`, spelled forwards and backwards. The independent
+        source is the record's own `_raw_input` snapshot: a field with no
+        declaration has to still equal what the caller passed, because the only
+        sanctioned way to move one is to declare it.
+        """
+        moved = []
         for shape in _SHAPES:
             server_args = self._resolve(shape)
             overlay = _stash_overlay(server_args)
-            for field, declared in overlay.items():
-                if field not in _RESOLVED_FIELDS:
+            raw_input = getattr(server_args, "_raw_input", None)
+            self.assertTrue(raw_input, f"{shape}: the record kept no raw snapshot")
+            for field in dataclasses.fields(server_args):
+                name = field.name
+                if name in overlay or name not in raw_input:
                     continue
-                actual = getattr(server_args, field)
-                if actual != declared:
-                    mismatches.append(
-                        f"{shape} -> {field}: field={actual!r} stash={declared!r}"
+                current = getattr(server_args, name, None)
+                if current != raw_input[name]:
+                    moved.append(
+                        f"{shape} -> {name}: raw={raw_input[name]!r} "
+                        f"field={current!r}"
                     )
         self.assertEqual(
-            mismatches,
+            moved,
             [],
-            "a declared field and its stash entry disagree, so something "
-            "assigned the field behind the declaration:\n  " + "\n  ".join(mismatches),
+            "these fields moved without a declaration, so the bags publish one "
+            "value while the record shows another:\n  " + "\n  ".join(moved),
         )
 
     def test_no_immediate_writer_overrides_a_deferred_one(self):

test/registered/unit/server_args/test_resolution_is_reproducible.py

@@ -768,31 +768,43 @@ class TestACopyStaysResolved(_RestoresProcessState, CustomTestCase):
         server_args.resolve_once()
         return server_args
 
-    def test_a_bare_replace_would_resolve_a_second_time(self):
-        """Why the helper exists. If this stops drifting, the pipeline became
-        idempotent and the helper's reason is gone -- read it again before
-        deleting either."""
+    def test_a_bare_replace_resolves_again_and_lands_in_the_same_place(self):
+        """A bare copy resolves to the same place: the fields are the raw input.
+
+        `dataclasses.replace` copies the fields, so a bare copy re-runs
+        resolution over the *same input* the parent got -- the DP-attention
+        halving and the conservativeness scaling apply once. `replace_resolved`
+        buys something else: it carries the parent's declarations and its
+        `model_config`, so the copy answers without resolving at all.
+        """
         parent = self._resolved()
         bare = dataclasses.replace(parent, dist_init_addr="1.2.3.4:5000")
         self.assertFalse(
-            getattr(bare, "_declarations_materialized", False),
+            getattr(bare, "_resolution_finished", False),
             "a bare replace carried the flag; then this test proves nothing",
         )
         bare.resolve_once()
+        drifted = {
+            field.name: (
+                resolution_result(parent, field.name),
+                resolution_result(bare, field.name),
+            )
+            for field in dataclasses.fields(parent)
+            if field.name not in ("dist_init_addr", "random_seed")
+            and repr(resolution_result(parent, field.name))
+            != repr(resolution_result(bare, field.name))
+        }
         self.assertEqual(
-            (bare.chunked_prefill_size, round(bare.schedule_conservativeness, 4)),
-            (
-                parent.chunked_prefill_size // 2,
-                round(parent.schedule_conservativeness * 0.3, 4),
-            ),
-            "the second pass no longer drifts; this is the drift the copy "
-            "helper exists to avoid",
+            drifted,
+            {},
+            "resolving a bare copy landed somewhere else, so the pipeline is "
+            "reading its own output again",
         )
 
     def test_replace_resolved_keeps_the_parents_resolution(self):
         parent = self._resolved()
         copy_ = parent.replace_resolved("ray.test", dist_init_addr="1.2.3.4:5000")
-        self.assertTrue(getattr(copy_, "_declarations_materialized", False))
+        self.assertTrue(getattr(copy_, "_resolution_finished", False))
         drifted = {
             field.name: (getattr(parent, field.name), getattr(copy_, field.name))
             for field in dataclasses.fields(parent)

test/registered/unit/server_args/test_resolution_reads_the_declarations.py

@@ -0,0 +1,612 @@
+"""Resolution reads its own decisions, not the record's fields.
+
+`declare_resolution` records a decision in the declaration stash and writes
+nothing. The fields keep what the caller passed, so a resolver that reads a
+field another resolver may have decided reads the raw input -- silently, and
+only on the configurations where that other resolver fires. The whole pipeline
+therefore reads through `resolving_view` (or `ServerArgs._resolved()`, which is
+the same view spelled as the record's own member), and this pins that there is
+nothing left reading a field directly.
+
+Subjects: every function in `arg_groups/` that takes a config, every
+`ServerArgs` handler the dispatcher reaches, and every member of `ServerArgs` /
+`PortArgs` -- the members are reached from the hooks and from business code,
+which the handler walk cannot see, and a member that recomputes from a raw field
+decides from what was typed. All three
+are derived -- a new hook file, a new handler or a new member is covered the
+moment it is written. Readers *outside* those
+two -- the platform defaults, `ModelConfig`, the spec-algo hook -- are reached by
+resolution too and have moved to the view as well, but enumerating them needs
+the call-graph derivation `test_resolution_reads_no_bag` owns; this file pins
+the two scopes it can derive exactly.
+"""
+
+import ast
+import dataclasses
+import pathlib
+import re
+
+import sglang
+from sglang.srt.server_args import ServerArgs
+from sglang.test.ci.ci_register import register_cpu_ci
+from sglang.test.test_utils import CustomTestCase
+
+register_cpu_ci(est_time=8, suite="base-a-test-cpu")
+
+_SRT = pathlib.Path(sglang.__file__).resolve().parent / "srt"
+_FIELDS = frozenset(field.name for field in dataclasses.fields(ServerArgs))
+
+# Names a config travels under. `args` is included because the platform hooks
+# use it; a false positive would be a function taking an argparse Namespace and
+# reading an attribute that happens to be a ServerArgs field name, which the
+# allowlist below would then have to carry.
+_HOLDER_NAMES = frozenset({"server_args", "sa", "args"})
+
+
+def _holders(fn):
+    names = {
+        arg.arg
+        for arg in list(fn.args.posonlyargs)
+        + list(fn.args.args)
+        + list(fn.args.kwonlyargs)
+        if arg.arg in _HOLDER_NAMES
+    }
+    for arg in (
+        list(fn.args.posonlyargs) + list(fn.args.args) + list(fn.args.kwonlyargs)
+    ):
+        annotation = arg.annotation
+        text = (
+            annotation.value
+            if isinstance(annotation, ast.Constant)
+            else (
+                annotation.id
+                if isinstance(annotation, ast.Name)
+                else annotation.attr if isinstance(annotation, ast.Attribute) else None
+            )
+        )
+        if text == "ServerArgs":
+            names.add(arg.arg)
+    return names
+
+
+def _field_reads(fn, holders):
+    for node in ast.walk(fn):
+        if (
+            isinstance(node, ast.Attribute)
+            and node.attr in _FIELDS
+            and isinstance(node.value, ast.Name)
+            and node.value.id in holders
+            and isinstance(node.ctx, ast.Load)
+        ):
+            yield node.lineno, node.attr
+
+
+def _resolution_handlers():
+    """The `ServerArgs` methods the dispatcher reaches, transitively."""
+    tree = ast.parse((_SRT / "server_args.py").read_text(encoding="utf-8-sig"))
+    cls = next(
+        node
+        for node in ast.walk(tree)
+        if isinstance(node, ast.ClassDef) and node.name == "ServerArgs"
+    )
+    methods = {
+        node.name: node
+        for node in cls.body
+        if isinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef))
+    }
+    assert "_run_resolution_pipeline" in methods, "the dispatcher was renamed"
+    seen, stack = set(), ["_run_resolution_pipeline"]
+    while stack:
+        name = stack.pop()
+        if name in seen or name not in methods:
+            continue
+        seen.add(name)
+        for node in ast.walk(methods[name]):
+            if (
+                isinstance(node, ast.Call)
+                and isinstance(node.func, ast.Attribute)
+                and isinstance(node.func.value, ast.Name)
+                and node.func.value.id == "self"
+            ):
+                stack.append(node.func.attr)
+    return {name: methods[name] for name in seen}
+
+
+_DECLARERS = frozenset(
+    {
+        "_declare",
+        "declare_resolution",
+        "declare_late_resolution",
+        "declare_direct_writes",
+    }
+)
+
+
+def _declared_fields():
+    """The fields resolution decides, read off every shape that reaches the stash.
+
+    A keyword on a `declare_*` call is only one shape: the model-override and
+    post-process passes build a mapping instead (`MODEL_OVERRIDES` literals,
+    `overrides["dtype"] = ...`, a returned dict), and late resolution splats a
+    variable-keyed one. Deriving from keywords alone leaves nineteen fields
+    outside the subject set, `dtype` and `reasoning_parser` among them.
+    """
+    fields = set()
+    # The declaration calls live wherever a resolver does; the mapping channels
+    # only exist where the override providers and post-process passes are.
+    keyword_sources = [_SRT / "server_args.py"]
+    for sub in ("arg_groups", "hardware_backend", "parser"):
+        keyword_sources += sorted((_SRT / sub).rglob("*.py"))
+    mapping_sources = {_SRT / "server_args.py", *(_SRT / "arg_groups").rglob("*.py")}
+    for path in keyword_sources:
+        tree = ast.parse(path.read_text(encoding="utf-8-sig"))
+        for node in ast.walk(tree):
+            # 1. `declare_resolution(sa, src, page_size=64)` and its siblings
+            if isinstance(node, ast.Call):
+                name = (
+                    node.func.id
+                    if isinstance(node.func, ast.Name)
+                    else getattr(node.func, "attr", None)
+                )
+                if name in _DECLARERS:
+                    for keyword in node.keywords:
+                        if keyword.arg:
+                            fields.add(keyword.arg)
+                        elif isinstance(keyword.value, ast.Dict):
+                            fields.update(_string_keys(keyword.value))
+            # 2. every mapping literal in the files that declare through one:
+            #    the MODEL_OVERRIDES tables, the dicts the override providers
+            #    return, the ones the post-process passes build. Scanning
+            #    unrelated files here would collect a plain kwarg dict
+            #    (`tokenizer_config={"trust_remote_code": ...}`) and turn a
+            #    passthrough read into a violation.
+            if isinstance(node, ast.Dict) and path in mapping_sources:
+                fields.update(_string_keys(node))
+            # 3. `overrides["field"] = ...`
+            if (
+                path in mapping_sources
+                and isinstance(node, ast.Assign)
+                and isinstance(node.targets[0], ast.Subscript)
+                and isinstance(node.targets[0].slice, ast.Constant)
+                and isinstance(node.targets[0].slice.value, str)
+            ):
+                fields.add(node.targets[0].slice.value)
+    return frozenset(fields & _FIELDS)
+
+
+def _string_keys(node: ast.Dict) -> set:
+    return {
+        key.value
+        for key in node.keys
+        if isinstance(key, ast.Constant) and isinstance(key.value, str)
+    }
+
+
+def _record_members():
+    """Every member of `ServerArgs` / `PortArgs`, by class and name."""
+    tree = ast.parse((_SRT / "server_args.py").read_text(encoding="utf-8-sig"))
+    members = {}
+    for node in ast.walk(tree):
+        if isinstance(node, ast.ClassDef) and node.name in ("ServerArgs", "PortArgs"):
+            for member in node.body:
+                if isinstance(member, (ast.FunctionDef, ast.AsyncFunctionDef)):
+                    members[f"{node.name}.{member.name}"] = member
+    return members
+
+
+def _config_reading_helpers():
+    """Module functions that load a decided field off the config they are handed.
+
+    A member that hands them `self`, or a call site that hands them a record,
+    reads the raw input through the callee -- the shape neither an attribute
+    scan nor a `getattr` scan can see, because the field name is spelled in the
+    helper and the record is spelled at the call site.
+    """
+    decided = _declared_fields()
+    helpers = {}
+    sources = [_SRT / "server_args.py"] + sorted((_SRT / "arg_groups").rglob("*.py"))
+    for path in sources:
+        tree = ast.parse(path.read_text(encoding="utf-8-sig"))
+        for fn in ast.walk(tree):
+            if not isinstance(fn, (ast.FunctionDef, ast.AsyncFunctionDef)):
+                continue
+            params = {
+                arg.arg
+                for arg in list(fn.args.posonlyargs)
+                + list(fn.args.args)
+                + list(fn.args.kwonlyargs)
+            } - {"self", "cls"}
+            if not params:
+                continue
+            reads = {
+                node.attr
+                for node in ast.walk(fn)
+                if isinstance(node, ast.Attribute)
+                and isinstance(node.value, ast.Name)
+                and node.value.id in params
+                and isinstance(node.ctx, ast.Load)
+                and node.attr in decided
+            }
+            if reads:
+                helpers[fn.name] = sorted(reads)
+    return helpers
+
+
+# The accessors that hand back the process-global record itself. A helper that
+# is handed one of these reads the raw input exactly as a bare `self` would.
+_RECORD_ACCESSORS = frozenset({"get_server_args", "global_server_args"})
+
+# `self._server_args` is the same record under a private name; the scan has to
+# see it or a reader inside the context object escapes every shape above.
+_RECORD_ATTR = re.compile(r"^_*(server_args|sa)$")
+
+
+def _record_arguments(node, aliases=frozenset()):
+    """The bare-record arguments of a call.
+
+    Four spellings reach a helper with a record: the bare name (`self`, `sa`),
+    an attribute (`runner.server_args`), the process-global accessor called
+    inline (`get_server_args()`), and a local bound to either of the last two
+    earlier in the same function.
+    """
+    out = []
+    for arg in node.args:
+        if isinstance(arg, ast.Name) and arg.id in ("self", "server_args", "sa"):
+            out.append(arg.id)
+        elif isinstance(arg, ast.Attribute) and _RECORD_ATTR.match(arg.attr or ""):
+            out.append(ast.unparse(arg))
+        elif (
+            isinstance(arg, ast.Call)
+            and isinstance(arg.func, ast.Name)
+            and arg.func.id in _RECORD_ACCESSORS
+        ):
+            out.append(ast.unparse(arg))
+        elif isinstance(arg, ast.Name) and arg.id in aliases:
+            out.append(arg.id)
+    return out
+
+
+def _record_aliases(function):
+    """Locals bound to the record under a name of their own.
+
+    `_sa = getattr(runner, "server_args", None)`, `cfg = get_server_args()` and
+    `engine_args = ServerArgs.from_cli_args(args)` all put the record behind a
+    name the argument scan does not recognise, so a later
+    `getattr(_sa, "<decided leaf>")` reads what the operator typed.
+    """
+    aliases = set()
+    for node in ast.walk(function):
+        if not isinstance(node, ast.Assign) or len(node.targets) != 1:
+            continue
+        target = node.targets[0]
+        if not isinstance(target, ast.Name):
+            continue
+        value = node.value
+        if isinstance(value, ast.Attribute):
+            if _RECORD_ATTR.match(value.attr or ""):
+                aliases.add(target.id)
+            continue
+        if not isinstance(value, ast.Call):
+            continue
+        func = value.func
+        if isinstance(func, ast.Name):
+            if func.id in _RECORD_ACCESSORS or func.id == "ServerArgs":
+                aliases.add(target.id)
+            elif (
+                func.id == "getattr"
+                and len(value.args) >= 2
+                and isinstance(value.args[1], ast.Constant)
+                and _RECORD_ATTR.match(str(value.args[1].value))
+            ):
+                aliases.add(target.id)
+        elif (
+            isinstance(func, ast.Attribute)
+            and func.attr in ("from_cli_args", "replace_resolved")
+            and isinstance(func.value, ast.Name)
+            and func.value.id == "ServerArgs"
+        ):
+            aliases.add(target.id)
+    return aliases
+
+
+# The one reader for which the raw field is the right answer. The gateway sizes
+# its worker pool from the operator's requested replica count; `--dwdp-size`
+# makes resolution declare a `dp_size` describing one multi-rank server's
+# internal topology, so reading the decision there would spawn dp_size
+# single-rank children and ask for dp_size^2 GPUs. A new entry here needs that
+# kind of reason next to it.
+_NO_RESOLVED_SURFACE = frozenset(
+    {
+        (
+            "sgl-model-gateway/bindings/python/src/sglang_router/launch_server.py",
+            "server_args.dp_size",
+        ),
+    }
+)
+
+
+def _is_record_base(node, aliases):
+    """Is this expression the record itself?
+
+    A local bound to one, a parameter that carries one (`server_args`, `sa`,
+    `engine_args`), or an attribute holding one (`self._server_args`).
+    """
+    if isinstance(node, ast.Name):
+        return node.id in aliases
+    if isinstance(node, ast.Attribute):
+        return bool(_RECORD_ATTR.match(node.attr or ""))
+    return False
+
+
+def _record_handoff_offenders(rel, tree, helpers, decided, is_record=False):
+    """Every way a decided leaf is reached through a record in one module.
+
+    Two shapes, both scanned under the record aliases the function binds:
+    handing the record to a helper that loads a decided field, and loading one
+    off the alias directly (`alias.<leaf>` or `getattr(alias, "<leaf>")`). The
+    second is what the MiniMax backend spelled, and an argument scan cannot see
+    it -- the leaf never appears at a call site.
+    """
+    offenders, seen = [], set()
+
+    def record(lineno, text):
+        if (lineno, text) in seen:
+            return
+        seen.add((lineno, text))
+        offenders.append(f"{rel}:{lineno} {text}")
+
+    scopes = [(tree, frozenset())] + [
+        (fn, _record_aliases(fn))
+        for fn in ast.walk(tree)
+        if isinstance(fn, (ast.FunctionDef, ast.AsyncFunctionDef))
+    ]
+    for scope, aliases in scopes:
+        for node in ast.walk(scope):
+            if isinstance(node, ast.Call):
+                name = (
+                    node.func.id
+                    if isinstance(node.func, ast.Name)
+                    else getattr(node.func, "attr", None)
+                )
+                if name in helpers:
+                    for arg in _record_arguments(node, aliases):
+                        if arg == "self" and not is_record:
+                            continue
+                        record(
+                            node.lineno,
+                            f"{name}({arg}) reads {', '.join(helpers[name])}",
+                        )
+                if (
+                    isinstance(node.func, ast.Name)
+                    and node.func.id == "getattr"
+                    and len(node.args) >= 2
+                    and isinstance(node.args[0], ast.Name)
+                    and node.args[0].id in aliases
+                    and isinstance(node.args[1], ast.Constant)
+                    and node.args[1].value in decided
+                ):
+                    record(
+                        node.lineno,
+                        f'getattr({node.args[0].id}, "{node.args[1].value}")',
+                    )
+            elif (
+                isinstance(node, ast.Attribute)
+                and isinstance(node.ctx, ast.Load)
+                and node.attr in decided
+                and _is_record_base(node.value, aliases)
+            ):
+                record(node.lineno, f"{ast.unparse(node.value)}.{node.attr}")
+    return offenders
+
+
+# Source the scanner must read the same way whether or not the tree happens to
+# contain these shapes today. The first four are the spellings that reached
+# production and were converted; the last two are the legal forms next to them,
+# which have to stay quiet or the guard is unusable.
+_SPELLINGS = """
+def hands_the_alias_to_a_helper(runner):
+    _sa = getattr(runner, "server_args", None)
+    return m3_fp8_attn_gemm_enabled(_sa)
+
+
+def loads_a_leaf_off_the_alias(runner):
+    _sa = getattr(runner, "server_args", None)
+    return getattr(_sa, "speculative_num_draft_tokens", None)
+
+
+def reads_a_leaf_through_the_alias(runner):
+    sa_local = runner.server_args
+    return sa_local.attention_backend
+
+
+def hands_the_accessor_to_a_helper():
+    return compute_world_size(get_server_args())
+
+
+def reads_the_view(runner):
+    cfg = resolving_view(runner.server_args)
+    return cfg.attention_backend
+
+
+def reads_an_undecided_leaf(runner):
+    _sa = runner.server_args
+    return _sa.tp_size
+
+
+def reads_a_leaf_off_a_private_attribute(self):
+    return self._server_args.attention_backend
+
+
+def reads_a_leaf_off_a_constructed_record(cli):
+    engine_args = ServerArgs.from_cli_args(cli)
+    engine_args.resolve_once()
+    return engine_args.attention_backend
+"""
+
+
+class TestResolutionReadsTheDeclarations(CustomTestCase):
+    def test_no_hook_reads_a_field_off_the_record(self):
+        offenders = []
+        files = sorted((_SRT / "arg_groups").glob("*.py"))
+        self.assertGreater(len(files), 5, "the hook scan found almost nothing")
+        for path in files:
+            rel = f"arg_groups/{path.name}"
+            tree = ast.parse(path.read_text(encoding="utf-8-sig"))
+            for fn in ast.walk(tree):
+                if not isinstance(fn, (ast.FunctionDef, ast.AsyncFunctionDef)):
+                    continue
+                holders = _holders(fn)
+                if not holders:
+                    continue
+                for lineno, field in _field_reads(fn, holders):
+                    offenders.append(f"{rel}:{lineno} {fn.name} reads .{field}")
+        self.assertEqual(
+            offenders,
+            [],
+            "a resolution hook reads a field off the record; the field holds the "
+            "raw input, so this decides from what was typed rather than from "
+            "what resolution decided. Read `resolving_view(server_args)`:\n  "
+            + "\n  ".join(offenders),
+        )
+
+    def test_no_handler_reads_a_field_off_self(self):
+        handlers = _resolution_handlers()
+        self.assertGreater(
+            len(handlers), 50, f"only {len(handlers)} handlers were reached"
+        )
+        offenders = []
+        for name, fn in sorted(handlers.items()):
+            for lineno, field in _field_reads(fn, {"self"}):
+                offenders.append(f"server_args.py:{lineno} {name} reads self.{field}")
+        self.assertEqual(
+            offenders,
+            [],
+            "a resolution handler reads its own field; the field holds the raw "
+            "input. Bind `cfg = resolving_view(self)` and read that:\n  "
+            + "\n  ".join(offenders),
+        )
+
+    def test_no_member_recomputes_from_a_raw_field(self):
+        decided = _declared_fields()
+        self.assertGreater(
+            len(decided), 100, f"the declaration set derived only {len(decided)} fields"
+        )
+        members = _record_members()
+        self.assertGreater(len(members), 100, f"only {len(members)} members were found")
+        offenders = []
+        for name, fn in sorted(members.items()):
+            holders = _holders(fn) | {"self"}
+            for lineno, field in _field_reads(fn, holders):
+                if field in decided:
+                    offenders.append(f"server_args.py:{lineno} {name} reads .{field}")
+        self.assertEqual(
+            offenders,
+            [],
+            "a record member recomputes from a field resolution decides; the "
+            "field holds the raw input, so the member answers for what was "
+            "typed. Bind `cfg = resolving_view(self)` and read that:\n  "
+            + "\n  ".join(offenders),
+        )
+
+    def test_no_reader_hands_the_record_to_a_config_helper(self):
+        helpers = _config_reading_helpers()
+        self.assertGreater(
+            len(helpers), 5, f"the helper derivation found only {len(helpers)}"
+        )
+        decided = _declared_fields()
+        offenders = []
+        # `scripts/`, `examples/` and the gateway binding are outside the
+        # package but hold records they resolve themselves, and every reader
+        # this scan found in them was reading a field resolution fills in.
+        _REPO = _SRT.parent.parent.parent
+        roots = (
+            [_SRT]
+            + [_SRT.parent / d for d in ("benchmark", "lang")]
+            + [
+                _REPO / d
+                for d in (
+                    "scripts",
+                    "examples",
+                    "sgl-model-gateway/bindings/python/src",
+                )
+            ]
+        )
+        for root in roots:
+            if not root.exists():
+                continue
+            for path in sorted(root.rglob("*.py")):
+                # Package files keep their `srt/...` spelling (the skips below
+                # key on it); the repo-level roots are named from the repo.
+                try:
+                    rel = path.relative_to(_SRT.parent).as_posix()
+                except ValueError:
+                    rel = path.relative_to(_REPO).as_posix()
+                if rel.startswith(("srt/arg_groups/", "multimodal_gen/")):
+                    continue
+                try:
+                    tree = ast.parse(path.read_text(encoding="utf-8-sig"))
+                except SyntaxError:
+                    continue
+                offenders += _record_handoff_offenders(
+                    rel, tree, helpers, decided, is_record=rel == "srt/server_args.py"
+                )
+        offenders = [
+            line
+            for line in offenders
+            if (line.split(":", 1)[0], line.split(" ", 1)[1])
+            not in _NO_RESOLVED_SURFACE
+        ]
+        self.assertEqual(
+            offenders,
+            [],
+            "a caller hands the record to a helper that loads a field "
+            "resolution decides; the helper then reads the raw input. Hand it "
+            "`resolving_view(record)` (or the published bag):\n  "
+            + "\n  ".join(offenders),
+        )
+
+    def test_the_scan_sees_every_spelling_that_reached_production(self):
+        """Every spelling that reached production, pinned next to the scanner.
+
+        A shape the scan stops seeing is a silent hole, so each one is listed
+        here with the legal forms beside it and the flagged set compared
+        exactly.
+
+        What it does not reach: a record that arrives as a *parameter* and was
+        resolved by the caller (`scripts/playground/bench_speculative.py` hands
+        `main(args, server_args)` one). Binding that would need the call graph,
+        and naming a parameter `server_args` is also how the resolution-time
+        readers spell a view.
+        """
+        helpers = _config_reading_helpers()
+        decided = _declared_fields()
+        for name in ("m3_fp8_attn_gemm_enabled", "compute_world_size"):
+            self.assertIn(name, helpers, f"the helper derivation lost {name}")
+        for field in ("speculative_num_draft_tokens", "attention_backend"):
+            self.assertIn(field, decided, f"the declared set lost {field}")
+
+        offenders = _record_handoff_offenders(
+            "sample.py", ast.parse(_SPELLINGS), helpers, decided
+        )
+        flagged = {line.split(" ", 1)[1] for line in offenders}
+        self.assertEqual(
+            flagged,
+            {
+                "m3_fp8_attn_gemm_enabled(_sa)"
+                " reads " + ", ".join(helpers["m3_fp8_attn_gemm_enabled"]),
+                'getattr(_sa, "speculative_num_draft_tokens")',
+                "sa_local.attention_backend",
+                "self._server_args.attention_backend",
+                "engine_args.attention_backend",
+                "compute_world_size(get_server_args())"
+                " reads " + ", ".join(helpers["compute_world_size"]),
+            },
+            "the scan lost a spelling, or started flagging a legal one:\n  "
+            + "\n  ".join(sorted(flagged)),
+        )
+
+
+if __name__ == "__main__":
+    import unittest
+
+    unittest.main()

test/registered/unit/test_model_overrides.py

@@ -20,6 +20,7 @@ from sglang.srt.arg_groups.arg_utils import A, Arg, resolvable_fields
 from sglang.srt.arg_groups.overrides import (
     collect_model_override_declarations,
     register_model_override,
+    resolution_result,
     validate_declarations,
 )
 from sglang.srt.configs.minicpm import MiniCPMHybridConfig
@@ -294,9 +295,28 @@ class TestPublishInstallsSlot(_IsolatedPublish):
 
 class TestGoldenModelOverrides(_IsolatedPublish):
     """Per-arch golden diff for migrated families: the declarative path must
-    reproduce the legacy imperative writes byte-identically on the
-    materialized server_args fields; the publish round-trip returns the same
-    object."""
+    reproduce the legacy imperative writes byte-identically in the resolution
+    result; the publish round-trip returns the same object.
+
+    `_resolved` is how the assertions read it. A model-specific override only
+    declares -- it does not write the field -- so the record keeps what the
+    caller passed and the projection carries the override.
+    """
+
+    def _resolved(self, server_args, field):
+        from sglang.srt.arg_groups.overrides import resolution_result
+
+        return resolution_result(server_args, field)
+
+    def _leaf(self, field):
+        """The published value of `field`, whichever bag owns it.
+
+        The publish round-trip is checked on the bags: the record the process
+        publishes is the raw input, and the leaf is what every reader reads.
+        """
+        from sglang.srt.runtime_context import get_context
+
+        return get_context().config_leaf(field)
 
     _MINI_CONFIG = {
         "hidden_size": 64,
@@ -571,40 +591,42 @@ class TestGoldenModelOverrides(_IsolatedPublish):
 
     def test_mistral_large3_forces_bfloat16(self):
         sa = self._construct("MistralLarge3ForCausalLM", "mistral")
-        self.assertEqual(sa.dtype, "bfloat16")  # materialized at end of resolution
+        self.assertEqual(
+            self._resolved(sa, "dtype"), "bfloat16"
+        )  # materialized at end of resolution
         self.assertIn(
             ("MODEL_OVERRIDES['MistralLarge3ForCausalLM']", {"dtype": "bfloat16"}),
             sa._resolved_overrides,
         )
-        self.assertEqual(self._publish(sa).dtype, "bfloat16")
+        self.assertEqual((self._publish(sa), self._leaf("dtype"))[1], "bfloat16")
 
     def test_user_requested_dtype_is_still_overridden(self):
         # Legacy fidelity: the arch branch overwrote dtype unconditionally,
-        # so the declaration must too. The pristine request survives on
-        # provenance; the materialized field carries the override.
+        # so the declaration must too. The request survives on the record; the
+        # projection carries the override.
         sa = self._construct("MistralLarge3ForCausalLM", "mistral", dtype="float16")
-        self.assertEqual(sa.dtype, "bfloat16")  # materialized
-        self.assertEqual(self._publish(sa).dtype, "bfloat16")
+        self.assertEqual(self._resolved(sa, "dtype"), "bfloat16")
+        self.assertEqual((self._publish(sa), self._leaf("dtype"))[1], "bfloat16")
 
     def test_control_arch_keeps_pristine_dtype(self):
         sa = self._construct("LlamaForCausalLM", "llama")
-        self.assertEqual(sa.dtype, "auto")
+        self.assertEqual(self._resolved(sa, "dtype"), "auto")
         declared = {f for _s, d in sa._resolved_overrides for f in d}
         self.assertNotIn("dtype", declared)  # no arch declaration for Llama
-        # publish still materializes the whitelisted leaf with the pristine
+        # publish still projects the whitelisted leaf with the pristine
         # value: readers only ever read flags.
-        self.assertEqual(self._publish(sa).dtype, "auto")
+        self.assertEqual((self._publish(sa), self._leaf("dtype"))[1], "auto")
 
     def test_minimax_m2_enables_tf32_matmul(self):
         sa = self._construct("MiniMaxM2ForCausalLM", "llama")
-        self.assertTrue(sa.enable_tf32_matmul)  # materialized
+        self.assertTrue(self._resolved(sa, "enable_tf32_matmul"))
         self.assertIn(
             ("_minimax_m2_overrides", {"enable_tf32_matmul": True}),
             sa._resolved_overrides,
         )
         flags = self._publish(sa)
-        self.assertTrue(flags.enable_tf32_matmul)
-        self.assertFalse(flags.enable_multi_layer_eagle)  # pristine materialize
+        self.assertTrue(self._leaf("enable_tf32_matmul"))
+        self.assertFalse(self._leaf("enable_multi_layer_eagle"))  # the pristine value
 
     def test_minimax_m2_sm10x_nvfp4_uses_routed_trtllm(self):
         """MiniMax-M2 NVFP4 auto must avoid the unsupported plain TRT-LLM path."""
@@ -622,10 +644,14 @@ class TestGoldenModelOverrides(_IsolatedPublish):
                 "MiniMaxM2ForCausalLM", "llama", quantization="modelopt_fp4"
             )
 
-        self.assertEqual(explicit.moe_runner_backend, "flashinfer_cutlass")
-        self.assertEqual(non_nvfp4.moe_runner_backend, "auto")
-        self.assertEqual(nvfp4.moe_runner_backend, "flashinfer_trtllm_routed")
-        self.assertTrue(nvfp4.disable_shared_experts_fusion)
+        self.assertEqual(
+            self._resolved(explicit, "moe_runner_backend"), "flashinfer_cutlass"
+        )
+        self.assertEqual(self._resolved(non_nvfp4, "moe_runner_backend"), "auto")
+        self.assertEqual(
+            self._resolved(nvfp4, "moe_runner_backend"), "flashinfer_trtllm_routed"
+        )
+        self.assertTrue(self._resolved(nvfp4, "disable_shared_experts_fusion"))
         self.assertIn(
             (
                 "_minimax_m2_overrides",
@@ -649,7 +675,7 @@ class TestGoldenModelOverrides(_IsolatedPublish):
             non_sm10x = self._construct(
                 "MiniMaxM2ForCausalLM", "llama", quantization="modelopt_fp4"
             )
-        self.assertEqual(non_sm10x.moe_runner_backend, "auto")
+        self.assertEqual(self._resolved(non_sm10x, "moe_runner_backend"), "auto")
 
         self._publish(nvfp4)
         self.assertEqual(get_exec().moe.moe_runner_backend, "flashinfer_trtllm_routed")
@@ -1000,25 +1026,25 @@ class TestGoldenModelOverrides(_IsolatedPublish):
             enable_hierarchical_cache=True,
         )
         # materialized at the end of resolution
-        self.assertEqual(sa.swa_full_tokens_ratio, 1.0)
-        self.assertTrue(sa.disable_hybrid_swa_memory)
+        self.assertEqual(self._resolved(sa, "swa_full_tokens_ratio"), 1.0)
+        self.assertTrue(self._resolved(sa, "disable_hybrid_swa_memory"))
         flags = self._publish(sa)
-        self.assertEqual(flags.swa_full_tokens_ratio, 1.0)
-        self.assertTrue(flags.disable_hybrid_swa_memory)
+        self.assertEqual(self._leaf("swa_full_tokens_ratio"), 1.0)
+        self.assertTrue(self._leaf("disable_hybrid_swa_memory"))
 
     def test_gemma2_disables_hybrid_swa_memory(self):
         sa = self._construct("Gemma2ForCausalLM", "llama")
-        self.assertTrue(sa.disable_hybrid_swa_memory)  # materialized
+        self.assertTrue(self._resolved(sa, "disable_hybrid_swa_memory"))  # materialized
         self.assertIn(
             ("_gemma2_gemma3_overrides", {"disable_hybrid_swa_memory": True}),
             sa._resolved_overrides,
         )
-        self.assertTrue(self._publish(sa).disable_hybrid_swa_memory)
+        self.assertTrue((self._publish(sa), self._leaf("disable_hybrid_swa_memory"))[1])
 
     def test_olmo2_disables_hybrid_swa_memory(self):
         sa = self._construct("Olmo2ForCausalLM", "llama")
-        self.assertTrue(sa.disable_hybrid_swa_memory)  # materialized
-        self.assertTrue(self._publish(sa).disable_hybrid_swa_memory)
+        self.assertTrue(self._resolved(sa, "disable_hybrid_swa_memory"))  # materialized
+        self.assertTrue((self._publish(sa), self._leaf("disable_hybrid_swa_memory"))[1])
 
     def test_exaone_conditional_on_sliding_window_pattern(self):
         # With the pattern the branch also asserts an explicit backend.
@@ -1028,8 +1054,8 @@ class TestGoldenModelOverrides(_IsolatedPublish):
             config_extra={"sliding_window_pattern": "LLLG"},
             attention_backend="fa3",
         )
-        self.assertTrue(sa.disable_hybrid_swa_memory)  # materialized
-        self.assertTrue(self._publish(sa).disable_hybrid_swa_memory)
+        self.assertTrue(self._resolved(sa, "disable_hybrid_swa_memory"))  # materialized
+        self.assertTrue((self._publish(sa), self._leaf("disable_hybrid_swa_memory"))[1])
 
     def test_exaone_without_pattern_declares_nothing(self):
         from sglang.srt.arg_groups.overrides import _exaone_overrides
@@ -1051,13 +1077,13 @@ class TestGoldenModelOverrides(_IsolatedPublish):
             "llama",
             config_extra={"quantization_config": {"quant_method": "mxfp4"}},
         )
-        self.assertEqual(sa.dtype, "bfloat16")  # materialized
-        self.assertEqual(self._publish(sa).dtype, "bfloat16")
+        self.assertEqual(self._resolved(sa, "dtype"), "bfloat16")
+        self.assertEqual((self._publish(sa), self._leaf("dtype"))[1], "bfloat16")
 
     def test_gpt_oss_without_mxfp4_keeps_pristine_dtype(self):
         sa = self._construct("GptOssForCausalLM", "llama")
-        self.assertEqual(sa.dtype, "auto")
-        self.assertEqual(self._publish(sa).dtype, "auto")
+        self.assertEqual(self._resolved(sa, "dtype"), "auto")
+        self.assertEqual((self._publish(sa), self._leaf("dtype"))[1], "auto")
 
     def test_gpt_oss_xpu_dtype_validation_reads_pristine(self):
         from sglang.srt.arg_groups.overrides import _gpt_oss_overrides
@@ -1077,28 +1103,36 @@ class TestGoldenModelOverrides(_IsolatedPublish):
 
         sa = self._construct("LlamaForCausalLM", "llama")
         expected = "flashinfer" if is_flashinfer_available() else "pytorch"
-        self.assertEqual(sa.sampling_backend, expected)  # materialized
+        self.assertEqual(
+            self._resolved(sa, "sampling_backend"), expected
+        )  # materialized
         self.assertIn(
             ("_sampling_backend_default", {"sampling_backend": expected}),
             sa._resolved_overrides,
         )
-        self.assertEqual(self._publish(sa).sampling_backend, expected)
+        self.assertEqual(
+            (self._publish(sa), self._leaf("sampling_backend"))[1], expected
+        )
 
     def test_sampling_backend_user_choice_survives(self):
         sa = self._construct("LlamaForCausalLM", "llama", sampling_backend="pytorch")
-        self.assertEqual(sa.sampling_backend, "pytorch")
+        self.assertEqual(self._resolved(sa, "sampling_backend"), "pytorch")
         # the pass declared nothing; publish materializes the pristine choice
-        self.assertEqual(self._publish(sa).sampling_backend, "pytorch")
+        self.assertEqual(
+            (self._publish(sa), self._leaf("sampling_backend"))[1], "pytorch"
+        )
 
     def test_deterministic_inference_forces_pytorch_sampling(self):
         sa = self._construct(
             "LlamaForCausalLM", "llama", enable_deterministic_inference=True
         )
-        # two pass writers chain: default fill, then the deterministic force —
-        # last writer wins; materialization lands the end state on the fields.
-        self.assertEqual(sa.sampling_backend, "pytorch")
+        # two pass writers chain: default fill, then the deterministic force --
+        # last writer wins. The end state lives in the stash, which is what the
+        # projection reads and the bags are built from; the field still holds
+        # what the caller passed.
+        self.assertEqual(resolution_result(sa, "sampling_backend"), "pytorch")
         flags = self._publish(sa)
-        self.assertEqual(flags.sampling_backend, "pytorch")
+        self.assertEqual(self._leaf("sampling_backend"), "pytorch")
         # the deterministic attention fill declared a compatible backend and
         # the compatibility default-fill then had nothing to do
         deterministic_fills = [
@@ -1107,8 +1141,10 @@ class TestGoldenModelOverrides(_IsolatedPublish):
             if source == "_deterministic_attention_backend"
         ]
         self.assertEqual(len(deterministic_fills), 1)
-        self.assertEqual(sa.attention_backend, deterministic_fills[0])
-        self.assertEqual(flags.attention_backend, deterministic_fills[0])
+        self.assertEqual(
+            resolution_result(sa, "attention_backend"), deterministic_fills[0]
+        )
+        self.assertEqual(self._leaf("attention_backend"), deterministic_fills[0])
 
     def test_deterministic_incompatible_backend_raises(self):
         from sglang.srt.arg_groups.overrides import (
@@ -1148,13 +1184,17 @@ class TestGoldenModelOverrides(_IsolatedPublish):
             disable_radix_cache=True,
             attention_backend="triton",
         )
-        self.assertEqual(sa.attention_backend, "flashinfer")  # materialized
+        self.assertEqual(
+            self._resolved(sa, "attention_backend"), "flashinfer"
+        )  # materialized
         self.assertIn(
             ("_dllm_attention_backend", {"attention_backend": "flashinfer"}),
             sa._resolved_overrides,
         )
         # the deterministic fill lands on the attention_backend field
-        self.assertEqual(self._publish(sa).attention_backend, "flashinfer")
+        self.assertEqual(
+            (self._publish(sa), self._leaf("attention_backend"))[1], "flashinfer"
+        )
 
     def test_attention_backend_leaf_materializes_end_state(self):
         # The default-fill pass declares the platform-selected backend; the
@@ -1167,8 +1207,12 @@ class TestGoldenModelOverrides(_IsolatedPublish):
             if "attention_backend" in d
         ]
         self.assertTrue(declared_values)  # default fill declared
-        self.assertEqual(sa.attention_backend, declared_values[-1])  # materialized
-        self.assertEqual(self._publish(sa).attention_backend, declared_values[-1])
+        self.assertEqual(
+            self._resolved(sa, "attention_backend"), declared_values[-1]
+        )  # materialized
+        self.assertEqual(
+            (self._publish(sa), self._leaf("attention_backend"))[1], declared_values[-1]
+        )
 
     def test_post_materialize_pass_writes_through(self):
         from sglang.srt.arg_groups.overrides import run_post_process_pass
@@ -1177,7 +1221,7 @@ class TestGoldenModelOverrides(_IsolatedPublish):
         # legacy runner-side adjustments) declares AND writes through, so
         # field readers and the publish see the same end state.
         sa = self._construct("LlamaForCausalLM", "llama")
-        resolved_before = sa.attention_backend
+        resolved_before = self._resolved(sa, "attention_backend")
 
         def _force_triton(view):
             if view.attention_backend != "triton":
@@ -1186,13 +1230,18 @@ class TestGoldenModelOverrides(_IsolatedPublish):
 
         run_post_process_pass(sa, _force_triton)
         if resolved_before != "triton":
-            self.assertEqual(sa.attention_backend, "triton")
-        self.assertEqual(self._publish(sa).attention_backend, sa.attention_backend)
+            self.assertEqual(self._resolved(sa, "attention_backend"), "triton")
+        self.assertEqual(
+            (self._publish(sa), self._leaf("attention_backend"))[1],
+            self._resolved(sa, "attention_backend"),
+        )
 
     def test_attention_backend_user_choice_declares_nothing_extra(self):
         sa = self._construct("LlamaForCausalLM", "llama", attention_backend="triton")
-        self.assertEqual(sa.attention_backend, "triton")
-        self.assertEqual(self._publish(sa).attention_backend, "triton")
+        self.assertEqual(self._resolved(sa, "attention_backend"), "triton")
+        self.assertEqual(
+            (self._publish(sa), self._leaf("attention_backend"))[1], "triton"
+        )
 
     def test_compatibility_passes_at_callable_level(self):
         from sglang.srt.arg_groups.overrides import (

test/registered/unit/test_runtime_context_config_bags.py

@@ -11,6 +11,7 @@ from unittest import mock
 
 from sglang.srt import runtime_context as rc
 from sglang.srt.arg_groups.arg_utils import NS, A
+from sglang.srt.arg_groups.overrides import resolution_result
 from sglang.srt.server_args import ServerArgs
 from sglang.test.ci.ci_register import register_cpu_ci
 from sglang.test.test_utils import CustomTestCase
@@ -96,16 +97,15 @@ class TestConfigBags(CustomTestCase):
         none-flags) the first resolution may have written -- so the assertion
         is "bag == what resolution produces", not "bag == the instance publish
         copied from". Reproducibility (`test_resolution_is_reproducible`)
-        licenses the sibling as a stand-in for the pipeline's output. The
-        raw-differs guard keeps the comparison meaningful: every sampled leaf
-        must have moved off its dataclass default, so each equality compares a
-        value resolution demonstrably wrote. Supplied construction inputs
-        (`model_path`, `device`, `random_seed`) and leaves resolution leaves
-        alone never enter the sample -- projection coverage for those lives in
-        `test_passthrough_leaves_project_into_their_namespaces`. Step 12 keeps
-        records at the user's raw input; then the sibling goes raw and this
-        assertion starts failing for every sampled leaf, which is the signal
-        the bags became the only home of the effective value.
+        licenses the sibling as a stand-in for the pipeline's output.
+
+        The reference's resolved values are read through `resolution_result`,
+        because a record holds the user's raw input: the decision lives in the
+        declarations, and the bags are where a process reads it. The
+        raw-differs guard keeps the comparison meaningful -- every sampled leaf
+        must have moved off its dataclass default -- and the last assertion is
+        the other half of that invariant: the record still answers the raw
+        input for a leaf resolution decided.
         """
         import dataclasses
 
@@ -124,12 +124,13 @@ class TestConfigBags(CustomTestCase):
                 # The raw-differs guard: a sampled leaf that still sits on its
                 # default (or has none to differ from) proves nothing.
                 self.assertIsNot(defaults[leaf], dataclasses.MISSING)
-                self.assertNotEqual(getattr(reference, leaf), defaults[leaf])
-                self.assertEqual(accessor(), getattr(reference, leaf))
-        # And the record agrees today, which is what step 12 changes: when this
-        # assertion starts failing for a resolution-written leaf, the flip
-        # landed and the bag is the only place the effective value lives.
-        self.assertEqual(rc.get_schedule().page_size, sa.page_size)
+                resolved = resolution_result(reference, leaf)
+                self.assertNotEqual(resolved, defaults[leaf])
+                self.assertEqual(accessor(), resolved)
+        # The record is the raw input, so the field still reads as the default
+        # for a leaf the bag now answers for.
+        self.assertEqual(sa.page_size, defaults["page_size"])
+        self.assertNotEqual(rc.get_schedule().page_size, sa.page_size)
 
     def test_passthrough_leaves_project_into_their_namespaces(self):
         """Thin projection smoke over leaves resolution does not move.
@@ -141,7 +142,7 @@ class TestConfigBags(CustomTestCase):
         sa = self._publish()
         sampled = (
             (lambda: rc.get_serving().host, "host"),
-            (lambda: rc.get_memory().hicache_ratio, "hicache_ratio"),
+            (lambda: rc.get_memory().hicache_write_policy, "hicache_write_policy"),
             (lambda: rc.get_exec().moe.moe_runner_backend, "moe_runner_backend"),
             (lambda: rc.get_model().model_path, "model_path"),
         )
@@ -230,8 +231,8 @@ class TestConfigBags(CustomTestCase):
             rc.get_memory().hicache_ratio = 9.0
 
     def test_scoped_override_restores(self):
-        sa = self._publish()
-        original = sa.hicache_ratio
+        self._publish()
+        original = rc.get_memory().hicache_ratio
         with rc.get_memory().override(hicache_ratio=original + 1.0):
             self.assertEqual(rc.get_memory().hicache_ratio, original + 1.0)
         self.assertEqual(rc.get_memory().hicache_ratio, original)

test/registered/unit/test_runtime_context_override.py

@@ -110,7 +110,7 @@ class TestContextOverride(CustomTestCase):
         # server_args is read-only after resolution: resolved config changes go
         # to the bags, a per-runner config to a derived variant.
         sa = ServerArgs(model_path="dummy")
-        object.__setattr__(sa, "_declarations_materialized", True)
+        object.__setattr__(sa, "_resolution_finished", True)
         with self.assertRaises(AttributeError):
             sa.page_size = 999
 

test/registered/unit/test_server_args_no_instance_mutation_entry.py

@@ -6,9 +6,9 @@ resolution the fields are the record the config bags were projected from, so a
 write desyncs every namespace reader, and a copy invites publishing stale
 variants. Both are gone: post-publish changes go to the bags
 (``get_context().override``), a value one runner or worker owns travels as a
-constructor argument, and late launcher-stage resolution writes in place
-through ``arg_groups.overrides.declare_late_resolution``, which refuses the
-published instance.
+constructor argument, and late launcher-stage resolution declares through
+``arg_groups.overrides.declare_late_resolution``, which writes no field and
+refuses the published instance.
 
 The textual half of this guard matters because the resolution pipeline's own file
 is exempt from the mutation ratchet: a ``self.override(...)`` there — exactly

test/registered/unit/test_supplied_instance_exposure_ratchet.py

@@ -535,9 +535,9 @@ class TestSuppliedInstanceExposure(CustomTestCase):
 
         ``MODEL_OVERRIDES`` maps arch -> {field: value}, and the
         ``@register_model_override``(-``_predicate``) providers return (or
-        build by subscript) {field: value} dicts; ``materialize_declarations``
-        applies them all via setattr, so no assignment scan sees these writes
-        and a llama-only matrix never triggers them. Keys must be
+        build by subscript) {field: value} dicts, which go straight into the
+        declaration stash, so no assignment scan sees these writes and a
+        llama-only matrix never triggers them. Keys must be
         string literals; anything else fails loudly.
         """
         tree = ast.parse(