fix(openai): drop legacy MMDD snapshot suffixes from picker

Codex P2 follow-up on PR #5684 (providers.py:104): the new OpenAI
denylist only stripped the modern `-YYYY-MM-DD` dated form, so
legacy compact snapshots like `gpt-3.5-turbo-0125`, `gpt-4-0613`,
`gpt-4-1106-preview`, and `gpt-4-0125-preview` slipped through. The
listing returns both the snapshot and the canonical id; the picker
should surface only the canonical so users do not accidentally
select a deprecated snapshot.

Extends the dated-suffix branch with `-\d{4}(?:-preview)?$` to
cover the compact `MMDD` form and the `-MMDD-preview` variant.
The new rule is anchored to the end of the id so canonical chat
ids whose minor version happens to be a year-like number
(`gpt-4.5`, `gpt-5.5`, `o3`) are unaffected.

Added `test_openai_legacy_compact_snapshot_suffixes_are_dropped`
to pin both sides (8 snapshot ids dropped, 7 canonical ids kept).
10 / 10 filter tests pass locally.

studio/backend/core/inference/external_provider.py

@@ -68,6 +68,21 @@ _ANTHROPIC_4_7_SAMPLING_REMOVED = re.compile(
 )
 _OPENAI_REASONING_SUMMARY_UNSUPPORTED = re.compile(r"^o3(?:[-.]|$)")
 
+# Reasoning-class OpenAI families that reject `temperature` and `top_p`
+# with "Unsupported parameter" 400s on /v1/responses (and on
+# /v1/chat/completions for the same families). Sampling knobs MUST be
+# dropped for these. Other chat-completion families (gpt-4o*,
+# gpt-4.1*, gpt-3.5-turbo*, gpt-4*, gpt-audio*, gpt-realtime*)
+# accept the standard sampling shape and we forward both fields
+# verbatim so the user's slider settings actually take effect.
+#
+# Source: OpenAI's reasoning guide
+# (https://developers.openai.com/api/docs/guides/reasoning) and the
+# /v1/responses reference. Covers gpt-5.x family, o1/o3/o4 family,
+# and gpt-4.5 family. The `(?:[-.]|$)` anchor keeps gpt-50 / o30
+# hypotheticals out.
+_OPENAI_REASONING_FAMILY = re.compile(r"^(?:gpt-5(?:\.\d+)?|o[134]|gpt-4\.5)(?:[-.]|$)")
+
 
 class _AnthropicThinkingSpec(NamedTuple):
     prefixes: tuple[str, ...]
@@ -2650,21 +2665,35 @@ class ExternalProviderClient:
                 if translated_parts:
                     input_items.append({"role": role, "content": translated_parts})
 
-        # NOTE: gpt-5.x / o3 / gpt-4.5 are reasoning-class models. They reject
-        # temperature and top_p with `Unsupported parameter` 400s on
-        # /v1/responses (and on /v1/chat/completions for the same families).
-        # The PROVIDER_REGISTRY['openai'] model_id_allowlist already scopes
-        # the picker to those families, so we never need to send sampling
-        # knobs here. ``reasoning.effort`` defaults to "medium" server-side
-        # if omitted — surface it in a future commit if a knob is wanted.
-        del temperature, top_p  # explicit drop — params are accepted for
-        # API symmetry with the other stream methods but not forwarded.
-
+        # Sampling knob handling. The old allowlist-scoped picker only
+        # admitted reasoning-class families (gpt-5.x / o3 / gpt-4.5),
+        # all of which reject `temperature` and `top_p` with
+        # "Unsupported parameter" 400s on /v1/responses -- so the
+        # earlier code unconditionally dropped both.
+        #
+        # The denylist-based picker (PR 5684) now also admits
+        # non-reasoning chat models (gpt-4o*, gpt-4.1*, gpt-4*,
+        # gpt-3.5-turbo*, gpt-audio*, gpt-realtime*) that accept the
+        # standard sampling shape. Forward temperature/top_p for those;
+        # keep dropping them for the reasoning families.
         body: dict[str, Any] = {
             "model": model,
             "input": input_items,
             "stream": True,
         }
+        is_reasoning_family = bool(
+            _OPENAI_REASONING_FAMILY.match(model.strip().lower())
+        )
+        if not is_reasoning_family:
+            if temperature is not None:
+                body["temperature"] = temperature
+            if top_p is not None:
+                body["top_p"] = top_p
+        else:
+            # Reasoning-class: explicit drop. ``reasoning.effort`` is
+            # the only knob the API accepts and defaults to "medium"
+            # server-side if omitted.
+            del temperature, top_p
         # `summary: "auto"` is what makes /v1/responses emit reasoning
         # summary events — without it OpenAI returns no thinking text on
         # most reasoning models, the SSE handler has no <think>…</think>

studio/backend/core/inference/providers.py

@@ -26,14 +26,89 @@ PROVIDER_REGISTRY: dict[str, dict[str, Any]] = {
         "supports_tool_calling": True,
         "auth_header": "Authorization",
         "auth_prefix": "Bearer ",
-        # Keep the model picker scoped to the current generation. The remote
-        # /v1/models listing returns dozens of historical snapshots, fine-tunes
-        # and non-chat models (embeddings, TTS, image, moderation) that we
-        # never want to surface in the chat UI. Filtering here so backend
-        # is the single source of truth.
-        "model_id_allowlist": re.compile(r"^(gpt-5\.[345]|gpt-4\.5|o3)(?:[-.]|$)"),
-        # Hide dated snapshots and the retired plain gpt-5.3 id.
-        "model_id_denylist": re.compile(r"^(gpt-5\.3)$|-\d{4}-\d{2}-\d{2}$"),
+        # The remote /v1/models listing returns the full account catalog,
+        # including non-chat models (embeddings, TTS, image, moderation,
+        # whisper, dall-e) and fine-tunes. Previously we used a hardcoded
+        # family allowlist (`gpt-5\.[345]|gpt-4\.5|o3`) which silently
+        # dropped every new family OpenAI shipped, including the gpt-5.5
+        # generation today. Switch to a non-chat denylist instead so any
+        # new chat family auto-appears the moment OpenAI lists it.
+        #
+        # Pattern strategy:
+        # - Unambiguous *feature* indicators (tts/whisper/transcribe/
+        #   image/embedding/moderation/sora) match anywhere in the id
+        #   with `(?:^|-)` because OpenAI uses them as the primary
+        #   qualifier on every variant -- e.g. canonical `tts-1` AND
+        #   family variants `gpt-4o-tts`, `gpt-4o-mini-tts`. These
+        #   words don't appear in legitimate chat model ids mid-string,
+        #   so the mid-id match is intentional and safe.
+        # - `audio` and `realtime` are INTENTIONALLY NOT in the
+        #   mid-id set. Both the `gpt-audio*` and `gpt-realtime*`
+        #   families are chat/responses-capable today -- per OpenAI's
+        #   audio and realtime guides they accept text in via
+        #   /v1/chat/completions and /v1/responses, not only the
+        #   specialised /v1/realtime WebSocket transport. Dropping
+        #   them hid supported chat models from the picker. The
+        #   audio-only endpoint families (`tts-*`, `whisper-*`,
+        #   `*-transcribe`) are still caught above.
+        # - `search` is INTENTIONALLY NOT in the mid-id set because
+        #   `gpt-4o-search-preview` and `gpt-4o-mini-search-preview` are
+        #   chat-with-retrieval models that absolutely belong in the
+        #   picker. The standalone search API is caught separately by
+        #   `-search-api` (suffix) which never appears on a chat id.
+        # - Legacy completion bases (babbage / davinci / ada / curie)
+        #   are ^-anchored: they ONLY ever begin a legacy id like
+        #   `babbage-002`, `davinci-002`, `text-davinci-003`. A future
+        #   hypothetical `gpt-7-davinci-edition` chat model would NOT
+        #   be dropped, which is the right default for a denylist.
+        # - Prefix-only patterns (`^dall-e`, `^computer-use`, `^ft:`,
+        #   `^gpt-image`) cover canonical non-chat families without
+        #   risk of mid-id false positives.
+        #
+        # Verified against the live /v1/models listing 2026-05-22.
+        "model_id_denylist": re.compile(
+            # Feature suffixes that mark a non-chat variant on any base.
+            # `audio`/`realtime` are NOT in this group so `gpt-audio`
+            # (chat-capable, streaming) stays; specific non-streaming
+            # IDs are caught further down.
+            r"(?:^|-)(?:embedding|tts|whisper|moderation|image|"
+            r"transcribe|translate|instruct|sora)\b"
+            # OpenAI realtime/audio variants that don't support chat
+            # streaming. Studio always sends `stream: true`, and OpenAI
+            # marks the full Realtime family as Streaming: Not supported
+            # (Realtime API only, WebRTC/WebSocket transport): `gpt-realtime`,
+            # `gpt-realtime-mini`, `gpt-4o-realtime-preview*` and
+            # `gpt-4o-mini-realtime-preview*`, plus `gpt-audio-mini`.
+            # Selecting them from the picker would 4xx at request time.
+            # `gpt-audio` and `gpt-4o-audio-preview` are kept -- they
+            # stream over Chat Completions / Responses.
+            r"|^gpt-realtime(?:$|-)"
+            r"|^gpt-4o(?:-mini)?-realtime\b"
+            r"|^gpt-audio-mini\b"
+            # Legacy completion bases -- ^-anchored to avoid false
+            # positives on hypothetical future chat ids containing
+            # those words mid-string.
+            r"|^(?:babbage|davinci|ada|curie)\b"
+            r"|^text-(?:embedding|moderation|davinci|curie|babbage|ada)\b"
+            # Standalone search API (separate endpoint shape).
+            # `gpt-4o-search-preview` (chat-with-search) is intentionally
+            # NOT matched here.
+            r"|-search-api(?:-\d{4}-\d{2}-\d{2})?$"
+            # Canonical non-chat prefixes.
+            r"|^dall-e\b"
+            r"|^computer-use\b"
+            # Fine-tunes carry the user's tenant in the id.
+            r"|^ft:"
+            # Dated snapshot suffixes hide behind the canonical id
+            # which is also in the listing. Covers both the modern
+            # `-YYYY-MM-DD` dated form and the legacy compact
+            # 4-digit `MMDD` form (e.g. `gpt-3.5-turbo-0125`,
+            # `gpt-4-0613`, `gpt-4-1106-preview`) so the picker only
+            # surfaces the canonical id even when the listing still
+            # returns the snapshot copy.
+            r"|-\d{4}-\d{2}-\d{2}$"
+            r"|-\d{4}(?:-preview)?$"
+        ),
     },
     "anthropic": {
         "display_name": "Anthropic",
@@ -42,16 +117,17 @@ PROVIDER_REGISTRY: dict[str, dict[str, Any]] = {
             "claude-opus-4-7",
             "claude-opus-4-6",
             "claude-sonnet-4-6",
-            "claude-opus-4-5",
-            "claude-sonnet-4-5",
-            "claude-haiku-4-5",
+            "claude-opus-4-5-20251101",
+            "claude-sonnet-4-5-20250929",
+            "claude-haiku-4-5-20251001",
         ],
-        # Anthropic /v1/models returns dated snapshot ids alongside the
-        # canonical names (e.g. claude-3-5-sonnet-20241022). Hide the
-        # YYYYMMDD-suffixed variants from the picker — same intent as the
-        # OpenAI denylist, just a different date format (no dashes between
-        # year/month/day).
-        "model_id_denylist": re.compile(r"-\d{8}$"),
+        # Anthropic's /v1/models returns dated ids for every model in the
+        # pre-4.6 generation -- `claude-opus-4-5-20251101`,
+        # `claude-haiku-4-5-20251001`, `claude-sonnet-4-5-20250929`,
+        # `claude-opus-4-1-20250805`. Per the models overview, those
+        # dated ids ARE the canonical names for that generation, not
+        # snapshots to hide. Dropping the previous `-\d{8}$` denylist
+        # so every live model the API returns reaches the picker.
         "supports_streaming": True,
         "supports_vision": True,
         "supports_tool_calling": False,

studio/backend/tests/test_openai_responses_translation.py

@@ -101,9 +101,11 @@ def test_responses_request_body_uses_input_and_instructions(monkeypatch):
     assert body["input"] == [{"role": "user", "content": "Hi"}]
     assert body["max_output_tokens"] == 512
     assert body["stream"] is True
-    # Responses API on reasoning-class models (gpt-5.x / o3 / gpt-4.5 — the
-    # only OpenAI ids the registry allowlist exposes) rejects these as
-    # `Unsupported parameter`. Make sure we never silently forward them.
+    # gpt-5.5 is reasoning-class: Responses API rejects temperature
+    # and top_p with `Unsupported parameter` 400s, so the helper must
+    # drop them. Non-reasoning models (gpt-4o*, gpt-4.1*, gpt-3.5-turbo*,
+    # gpt-audio*, gpt-realtime*) are covered in a sibling test that
+    # asserts the inverse forwarding.
     assert "temperature" not in body
     assert "top_p" not in body
     assert "presence_penalty" not in body
@@ -112,6 +114,104 @@ def test_responses_request_body_uses_input_and_instructions(monkeypatch):
     assert "messages" not in body
 
 
+def test_responses_forwards_sampling_for_non_reasoning_chat_families(monkeypatch):
+    # Codex P1 follow-up to the picker filter change (PR 5684): the
+    # OpenAI denylist now admits non-reasoning chat families
+    # (gpt-4o*, gpt-4.1*, gpt-3.5-turbo*, gpt-audio*, gpt-realtime*).
+    # The Responses API ACCEPTS temperature and top_p on those, so
+    # the helper must forward the user's slider settings instead of
+    # silently dropping them.
+    for model in (
+        "gpt-4o",
+        "gpt-4o-mini",
+        "gpt-4o-2026-01-01",
+        "gpt-4.1",
+        "gpt-4",
+        "gpt-3.5-turbo",
+        "gpt-audio",
+        "gpt-realtime",
+    ):
+        captured: dict = {}
+
+        def handler(request: httpx.Request, _captured = captured) -> httpx.Response:
+            _captured["body"] = json.loads(request.content.decode("utf-8"))
+            return httpx.Response(
+                200,
+                content = _responses_sse(
+                    [{"type": "response.completed", "response": {}}]
+                ),
+                headers = {"content-type": "text/event-stream"},
+            )
+
+        _mock_http_client(monkeypatch, handler)
+
+        async def run():
+            client = _make_client()
+            async for _ in client._stream_openai_responses(
+                messages = [{"role": "user", "content": "Hi"}],
+                model = model,
+                temperature = 0.42,
+                top_p = 0.85,
+                max_tokens = 32,
+                enable_thinking = None,
+                reasoning_effort = None,
+            ):
+                pass
+            await client.close()
+
+        _drive(run())
+        body = captured["body"]
+        assert body["temperature"] == 0.42, (model, body)
+        assert body["top_p"] == 0.85, (model, body)
+
+
+def test_responses_still_drops_sampling_for_reasoning_families(monkeypatch):
+    # Sanity: parametrise across the reasoning-class families so a
+    # future regex tweak that accidentally weakens the drop surfaces
+    # here.
+    for model in (
+        "gpt-5.5",
+        "gpt-5.4",
+        "gpt-5",
+        "o1",
+        "o3-mini",
+        "o4-mini",
+        "gpt-4.5-preview",
+    ):
+        captured: dict = {}
+
+        def handler(request: httpx.Request, _captured = captured) -> httpx.Response:
+            _captured["body"] = json.loads(request.content.decode("utf-8"))
+            return httpx.Response(
+                200,
+                content = _responses_sse(
+                    [{"type": "response.completed", "response": {}}]
+                ),
+                headers = {"content-type": "text/event-stream"},
+            )
+
+        _mock_http_client(monkeypatch, handler)
+
+        async def run():
+            client = _make_client()
+            async for _ in client._stream_openai_responses(
+                messages = [{"role": "user", "content": "Hi"}],
+                model = model,
+                temperature = 0.42,
+                top_p = 0.85,
+                max_tokens = 32,
+                enable_thinking = None,
+                reasoning_effort = None,
+            ):
+                pass
+            await client.close()
+
+        _drive(run())
+        body = captured["body"]
+        assert "temperature" not in body, (model, body)
+        assert "top_p" not in body, (model, body)
+
+
 def test_responses_translates_image_parts(monkeypatch):
     captured: dict = {}
 

studio/backend/tests/test_provider_registry_filters.py

@@ -0,0 +1,332 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Provider registry model-id filter regression tests.
+
+The OpenAI ``model_id_allowlist`` previously hardcoded the gpt-5.3/4/5
+families plus gpt-4.5 / o3 -- silently dropping every future family
+OpenAI shipped. Anthropic's ``model_id_denylist`` previously stripped
+every dated id, hiding the canonical names of every pre-4.6 model
+(Opus 4.5, Sonnet 4.5, Haiku 4.5, Opus 4.1, the 4.0 family).
+
+These tests pin the new non-chat denylist (OpenAI) and the empty
+denylist (Anthropic) by walking realistic ``/v1/models`` listings
+through ``PROVIDER_REGISTRY`` and asserting the surviving set.
+"""
+
+from core.inference.providers import PROVIDER_REGISTRY
+
+
+def _apply(provider_type: str, candidate_ids: list[str]) -> list[str]:
+    """Mirror the filter logic in ``routes/providers.list_models``."""
+    info = PROVIDER_REGISTRY[provider_type]
+    out = list(candidate_ids)
+    allow = info.get("model_id_allowlist")
+    if allow is not None:
+        out = [m for m in out if allow.match(m)]
+    deny = info.get("model_id_denylist")
+    if deny is not None:
+        out = [m for m in out if not deny.search(m)]
+    return out
+
+
+# ── OpenAI: non-chat denylist drops only non-chat ids ──────────────
+
+
+def test_openai_keeps_every_known_chat_family():
+    live = [
+        # Current generation (must survive).
+        "gpt-5.5",
+        "gpt-5.5-pro",
+        "gpt-5.4",
+        "gpt-5.4-pro",
+        "gpt-5.4-mini",
+        "gpt-5.4-nano",
+        "gpt-5.3-codex",
+        "gpt-5.3-chat-latest",
+        "o3",
+        "o3-pro",
+        "o3-mini",
+        "o3-deep-research",
+        # `gpt-4o-search-preview` and the mini variant are chat-with-
+        # retrieval models that respond to standard /v1/chat/completions
+        # and absolutely belong in the picker. The previous regex
+        # dropped them as a false positive of `(?:^|-)search`; the
+        # tightened denylist intentionally only catches the standalone
+        # search-api suffix.
+        "gpt-4o-search-preview",
+        "gpt-4o-mini-search-preview",
+        # gpt-audio is chat-completion-capable with streaming. The
+        # `-mini` variant does NOT stream (Realtime API only) and is
+        # asserted dropped in the realtime/audio split test below.
+        "gpt-audio",
+        "gpt-audio-1.5",
+        # Hypothetical future families that the old allowlist would have
+        # silently dropped -- they MUST surface under the new denylist.
+        "gpt-5.6",
+        "gpt-5.6-mini",
+        "gpt-6",
+        "gpt-6-pro",
+        "o4",
+        "o4-pro",
+        "o5",
+    ]
+    surviving = _apply("openai", live)
+    assert surviving == live, surviving
+
+
+def test_openai_audio_and_realtime_families_split_on_streaming_support():
+    # Pin the chat/non-chat split: Studio always sends `stream: true`,
+    # so the picker keeps the audio chat families (gpt-audio* without
+    # -mini, plus gpt-4o-audio-preview*) which stream over
+    # /v1/chat/completions and /v1/responses, but drops the entire
+    # Realtime family (gpt-realtime*, gpt-4o-realtime-preview*,
+    # gpt-4o-mini-realtime-preview*) and gpt-audio-mini, which OpenAI's
+    # model cards mark Streaming: Not supported (Realtime API only,
+    # WebRTC/WebSocket transport).
+    kept = _apply(
+        "openai",
+        [
+            "gpt-audio",
+            "gpt-audio-1.5",
+            "gpt-4o-audio-preview",
+            "gpt-4o-audio-preview-2024-12-17",
+        ],
+    )
+    assert kept == [
+        "gpt-audio",
+        "gpt-audio-1.5",
+        "gpt-4o-audio-preview",
+        # Dated audio-preview snapshot is dropped by the date-suffix rule;
+        # the canonical id above survives.
+    ], kept
+
+    dropped = _apply(
+        "openai",
+        [
+            "gpt-audio-mini",
+            "gpt-realtime",
+            "gpt-realtime-mini",
+            "gpt-realtime-1.5",
+            "gpt-realtime-2",
+            "gpt-4o-realtime-preview",
+            "gpt-4o-mini-realtime-preview",
+            "gpt-4o-transcribe",
+            "gpt-4o-mini-transcribe",
+        ],
+    )
+    assert dropped == [], dropped
+
+
+def test_openai_drops_non_chat_ids():
+    noise = [
+        # Embeddings / TTS / image / moderation / whisper / etc.
+        # gpt-audio (no -mini) and gpt-4o-audio-preview are intentionally
+        # OMITTED from this list -- they DO stream chat. See
+        # test_openai_audio_and_realtime_families_split_on_streaming_support.
+        "text-embedding-3-small",
+        "text-embedding-3-large",
+        "text-embedding-ada-002",
+        "text-moderation-latest",
+        "text-moderation-stable",
+        "tts-1",
+        "tts-1-hd",
+        "gpt-4o-tts",
+        "whisper-1",
+        "dall-e-2",
+        "dall-e-3",
+        "gpt-image-1",
+        "gpt-image-2",
+        "gpt-image-1-mini",
+        "chatgpt-image-latest",
+        "gpt-4o-transcribe",
+        "gpt-4o-mini-transcribe",
+        "gpt-4o-mini-tts",
+        "omni-moderation-latest",
+        # Standalone search API endpoint (distinct from the
+        # `*-search-preview` chat models above).
+        "gpt-5-search-api",
+        "gpt-5-search-api-2025-10-14",
+        # Video generation.
+        "sora-2",
+        "sora-2-pro",
+        # Computer-use is an agentic harness, not a chat id.
+        "computer-use-preview",
+        # Legacy bases.
+        "babbage-002",
+        "davinci-002",
+        "text-davinci-003",
+        "text-curie-001",
+        "text-ada-001",
+        # Fine-tunes.
+        "ft:gpt-4o-mini:acme:abc:xyz",
+        # Dated snapshots are still hidden.
+        "gpt-4o-2024-08-06",
+        "gpt-4o-mini-2024-07-18",
+        "gpt-5.5-2026-04-23",
+    ]
+    surviving = _apply("openai", noise)
+    assert surviving == [], surviving
+
+
+def test_openai_realtime_translate_variants_are_dropped_but_parent_chat_family_survives():
+    """gpt-audio is chat-capable (streams over /v1/chat/completions)
+    and stays, but the audio-translation variants share the chat
+    picker's transport and would 4xx, so they must be filtered. The
+    full Realtime family (gpt-realtime*, gpt-4o*-realtime-preview*)
+    plus gpt-audio-mini are Realtime-only and dropped by a sibling
+    assertion."""
+    kept = _apply("openai", ["gpt-audio"])
+    assert kept == ["gpt-audio"], kept
+
+    dropped = _apply(
+        "openai",
+        [
+            "gpt-realtime-translate",
+            "gpt-realtime-translate-mini",
+            "gpt-audio-translate",
+            "gpt-4o-realtime-translate-preview",
+        ],
+    )
+    assert dropped == [], dropped
+
+
+def test_openai_legacy_instruct_completion_ids_are_dropped():
+    """Legacy `*-instruct` completion-only ids (gpt-3.5-turbo-instruct
+    and friends) speak /v1/completions, not chat/responses. Our OpenAI
+    bridge only knows the chat/responses transport, so admitting them
+    into the picker would 4xx every selection."""
+    dropped = _apply(
+        "openai",
+        [
+            "gpt-3.5-turbo-instruct",
+            "gpt-3.5-turbo-instruct-0914",
+            "davinci-002-instruct",
+        ],
+    )
+    assert dropped == [], dropped
+
+
+def test_openai_legacy_compact_snapshot_suffixes_are_dropped():
+    """Legacy `-MMDD` snapshot suffixes (gpt-3.5-turbo-0125,
+    gpt-4-0613, gpt-4-1106-preview, etc.) hide behind the canonical
+    id which the listing also returns; surface only the canonical so
+    users do not pick a deprecated snapshot by accident. The
+    `-\\d{4}(?:-preview)?$` rule must not catch canonical ids whose
+    minor version happens to be a year-like number (e.g. gpt-4.5,
+    o3) -- those are tested as KEEP below."""
+    dropped = _apply(
+        "openai",
+        [
+            "gpt-3.5-turbo-0125",
+            "gpt-3.5-turbo-0301",
+            "gpt-3.5-turbo-16k-0613",
+            "gpt-4-0613",
+            "gpt-4-0314",
+            "gpt-4-32k-0613",
+            "gpt-4-1106-preview",
+            "gpt-4-0125-preview",
+        ],
+    )
+    assert dropped == [], dropped
+
+    # Canonical chat ids that share a digit-heavy tail must survive.
+    kept = _apply(
+        "openai",
+        [
+            "gpt-3.5-turbo",
+            "gpt-4o",
+            "gpt-4.5",
+            "gpt-5.5",
+            "gpt-5.5-mini",
+            "gpt-5.5-pro",
+            "o3",
+        ],
+    )
+    assert set(kept) >= {
+        "gpt-3.5-turbo",
+        "gpt-4o",
+        "gpt-4.5",
+        "gpt-5.5",
+        "gpt-5.5-mini",
+        "gpt-5.5-pro",
+        "o3",
+    }, kept
+
+
+def test_openai_search_preview_is_kept_search_api_is_dropped():
+    # Pin the search-vs-search-api distinction so a future regex tweak
+    # doesn't silently regress to dropping chat-with-search models.
+    kept = _apply(
+        "openai",
+        [
+            "gpt-4o-search-preview",
+            "gpt-4o-mini-search-preview",
+        ],
+    )
+    assert kept == [
+        "gpt-4o-search-preview",
+        "gpt-4o-mini-search-preview",
+    ], kept
+
+    dropped = _apply(
+        "openai",
+        [
+            "gpt-5-search-api",
+            "gpt-5-search-api-2025-10-14",
+        ],
+    )
+    assert dropped == [], dropped
+
+
+def test_openai_legacy_completion_names_only_match_at_id_start():
+    # Hypothetical future chat ids that happen to contain a legacy
+    # completion-family name mid-string must NOT be dropped. The
+    # `^(?:babbage|davinci|ada|curie)\b` anchor is what makes this safe.
+    kept = _apply(
+        "openai",
+        [
+            "gpt-7-davinci-edition",
+            "gpt-7-ada-chat",
+            "gpt-7-curie-pro",
+            "gpt-7-babbage-mini",
+        ],
+    )
+    assert kept == [
+        "gpt-7-davinci-edition",
+        "gpt-7-ada-chat",
+        "gpt-7-curie-pro",
+        "gpt-7-babbage-mini",
+    ], kept
+    # ...but the actual legacy-base ids stay dropped.
+    dropped = _apply(
+        "openai",
+        ["babbage-002", "davinci-002", "text-davinci-003"],
+    )
+    assert dropped == [], dropped
+
+
+# ── Anthropic: empty denylist; dated ids ARE canonical ───────────────
+
+
+def test_anthropic_surfaces_every_live_model_including_dated_ids():
+    # The full set of ids /v1/models returns today.
+    live = [
+        "claude-opus-4-7",
+        "claude-sonnet-4-6",
+        "claude-opus-4-6",
+        "claude-opus-4-5-20251101",
+        "claude-sonnet-4-5-20250929",
+        "claude-haiku-4-5-20251001",
+        "claude-opus-4-1-20250805",
+        "claude-opus-4-20250514",
+        "claude-sonnet-4-20250514",
+    ]
+    surviving = _apply("anthropic", live)
+    assert surviving == live, surviving
+
+
+def test_anthropic_default_models_match_filter():
+    info = PROVIDER_REGISTRY["anthropic"]
+    surviving = _apply("anthropic", list(info["default_models"]))
+    assert surviving == list(info["default_models"]), surviving