Migrating to GPT-5.x Without Breaking GPT-4: A Practical, Backward-Compatible Playbook
The first request your service sends after swapping gpt-4o for gpt-5.1 in production will return HTTP 400. Not in two weeks. On the first call. And the parameter the error points to isn't one you set anywhere in your code - it's bound onto the request by a LangChain helper you've used for two years. This post walks through every breaking change between the GPT-4 and GPT-5 families on Azure OpenAI in Microsoft Foundry, the integration cliffs nobody warns you about, and the small set of files you need so the same call sites work against both model families without branching. Who this is for: engineers maintaining an existing production codebase that calls Azure OpenAI / OpenAI - directly or through LangChain - and needs to onboard GPT-5.x while keeping the GPT-4 deployments alive during rollout. What you'll leave with: one copy-paste compatibility module, a tiny LangChain subclass, a prompt-audit harness, and a 10-step rollout checklist. 1. Why this migration is different Every previous Azure OpenAI bump - 3.5 → 4, 4 → 4o, 4o → 4o-mini - was additive. You changed engine="gpt-4o" and everything kept working. GPT-5.x is the first generation that is subtractive: parameters you used to send now return 400 Unsupported parameter. The wire protocol itself changed because GPT-5 is a reasoning model - it spends tokens thinking internally before it answers, so the parameters that controlled the old sampling pipeline (temperature, top_p, presence_penalty, frequency_penalty) no longer exist on the request schema. What this means for production code: A passing test suite against gpt-4o will fail on the first call against gpt-5.1 with HTTP 400. A passing test suite against gpt-5.1 will fail on every legacy gpt-4* deployment because the new reasoning controls (reasoning_effort, verbosity) are not recognised there. LangChain helpers that worked unmodified for two years (notably create_sql_query_chain) silently bind stop=[...] onto your LLM and trigger the same 400. Source-grep won't find the offending line because it lives inside the library. The good news: the divergence is mechanical. With one detection helper, one parameter-builder, and one tiny LangChain subclass you can run the same code against both families. 2. The breaking-changes matrix Concern GPT-4 / GPT-4o (legacy) GPT-5.x / o1 / o3 (reasoning) Output budget max_tokens max_completion_tokens (rejects max_tokens) temperature 0.0–1.0 Only the default (1) is accepted - omit it top_p Supported Rejected presence_penalty, frequency_penalty Supported Rejected logprobs, logit_bias Supported Rejected stop sequences Supported Rejected on most reasoning deployments reasoning_effort Rejected New: minimal | low | medium | high verbosity Rejected New: low | medium | high (sometimes via extra_body) System instruction role system developer recommended; system still works as alias Output token cost Output tokens only Output + reasoning tokens count against your cap Recommended API version 2024-12-01-preview or earlier 2025-03-01-preview or later Two consequences are easy to miss: max_completion_tokens is a shared budget. GPT-5.1 can burn 2–4× more tokens internally before emitting the first response token. A cap of 4096 that comfortably held a SQL query on GPT-4o now silently truncates the answer mid-token on GPT-5.1. Multiply your legacy budgets by ~2.5× and add a floor (e.g. 4096) before sending. The stop parameter is the silent killer. Any helper that calls llm.bind(stop=[...]) - and there are several in langchain - will turn a working code path into a 400 the moment you swap deployments. 3. Compatibility strategy: detect, don't fork The temptation is to fork: one branch for GPT-4, one for GPT-5. Don't. The right unit of abstraction is one function that classifies the deployment into a family, and one function that builds a kwargs dict the SDK will accept for that family. Every call site - SDK, LangChain, raw HTTP - drains into the same kwargs builder. When you eventually retire GPT-4 you delete the legacy branch in one file, not in fifty. 4. The industry-agnostic compatibility module Drop the following file into your project. It has no Azure / OpenAI / LangChain imports at module load time, so the same file works from a web service, a serverless function, a notebook, or a CLI tool. 4.1 model_compat.py """ Model compatibility helper for GPT-5.x with GPT-4 backward compatibility. This module centralises the parameter translation needed to talk to the "reasoning" generation of OpenAI / Azure OpenAI models (GPT-5, GPT-5.1, o1, o3, o4) while keeping older deployments (gpt-4, gpt-4o, gpt-4-32k, gpt-3.5-turbo, etc.) working unchanged. """ from __future__ import annotations import logging import os import re from typing import Any, Dict, Iterable, Mapping, Optional # --------------------------------------------------------------------------- # Family detection # --------------------------------------------------------------------------- _REASONING_PATTERNS = ( # gpt-5, gpt5, gpt-5.1, gpt_5, GPT 5, gpt5mini-prod-eu, ... re.compile(r"(?i)(^|[^a-z0-9])gpt[-_ ]?5(\.\d+)?([^0-9]|$)"), # o1, o3, o4, o1-mini, o3-preview ... re.compile(r"(?i)(^|[^a-z0-9])o[134](-mini|-preview)?([^a-z0-9]|$)"), ) _LEGACY_PATTERNS = ( re.compile(r"(?i)gpt[-_ ]?4o"), re.compile(r"(?i)gpt[-_ ]?4(?!\d)"), re.compile(r"(?i)gpt[-_ ]?4[-_ ]?32k"), re.compile(r"(?i)gpt[-_ ]?3\.?5"), re.compile(r"(?i)gpt[-_ ]?35"), ) def get_model_family(model_or_deployment: Optional[str]) -> str: """Return ``"reasoning"`` for GPT-5.x / o-series, ``"legacy"`` otherwise. Honours an ``OPENAI_MODEL_FAMILY`` env-var override for deployments whose user-defined name does not embed the model family (e.g. ``prod-default``). """ override = (os.getenv("OPENAI_MODEL_FAMILY") or "").strip().lower() if override in {"reasoning", "gpt-5", "gpt5", "gpt-5.1", "o-series", "o1", "o3"}: return "reasoning" if override in {"legacy", "gpt-4", "gpt4", "gpt-3.5", "gpt35", "chat"}: return "legacy" name = (model_or_deployment or "").strip() if not name: # Fail closed: when we don't know, assume legacy so old code keeps # working. Misclassifying a reasoning deployment as legacy fails fast # with a clear "Unsupported parameter" 400; the reverse silently # drops parameters the caller expected. return "legacy" for pat in _REASONING_PATTERNS: if pat.search(name): return "reasoning" for pat in _LEGACY_PATTERNS: if pat.search(name): return "legacy" return "legacy" def is_reasoning_model(model_or_deployment: Optional[str]) -> bool: return get_model_family(model_or_deployment) == "reasoning" # --------------------------------------------------------------------------- # Reasoning controls # --------------------------------------------------------------------------- _VALID_REASONING_EFFORT = {"minimal", "low", "medium", "high"} _VALID_VERBOSITY = {"low", "medium", "high"} def _coerce_choice(raw: Optional[str], valid: Iterable[str]) -> Optional[str]: if raw is None: return None value = str(raw).strip().lower() if not value: return None if value not in set(valid): logging.warning( "Ignoring unsupported value '%s'; expected one of %s", raw, sorted(valid), ) return None return value def get_reasoning_effort(override: Optional[str] = None) -> Optional[str]: return _coerce_choice( override if override is not None else os.getenv("OPENAI_REASONING_EFFORT"), _VALID_REASONING_EFFORT, ) def get_verbosity(override: Optional[str] = None) -> Optional[str]: return _coerce_choice( override if override is not None else os.getenv("OPENAI_VERBOSITY"), _VALID_VERBOSITY, ) # --------------------------------------------------------------------------- # max_completion_tokens scaling # --------------------------------------------------------------------------- def _reasoning_token_scale() -> float: """Multiplier applied to legacy ``max_tokens`` when targeting a reasoning model.""" try: scale = float(os.getenv("OPENAI_REASONING_TOKEN_SCALE", "2.5")) except (TypeError, ValueError): scale = 2.5 return scale if scale > 0 else 1.0 def _reasoning_token_floor() -> int: try: floor = int(os.getenv("OPENAI_REASONING_TOKEN_FLOOR", "4096")) except (TypeError, ValueError): floor = 4096 return floor if floor > 0 else 4096 def scale_max_tokens_for_reasoning(max_tokens: Optional[int]) -> Optional[int]: """Scale a legacy ``max_tokens`` budget up for reasoning models. ``None`` and ``-1`` ("no explicit cap") are passed through. """ if max_tokens is None: return None if max_tokens == -1: return -1 return max(int(round(max_tokens * _reasoning_token_scale())), _reasoning_token_floor()) # --------------------------------------------------------------------------- # Kwargs builders # --------------------------------------------------------------------------- _SAMPLING_KEYS = ("temperature", "top_p", "presence_penalty", "frequency_penalty") def _drop_none(mapping: Mapping[str, Any]) -> Dict[str, Any]: return {k: v for k, v in mapping.items() if v is not None} def build_openai_chat_kwargs( model: str, *, max_tokens: Optional[int] = None, temperature: Optional[float] = None, top_p: Optional[float] = None, presence_penalty: Optional[float] = None, frequency_penalty: Optional[float] = None, reasoning_effort: Optional[str] = None, verbosity: Optional[str] = None, extra: Optional[Mapping[str, Any]] = None, ) -> Dict[str, Any]: """Build kwargs for ``openai.OpenAI / AzureOpenAI .chat.completions.create``. Splat the result directly: ``client.chat.completions.create(**kwargs)``. Unsupported parameters are silently omitted for reasoning models; legacy deployments retain the historical behaviour. """ family = get_model_family(model) kwargs: Dict[str, Any] = {"model": model} # ---- output budget ---- if max_tokens is not None and max_tokens != -1: if family == "reasoning": kwargs["max_completion_tokens"] = scale_max_tokens_for_reasoning(int(max_tokens)) else: kwargs["max_tokens"] = int(max_tokens) # ---- sampling ---- if family == "legacy": kwargs.update(_drop_none({ "temperature": temperature, "top_p": top_p, "presence_penalty": presence_penalty, "frequency_penalty": frequency_penalty, })) else: for key, value in ( ("temperature", temperature), ("top_p", top_p), ("presence_penalty", presence_penalty), ("frequency_penalty", frequency_penalty), ): if value is not None: logging.debug( "Dropping unsupported parameter '%s' for reasoning model '%s'", key, model, ) # ---- reasoning controls ---- if family == "reasoning": effort = get_reasoning_effort(reasoning_effort) if effort is not None: kwargs["reasoning_effort"] = effort verb = get_verbosity(verbosity) if verb is not None: # ``verbosity`` is not a top-level kwarg in openai-python <= 1.65.x; # route it via ``extra_body`` so it lands in the JSON without a # TypeError from the SDK. kwargs.setdefault("extra_body", {})["verbosity"] = verb # ---- caller-supplied extras (already filtered) ---- if extra: for key, value in extra.items(): if value is None: continue if family == "reasoning" and key in _SAMPLING_KEYS: continue kwargs[key] = value return kwargs def build_langchain_chat_kwargs( deployment_name: str, *, max_tokens: Optional[int] = None, temperature: Optional[float] = None, top_p: Optional[float] = None, reasoning_effort: Optional[str] = None, verbosity: Optional[str] = None, ) -> Dict[str, Any]: """Build kwargs for ``langchain_openai.AzureChatOpenAI`` / ``ChatOpenAI``. Older ``langchain-openai`` releases don't expose ``max_completion_tokens`` as a top-level kwarg, so we forward it through ``model_kwargs`` (which langchain passes straight to the SDK). """ family = get_model_family(deployment_name) kwargs: Dict[str, Any] = {} model_kwargs: Dict[str, Any] = {} if max_tokens is not None and max_tokens != -1: if family == "reasoning": model_kwargs["max_completion_tokens"] = scale_max_tokens_for_reasoning(int(max_tokens)) else: kwargs["max_tokens"] = int(max_tokens) if family == "reasoning": effort = get_reasoning_effort(reasoning_effort) if effort is not None: model_kwargs["reasoning_effort"] = effort verb = get_verbosity(verbosity) if verb is not None: model_kwargs.setdefault("extra_body", {})["verbosity"] = verb else: if temperature is not None: kwargs["temperature"] = temperature if top_p is not None: kwargs["top_p"] = top_p if model_kwargs: kwargs["model_kwargs"] = model_kwargs return kwargs def get_system_role(model_or_deployment: Optional[str] = None) -> str: """Return ``"developer"`` for reasoning models when opted in, ``"system"`` otherwise. Defaulting to ``"system"`` preserves compatibility with LangChain prompt templates and SDK helpers that don't yet recognise the new role. Opt in with ``OPENAI_USE_DEVELOPER_ROLE=1`` once your stack supports it. """ if not is_reasoning_model(model_or_deployment): return "system" raw = os.getenv("OPENAI_USE_DEVELOPER_ROLE", "") return "developer" if raw.strip().lower() in {"1", "true", "yes", "on"} else "system" 4.2 What this buys you Every direct-SDK call collapses to two lines: from openai import AzureOpenAI from model_compat import build_openai_chat_kwargs client = AzureOpenAI( azure_endpoint=os.environ["AZURE_OPENAI_ENDPOINT"], api_version=os.environ["OPENAI_API_VERSION"], api_key=os.environ["AZURE_OPENAI_API_KEY"], ) kwargs = build_openai_chat_kwargs( model=os.environ["OPENAI_ENGINE"], max_tokens=4096, # automatically becomes max_completion_tokens for GPT-5 temperature=0.2, # automatically dropped for GPT-5 reasoning_effort="low", # automatically dropped for GPT-4 ) response = client.chat.completions.create( messages=[ {"role": "system", "content": "You are a helpful assistant."}, {"role": "user", "content": user_input}, ], **kwargs, ) The same call site now correctly targets gpt-5.1, gpt-4o, gpt-4-32k, o3-mini, or any future deployment whose name embeds the family - and you can override with the OPENAI_MODEL_FAMILY env var when the deployment alias is opaque. 4.3 Raw HTTP call sites Some legacy code paths bypass the SDK and POST JSON directly. The same builder works there: import json import requests from model_compat import build_openai_chat_kwargs, get_system_role deployment = os.environ["OPENAI_ENGINE"] api_version = os.environ["OPENAI_API_VERSION"] endpoint = ( f"{os.environ['AZURE_OPENAI_ENDPOINT']}/openai/deployments/{deployment}" f"/chat/completions?api-version={api_version}" ) payload = { "messages": [ {"role": get_system_role(deployment), "content": system_prompt}, {"role": "user", "content": user_prompt}, ], } # Splat the kwargs into the payload, then strip the SDK-only ``model`` key. payload.update(build_openai_chat_kwargs( model=deployment, max_tokens=800, temperature=0.7, top_p=0.95, reasoning_effort="low", )) payload.pop("model", None) # ``model`` is encoded in the URL for Azure payload.pop("extra_body", None) # already on the payload root resp = requests.post( endpoint, headers={"Content-Type": "application/json", "api-key": api_key}, data=json.dumps(payload), timeout=60, ) resp.raise_for_status() 5. LangChain: the hidden stop parameter langchain.chains.sql_database.query.create_sql_query_chain calls llm.bind(stop=["\nSQLResult:"]) internally to terminate the model's output before the example block in its prompt. That stop value is forwarded to the SDK on every invocation. GPT-5.1 rejects it: openai.BadRequestError: Error code: 400 - {'error': { 'message': "Unsupported parameter: 'stop' is not supported with this model.", 'type': 'invalid_request_error', 'param': 'stop', }} You can't reach into the chain to disable it. The clean fix is a thin AzureChatOpenAI subclass that drops stop for reasoning models only: 5.1 langchain_compat.py """LangChain-side compatibility shim for reasoning-class deployments.""" from __future__ import annotations from typing import Any, List, Optional from langchain_core.callbacks.manager import ( AsyncCallbackManagerForLLMRun, CallbackManagerForLLMRun, ) from langchain_core.messages import BaseMessage from langchain_core.outputs import ChatResult from langchain_openai import AzureChatOpenAI # use ChatOpenAI for non-Azure from model_compat import is_reasoning_model class ReasoningSafeAzureChatOpenAI(AzureChatOpenAI): """``AzureChatOpenAI`` variant that hides parameters reasoning models reject. Reasoning models (GPT-5.x, o1/o3/o4) return HTTP 400 when a request payload carries ``stop``. LangChain's SQL helpers unconditionally bind it, so the unsupported parameter reaches the SDK regardless of how the caller configured the LLM. This subclass strips ``stop`` for reasoning deployments while forwarding it unchanged for legacy GPT-4 / GPT-3.5 deployments - the behaviour is byte-identical to upstream LangChain for those models. """ def _deployment_id(self) -> str: # ``langchain-openai`` >= 0.2 exposes ``azure_deployment``; older # releases use ``deployment_name``. Either may be set by the caller. return ( getattr(self, "azure_deployment", None) or getattr(self, "deployment_name", None) or "" ) def _generate( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[CallbackManagerForLLMRun] = None, **kwargs: Any, ) -> ChatResult: if is_reasoning_model(self._deployment_id()): stop = None return super()._generate(messages, stop=stop, run_manager=run_manager, **kwargs) async def _agenerate( self, messages: List[BaseMessage], stop: Optional[List[str]] = None, run_manager: Optional[AsyncCallbackManagerForLLMRun] = None, **kwargs: Any, ) -> ChatResult: if is_reasoning_model(self._deployment_id()): stop = None return await super()._agenerate(messages, stop=stop, run_manager=run_manager, **kwargs) Use it as a drop-in replacement: from langchain_compat import ReasoningSafeAzureChatOpenAI from model_compat import build_langchain_chat_kwargs llm_kwargs = build_langchain_chat_kwargs( deployment_name=os.environ["OPENAI_ENGINE"], max_tokens=6000, temperature=0, reasoning_effort="low", ) llm = ReasoningSafeAzureChatOpenAI( azure_endpoint=os.environ["AZURE_OPENAI_ENDPOINT"], azure_deployment=os.environ["OPENAI_ENGINE"], openai_api_version=os.environ["OPENAI_API_VERSION"], api_key=os.environ["AZURE_OPENAI_API_KEY"], **llm_kwargs, ) That single substitution makes create_sql_query_chain, SQLDatabaseChain, and the ChatOpenAI-based RAG helpers all work against GPT-5.1 without any other changes. 6. The second LangChain gotcha: prose where SQL should be create_sql_query_chain is documented to return the literal string "I don't know" (or a similar fallback) when the LLM cannot form a query. The default code path takes the chain output and runs it against the database: sql = chain.invoke({...}) # -> "I don't know" result = db.run(sql) # -> sends "I don't know" to pyodbc The database faithfully returns: [42000] Unclosed quotation mark after the character string 't know'. (105) Which surfaces to the end user as a misleading "SQL syntax error". The mitigation is a one-line guard that validates the chain output looks like SQL before execution: import re _SQL_START_RE = re.compile( r"^\s*(?:WITH|SELECT|INSERT|UPDATE|DELETE|CREATE|DROP|ALTER|MERGE|EXEC|EXECUTE|TRUNCATE)\b", re.IGNORECASE, ) def looks_like_sql(text: str) -> bool: """True only if ``text`` starts with a recognised SQL DML/DDL keyword.""" if not text or not text.strip(): return False return bool(_SQL_START_RE.match(text)) sql = extract_sql_query(chain.invoke({...})) if not looks_like_sql(sql): logging.warning("SQL chain returned a non-SQL response: %r", sql[:200]) return ( "I couldn't form a SQL query for that question. " "Please rephrase or add more context." ) result = db.run(sql) This isn't specific to GPT-5.1 - it's good hygiene for any LLM that backs a SQL agent - but the failure mode becomes much more frequent on reasoning models because they're better at refusing. 7. Cleaning Markdown out of create_sql_query_chain output Reasoning models like to wrap their answer in a markdown fence and append a "Note:" or "Explanation:" paragraph. None of that survives db.run(). A defensive extract_sql_query handles all the variants: import re def extract_sql_query(text: str) -> str: """Strip markdown fences, leading prose, and trailing explanations.""" # 1) Prefer SQL inside a markdown code fence. m = re.search(r"```(?:sql|SQL|Sql)?\s*\n(.*?)\n```", text, re.DOTALL) if m: text = m.group(1) text = text.strip() # 2) Drop any prose *before* the SQL by jumping to the first SQL keyword. m = re.search( r"(?im)^\s*(WITH|SELECT|INSERT|UPDATE|DELETE|CREATE|DROP|ALTER|MERGE|EXEC|EXECUTE|TRUNCATE)\b", text, ) if m: text = text[m.start(1):] # 3) Cut at the first "Explanation:" / "Note:" / "This query..." marker. m = re.compile( r"(?im)^\s*(?:Explanation|Note|Notes|Here(?:'|\u2019)?s|" r"This\s+(?:query|SQL|statement|returns|counts|selects|will|gets|finds)|" r"The\s+(?:query|SQL|above|result|statement)|" r"Result|Results|Description|Output|Answer)\b[^\n]*" ).search(text) if m: text = text[: m.start()].rstrip() # 4) Drop any trailing fence that survived step 1. if text.endswith("```"): text = text[:-3].rstrip() return text.strip() 8. Package versioning The bare minimum your requirements.txt / environment.yml needs: Package Last GPT-4-only version First GPT-5.x-safe version Notes openai 1.55.x 1.65.x (recommend 1.65.4+) Earlier versions reject max_completion_tokens and reasoning_effort as unknown kwargs langchain-openai 0.2.14 0.3.7+ 0.3.x line exposes azure_deployment and forwards model_kwargs correctly to the new SDK langchain 0.3.14 0.3.21+ Pin together with langchain-openai and langchain-core langchain-core 0.3.29 0.3.49+ Update in lockstep with the others langchain-community 0.3.14 0.3.20+ Mostly transitive; needed for SQLDatabase helpers tiktoken 0.7.x 0.8.0+ Encodings for GPT-5.1 ship in 0.8.0; older versions fall back to cl100k_base for unknown models tokencost (optional) 0.1.16 0.1.20+ Update for GPT-5.x price tables Azure OpenAI API version 2024-12-01-preview 2025-03-01-preview First version that ships reasoning_effort and the GPT-5.x routing Pin exact versions after testing - LangChain has a habit of moving public re-exports between minor releases. requirements.txt snippet: openai==1.65.4 langchain==0.3.21 langchain-core==0.3.49 langchain-openai==0.3.7 langchain-community==0.3.20 tiktoken==0.8.0 9. New GPT-5.x knobs worth using Once you're on a reasoning deployment, two new parameters become available. Both are optional, both default to a sensible value, and both are stripped by the kwargs builder above when the target is a legacy model. reasoning_effort minimal - one-shot lookups, classification. low - deterministic structured output (SQL, JSON-schema extraction, rule-based rewrites). Lowest cost overhead. medium (default) - RAG, summarisation, normal Q&A. high - multi-step analytical reasoning, complex code synthesis. A useful pattern is to choose the level by task profile rather than at the call site: TASK_EFFORT = { "sql": "low", "structured_extract": "low", "kg_cleaning": "low", "rag_qa": "medium", "vision": "medium", "analytical": "high", } verbosity low | medium | high. Controls the length of the response, not its substance. Useful for grounding chat UIs where you want crisp answers - set low for /answer endpoints and high for "explain like a senior engineer" panels. Note: in openai-python <= 1.65.x, verbosity is not yet a top-level keyword argument; pass it through extra_body (the builder above already does this). developer role GPT-5.x prefers {"role": "developer", "content": "..."} for instructions that previously used system. The change is non-breaking on the Azure side - system is still accepted as an alias - but some downstream LangChain prompt templates predate the role and will reject it on construction. Treat developer as opt-in (OPENAI_USE_DEVELOPER_ROLE=1) for now; flip the default after your prompt-template version is known good. 10. Auditing your existing prompts When the wire-level migration is done your service will talk to GPT-5.x - but that doesn't mean it says the right thing. Reasoning models read prompts differently in ways that won't show up as 400s: They take instructions more literally. A prompt that worked when GPT-4o rounded the corners may surface every edge case verbatim. They refuse more often. "I don't know" / "I cannot help with that" are more frequent because reasoning models are less willing to confabulate. They ignore "be concise" / "be terse". Use the new verbosity knob. Step-by-step / chain-of-thought instructions become redundant. The model already reasons internally; extra "think before you answer" prose competes with its own chain of thought and often hurts output quality. Negative-only instructions can backfire. "Never output X" prompts occasionally cause refusals where you'd rather have a workaround. 10.1 Build a prompt regression harness Capture every system+user prompt your service emits in a CSV, then replay each one against both deployments and diff the output. The diff is the single most useful artefact you can produce before the cutover: # prompt_audit.py - minimal differential tester import csv from openai import AzureOpenAI from model_compat import build_openai_chat_kwargs LEGACY = "gpt-4o" REASONING = "gpt-5.1" client = AzureOpenAI( azure_endpoint=os.environ["AZURE_OPENAI_ENDPOINT"], api_version=os.environ["OPENAI_API_VERSION"], api_key=os.environ["AZURE_OPENAI_API_KEY"], ) def run(model: str, system: str, user: str) -> str: kw = build_openai_chat_kwargs( model=model, max_tokens=4096, temperature=0.2, # auto-dropped for reasoning reasoning_effort="medium", # auto-dropped for legacy ) resp = client.chat.completions.create( messages=[ {"role": "system", "content": system}, {"role": "user", "content": user}, ], **kw, ) return resp.choices[0].message.content or "" with open("prompts.csv") as f_in, open("diff.tsv", "w", newline="") as f_out: writer = csv.writer(f_out, delimiter="\t") writer.writerow(["id", "legacy_first80", "reasoning_first80", "len_legacy", "len_new", "identical"]) for row in csv.DictReader(f_in): legacy = run(LEGACY, row["system"], row["user"]) new = run(REASONING, row["system"], row["user"]) writer.writerow([ row["id"], legacy[:80].replace("\n", " "), new[:80].replace("\n", " "), len(legacy), len(new), legacy.strip() == new.strip(), ]) Capture three signals per prompt - they're enough to triage 95% of drift: Format compliance. Did the output still parse as the expected JSON / YAML / Markdown / SQL? Run your existing downstream parser on both columns. Token cost delta. Reasoning models tend to be more verbose by default. Anything beyond +20% is a candidate for the verbosity="low" knob. Semantic drift. Spot-check 5–10% of rows by hand. You're looking for changes in intent, not changes in wording. 10.2 Common rewrites to make prompts model-agnostic The goal isn't to write two prompts. It's to write one prompt that produces correct output on both families by moving constraints out of the natural-language body and into the request shape. 10.2a. Format constraints belong in response_format, not the prose Don't: Output ONLY a JSON object with keys `name` and `score`. Do not include any explanation. Do not wrap in markdown. Do not say anything else. Do: resp = client.chat.completions.create( messages=[...], response_format={ "type": "json_schema", "json_schema": { "name": "scored_entity", "schema": { "type": "object", "properties": { "name": {"type": "string"}, "score": {"type": "number"}, }, "required": ["name", "score"], "additionalProperties": False, }, "strict": True, }, }, **kw, ) response_format is honoured by both gpt-4o (>= 2024-08-06) and the entire GPT-5.x line. The prompt loses three lines of brittle natural-language constraints and you get schema-validated output for free. 10.2b. Replace "think step by step" with reasoning_effort Don't: Let's think step by step. First identify the entity. Then find the category. Then compute the score. Then format the answer. Do: delete the prose and pass reasoning_effort="medium" (or "high") for reasoning deployments. The kwargs builder drops the parameter automatically for GPT-4 models, so the same prompt now produces: step-by-step reasoning internally on GPT-5.x (lower output token cost), the same final answer on GPT-4o that the verbose prompt used to elicit. 10.2c. Replace temperature-based variety with n sampling If your code relied on temperature=0.9 to get diverse completions, GPT-5.x will return roughly the same answer every time. Generate variety the explicit way: resp = client.chat.completions.create(messages=[...], n=5, **kw) candidates = [c.message.content for c in resp.choices] Or call the model N times with slightly different framings. Both patterns work against either family with no further code changes. 10.2d. Move procedural instructions to the developer role For multi-step workflows, the new developer role gives clearer separation between what the system enforces and what the user is asking: messages = [ {"role": get_system_role(deployment), "content": role_card_for_assistant}, {"role": "developer", "content": procedural_instructions}, {"role": "user", "content": user_question}, ] get_system_role returns "system" for legacy models and "developer" for reasoning models opted in via OPENAI_USE_DEVELOPER_ROLE=1. Once your LangChain templates support the new role you can flip the default. 10.2e. Add a literal-execution header for strict formats For prompts where the exact output shape matters (table generation, SQL with a fixed column order, structured incident reports), prepend an explicit literal-execution header so reasoning models don't drift into "helpful improvements": LITERAL_EXECUTION_HEADER = ( "Execution mode: follow the instructions below literally and in order. " "Do not infer intent, skip, reorder, merge, or add steps. Honour the " "exact formatting, tone, and verbosity specified. If a step is " "ambiguous, respond with the literal interpretation and flag the " "ambiguity instead of guessing." ) def apply_literal_execution(prompt: str) -> str: if LITERAL_EXECUTION_HEADER in prompt: return prompt return f"{LITERAL_EXECUTION_HEADER}\n\n{prompt}" It's a no-op on GPT-4o (the older models already follow instructions literally enough) and a meaningful guard rail on GPT-5.1. Wire it behind an OPENAI_LITERAL_EXECUTION flag so you can disable it without redeploying. 10.3 A prompt-shaped checklist Run every prompt your service emits past these questions: Question Action Does it specify output format in prose? Move to response_format (10.2a) Does it include "think step by step"? Remove; set reasoning_effort (10.2b) Does it set tone constraints ("be concise")? Use verbosity Does it use negative-only instructions ("never X")? Add positive alternative ("do Y instead") Does it embed example outputs with values that would change? Replace concrete values with placeholder tokens (<VALUE>) Does it rely on temperature > 0 for variety? Use n=K sampling (10.2c) Is the system prompt > 2k tokens? Split into role-card (system) + procedure (developer) Does output ordering matter? Add the literal-execution header (10.2e) 10.4 Score before you ship Don't approve a rewritten prompt by eyeballing one example. Score it: Format compliance rate. Percentage of N=50 outputs that pass your existing downstream parser / JSON schema validation. Token cost delta. Cap regression at +20% versus the legacy baseline. Beyond that, dial verbosity="low" or tighten the prompt. Latency p50 / p95 delta. Reasoning models add tail latency. If your SLA is tight, set reasoning_effort="low" for the path or move it to a background queue. A prompt that regresses on any of those by more than your tolerance window ships behind a feature flag with rollback wired in. 11. Testing strategy Two test layers catch >90% of regressions: Family-classification tests import pytest from model_compat import get_model_family, build_openai_chat_kwargs @pytest.mark.parametrize("name,expected", [ ("gpt-5.1", "reasoning"), ("gpt5", "reasoning"), ("gpt-5-prod-eu", "reasoning"), ("o3-mini", "reasoning"), ("o1", "reasoning"), ("gpt-4o", "legacy"), ("gpt-4", "legacy"), ("gpt-4-32k", "legacy"), ("gpt-35-turbo", "legacy"), ("", "legacy"), # unknown -> fail closed to legacy (None, "legacy"), ]) def test_family(name, expected): assert get_model_family(name) == expected def test_kwargs_for_reasoning_drops_temperature(): kw = build_openai_chat_kwargs( model="gpt-5.1", max_tokens=1000, temperature=0.2, top_p=0.9, reasoning_effort="low", ) assert "temperature" not in kw assert "top_p" not in kw assert kw["max_completion_tokens"] >= 4096 # floor applied assert kw["reasoning_effort"] == "low" def test_kwargs_for_legacy_keeps_temperature(): kw = build_openai_chat_kwargs( model="gpt-4o", max_tokens=1000, temperature=0.2, top_p=0.9, ) assert kw["max_tokens"] == 1000 assert kw["temperature"] == 0.2 assert kw["top_p"] == 0.9 assert "reasoning_effort" not in kw Wire-level smoke tests For each LLM call site you maintain, write a single integration test that exercises the chain against a real (or mocked) endpoint and asserts: HTTP 200, non-empty content, finish_reason != "length" (so you catch silent truncation), (optional) classifier-style assertions against a golden output. Run those tests once against the legacy deployment and once against the new one - same test code, two OPENAI_ENGINE values. 12. Things that don't change It's easy to over-correct. Several pieces of plumbing keep working without modification: Authentication. AAD token providers, managed identity, and API keys are unchanged. Embeddings. text-embedding-3-small, text-embedding-3-large, and text-embedding-ada-002 are not part of the reasoning generation; the embeddings call shape is identical. Function calling / tool use. Same JSON schema, same response shape. Streaming. SSE format is unchanged. Token counters. tiktoken still works, but bump to 0.8.0+ so the new model name resolves to the right encoding instead of silently falling back to cl100k_base. 13. Next steps If you only do four things from this post, do these - in order: Deploy a GPT-5.1 model side-by-side with your current GPT-4 deployment in Microsoft Foundry. Keep the GPT-4 deployment live; you'll need both for the parallel-run period. Drop model_compat.py and langchain_compat.py into your project (Sections 4 and 5). Replace every AzureChatOpenAI(...) construction with ReasoningSafeAzureChatOpenAI and route every kwargs literal through the builders. Run the prompt-audit harness (Section 10.1) against your top 50 most frequently invoked prompts. Triage the diff with the checklist in 10.3. Roll out behind a percentage-based flag. Start at 5% of traffic for 24 hours, compare quality and cost telemetry against the GPT-4o baseline, then ramp. Reference material Azure OpenAI in Microsoft Foundry - model overview Azure OpenAI model retirements and deprecations Reasoning models in Azure OpenAI Structured Outputs in Azure OpenAI openai-python SDK changelog langchain-openai release notes Talk to us Open an issue on the Microsoft Foundry GitHub samples repository if you hit a gap this post didn't cover. Share your migration story or numbers in the comments below - field data is the fastest way to make this guide better for the next team. If you operate a regulated workload (finance, health, public sector) and need help sequencing the rollout with your model retirement deadlines, reach out to your Microsoft account team or a Microsoft Foundry partner. GPT-5.x is the first major model bump in two years that requires code changes - but the changes collapse into one small compatibility module and a one-line LangChain subclass. With those in place your code is forwards-compatible (works on reasoning models today) and backwards- compatible (still works on every GPT-4 deployment you haven't migrated yet). The investment pays a recurring dividend: when the next reasoning bump ships, the only file that needs updating is model_compat.py. Appendix A - Minimal .env template # Endpoint and auth (unchanged between families) AZURE_OPENAI_ENDPOINT=https://<resource>.openai.azure.com AZURE_OPENAI_API_KEY=<key> # The deployment name decides the family. The classifier reads it. OPENAI_ENGINE=gpt-5.1 OPENAI_API_VERSION=2025-03-01-preview # Optional override for opaque deployment names # OPENAI_MODEL_FAMILY=reasoning # or "legacy" # Optional reasoning controls (ignored for legacy deployments) OPENAI_REASONING_EFFORT=medium OPENAI_VERBOSITY=medium OPENAI_REASONING_TOKEN_SCALE=2.5 OPENAI_REASONING_TOKEN_FLOOR=4096 # Flip when your LangChain templates support it # OPENAI_USE_DEVELOPER_ROLE=1 Appendix B - One-liner sanity checks # Does a deployment name classify correctly? python -c "from model_compat import get_model_family; print(get_model_family('gpt-5.1'))" # -> reasoning # Does the LangChain LLM strip ``stop`` when the deployment is GPT-5.1? python -c " from langchain_compat import ReasoningSafeAzureChatOpenAI import inspect; print(inspect.getsource(ReasoningSafeAzureChatOpenAI._generate)) " Companion repository: drop model_compat.py and langchain_compat.py next to each other in your utils/ package. They are zero-dependency on import, so you can vendor them into any service - web, function, batch job - without dragging Azure SDK or LangChain into module-load.
Upcoming Changes to Azure Relay IP Addresses and DNS Support
Azure Relay is an integral part of modern hybrid cloud architectures, enabling seamless connectivity between on-premises and cloud resources. To ensure continued reliability and security, Microsoft is implementing important updates to the IP addresses and DNS naming conventions used by Azure Relay services. What’s Changing? As detailed in the changes to IP-addresses for Azure Relay and Azure Relay WCF and Hybrid Connections DNS Support reference blogs, customers should be aware of two primary changes: IP and Name Transitions: The IP addresses and corresponding DNS names for Azure Relay endpoints will change during the transition period. For example, g0-prod-bn-vaz0001-sb.servicebus.windows.net can change to gv0-prod-bn-vaz0001-sb.servicebus.windows.net DNS Support Enhancements: Improved DNS support will enhance reliability and future-proof connectivity for both WCF Relay and Hybrid Connections users. Recommended Actions for Customers To minimize disruption, it is crucial for users to update their network configurations and firewall rules to accommodate these new IP addresses and DNS names as soon as possible. These will be made available using the below PS1 script - Update Allow Lists: Ensure that your firewalls and network security groups permit traffic to the new IP ranges and DNS endpoints as specified in the official documentation. Monitor Transition Phases: Be prepared for two rounds of changes. Apply updates promptly during both the initial and final transitions. Automating Namespace Information Retrieval To assist with this transition, Microsoft has updated the PowerShell script for retrieving namespace information, which now reflects the planned changes. You can access the latest script here: GetNamespaceInfo.ps1 (azure-relay-dotnet/tools) (Instructions on how to use the ps1 script is available in the README) This script allows you to efficiently check the current configuration of your Azure Relay namespaces and validate connectivity against the updated endpoints. Sample output PS D:\AzureVMSSEssentials\Tools\GetNamespaceInfoWithIpRanges> .\GetNamespaceInfo.ps1 <your-relay-namespace>.servicebus.windows.net Namespace : <your-relay-namespace>.servicebus.windows.net Deployment : PROD-BN-VAZ0001 ClusterDNS : ns-prod-bn-vaz0001.eastus2.cloudapp.azure.com ClusterRegion : eastus2 ClusterVIP : 40.84.75.3 GatewayDnsFormat : g{0}-bn-vaz0001-sb.servicebus.windows.net or gv{0}-bn-vaz0001-sb.servicebus.windows.net Notes : Entries with 'FUTURE' IPAddress may be added at a later time as needed Current IP Ranges Name IPAddress ---- --------- g0-bn-vaz0001-sb.servicebus.windows.net 20.36.144.8 g1-bn-vaz0001-sb.servicebus.windows.net 20.36.144.1 g2-bn-vaz0001-sb.servicebus.windows.net 20.36.144.2 g3-bn-vaz0001-sb.servicebus.windows.net 20.36.144.11 g4-bn-vaz0001-sb.servicebus.windows.net 20.36.144.3 g5-bn-vaz0001-sb.servicebus.windows.net FUTURE g6-bn-vaz0001-sb.servicebus.windows.net FUTURE ... g98-bn-vaz0001-sb.servicebus.windows.net FUTURE g99-bn-vaz0001-sb.servicebus.windows.net FUTURE Future IP Ranges for Region:eastus2 addressPrefixes --------------- 135.18.130.0/23 135.18.132.0/26 135.18.132.64/27Security baseline for Windows Server 2025, version 2602
Microsoft is pleased to announce the February 2026 Revision (v2602) of the security baseline package for Windows Server 2025! You can download the baseline package from the Microsoft Security Compliance Toolkit, test the recommended configurations in your environment, and customize / implement them as appropriate. Summary of Changes in This Release This release includes several changes made since the Security baseline for Windows Server 2025, version 2506 to further assist in the security of enterprise customers along with better aligning with the latest capabilities and standards. The changes include what is now depicted in the table below. Security Policy Change Summary Configure the behavior of the sudo command Configured as Enabled: Disabled on both MS and DC Configure Validation of ROCA-vulnerable WHfB keys during authentication Configured as Enabled: Block on DC to block Windows Hello for Business (WHfB) keys that are vulnerable to the Return of Coppersmith's attack (ROCA) Disable Internet Explorer 11 Launch Via COM Automation Configured as Enabled to prevent legacy scripts and applications from programmatically launching Internet Explorer 11 using COM automation interfaces Do not apply the Mark of the Web tag to files copied from insecure sources Configured as Disabled on both MS and DC Network security: Restrict NTLM: Audit Incoming NTLM Traffic Configured as Enable auditing for all accounts on both MS and DC Network security: Restrict NTLM: Audit NTLM authentication in this domain Configured as Enable all on DC Network security: Restrict NTLM: Outgoing NTLM traffic to remote servers Configured as Audit all on both MS and DC NTLM Auditing Enhancements Already enabled by default to improve visibility into NTLM usage within your environment Prevent downloading of enclosures Remove from the baseline as it is not applicable for Windows Server 2025. It depends on IE – RSS feed Printer: Configure RPC connection settings Enforce the default, RPC over TCP with Authentication Enabled, on both MS and DC Printer: Configure RPC listener settings Configure as RPC over TCP | Kerberos on MS Printer: Impersonate a client after authentication Add RESTRICTED SERVICES\PrintSpoolerService to allow the Print Spooler’s restricted service identity to impersonate clients securely Configure the behavior of the sudo command Sudo for Windows can be used as a potential escalation of privilege vector when enabled in certain configurations. It may allow attackers or malicious insiders to run commands with elevated privileges, bypassing traditional UAC prompts. This is especially concerning in environments with Active Directory or domain controllers. We recommend to configuring the policy Configure the behavior of the sudo command (System) as Enabled with the maximum allowed sudo mode as Disabled to prevent the sudo command from being used. Configure Validation of ROCA-vulnerable WHfB keys during authentication To mitigate Windows Hello for Business (WHfB) keys that are vulnerable to the Return of Coppersmith's attack (ROCA), we recommend enabling the setting Configure Validation of ROCA-vulnerable WHfB keys during authentication (System\Security Account Manager) in a Block mode in domain controllers. To ensure there are no incompatible devices/orphaned/vulnerable keys in use that will break when blocked, please see Using WHfBTools PowerShell module for cleaning up orphaned Windows Hello for Business Keys - Microsoft Support. Note: A reboot is not required for changes to this setting to take effect. Disable Internet Explorer 11 Launch Via COM Automation Similar to the Windows 11 version 25H2 security baseline, we recommend disabling Internet Explorer 11 Launch Via COM Automation (Windows Components\Internet Explorer) to prevent legacy scripts and applications from programmatically launching Internet Explorer 11 using COM automation interfaces such as CreateObject("InternetExplorer.Application"). Allowing such behavior poses a significant risk by exposing systems to the legacy MSHTML and ActiveX components, which are vulnerable to exploitation. Do not apply the Mark of the Web tag to files copied from insecure sources We have included the setting Do not apply the Mark of the Web tag to files copied from insecure sources (Windows Components\File Explorer) configured as Disabled, which is consistent with Windows 11 security baseline. When this configuration is set to Disabled, Windows applies the Mark of the Web (MotW) tag to files copied from locations classified as Internet or other untrusted zones. This tag helps enforce additional protections such as SmartScreen checks and Office macro blocking, reducing the risk of malicious content execution. NTLM Auditing As part of our ongoing effort to help customers transition away from NTLM and adopt Kerberos for a more secure environment, we introduce new recommendations to strengthen monitoring and prepare for future NTLM restrictions on Windows Server 2025. Configure Network security: Restrict NTLM: Audit Incoming NTLM Traffic (Security Options) to Enable auditing for all accounts on both member servers and domain controllers. When enabled, the server logs events for all NTLM authentication requests that would be blocked once incoming NTLM traffic restrictions are enforced. Configure Network security: Restrict NTLM: Audit NTLM authentication in this domain (Security Options) to Enable all on domain controllers. This setting logs NTLM pass-through authentication requests from servers and accounts that would be denied when NTLM authentication restrictions are applied at the domain level. Configure Outgoing NTLM traffic to remote servers (Security Options) to Audit all on both member servers and domain controllers to log an event for each NTLM authentication request sent to a remote server, helping identify servers that still receive NTLM traffic. In addition, there are two new NTLM auditing capabilities enabled by default that were recently introduced in Windows Server 2025 and Windows 11 version 25H2. These enhancements provide detailed audit logs to help security teams monitor and investigate authentication activity, identify insecure practices, and prepare for future NTLM restrictions. Since these auditing improvements are enabled by default, no additional configuration is required, and thus the baseline does not explicitly enforce them. For more details, see Overview of NTLM auditing enhancements in Windows 11 and Windows Server 2025. Prevent Downloading of Enclosures The policy Prevent downloading of enclosures (Windows Components\RSS Feeds) has been removed from the Windows Server 2025 security baseline. This setting is not applicable to Windows Server 2025 because it depends on Internet Explorer functionality for RSS feeds. Printer security enhancements There are two new policies in Windows Server 2025 designed to significantly improve security posture of printers: Require IPPS for IPP printers (Printers) Set TLS/SSL security policy for IPP printers (Printers) Enabling these policies may cause operational challenges in environments that still rely on IPP or use self-signed or locally issued certificates. For this reason, these policies are not ter enforced in the Windows Server 2025 security baseline. However, we do recommend customers transition out of IPP or self-signed certificates and restricting them for a more secure environment. In addition, there are some changes to printer security Added RESTRICTED SERVICES\PrintSpoolerServiceto the Impersonate a client after authentication (User Rights Assignments) policy for both member servers and domain controllers, consistent with security baseline for Windows 11 version 25H2. Enforced the default setting for Configure RPC connection settings (Printers) to always use RPC over TCP with Authentication Enabled on both member servers and domain controllers. This prevents misconfiguration that could introduce security risks. Raised the security bar of the policy Configure RPC listener settings (Printers) from Negotiate (default) to Kerberos on member servers. This change encourages customers to move away from NTLM and adopt Kerberos for a more secure environment. Secure Boot certificate update To help organizations deploy, manage, and monitor the Secure Boot certificate update, Windows includes several policy settings under Administrative Templates\Windows Components\Secure Boot. These settings are deployment controls and aids. Enable Secure Boot Certificate Deployment allows an organization to explicitly initiate certificate deployment on a device. When enabled, Windows begins the Secure Boot certificate update process the next time the Secure Boot task runs. This setting does not override firmware compatibility checks or force updates onto unsupported devices. Automatic Certificate Deployment via Updates controls whether Secure Boot certificate updates are applied automatically through monthly Windows security and non‑security updates. By default, devices that Microsoft has identified as capable of safely applying the updates will receive and apply them automatically as part of cumulative servicing. If this setting is disabled, automatic deployment is blocked and certificate updates must be initiated through other supported deployment methods. Certificate Deployment via Controlled Feature Rollout allows organizations to opt devices into a Microsoft‑managed Controlled Feature Rollout for Secure Boot certificate updates. When enabled, Microsoft assists with coordinating deployment across enrolled devices to reduce risk during rollout. Devices participating in a Controlled Feature Rollout must have diagnostic data enabled. Devices that are not enrolled will not participate. Secure Boot certificate updates depend on device firmware support. Some devices have known firmware limitations that can prevent updates from being applied safely. Organizations should test representative hardware, monitor Secure Boot event logs, and consult the deployment guidance at https://aka.ms/GetSecureBoot for detailed recommendations and troubleshooting information. SMB Server hardening feature SMB Server has been susceptible to relay attacks (e.g., CVE-2025-55234), and Microsoft has released multiple features to protect against the relay attacks including SMB Server signing, which can be enabled with the setting of Microsoft network server: Digitally sign communications (always) (Security Option) SMB Server extended protection for authentication (EPA), which can be enabled with the setting of Microsoft network server: Server SPN target name validation level (Security Option) To further support customers to adopt these SMB Server hardening features, in the September 2025 Security Updates, Microsoft has released support for Audit events, across all supported in-market platforms, to audit SMB client compatibility for SMB Server signing as well as SMB Server EPA. These audit capabilities can be controlled via the two policies located at Network\Lanman Server Audit client does not support signing Audit SMB client SPN support This allows you to identify any potential device or software incompatibility issues before deploying the hardening measures that are already supported by SMB Server. Our recommendation is For domain controllers, the SMB signing is already enabled by default so there is no action needed for hardening purposes. For member servers, first enabling the two new audit features to assess the environment and then decide whether SMB Server Signing or EPA should be used to mitigate the attack vector. Please let us know your thoughts by commenting on this post or through the Security Baseline Community.
Find anomalies in Prometheus and OpenTelemetry metrics with Dynamic Thresholds (Preview)
Dynamic thresholds are extended to query-based metric alerts in Azure Monitor, allowing to detect and alert on anomalies in Azure Monitor managed Prometheus metrics and OpenTelemetry metrics stored in an Azure Monitor Workspace. This follows the introduction of Dynamic Thresholds for Log search alerts — Azure Monitor now offers consistent Dynamic Thresholds support across logs and metrics — platform metrics, log search queries, and now query-based metric alerts. A consistent anomaly-detection approach, wherever your signals live. Dynamic thresholds are not a single static formula. They apply a range of machine-learning models and algorithms to historical query results, learn each series’ normal rhythm — including hourly, daily, and weekly seasonality — and automatically fit the most appropriate baseline separately to every time series. This way, a single alert rule can monitor many resources or dimensions while each one gets its own independent, self-refining baseline. Why Dynamic Thresholds Matter Simpler configuration: Reduce the need to define, maintain, and continuously tune static thresholds inside PromQL alert logic. Adaptive monitoring: Let alert thresholds adjust to changing workload behavior, recurring traffic peaks, and seasonal usage patterns. At-scale intelligence: Monitor multiple time series with a single alert rule, while Azure Monitor learns an independent baseline for each resource or dimension combination. Example 1 — Spot CPU anomalies in AKS workloads Scenario: Monitor container CPU utilization across pods or deployments in AKS with a query-based metric alert built on Prometheus metrics. Example query: sum by (microsoft_resource_id, namespace, deployment, container) (rate(container_cpu_usage_seconds_total[5m])) / sum by (microsoft_resource_id, namespace, deployment, container) (container_spec_cpu_quota / container_spec_cpu_period) Why dynamic thresholds help: CPU usage of a Kubernetes workload changes with workload mix, deployment timing, scaling activity, and traffic patterns. Static thresholds can be difficult to tune across namespaces, deployments, and containers. Dynamic thresholds learn a separate baseline for each monitored time series — in this example, for every pod, deployment, and container combination — so genuine CPU spikes stand out while expected variation from autoscaling and traffic mix stays quiet. Example 2 — Catch application latency regressions sooner Scenario: Detect abnormal latency patterns in an application by alerting on custom OpenTelemetry metrics stored in an Azure Monitor Workspace. Example query: histogram_quantile(0.95, sum by (le, service_name, http_route, http_method) (rate(http_server_duration_seconds_bucket[5m]))) Why dynamic thresholds help: Application latency naturally changes with traffic, user behavior, and release cadence. Fixed thresholds can be noisy during peak periods and too loose during quiet ones. Dynamic thresholds learn a separate baseline for each time series — here, for every service, route, and method — so real p95 latency regressions surface even as traffic and release cadence shift throughout the day. Best practices for better results To get the best results from dynamic thresholds for PromQL-based alerts, design your query so Azure Monitor can learn a clear, stable signal over time: Keep the expression numeric. Dynamic thresholds work best when the query returns a continuous numeric signal rather than a Boolean true/false result. For example, use an expression that calculates CPU usage, not a Boolean comparison like CPU > 0.8. Use meaningful dimensions. Split by dimensions such as namespace, deployment, service, or route when you want separate baselines for different workloads or endpoints. Prefer stable entities. Use longer-lived dimensions or aggregate across short-lived entities so the model has enough consistent history to learn from. In Kubernetes, for example, deployment is usually a better baseline dimension than individual pod ID. Choose the right threshold behavior. Decide whether the alert should trigger on values above the learned upper bound, below the lower bound, or both. Start with medium sensitivity. Use Medium as a balanced default, then tune up or down based on noise and missed anomalies. Allow enough historical data. Dynamic thresholds improve as more history is collected. Initial seasonal patterns use recent history, and weekly seasonality becomes more effective after several weeks of data. Get started Ready to try it? Create a query-based metric alert with dynamic thresholds on your metrics in Azure Monitor Workspace. You can create such rules in the Azure portal, where the built-in preview chart shows when your dynamic threshold alert would have fired based on historical baseline analysis. Use the preview chart to tune both the PromQL query and the dynamic threshold sensitivity before enabling the rule. You can also create query-based metric alert rules using programmatic interfaces or resource templates. Figure 1. Dynamic thresholds preview chart showing the learned baseline and the points where an alert would have fired. Dynamic thresholds cut alert noise where it starts — at detection. The alerts that do fire connect into Azure Monitor’s broader AIOps experience, where the Azure Copilot Observability Agent can help correlate signals into investigated issues with explainable reasoning — with humans in control. Next steps Related blog: Anomaly detection made easy with Dynamic thresholds for Log search alerts Dynamic thresholds in Azure Monitor Query-based metric alerts overview Create query-based metric alerts Prometheus metrics in Azure Monitor OpenTelemetry on Azure Monitor Stay connected Follow the Azure Observability Blog for more updates on Azure Monitor, Prometheus-based monitoring, alerting, and troubleshooting experiences. We’ll continue sharing product updates, practical guidance, and examples to help you improve observability across your Azure environments. Feedback We’d love to hear how dynamic thresholds for query-based metric alerts work for your scenarios. Share your feedback through your Microsoft account team, Azure support channels, or the feedback options in the Azure portal so we can continue improving the experience.Windows 11, version 25H2 security baseline
Microsoft is pleased to announce the security baseline package for Windows 11, version 25H2! You can download the baseline package from the Microsoft Security Compliance Toolkit, test the recommended configurations in your environment, and customize / implement them as appropriate. Summary of changes This release includes several changes made since the Windows 11, version 24H2 security baseline to further assist in the security of enterprise customers, to include better alignment with the latest capabilities and standards. The changes include what is depicted in the table below. Security Policy Change Summary Printer: Impersonate a client after authentication Add “RESTRICTED SERVICES\PrintSpoolerService” to allow the Print Spooler’s restricted service identity to impersonate clients securely NTLM Auditing Enhancements Enable by default to improve visibility into NTLM usage within your environment MDAV: Attack Surface Reduction (ASR) Add "Block process creations originating from PSExec and WMI commands" (d1e49aac-8f56-4280-b9ba-993a6d77406c) with a recommended value of 2 (Audit) to improve visibility into suspicious activity MDAV: Control whether exclusions are visible to local users Move to Not Configured as it is overridden by the parent setting MDAV: Scan packed executables Remove from the baseline because the setting is no longer functional - Windows always scans packed executables by default Network: Configure NetBIOS settings Disable NetBIOS name resolution on all network adapters to reduce legacy protocol exposure Disable Internet Explorer 11 Launch Via COM Automation Disable to prevent legacy scripts and applications from programmatically launching Internet Explorer 11 using COM automation interfaces Include command line in process creation events Enable to improve visibility into how processes are executed across the system WDigest Authentication Remove from the baseline because the setting is obsolete - WDigest is disabled by default and no longer needed in modern Windows environments Printer Improving Print Security with IPPS and Certificate Validation To enhance the security of network printing, Windows introduces two new policies focused on controlling the use of IPP (Internet Printing Protocol) printers and enforcing encrypted communications. The setting, "Require IPPS for IPP printers", (Administrative Templates\Printers) determines whether printers that do not support TLS are allowed to be installed. When this policy is disabled (default), both IPP and IPPS transport printers can be installed - although IPPS is preferred when both are available. When enabled, only IPPS printers will be installed; attempts to install non-compliant printers will fail and generate an event in the Application log, indicating that installation was blocked by policy. The second policy, "Set TLS/SSL security policy for IPP printers" (same policy path) requires that printers present valid and trusted TLS/SSL certificates before connections can be established. Enabling this policy defends against spoofed or unauthorized printers, reducing the risk of credential theft or redirection of sensitive print jobs. While these policies significantly improve security posture, enabling them may introduce operational challenges in environments where IPP and self-signed or locally issued certificates are still commonly used. For this reason, neither policy is enforced in the security baseline, at this time. We recommend that you assess your printers, and if they meet the requirements, consider enabling those policies with a remediation plan to address any non-compliant printers in a controlled and predictable manner. User Rights Assignment Update: Impersonate a client after authentication We have added RESTRICTED SERVICES\PrintSpoolerService in the “Impersonate a client after authentication” User Rights Assignment policy. The baseline already includes Administrators, SERVICE, LOCAL SERVICE, and NETWORK SERVICE for this user right. Adding the restricted Print Spooler supports Microsoft’s ongoing effort to apply least privilege to system services. It enables Print Spooler to securely impersonate user tokens in modern print scenarios using a scoped, restricted service identity. Although this identity is associated with functionality introduced as part of Windows Protected Print (WPP), it is required to support proper print operations even if WPP is not currently enabled. The system manifests the identity by default, and its presence ensures forward compatibility with WPP-based printing. Note: This account may appear as a raw SID (e.g., S-1-5-99-...) in Group Policy or local policy tools before the service is fully initialized. This is expected and does not indicate a misconfiguration. Warning: Removing this entry will result in print failures in environments where WPP is enabled. We recommend retaining this entry in any custom security configuration that defines this user right. NTLM Auditing Enhancements Windows 11, version 25H2 includes enhanced NTLM auditing capabilities, enabled by default, which significantly improves visibility into NTLM usage within your environment. These enhancements provide detailed audit logs to help security teams monitor and investigate authentication activity, identify insecure practices, and prepare for future NTLM restrictions. Since these auditing improvements are enabled by default, no additional configuration is required, and thus the baseline does not explicitly enforce them. For more details, see Overview of NTLM auditing enhancements in Windows 11 and Windows Server 2025. Microsoft Defender Antivirus Attack Surface Reduction (ASR) In this release, we've updated the Attack Surface Reduction (ASR) rules to add the policy Block process creations originating from PSExec and WMI commands (d1e49aac-8f56-4280-b9ba-993a6d77406c) with a recommended value of 2 (Audit). By auditing this rule, you can gain essential visibility into potential privilege escalation attempts via tools such as PSExec or persistence mechanisms using WMI. This enhancement helps organizations proactively identify suspicious activities without impacting legitimate administrative workflows. Control whether exclusions are visible to local users We have removed the configuration for the policy "Control whether exclusions are visible to local users" (Windows Components\Microsoft Defender Antivirus) from the baseline in this release. This change was made because the parent policy "Control whether or not exclusions are visible to Local Admins" is already set to Enabled, which takes precedence and effectively overrides the behavior of the former setting. As a result, explicitly configuring the child policy is unnecessary. You can continue to manage exclusion visibility through the parent policy, which provides the intended control over whether local administrators can view exclusion lists. Scan packed executables The “Scan packed executables” setting (Windows Components\Microsoft Defender Antivirus\Scan) has been removed from the security baseline because it is no longer functional in modern Windows releases. Microsoft Defender Antivirus always scans packed executables by default, therefore configuring this policy has no effect on the system. Disable NetBIOS Name Resolution on All Networks In this release, we start disabling NetBIOS name resolution on all network adapters in the security baseline, including those connected to private and domain networks. The change is reflected in the policy setting “Configure NetBIOS settings” (Network\DNS Client). We are trying to eliminate the legacy name resolution protocol that is vulnerable to spoofing and credential theft. NetBIOS is no longer needed in modern environments where DNS is fully deployed and supported. To mitigate potential compatibility issues, you should ensure that all internal systems and applications use DNS for name resolution. We recommend the following; test critical workflows in a staging environment prior to deployment, monitor for any resolution failures or fallback behavior, and inform support staff of the change to assist with troubleshooting as needed. This update aligns with our broader efforts to phase out legacy protocols and improve security. Disable Internet Explorer 11 Launch Via COM Automation To enhance the security posture of enterprise environments, we recommend disabling Internet Explorer 11 Launch Via COM Automation (Windows Components\Internet Explorer) to prevent legacy scripts and applications from programmatically launching Internet Explorer 11 using COM automation interfaces such as CreateObject("InternetExplorer.Application"). Allowing such behavior poses a significant risk by exposing systems to the legacy MSHTML and ActiveX components, which are vulnerable to exploitation. Include command line in process creation events We have enabled the setting "Include command line in process creation events" (System\Audit Process Creation) in the baseline to improve visibility into how processes are executed across the system. Capturing command-line arguments allows defenders to detect and investigate malicious activity that may otherwise appear legitimate, such as abuse of scripting engines, credential theft tools, or obfuscated payloads using native binaries. This setting supports modern threat detection techniques with minimal performance overhead and is highly recommended. WDigest Authentication We removed the policy "WDigest Authentication (disabling may require KB2871997)" from the security baseline because it is no longer necessary for Windows. This policy was originally enforced to prevent WDigest from storing user’s plaintext passwords in memory, which posed a serious credential theft risk. However, starting with 24H2 update, the engineering teams deprecated this policy. As a result, there is no longer a need to explicitly enforce this setting, and the policy has been removed from the baseline to reflect the current default behavior. Since the setting does not write to the normal policies location in the registry it will not be cleaned up automatically for any existing deployments. Please let us know your thoughts by commenting on this post or through the Security Baseline Community.IPv6 Dual-Stack Endpoints for Azure Container Registry (Public Preview)
By Johnson Shi, Aviral Takkar, Bin Du Introduction Two of the most common networking questions we hear from teams running Azure Container Registry (ACR) are: "Can my registry serve clients on IPv6 networks?" — Teams operating IPv6-only or dual-stack networks need their container registry reachable over IPv6. "How do we start moving registry traffic toward IPv6 without breaking anything?" — Organizations guarding against IPv4 address exhaustion, or operating under IPv6 transition mandates, want a migration path that doesn't disrupt existing IPv4 clients. Today, we're announcing the public preview of IPv6 dual-stack endpoints for Azure Container Registry for public endpoints and firewall rules, with IPv6 over private endpoints planned for GA. Set your registry's endpoint protocol to IPv4AndIPv6 , and its endpoints become reachable over both IPv4 and IPv6 — so IPv4-only, dual-stack, and IPv6-capable clients all connect to the same registry, each over whichever protocol their network stack selects. Key Takeaways ACR registries now support an endpointProtocol setting with two values: IPv4 (default) and IPv4AndIPv6 (dual stack, preview). Dual stack is additive — your registry continues serving IPv4 clients exactly as before. There is no IPv6-only mode. Dual stack requires dedicated data endpoints to be enabled ( --data-endpoint-enabled true ), and dedicated data endpoints require the Premium SKU. The service enforces this requirement. You can enable it today with Azure CLI 2.87.0 via az acr update --endpoint-protocol IPv4AndIPv6 . FQDN-based client firewall rules keep working unchanged; IP-based allowlists need to account for IPv6 traffic. Limitation: This public preview covers IPv6 for the registry's public endpoints and firewall rules only. IPv6 over private endpoints is planned for a future release. Limitation: ACR Tasks isn't supported on a registry that has IPv6 dual-stack enabled. Tasks does not work when the endpoint protocol isIPv6 dual-stack, including quick builds (with az acr build) and quick task runs (with az acr run). Support is planned for a future release. How to enable it On an existing registry (Azure CLI 2.87.0 or later) Dual stack requires dedicated data endpoints, so enable both in a single update: az acr update --name <your-registry> --data-endpoint-enabled true --endpoint-protocol IPv4AndIPv6 If dedicated data endpoints are already enabled, set the endpoint protocol on its own: az acr update --name <your-registry> --endpoint-protocol IPv4AndIPv6 Verify the configuration: az acr show --name <your-registry> --query "{endpointProtocol:endpointProtocol, dataEndpointEnabled:dataEndpointEnabled}" { "dataEndpointEnabled": true, "endpointProtocol": "IPv4AndIPv6" } Note: If your clients sit behind a firewall and you're enabling dedicated data endpoints for the first time, add firewall rules for <your-registry>.<region>.data.azurecr.io before enabling — switching from *.blob.core.windows.net to dedicated data endpoints changes where layer blobs are downloaded from. See Dedicated data endpoints for details. Reverting to IPv4 Dual stack is reversible at any time: az acr update --name <your-registry> --endpoint-protocol IPv4 Reverting the endpoint protocol leaves dedicated data endpoints enabled; disable them separately if desired. Scope of this preview This public preview enables IPv6 for the registry's public endpoints — the login server, dedicated data endpoints, and regional endpoints (if enabled). IPv6 over private endpoints isn't part of this preview. Support is planned for a future release. Until then, registries reached through a private endpoint continue to use IPv4. Additionally, IPv6 dual-stack support for ACR Tasks, including support for `az acr build` and `az acr run`, are not supported in the public preview. Support is planned for a future release. Requirements and how features compose Requirement Why Premium SKU Dedicated data endpoints are a Premium feature. Dedicated data endpoints enabled IPv4AndIPv6 requires dataEndpointEnabled: true ; the service rejects the setting otherwise. Azure CLI 2.87.0+ Adds --endpoint-protocol to az acr update . For geo-replicated registries, the endpoint protocol is a registry-level setting, and dedicated data endpoints exist in every replica region. Firewall guidance: rules based on registry FQDNs — the login server, dedicated data endpoints, and regional endpoints (if enabled) — continue to work unchanged for dual-stack registries; only IP-address-based allowlists need updating for IPv6. To learn more, see IPv6 dual-stack endpoints in Azure Container Registry (preview) and the ACR endpoint reference. If you have further questions about IPv6 dual-stack endpoints or dedicated data endpoints, reach out to us on the Azure Container Registry GitHub repository or file feedback through the Azure portal.
No updates showing under Windows Insider Experimental / Future Updates channel
No Preview Builds Offered Under Experimental / Future Updates Channel 🟢 Active Enrollment: Experimental Channel Issue Summary: Device recently registered in the Experimental / Future Updates channel. Upon accessing Settings > Windows Update, no new builds are offered, and scanning manually completes successfully without throwing any specific error messages or block codes. 🖥️ System Information Operating System: Windows 11 Enterprise Insider Preview Version & Build: 10.0.26300 (Build 26300) Device Hardware: Lenovo V15 G4 AMN System SKU: LENOVO_MT_82YU_BU_idea_FM_V15 G4 AMN Processor (CPU): AMD Ryzen 3 7320U (4 Cores / 8 Logical Processors) RAM & Boot Type: 8 GB | UEFI Boot Mode 📋 Troubleshooting Checklist (Completed) ✓ Verified Channel Enrollment: Checked registry and confirmed active status. ✓ Validated Linked Account: MSA linked properly under Windows Insider Settings. ✓ Confirmed Update Services Active: Verified wuauserv and dependent services are running. ✓ Verified Updates are NOT Paused: Confirmed no pause delay schedules exist. ✓ Triggered Manual Scans: Initiated multiple manual check cycles. ✓ Performed Diagnostics Cold Reboot: Power-cycled system to clear cached state. 🔄 Current State: "Up to date" shown. No future packages available or populating in flighting catalog. ❓ Requested Clarifications Device Compatibility Is the Lenovo V15 G4 AMN platform (AMD Ryzen 3 7320U) eligible for current Experimental/Future Updates? Rollout/Delivery Restraints Are there known blocks, feature flag restrictions, or throttled rollouts affecting build distribution for this ring? Additional Prerequisites Are there local configuration adjustments, registry switches, or diagnostic data levels required to trigger flighting? Thank you for analyzing this inquiry. Your guidance and support are highly appreciated!
Azure Copilot Observability Agent is generally available, with autonomous operations in preview
Complex cloud environments have outpaced manual operations. Agentic cloud operations connect people, tools, and data to streamline investigation workflows and move teams from scattered signals to evidence-backed next steps. With unified observability, teams can investigate Azure-monitored applications, Azure Kubernetes Service (AKS) environments, VMs, Foundry telemetry, infrastructure, and platform signals with greater context and control. Powered by Azure Monitor, the Azure Copilot Observability Agent is now generally available. It helps engineering, SRE, DevOps, and operations teams move from telemetry and alert noise to investigated issues, explainable reasoning, and recommended next steps that can reduce Time-To-Mitigate (TTM). Autonomous operations are also available in public preview. They help prepare context and reduce triage work while people remain responsible for mitigation decisions and any changes to the environment. From alert noise to investigated issues The Observability Agent helps teams reduce the effort required to understand operational problems. Instead of starting every investigation from a dashboard, query editor, or alert payload, teams can work with an AI companion that reasons across telemetry, Azure resource context, discovered topology, and custom instructions to identify what changed, what is correlated, and what evidence supports the conclusion. Teams can start with natural-language exploration and continue into deeper investigations when an issue requires more evidence. That light-to-deep workflow helps responders move from broad questions to a structured investigation without losing the reasoning trail. Here's what this looks like in practice: after a deployment, several alerts might fire across an app, database dependency, and compute resource. The Observability Agent can group those signals around the affected service, identify when the regression started, compare related dependencies and infrastructure metrics, and capture the findings in an Azure Monitor issue. The responder can then validate the evidence, add team context, route work to the right owner, and decide whether a rollback, configuration change, or code fix is appropriate. Explainable investigations across Azure-monitored signals Operations teams need more than a chatbot that answers questions. The Observability Agent follows an investigation workflow: it frames hypotheses, gathers evidence, compares signals by time, scope, and type, rules out weak explanations, and shows the reasoning path behind its findings. The Observability Agent can help teams: Investigate incidents and alerts across Azure-monitored applications, Azure Kubernetes Service (AKS) environments, VMs, Foundry telemetry, infrastructure, and platform signals Correlate related signals to reduce noise and surface higher-signal issues with context Explore telemetry using natural language while preserving transparency into the supporting data Compare signals by time, scope, and type to separate likely causes from coincidental changes Provide a reasoning trail that shows what the agent found, what it ruled out, and why Recommend next steps that engineers can review before deciding how to act This same investigation model applies to specialized skills and issue types, including customer's application, Azure Kubernetes Service (AKS), Foundry, VMs, and GenAI issues. When the relevant telemetry is available, the Observability Agent can correlate logs, metrics, traces, alerts, dependencies, resource graph, resource health, activity logs, Foundry telemetry, and changes. This helps teams investigate customer-visible issues with evidence, including latency, token spikes, tool-call failures, agent errors, hallucinations, deployments, API failures, performance regressions, infrastructure dependencies, and platform incidents. This explainability is central to the product. In production operations, trust is earned through evidence. The Observability agent is built to support human judgment, not bypass it. . Azure expertise, with context from your environment Context matters in every investigation. The same symptom can mean different things depending on application architecture, recent deployments, dependencies, historical incidents, and team practices. The Observability Agent brings Microsoft and Azure operational knowledge into the investigation experience. It can use discovered topology, Azure resource context, logs, metrics, traces, and custom instructions to ground investigations in signals that are more relevant to your environment. Native to Azure Monitor, with humans in control Because the Observability Agent is built into Azure Monitor, teams can use it close to the telemetry, alerts, and workflows they already rely on. Investigations can also be captured as Azure Monitor issues, creating a shared case file for humans and agents to collaborate on evidence, reasoning, and next steps. The Observability Agent is designed for governed AI operations inside Azure Monitor. Interactive chat and investigations use the signed-in user's identity and Azure role-based access control (RBAC). Prompts and responses are not used to train foundation models, and the agent doesn't restart resources, change configuration, or resolve issues on its own. Autonomous operations in public preview Alongside general availability, autonomous operations for the Observability Agent are available in public preview. When enabled, the agent can analyze alerts in the background, correlate related alerts when they likely represent the same incident, create Azure Monitor issues automatically, and run deep investigations on agent-created issues. This automatic triage helps reduce alert noise by turning streams of individual alerts into higher-signal issues with context, findings, and recommended next steps. Teams can review the issue, continue the investigation, and decide what action to take. Autonomous operations are designed to prepare context and reduce triage work, not to remove human control. Engineers remain responsible for decisions, approvals, and any changes to the environment. Next steps Check out our latest announcements and related blogs: Azure Blog and OMB Blog. Learn how to use the Observability Agent in Azure Copilot Observability Agent. Explore how investigations work in Deep investigations in the Azure Copilot Observability Agent. Learn more on how to Chat with your observability data Learn how teams preserve context in Azure Monitor issues. Review preview details in Autonomous operations in the Azure Copilot Observability Agent. Stay connected Follow this blog for ongoing deep dives, updates on current capabilities, and a preview of what's coming next. Live webinar - a walkthrough of real Observability Agent scenarios, best practices, and what's available today - along with a look at what's coming next, and live Q&A with the product team. Register for the Observability Agent webinar. We'd love your feedback The Observability agent continues to evolve based on real-world usage and operator feedback. Share your thoughts directly through the Give Feedback option in the experience, or reach us at enauerman@microsoft.com.
