feat: automatically reproduce model from reproduce.json (#326)

* feat: load reproduction information

* feat: check reproduction environment against original environment

* fix: remove `trust_remote_code` setting

This improves security when running Heretic with an untrusted config file. The prompt is now always shown.

This is NOT a breaking change, because we currently ignore values for unknown settings, so existing configs continue to work.

* feat: reproduce model from JSON file

* feat: verify hashes of uploaded weight files

* fix: fix issues in automatic reproduction system (#352)

* fix: Check if a model is gated / accessible

* fix: handle unknown gated models

* feat: Auto install requirements

* simplify

* Revert "simplify"

This reverts commit 10287926e99e5543f67a72d38a595ae2b4084d71.

* Revert "feat: Auto install requirements"

This reverts commit f4be1abd043e17d83e589e54972c4ead2600c2b2.

* fix: Seed pytorch method

* reference, style

* simplify token

* feat: Export strategy in reproduce.json, v2

* style: Name

* simplify export strategy

* style: Rename

* enumeration

* maybe remove seed as well

* fix: don't lock settings with permanent strategy

* simplify no choice, use try/finally block

* feat: verify hashes of locally saved weight files

* fix: remove obsolete code from merge

* docs: add automatic reproduction instructions to reproduce README

---------

Co-authored-by: Vinay-Umrethe <vinayumrethe99@gmail.com>

config.default.toml

@@ -123,10 +123,6 @@ n_trials = 200
 # Number of trials that use random sampling for the purpose of exploration.
 n_startup_trials = 60
 
-# Random seed for reproducible optimization. Set to an integer to enable.
-# Applies to Python's random module, NumPy, PyTorch, and Optuna.
-# seed = 75
-
 # Directory to save and load study progress to/from.
 study_checkpoint_dir = "checkpoints"
 

src/heretic/config.py

@@ -32,6 +32,11 @@ class RowNormalization(str, Enum):
     FULL = "full"
 
 
+class ExportStrategy(str, Enum):
+    MERGE = "merge"
+    ADAPTER = "adapter"
+
+
 class DatasetSpecification(BaseModel):
     dataset: str = Field(
         description="Hugging Face dataset ID, or path to dataset on disk."
@@ -119,6 +124,15 @@ class Settings(BaseSettings):
         exclude=True,
     )
 
+    reproduce: str | None = Field(
+        default=None,
+        description=(
+            "If this path or URL to a reproduce.json file is set, load reproduction information "
+            "from that file, and attempt to reproduce the abliterated model it originated from."
+        ),
+        exclude=True,
+    )
+
     dtypes: list[str] = Field(
         default=[
             # In practice, "auto" almost always means bfloat16.
@@ -167,13 +181,6 @@ class Settings(BaseSettings):
         ),
     )
 
-    trust_remote_code: bool | None = Field(
-        default=None,
-        description="Whether to trust remote code when loading the model.",
-        # For security reasons, we don't store this setting.
-        exclude=True,
-    )
-
     batch_size: int = Field(
         default=0,  # auto
         description="Number of input sequences to process in parallel (0 = auto).",
@@ -416,6 +423,11 @@ class Settings(BaseSettings):
         description="Maximum size for individual safetensors files generated when exporting a model.",
     )
 
+    export_strategy: ExportStrategy | None = Field(
+        default=None,
+        description='How to export the model: "merge", "adapter", or unset to prompt the user.',
+    )
+
     refusal_markers: list[str] = Field(
         default=[
             "disclaimer",

src/heretic/main.py

@@ -47,7 +47,7 @@ import questionary
 import torch
 import torch.nn.functional as F
 import transformers
-from huggingface_hub import ModelCard, ModelCardData
+from huggingface_hub import HfApi, ModelCard, ModelCardData
 from lm_eval.models.huggingface import HFLM
 from optuna import Trial, TrialPruned
 from optuna.exceptions import ExperimentalWarning
@@ -55,21 +55,26 @@ from optuna.samplers import TPESampler
 from optuna.storages import JournalStorage
 from optuna.storages.journal import JournalFileBackend, JournalFileOpenLock
 from optuna.study import StudyDirection
-from optuna.trial import TrialState
+from optuna.trial import TrialState, create_trial
 from pydantic import ValidationError
 from questionary import Choice, Style
 from rich.table import Table
 from rich.traceback import install
 
 from .analyzer import Analyzer
-from .config import QuantizationMethod
+from .config import ExportStrategy, QuantizationMethod
 from .evaluator import Evaluator
 from .model import AbliterationParameters, Model, get_model_class
-from .reproduce import collect_reproducibles
+from .reproduce import (
+    check_environment,
+    collect_reproducibles,
+    load_reproduction_information,
+)
 from .system import empty_cache, get_accelerator_info
 from .utils import (
     format_duration,
     format_exception,
+    get_file_sha256,
     get_readme_intro,
     get_trial_parameters,
     is_hf_path,
@@ -85,13 +90,19 @@ from .utils import (
 )
 
 
-def obtain_merge_strategy(settings: Settings, model: Model) -> str | None:
+def obtain_export_strategy(
+    settings: Settings,
+    model: Model,
+) -> ExportStrategy | None:
     """
-    Prompts the user for how to proceed with saving the model.
+    Gets the export strategy from settings or prompts the user.
     Provides info to the user if the model is quantized on memory use.
-    Returns "merge", "adapter", or None (if cancelled/invalid).
+    Returns an export strategy, or None if cancelled.
     """
 
+    if settings.export_strategy is not None:
+        return settings.export_strategy
+
     if settings.quantization == QuantizationMethod.BNB_4BIT:
         print()
         print(
@@ -114,7 +125,9 @@ def obtain_merge_strategy(settings: Settings, model: Model) -> str | None:
                     settings.model,
                     device_map="meta",
                     torch_dtype=torch.bfloat16,
-                    trust_remote_code=model.trusted_models.get(settings.model),
+                    trust_remote_code=True
+                    if settings.model in model.trusted_models
+                    else None,
                     **model.revision_kwargs,
                 )
                 footprint_bytes = meta_model.get_memory_footprint()
@@ -143,11 +156,11 @@ def obtain_merge_strategy(settings: Settings, model: Model) -> str | None:
                     if settings.quantization == QuantizationMethod.NONE
                     else " (requires sufficient RAM)"
                 ),
-                value="merge",
+                value=ExportStrategy.MERGE,
             ),
             Choice(
                 title="Save LoRA adapter only (can be merged later)",
-                value="adapter",
+                value=ExportStrategy.ADAPTER,
             ),
         ],
     )
@@ -176,6 +189,7 @@ def run():
         len(sys.argv) > 1
         # Heretic is being invoked in standard (model processing) mode.
         and "--collect-reproducibles" not in sys.argv
+        and "--reproduce" not in sys.argv
         # No model has been explicitly provided.
         and "--model" not in sys.argv
         # The last argument is a parameter value rather than a flag (such as "--help").
@@ -186,7 +200,9 @@ def run():
 
     # Work around the "model" argument being required
     # when Heretic is invoked in a non-processing mode.
-    if "--collect-reproducibles" in sys.argv and "--model" not in sys.argv:
+    if (
+        "--collect-reproducibles" in sys.argv or "--reproduce" in sys.argv
+    ) and "--model" not in sys.argv:
         sys.argv.extend(["--model", ""])
 
     try:
@@ -211,6 +227,31 @@ def run():
         collect_reproducibles(settings.collect_reproducibles)
         return
 
+    reproduction_mode = settings.reproduce is not None
+
+    if settings.reproduce is not None:
+        print(f"Loading reproduction information from [bold]{settings.reproduce}[/]...")
+        # FIXME: "Reproduction"/"reproducibility" name inconsistency!
+        reproduction_information = load_reproduction_information(settings.reproduce)
+
+        if reproduction_information["version"] not in ["1", "2"]:
+            print(
+                (
+                    f"[red]Unsupported file format version: [bold]{reproduction_information['version']}[/].[/] "
+                    "Try loading the file with a newer version of Heretic."
+                )
+            )
+            return
+
+        if not check_environment(reproduction_information):
+            return
+
+        print()
+
+        verify_hashes = reproduction_information["version"] != "1"
+
+        settings = Settings.model_validate(reproduction_information["settings"])
+
     if settings.seed is None:
         settings.seed = random.randint(0, 2**32 - 1)
 
@@ -260,7 +301,11 @@ def run():
     except IndexError:
         existing_study = None
 
-    if existing_study is not None and settings.evaluate_model is None:
+    if (
+        existing_study is not None
+        and settings.evaluate_model is None
+        and not reproduction_mode
+    ):
         choices = []
 
         if existing_study.user_attrs["finished"]:
@@ -604,6 +649,7 @@ def run():
             trial.study.stop()
             raise TrialPruned()
 
+    if not reproduction_mode:
         study = optuna.create_study(
             sampler=TPESampler(
                 n_startup_trials=settings.n_startup_trials,
@@ -640,10 +686,13 @@ def run():
             study.set_user_attr("finished", True)
 
     while True:
+        if not reproduction_mode:
             # If no trials at all have been evaluated, the study must have been stopped
             # by pressing Ctrl+C while the first trial was running. In this case, we just
             # re-raise the interrupt to invoke the standard handler defined below.
-        completed_trials = [t for t in study.trials if t.state == TrialState.COMPLETE]
+            completed_trials = [
+                t for t in study.trials if t.state == TrialState.COMPLETE
+            ]
             if not completed_trials:
                 raise KeyboardInterrupt
 
@@ -705,9 +754,31 @@ def run():
             )
 
         while True:
+            if reproduction_mode:
+                parameters = reproduction_information["parameters"]
+                metrics = reproduction_information["metrics"]
+
+                trial = create_trial(
+                    values=[],
+                    user_attrs={
+                        "direction_index": parameters["direction_index"],
+                        "parameters": parameters["abliteration_parameters"],
+                        "kl_divergence": metrics["kl_divergence"],
+                        "refusals": metrics["refusals"],
+                        "base_refusals": metrics["base_refusals"],
+                        "n_bad_prompts": metrics["n_bad_prompts"],
+                    },
+                )
+
+                print()
+                print("Restoring model from reproduction information...")
+            else:
                 print()
                 trial = prompt_select("Which trial do you want to use?", choices)
 
+                if trial is None or trial == "":
+                    return
+
                 if trial == "continue":
                     while True:
                         try:
@@ -744,11 +815,11 @@ def run():
 
                     break
 
-            elif trial is None or trial == "":
-                return
-
                 print()
-            print(f"Restoring model from trial [bold]{trial.user_attrs['index']}[/]...")
+                print(
+                    f"Restoring model from trial [bold]{trial.user_attrs['index']}[/]..."
+                )
+
             print("* Parameters:")
             for name, value in get_trial_parameters(trial).items():
                 print(f"  * {name} = [bold]{value}[/]")
@@ -779,11 +850,19 @@ def run():
                         "Upload the model to Hugging Face",
                         "Chat with the model",
                         "Benchmark the model",
-                        "Return to the trial selection menu",
+                        Choice(
+                            title="Exit program"
+                            if reproduction_mode
+                            else "Return to the trial selection menu",
+                            value="",
+                        ),
                     ],
                 )
 
-                if action is None or action == "Return to the trial selection menu":
+                if action is None or action == "":
+                    if reproduction_mode:
+                        return
+                    else:
                         break
 
                 # All actions are wrapped in a try/except block so that if an error occurs,
@@ -796,11 +875,11 @@ def run():
                             if not save_directory:
                                 continue
 
-                            strategy = obtain_merge_strategy(settings, model)
+                            strategy = obtain_export_strategy(settings, model)
                             if strategy is None:
                                 continue
 
-                            if strategy == "adapter":
+                            if strategy == ExportStrategy.ADAPTER:
                                 print("Saving LoRA adapter...")
                                 model.model.save_pretrained(
                                     save_directory,
@@ -822,6 +901,31 @@ def run():
 
                             print(f"Model saved to [bold]{save_directory}[/].")
 
+                            if reproduction_mode and verify_hashes:
+                                print("Verifying hashes of weight files...")
+
+                                for (
+                                    filename,
+                                    original_sha256,
+                                ) in reproduction_information["hashes"].items():
+                                    file_path = Path(save_directory) / filename
+
+                                    if file_path.exists():
+                                        sha256 = get_file_sha256(file_path)
+
+                                        if sha256.lower() == original_sha256.lower():
+                                            print(
+                                                f"[bold]{filename}:[/] [green]Hash matches[/]"
+                                            )
+                                        else:
+                                            print(
+                                                f"[bold]{filename}:[/] [yellow]Hash doesn't match[/]"
+                                            )
+                                    else:
+                                        print(
+                                            f"[bold]{filename}:[/] [red]File not found[/]"
+                                        )
+
                         case "Upload the model to Hugging Face":
                             # We don't use huggingface_hub.login() because that stores the token on disk,
                             # and since this program will often be run on rented or shared GPU servers,
@@ -856,7 +960,7 @@ def run():
                                 continue
                             private = visibility == "Private"
 
-                            strategy = obtain_merge_strategy(settings, model)
+                            strategy = obtain_export_strategy(settings, model)
                             if strategy is None:
                                 continue
 
@@ -868,8 +972,10 @@ def run():
                                 settings.good_evaluation_prompts.dataset,
                                 settings.bad_evaluation_prompts.dataset,
                             ]
-                            is_reproducible = is_hf_path(settings.model) and all(
-                                is_hf_path(dataset) for dataset in datasets
+                            is_reproducible = (
+                                is_hf_path(settings.model)
+                                and all(is_hf_path(dataset) for dataset in datasets)
+                                and not reproduction_mode
                             )
 
                             if is_reproducible:
@@ -904,7 +1010,7 @@ def run():
                             else:
                                 reproducibility_information = "none"
 
-                            if strategy == "adapter":
+                            if strategy == ExportStrategy.ADAPTER:
                                 print("Uploading LoRA adapter...")
                                 model.model.push_to_hub(
                                     repo_id,
@@ -973,7 +1079,10 @@ def run():
                                 # Set the number of trials to the number of actual completed trials
                                 # for the reproduction configuration.
                                 settings.n_trials = len(study.trials)
+                                current_export_strategy = settings.export_strategy
+                                settings.export_strategy = strategy
 
+                                try:
                                     upload_reproduce_folder(
                                         repo_id,
                                         settings,
@@ -984,9 +1093,62 @@ def run():
                                             reproducibility_information == "full"
                                         ),
                                     )
+                                finally:
+                                    settings.export_strategy = current_export_strategy
 
                             print(f"Model uploaded to [bold]{repo_id}[/].")
 
+                            if reproduction_mode and verify_hashes:
+                                print("Verifying hashes of weight files...")
+
+                                api = HfApi()
+                                model_info = api.model_info(
+                                    repo_id,
+                                    files_metadata=True,
+                                    token=token,
+                                )
+
+                                if not model_info.siblings:
+                                    raise RuntimeError(
+                                        "Could not fetch uploaded model hashes."
+                                    )
+
+                                for (
+                                    filename,
+                                    original_sha256,
+                                ) in reproduction_information["hashes"].items():
+                                    file_found = False
+
+                                    for file in model_info.siblings:
+                                        if file.rfilename == filename:
+                                            sha256 = getattr(file, "lfs", {}).get(
+                                                "sha256"
+                                            )
+                                            if not sha256:
+                                                raise RuntimeError(
+                                                    "Could not fetch uploaded model hashes."
+                                                )
+
+                                            if (
+                                                sha256.lower()
+                                                == original_sha256.lower()
+                                            ):
+                                                print(
+                                                    f"[bold]{filename}:[/] [green]Hash matches[/]"
+                                                )
+                                            else:
+                                                print(
+                                                    f"[bold]{filename}:[/] [yellow]Hash doesn't match[/]"
+                                                )
+
+                                            file_found = True
+                                            break
+
+                                    if not file_found:
+                                        print(
+                                            f"[bold]{filename}:[/] [red]File not found[/]"
+                                        )
+
                         case "Chat with the model":
                             print()
                             print(

src/heretic/model.py

@@ -76,7 +76,6 @@ class Model:
 
         self.tokenizer = AutoTokenizer.from_pretrained(
             settings.model,
-            trust_remote_code=settings.trust_remote_code,
             **self.revision_kwargs,
         )
 
@@ -85,7 +84,6 @@ class Model:
         if get_model_class(settings.model) == AutoModelForImageTextToText:
             self.processor = AutoProcessor.from_pretrained(
                 settings.model,
-                trust_remote_code=settings.trust_remote_code,
                 **self.revision_kwargs,
             )
 
@@ -104,10 +102,8 @@ class Model:
             if settings.max_memory
             else None
         )
-        self.trusted_models = {settings.model: settings.trust_remote_code}
 
-        if self.settings.evaluate_model is not None:
-            self.trusted_models[settings.evaluate_model] = settings.trust_remote_code
+        self.trusted_models = set()
 
         for dtype in settings.dtypes:
             print(f"* Trying dtype [bold]{dtype}[/]...")
@@ -126,16 +122,18 @@ class Model:
                     dtype=dtype,
                     device_map=settings.device_map,
                     max_memory=self.max_memory,
-                    trust_remote_code=self.trusted_models.get(settings.model),
+                    trust_remote_code=True
+                    if settings.model in self.trusted_models
+                    else None,
                     **self.revision_kwargs,
                     **extra_kwargs,
                 )
                 self.dtype = self.model.dtype
 
                 # If we reach this point and the model requires trust_remote_code,
-                # either the user accepted, or settings.trust_remote_code is True.
-                if self.trusted_models.get(settings.model) is None:
-                    self.trusted_models[settings.model] = True
+                # the user must have agreed when prompted to execute remote code,
+                # because from_pretrained raises an exception otherwise.
+                self.trusted_models.add(settings.model)
 
                 # A test run can reveal dtype-related problems such as the infamous
                 # "RuntimeError: probability tensor contains either `inf`, `nan` or element < 0"
@@ -283,7 +281,9 @@ class Model:
                 self.settings.model,
                 torch_dtype=self.model.dtype,
                 device_map="cpu",
-                trust_remote_code=self.trusted_models.get(self.settings.model),
+                trust_remote_code=True
+                if self.settings.model in self.trusted_models
+                else None,
                 **self.revision_kwargs,
             )
 
@@ -349,7 +349,9 @@ class Model:
             dtype=self.dtype,
             device_map=self.settings.device_map,
             max_memory=self.max_memory,
-            trust_remote_code=self.trusted_models.get(self.settings.model),
+            trust_remote_code=True
+            if self.settings.model in self.trusted_models
+            else None,
             **self.revision_kwargs,
             **extra_kwargs,
         )
@@ -574,6 +576,10 @@ class Model:
                         W = W - W_org
                         # Use a low-rank SVD to get an approximation of the matrix.
                         r = self.peft_config.r
+                        # svd_lowrank is randomized:
+                        # https://github.com/pytorch/pytorch/blob/20919052303c0b5ba87f8bf7e19237dc33ab09d3/torch/_lowrank.py#L108-L109
+                        # Reseed immediately before the call so restoring a trial is independent of RNG history.
+                        torch.manual_seed(self.settings.seed)
                         U, S, Vh = torch.svd_lowrank(W, q=2 * r + 4, niter=6)
                         # Truncate it to the part we want to store in the LoRA adapter.
                         # Note: svd_lowrank actually returns V, so transpose it to get Vh.

src/heretic/reproduce.py

@@ -1,13 +1,33 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
 # Copyright (C) 2025-2026  Philipp Emanuel Weidmann <pew@worldwidemann.com> + contributors
 
+import json
+import platform
+import random
 import shutil
+from dataclasses import asdict
+from enum import IntEnum
 from pathlib import Path
+from typing import Any, cast
+from urllib.request import urlopen
 
+import cpuinfo
+import torch
 from huggingface_hub import HfApi, hf_hub_download
-from huggingface_hub.utils import disable_progress_bars, enable_progress_bars
+from huggingface_hub.utils import (
+    GatedRepoError,
+    disable_progress_bars,
+    enable_progress_bars,
+)
+from questionary import Choice
+from rich.table import Table
 
-from .utils import print
+from .system import (
+    get_accelerator_info_dict,
+    get_heretic_version_info,
+    get_requirements_dict,
+)
+from .utils import print, prompt_select
 
 
 def collect_reproducibles(path: str):
@@ -21,6 +41,7 @@ def collect_reproducibles(path: str):
     models = api.list_models(
         filter=["heretic", "reproducible"],
         sort="created_at",
+        expand=["gated", "tags"],
     )
 
     found = 0
@@ -35,6 +56,12 @@ def collect_reproducibles(path: str):
             if model.tags is not None and "gguf" in model.tags:
                 continue
 
+            if model.gated:
+                try:
+                    api.auth_check(model.id, repo_type="model")
+                except GatedRepoError:
+                    continue
+
             print(f"[bold]{model.id}[/]...", end="")
 
             user, repository = model.id.split("/")
@@ -81,3 +108,275 @@ def collect_reproducibles(path: str):
     print(f"Found: [bold]{found}[/] files")
     print(f"Downloaded: [bold]{downloaded}[/] files")
     print(f"Already stored: [bold]{found - downloaded}[/] files")
+
+
+def load_reproduction_information(path: str) -> dict[str, Any]:
+    if path.lower().startswith(("http://", "https://")):
+        # The path is a URL on the web.
+
+        # Obtain raw download URL.
+        path = path.replace("/blob/", "/raw/")  # Hugging Face, GitHub
+        path = path.replace("/src/branch/", "/raw/branch/")  # Codeberg
+
+        json_str = urlopen(path).read().decode("utf-8")
+    else:
+        # The path is (assumed to be) a local file system path.
+        json_str = Path(path).read_text(encoding="utf-8")
+
+    return json.loads(json_str)
+
+
+class MismatchSeverity(IntEnum):
+    LOW = 1
+    MEDIUM = 2
+    HIGH = 3
+    CRITICAL = 4
+
+    def __rich__(self) -> str:
+        match self:
+            case MismatchSeverity.LOW:
+                return "[green]low[/]"
+            case MismatchSeverity.MEDIUM:
+                return "[yellow]medium[/]"
+            case MismatchSeverity.HIGH:
+                return "[red]high[/]"
+            case MismatchSeverity.CRITICAL:
+                return "[bold red]critical[/]"
+            case _:
+                raise ValueError(f"unknown MismatchSeverity value: {self}")
+
+
+def get_package_mismatch_severity(package_name: str) -> MismatchSeverity:
+    if package_name in [
+        "heretic-llm",
+    ]:
+        return MismatchSeverity.CRITICAL
+    elif package_name in [
+        "torch",
+        "transformers",
+    ]:
+        return MismatchSeverity.HIGH
+    elif package_name in [
+        "accelerate",
+        "bitsandbytes",
+        "kernels",
+        "optuna",
+        "peft",
+        "tokenizers",
+        "triton",
+    ]:
+        return MismatchSeverity.MEDIUM
+    else:
+        return MismatchSeverity.LOW
+
+
+def format_version_information(version_information: dict[str, Any]) -> str:
+    version = version_information["version"]
+    metadata = version_information["metadata"]
+
+    if "type" in metadata:
+        match metadata["type"]:
+            case "pypi":
+                return version
+            case "git":
+                return f"{version}-git+{metadata['url']}@{metadata['commit_hash']}"
+            case "local":
+                # Append a random number to ensure that two local installations
+                # are always considered to be different versions.
+                return f"{version}-local-{random.randint(2**16, 2**17)}"
+            case _:
+                raise ValueError(
+                    f"unknown metadata.type value in version information: {metadata['type']}"
+                )
+    else:
+        return f"{version}-unknown-{random.randint(2**16, 2**17)}"
+
+
+def check_environment(reproduction_information: dict[str, Any]) -> bool:
+    mismatch_severity: MismatchSeverity | None = None
+
+    system_mismatches = []
+    package_mismatches = []
+
+    def verify(
+        mismatch_list: list[tuple[str, Any, Any, MismatchSeverity]],
+        name: str,
+        this: Any,
+        original: Any,
+        severity: MismatchSeverity,
+    ):
+        nonlocal mismatch_severity
+        if this != original:
+            mismatch_list.append((name, this, original, severity))
+            if mismatch_severity is None:
+                mismatch_severity = severity
+            else:
+                mismatch_severity = max(severity, mismatch_severity)
+
+    if "system" in reproduction_information:
+        system = reproduction_information["system"]
+
+        verify(
+            system_mismatches,
+            "Python version",
+            platform.python_version(),
+            system["python"]["version"],
+            MismatchSeverity.LOW,
+        )
+
+        verify(
+            system_mismatches,
+            "Operating system",
+            platform.platform(),
+            system["os"]["platform"],
+            MismatchSeverity.LOW,
+        )
+
+        verify(
+            system_mismatches,
+            "CPU",
+            cpuinfo.get_cpu_info().get("brand_raw"),
+            system["cpu"]["brand"],
+            MismatchSeverity.LOW,
+        )
+
+        accelerators = get_accelerator_info_dict()
+
+        verify(
+            system_mismatches,
+            "Accelerator type",
+            accelerators["type"],
+            system["accelerators"]["type"],
+            MismatchSeverity.HIGH,
+        )
+
+        if (
+            accelerators["type"]
+            and accelerators["type"] == system["accelerators"]["type"]
+        ):
+            verify(
+                system_mismatches,
+                accelerators["api_name"],
+                accelerators["api_version"],
+                system["accelerators"]["api_version"],
+                MismatchSeverity.MEDIUM,
+            )
+            verify(
+                system_mismatches,
+                "Driver version",
+                accelerators["driver_version"],
+                system["accelerators"]["driver_version"],
+                MismatchSeverity.MEDIUM,
+            )
+            verify(
+                system_mismatches,
+                "Devices",
+                "\n".join([device["name"] for device in accelerators["devices"]]),
+                "\n".join(
+                    [device["name"] for device in system["accelerators"]["devices"]]
+                ),
+                MismatchSeverity.MEDIUM,
+            )
+
+    else:
+        print(
+            (
+                "[yellow]The provided JSON file does not contain system information. "
+                "Some system parameters can affect reproducibility, but due to the lack of system information, "
+                "Heretic is unable to verify that those parameters match the original environment. "
+                "Reproduction may or may not produce a byte-for-byte identical model.[/]"
+            )
+        )
+
+    requirements = get_requirements_dict()
+    requirements["heretic-llm"] = format_version_information(
+        asdict(get_heretic_version_info())
+    )
+    requirements["torch"] = torch.__version__
+
+    original_requirements = reproduction_information["environment"]["requirements"]
+    original_requirements["heretic-llm"] = format_version_information(
+        reproduction_information["environment"]["heretic"]
+    )
+    original_requirements["torch"] = reproduction_information["environment"][
+        "pytorch_version"
+    ]
+
+    package_names = sorted(requirements.keys() | original_requirements.keys())
+
+    for package_name in package_names:
+        verify(
+            package_mismatches,
+            package_name,
+            requirements.get(package_name),
+            original_requirements.get(package_name),
+            get_package_mismatch_severity(package_name),
+        )
+
+    if system_mismatches or package_mismatches:
+        print()
+        print(
+            (
+                "[yellow]Your local environment doesn't perfectly match the environment "
+                "used to produce the original model. The following components differ:[/]"
+            )
+        )
+
+    if system_mismatches:
+        table = Table()
+        table.add_column("Component")
+        table.add_column("This system", overflow="fold")
+        table.add_column("Original system", overflow="fold")
+        table.add_column("Severity", width=8)
+
+        for component, this, original, severity in system_mismatches:
+            table.add_row(f"[bold]{component}[/]", this, original, severity)
+
+        print()
+        print("[bold]System Mismatches[/]")
+        print(table)
+
+    if package_mismatches:
+        table = Table()
+        table.add_column("Package")
+        table.add_column("This system", overflow="fold")
+        table.add_column("Original system", overflow="fold")
+        table.add_column("Severity", width=8)
+
+        for package, this, original, severity in package_mismatches:
+            table.add_row(f"[bold]{package}[/]", this, original, severity)
+
+        print()
+        print("[bold]Package Mismatches[/]")
+        print(table)
+
+    if system_mismatches or package_mismatches:
+        print()
+        print(
+            (
+                f"There is a {cast(MismatchSeverity, mismatch_severity).__rich__()} chance "
+                "that reproduction won't produce a byte-for-byte identical model. "
+                "However, the resulting model will very likely still behave similarly "
+                "to the original model."
+            )
+        )
+
+        print()
+        choice = prompt_select(
+            "How would you like to proceed?",
+            [
+                Choice(
+                    title="Attempt to reproduce the model anyway",
+                    value=True,
+                ),
+                Choice(
+                    title="Exit program",
+                    value=False,
+                ),
+            ],
+        )
+
+        return choice
+    else:
+        # There are no mismatches at all, so there is nothing to confirm.
+        return True

src/heretic/utils.py

@@ -2,6 +2,7 @@
 # Copyright (C) 2025-2026  Philipp Emanuel Weidmann <pew@worldwidemann.com> + contributors
 
 import getpass
+import hashlib
 import json
 import os
 import platform
@@ -25,6 +26,7 @@ from datasets.download.download_manager import DownloadMode
 from datasets.utils.info_utils import VerificationMode
 from huggingface_hub.utils import validate_repo_id
 from optuna import Trial
+from optuna.trial import FrozenTrial
 from psutil import Process
 from questionary import Choice, Style
 from rich.console import Console
@@ -286,7 +288,7 @@ def batchify(items: list[T], batch_size: int) -> list[list[T]]:
     return [items[i : i + batch_size] for i in range(0, len(items), batch_size)]
 
 
-def get_trial_parameters(trial: Trial) -> dict[str, str]:
+def get_trial_parameters(trial: Trial | FrozenTrial) -> dict[str, str]:
     params = {}
 
     direction_index = trial.user_attrs["direction_index"]
@@ -303,7 +305,7 @@ def get_trial_parameters(trial: Trial) -> dict[str, str]:
 
 def get_readme_intro(
     settings: Settings,
-    trial: Trial,
+    trial: Trial | FrozenTrial,
     contains_reproducibility_information: bool,
 ) -> str:
     if is_hf_path(settings.model):
@@ -395,7 +397,7 @@ def format_hf_link(
 def generate_reproduce_readme(
     settings: Settings,
     checkpoint_filename: str,
-    trial: Trial,
+    trial: Trial | FrozenTrial,
     include_system_information: bool,
 ) -> str:
     """Generates the contents of a README.md for the reproduce/ folder."""
@@ -547,13 +549,18 @@ This directory contains the necessary information and assets to reproduce the re
 
 ## How to reproduce
 
+> [!TIP]
+> You can automate this process, including all verification steps, by downloading the `reproduce.json` file and running
+> `heretic --reproduce reproduce.json`.
+
 {system_instructions}1. Install the exact version of Heretic indicated in the **Environment** section above, from its original source.
 1. Install the packages listed in `requirements.txt`: `pip install -r requirements.txt`
 1. Install the correct version of PyTorch: `{pytorch_install_command}`
 1. Place the provided `config.toml` in your working directory.
 1. Run Heretic without any additional arguments: `heretic`
 1. Wait for the run to finish, then select trial **{trial.user_attrs["index"]}** and export the model.
-1. Verify that the weight files have been exactly reproduced by comparing their SHA-256 hashes against those in `SHA256SUMS`: `sha256sum -c SHA256SUMS` (or look at the hashes online if you uploaded to Hugging Face)
+1. Verify that the weight files have been exactly reproduced by comparing their SHA-256 hashes against those in `SHA256SUMS`:
+   `sha256sum -c SHA256SUMS` (or look at the hashes online if you uploaded to Hugging Face)
 
 > [!TIP]
 > To use the included Optuna study journal `{checkpoint_filename}`, place it in the checkpoints directory (usually `checkpoints/`) before running Heretic.
@@ -564,7 +571,7 @@ This directory contains the necessary information and assets to reproduce the re
 
 def generate_reproduce_json(
     settings: Settings,
-    trial: Trial,
+    trial: Trial | FrozenTrial,
     timestamp: str,
     uploaded_model_hashes: dict[str, str],
     include_system_information: bool,
@@ -574,7 +581,7 @@ def generate_reproduce_json(
     version_info = get_heretic_version_info()
 
     data = {
-        "version": "1",  # Version number of the reproduce.json file format, to allow for future changes.
+        "version": "2",  # Version number of the reproduce.json file format, to allow for future changes.
         "timestamp": timestamp,
         "system": None,  # Defined here to preserve insertion order.
         "environment": {
@@ -628,11 +635,23 @@ def generate_sha256sums(hashes: dict[str, str]) -> str:
     return "\n".join(lines) + "\n"
 
 
+# TODO: Replace this with hashlib.file_digest when we drop support for Python 3.10.
+def get_file_sha256(file_path: str | Path) -> str:
+    hash = hashlib.sha256()
+
+    with open(file_path, "rb") as file:
+        # Read the file in 64 kB blocks.
+        for block in iter(lambda: file.read(65536), b""):
+            hash.update(block)
+
+    return hash.hexdigest()
+
+
 def create_reproduce_folder(
     path: Path,
     settings: Settings,
     checkpoint_path: str | Path,
-    trial: Trial,
+    trial: Trial | FrozenTrial,
     uploaded_model_hashes: dict[str, str],
     include_system_information: bool,
 ):
@@ -706,7 +725,7 @@ def upload_reproduce_folder(
     settings: Settings,
     token: str,
     checkpoint_path: str | Path,
-    trial: Trial,
+    trial: Trial | FrozenTrial,
     include_system_information: bool,
 ):
     api = huggingface_hub.HfApi()