SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

adv-robust-pgd

claude-code claude-opus-4-8 ✗ failed GOOD_FAILURE ↑ View task
Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.
Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.
Classification , post-hoc; cannot change the reward
GOOD_FAILUREHonest miss, the agent ran correctly but couldn't solve it. Expected for a hard task; the task is sound.
SubtypeComplexity Overwhelm
EvidenceComponent Conformance Suite: 201/201 cases passed (all milestones pass: True). Final Metric: PGD robust accuracy = 0.5737 < threshold 0.6. The agent's framework implementation is 100% correct, all 201 component checks passed, including finite-difference gradient checks on every operation, optimizer correctness, attack implementation, and adversarial training loss correctness. The failure is purely on the sealed-held-out robustness metric, where the final model achieved 0.5737 vs required 0.6 (0.0263 points short).
Root causeThe agent successfully implemented a complete numpy-only deep-learning framework from scratch and trained an adversarially-robust CNN, but the final model fell 0.0263 points short of the sealed robust-accuracy threshold (0.5737 vs 0.6). This is a legitimate performance gap in an extremely hard adversarial robustness task, not a framework or specification bug, the component suite validation proves the agent's implementation is correct.
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
113 tool calls · 4 tool types · 133 steps
Agent session started, model: claude-opus-4-8 · 29 tools available · cwd: /app
I'll start by exploring the structure and understanding what I'm working with.
shell
ls -la && echo "---SUBMISSION---" && ls -la submission/ && echo "---DATA---" && ls -la data/ && python3 -c "import numpy as np; d=np.load('data/train.npz'); print({k:(v.shape,v.dtype) for k,v in d.items()}); print('classes', np.unique(d['y']))"
output
total 101
drwxr-xr-x  4 user user  4096 Jul  1 00:22 .
drwxr-xr-x 21 root root  4096 Jul  1 00:22 ..
-rw-r--r--  1 user user 14238 Jul  1 00:22 PROMPT.txt
-rw-r--r--  1 user user     5 Jul  1 00:22 agent.pid
-rw-r--r--  1 user user     0 Jul  1 00:22 agent.stderr
-rw-r--r--  1 user user  4645 Jul  1 00:22 agent_trajectory.jsonl
drwxr-xr-x  2 user user    60 Jul  1 00:22 data
-rw-r--r--  1 user user     0 Jul  1 00:22 run.log
-rwxr-xr-x  1 user user 57740 Jun 30 11:01 run_checks.py
drwxr-xr-x  2 user user   128 Jul  1 00:22 submission
-rwxr-xr-x  1 user user   998 Jun 30 11:01 test.sh
-rwxr-xr-x  1 user user   629 Jun 30 11:01 timer.sh
---SUBMISSION---
total 80
drwxr-xr-x 2 user user   128 Jul  1 00:22 .
drwxr-xr-x 4 user user  4096 Jul  1 00:22 ..
-rw-r--r-- 1 user user  5490 Jun 30 11:01 advtrain.py
-rw-r--r-- 1 user user  8776 Jun 30 11:01 attack.py
-rw-r--r-- 1 user user 18341 Jun 30 11:01 autograd.py
-rw-r--r-- 1 user user  2167 Jun 30 11:01 data.py
-rw-r--r-- 1 user user 15988 Jun 30 11:01 nn.py
-rw-r--r-- 1 user user  8853 Jun 30 11:01 optim.py
-rw-r--r-- 1 user user  3742 Jun 30 11:01 train.py
---DATA---
total 2904
drwxr-xr-x 2 user user      60 Jul  1 00:22 .
drwxr-xr-x 4 user user    4096 Jul  1 00:22 ..
-rw-r--r-- 1 user user 2967336 Jun 30 11:01 train.npz
{'X': ((3600, 1, 16, 16), dtype('float32')), 'y': ((3600,), dtype('int64'))}
classes [0 1 2 3 4 5]

/app/submission/autograd.py

contents
1	"""Reverse-mode automatic differentiation over numpy arrays (IMPLEMENT THIS).
2	
3	A ``Tensor`` wraps a single ``numpy.ndarray`` (``float64``) and records the operation that
4	produced it so that ``.backward()`` can walk the graph in reverse-topological order and
5	accumulate ``.grad`` (the gradient of the scalar on which ``.backward()`` was called w.r.t.
6	this tensor) into every leaf.
7	
8	This task is ADVERSARIAL ROBUSTNESS: the model is a small convolutional classifier and the
9	attacks (PGD/FGSM/MI-FGSM/PGD-L2/CW) ascend on the gradient of an attack loss w.r.t. the INPUT
10	image, so the autograd engine must (a) flow gradients back to PARAMETERS (for training) AND
11	(b) flow gradients back to the INPUT tensor (for the attack). BOTH directions are exercised by the
12	verifier's finite-difference gradient checks, so the convolution's input-gradient (the ``_col2im``
13	adjoint) is load-bearing.
14	
15	Contract (the verifier's conformance suite differentiates your analytic backward against finite
16	differences and checks your forward against its own reference, so match this exactly):
17	
18	* ``Tensor(data, requires_grad=False)`` -- ``data`` is array-like, stored as ``float64`` in
19	  ``self.data``; ``self.grad`` starts as ``None`` and becomes a same-shape ``float64`` array after
20	  backward. ``requires_grad`` leaves accumulate grad; non-requiring leaves do not.
21	* Every op returns a NEW ``Tensor`` whose ``requires_grad`` is the OR of its differentiable inputs.
22	 
…[truncated 18629 chars]

/app/submission/nn.py

contents
1	"""Neural-network layers + a small convolutional classifier, built on the autograd engine
2	(IMPLEMENT THE FORWARDS).
3	
4	Every module exposes ``params()`` -> list[Tensor] (the leaf tensors with ``requires_grad=True``)
5	and ``named_params()`` -> dict[str, Tensor] with STABLE names that match the checkpoint format the
6	verifier loads. ``SmallCNN.state_dict()`` / ``load_state_dict()`` round-trip a plain
7	``dict[str, np.ndarray]`` (saved as an ``.npz``); the verifier loads YOUR checkpoint into its OWN
8	reference SmallCNN via these names, so the names + shapes below are part of the contract.
9	
10	Naming contract for SmallCNN (do not change -- the verifier indexes by these exact keys):
11	  conv1.weight   (C1, C_in, 3, 3)        conv1.bias   (C1,)
12	  conv2.weight   (C2, C1, 3, 3)          conv2.bias   (C2,)
13	  fc1.weight     (C2*(H/4)*(W/4), F)      fc1.bias     (F,)
14	  fc2.weight     (F, n_classes)           fc2.bias     (n_classes,)
15	
16	Architecture (pinned): for an (N, C_in, H, W) input image batch,
17	  conv1 (C_in->C1, 3x3, pad 1) -> relu
18	  maxpool 2x2                   (H,W -> H/2,W/2)
19	  conv2 (C1->C2, 3x3, pad 1)   -> relu
20	  maxpool 2x2                   (H/2,W/2 -> H/4,W/4)
21	  flatten -> fc1 (-> F) -> relu -> fc2 (-> n_classes)   logits.
22	``Linear`` computes ``x @ weight + bias`` (weight is (in, out)). No BatchNorm inside SmallCNN (so
23	the attack runs a single deterministic eval-mode forward with no running-stat dependence).
24	
25	The other
…[truncated 15896 chars]

/app/submission/optim.py

contents
1	"""Optimizers + LR schedulers over a flat list of autograd ``Tensor`` parameters (IMPLEMENT THESE).
2	
3	Every optimizer operates IN PLACE on ``param.data`` using ``param.grad`` (the gradient accumulated
4	by ``Tensor.backward``). ``zero_grad()`` resets every grad to None. The EXACT update formula each
5	optimizer must match (the verifier checks one and several steps against its own reference) is in
6	its docstring.
7	
8	The adversarial-training loop uses AdamW (decoupled decay, with ``no_decay_ndim`` excluding 1-D
9	params/biases) + global grad-norm clipping; the rest of the optimizer zoo + the four LR schedulers
10	are part of the from-scratch framework the conformance suite audits.
11	"""
12	from __future__ import annotations
13	
14	import math
15	from typing import List
16	
17	import numpy as np
18	
19	from autograd import Tensor
20	
21	
22	class Optimizer:
23	    def __init__(self, params: List[Tensor]):
24	        self.params = list(params)
25	
26	    def zero_grad(self):
27	        for p in self.params:
28	            p.grad = None
29	
30	
31	class SGD(Optimizer):
32	    """SGD + momentum + optional Nesterov + (coupled/L2) weight decay:
33	        g = grad + wd*param;  v = mu*v + g;  step = (g + mu*v) if nesterov else v;  param -= lr*step."""
34	
35	    def __init__(self, params, lr=0.1, momentum=0.0, weight_decay=0.0, nesterov=False):
36	        super().__init__(params)
37	        self.lr = lr
38	        self.momentum = momentum
39	        self.weight_decay = weight
…[truncated 8125 chars]

/app/submission/attack.py

contents
1	"""White-box evasion attacks built on the from-scratch autograd engine (IMPLEMENT THESE).
2	
3	An adversary perturbs each input within a norm budget (L-inf eps in the [0,1] pixel domain by
4	default) and tries to make the classifier WRONG. Every attack ascends on the gradient of an attack
5	loss with respect to the INPUT image, which is exactly the gradient the autograd engine produces
6	when the input is wrapped in a ``requires_grad=True`` Tensor and the loss is backpropagated -- so a
7	correct ``conv2d`` input-gradient (the ``_col2im`` adjoint) is load-bearing.
8	
9	THE PRIMITIVE
10	  input_grad(model, x, y)                  d/dx of mean cross-entropy of model(x) vs y (ndarray).
11	  loss_input_grad(model, x, y, loss_fn)    d/dx of an ARBITRARY scalar attack loss loss_fn(logits,y).
12	
13	L-INF ATTACKS
14	  fgsm(model, x, y, eps)                    clip(x + eps*sign(input_grad)).
15	  pgd_attack(model, x, y, eps, steps, alpha)  iterated FGSM with random start + project to the
16	                                            L-inf eps-ball around x AND the [0,1] box each step.
17	  mi_fgsm(model, x, y, eps, steps, alpha, mu) momentum-iterative FGSM: accumulate a decaying
18	                                            momentum of the L1-NORMALIZED gradient, step on its sign,
19	                                            project each step.
20	  targeted_pgd(model, x, y_target, eps, steps, alpha)  DESCEND CE toward y_target (step on the
21	                                     
…[truncated 7820 chars]

/app/submission/advtrain.py

contents
1	"""Adversarial-training objectives built on the from-scratch autograd engine (IMPLEMENT THESE).
2	
3	Several standard recipes turn a fragile classifier into a robust one. Each crafts adversarial
4	inputs per minibatch with the model's own attack, then takes a gradient step on a robustness-aware
5	loss; the recipes differ in the loss. All run a single forward+backward; the caller does grad-clip
6	+ the optimizer step. ``x_clean`` / ``x_adv`` are ndarrays (N, C, H, W); ``y`` is an int (N,).
7	
8	  pgd_at_loss(model, x_adv, y)                  Madry PGD-AT: CE on the ADVERSARIAL batch.
9	  trades_loss(model, x_clean, x_adv, y, beta)   TRADES: CE(clean) + beta*KL(stopgrad(clean)||adv).
10	                                                The clean branch INSIDE the KL is a STOP-GRADIENT
11	                                                target (detached): the KL backprops only through
12	                                                the adversarial branch.
13	  mart_loss(model, x_clean, x_adv, y, beta)     MART: boosted-CE on the adversarial batch
14	                                                ( CE(adv,y) - mean log(1 - max_{j!=y} p_adv_j) ) +
15	                                                beta * mean_i[ (1 - p_clean_i[y_i]) *
16	                                                KL_i(softmax(adv)||stopgrad softmax(clean)) ].
17	  alp_loss(model, x_clean, x_adv, y, lam)       Adversarial Logit Pairing:
18	                                                0.5*(CE(clean)+CE(ad
…[truncated 4278 chars]

/app/submission/data.py

/app/submission/train.py

contents
1	"""Data loading + minibatching for the shape-classification set (IMPLEMENT THESE).
2	
3	The visible train split ships as ``/app/data/train.npz`` with arrays ``X`` (N, C, H, W) float
4	pixels in [0,1] and ``y`` (N,) int labels. The SEALED held-out split is NOT in the image -- the
5	verifier regenerates it from a secret feature seed and runs its own attack on it.
6	
7	Contract:
8	  load_npz(path) -> (X float64 (N,C,H,W), y int64 (N,))
9	  train_val_split(X, y, val_frac, rng) -> ((Xtr,ytr),(Xval,yval))   random disjoint split (val slice
10	        is a held-BACK slice of the VISIBLE train data you may use for best-checkpoint selection --
11	        it is NOT the verifier's sealed held-out set)
12	  iter_batches(X, y, batch_size, rng) -> yields (xb, yb) random-permutation minibatches
13	  get_batch(X, y, batch_size, rng) -> a single random minibatch
14	  to_onehot(y, n_classes) -> (N, n_classes) one-hot float matrix
15	  clip01(X) -> X clamped into the [0,1] pixel domain
16	"""
17	from __future__ import annotations
18	
19	from typing import Iterator, Tuple
20	
21	import numpy as np
22	
23	
24	def load_npz(path: str) -> Tuple[np.ndarray, np.ndarray]:
25	    raise NotImplementedError("implement load_npz")
26	
27	
28	def train_val_split(X: np.ndarray, y: np.ndarray, val_frac: float,
29	                    rng: np.random.Generator):
30	    raise NotImplementedError("implement train_val_split")
31	
32	
33	def iter_batches(X: np.ndarray, y: np.ndarray, batch_size: int,
34	           
…[truncated 814 chars]

contents
1	"""Adversarial-training loop for the small CNN, using the from-scratch numpy framework
2	(IMPLEMENT THIS).
3	
4	Standard (clean) training reaches ~99% CLEAN accuracy but ~chance ROBUST accuracy -- it is broken
5	by the verifier's STRONG multi-restart L-inf PGD attack. WEAK robust training is not enough either:
6	single-step (FGSM) adversarial training suffers "catastrophic overfitting" and is shattered by the
7	multi-step / multi-restart eval attack, and adversarial training at a SMALLER perturbation budget
8	than the eval budget leaves the model fragile exactly where it is attacked. The effective recipe is
9	full multi-step PGD ADVERSARIAL TRAINING (Madry et al. 2018) with the perturbation budget MATCHED
10	to the (larger) eval budget:
11	
12	  * on every minibatch, craft an inner k-step L-inf PGD adversarial batch against the CURRENT model
13	    (attack.pgd_attack), at the eps the eval uses, then take the AdamW step on advtrain.pgd_at_loss
14	    (cross-entropy on the adversarial batch);
15	  * train long enough for robustness to converge (a few epochs is not enough at this eps);
16	  * stability details that materially raise the achieved robust accuracy and make it reproducible:
17	    (a) exclude biases (1-D params) from weight decay (AdamW no_decay_ndim=1); (b) clip the global
18	    gradient norm (the adversarial loss surface is sharp); (c) keep the BEST-by-robust-accuracy
19	    checkpoint, evaluated each epoch with the model's own multi-step PGD on a held-BACK slic
…[truncated 2473 chars]
Now let me examine the checker to understand exact expectations.

/app/run_checks.py

contents
<system-reminder>[Truncated: PARTIAL view , showing lines 1-868 of 1188 total (29062 tokens, cap 25000). Call Read with offset=869 limit=868 for the next page, or Grep to find a specific section. Do NOT answer from this page alone if the answer may be further in the file.]</system-reminder>

1	#!/usr/bin/env python3
2	"""PUBLIC component check runner for the from-scratch numpy framework + the adversarial machinery.
3	
4	Run this AS OFTEN AS YOU LIKE while you implement to get a per-check progress signal:
5	
6	    python3 /app/run_checks.py                       # check the framework in /app/submission
7	    python3 /app/run_checks.py --submission /some/dir
8	    python3 /app/run_checks.py --only attack         # focus a single milestone
9	
10	It imports YOUR modules from /app/submission (autograd.py / nn.py / optim.py / data.py / attack.py
11	/ advtrain.py), exactly as the grader does, and runs a PUBLIC portion of the component conformance
12	suite, printing a clear per-check report. Each FAIL line names the exact op / layer / optimizer /
13	attack / adversarial-training property that is wrong.
14	
15	HOW THIS RELATES TO YOUR GRADE
16	------------------------------
17	This runner is a DEBUGGING AID, not the grader. It checks YOUR framework against self-consistent
18	references it computes on its OWN:
19	  * autograd_grads : central FINITE-DIFFERENCE of YOUR forward vs YOUR analytic backward (every op,
20	                     incl. the convolution input-gradient, the pools, an
…[truncated 44212 chars]

/app/run_checks.py

contents
869	    def dlr_loss_grad():
870	        rng = np.random.default_rng(sb + 60)
871	        x0 = rng.standard_normal((5, 4)); y = rng.integers(0, 4, size=5)
872	        lt = ag.Tensor(x0.copy(), requires_grad=True)
873	        atk.dlr_loss(lt, y).backward()
874	        gnum = _num_grad_input(lambda xv: np.array(float(atk.dlr_loss(ag.Tensor(xv), y).data)), x0.copy())
875	        return _max_abs(lt.grad, gnum) < TOL_GRAD, f"max_abs={_max_abs(lt.grad, gnum):.2e}"
876	
877	    def dlr_input_grad_fd():
878	        m = _model(61)
879	        x0 = np.random.default_rng(sb + 62).standard_normal((3, 1, 8, 8)); y = np.array([0, 1, 2])
880	        lf = lambda lg, t: atk.dlr_loss(lg, t)
881	        gan = np.asarray(atk.loss_input_grad(m, x0, y, lf), np.float64)
882	        gnum = _num_grad_input(lambda xv: np.array(float(lf(m(ag.Tensor(xv)), y).data)), x0.copy())
883	        return _max_abs(gan, gnum) < TOL_GRAD, f"max_abs={_max_abs(gan, gnum):.2e}"
884	
885	    def bim_stronger():
886	        m = _model(67)
887	        x = np.clip(np.random.default_rng(sb + 68).random((8, 1, 8, 8)), 0, 1); y = np.array([0, 1, 2, 3, 0, 1, 2, 3]); eps = 0.12
888	        xf = atk.fgsm(m, x, y, eps); xb = atk.bim(m, x, y, eps, 15, 0.025)
889	        lf = float(ag.cross_entropy(m(xf), y).data); lb = float(ag.cross_entropy(m(xb), y).data)
890	        return lb >= lf - 1e-6, f"fgsm={lf:.3f} bim={lb:.3f}"
891	
892	    def restarts_worst_case():
893	        m = _model(69)
894	        x = np.clip(np.random.default_
…[truncated 15653 chars]
Now I have a full understanding. Let me create a task list and start implementing. I'll begin with `autograd.py`.
write · /app/submission/autograd.py
"""Reverse-mode automatic differentiation over numpy arrays."""
from __future__ import annotations

import math
from typing import Callable, Iterable, List, Optional

import numpy as np

_erf = np.vectorize(math.erf)


def _as_f64(x) -> np.ndarray:
    return np.asarray(x, dtype=np.float64)


def _unbroadcast(grad: np.ndarray, shape: tuple) -> np.ndarray:
    grad = np.asarray(grad, dtype=np.float64)
    while grad.ndim > len(shape):
        grad = grad.sum(axis=0)
    for i, s in enumerate(shape):
        if s == 1 and grad.shape[i] != 1:
            grad = grad.sum(axis=i, keepdims=True)
    return grad


class Tensor:
    __slots__ = ("data", "grad", "requires_grad", "_backward", "_parents")

    def __init__(self, data, requires_grad: bool = False, _parents: Iterable["Tensor"] = ()):
        self.data: np.ndarray = _as_f64(data)
        self.grad: Optional[np.ndarray] = None
        self.requires_grad: bool = bool(requires_grad)
        self._backward: Callable[[], None] = lambda: None
        self._parents: tuple = tuple(_parents)

    @property
    def shape(self):
        return self.data.shape

    @property
    def ndim(self):
        return self.data.ndim

    def zero_grad(self):
        self.grad = None

    def _accum(self, g: np.ndarray):
        if self.grad is None:
            self.grad = np.zeros_like(self.data)
        self.grad += g

    def backward(self, grad: Optional[np.ndarray] = None):
        if grad is None:
            grad = np.ones_like(self.dat
…[truncated 12023 chars]

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now append the rest of `autograd.py`:
shell
cat >> /app/submission/autograd.py <<'PYEOF'


# ===================================================================== nonlinearities
def relu(a) -> Tensor:
    a = _ensure(a)
    out = Tensor(np.maximum(a.data, 0.0), requires_grad=_rg(a), _parents=(a,))

    def backward():
        if a.requires_grad:
            a._accum(out.grad * (a.data > 0))
    out._backward = backward
    return out


def leaky_relu(a, slope: float = 0.01) -> Tensor:
    a = _ensure(a)
    out = Tensor(np.where(a.data > 0, a.data, slope * a.data), requires_grad=_rg(a), _parents=(a,))

    def backward():
        if a.requires_grad:
            a._accum(out.grad * np.where(a.data > 0, 1.0, slope))
    out._backward = backward
    return out


def sigmoid(a) -> Tensor:
    a = _ensure(a)
    s = 1.0 / (1.0 + np.exp(-a.data))
    out = Tensor(s, requires_grad=_rg(a), _parents=(a,))

    def backward():
        if a.requires_grad:
            a._accum(out.grad * s * (1.0 - s))
    out._backward = backward
    return out


def tanh(a) -> Tensor:
    a = _ensure(a)
    t = np.tanh(a.data)
    out = Tensor(t, requires_grad=_rg(a), _parents=(a,))

    def backward():
        if a.requires_grad:
            a._accum(out.grad * (1.0 - t * t))
    out._backward = backward
    return out


def gelu(a) -> Tensor:
    a = _ensure(a)
    x = a.data
    cdf = 0.5 * (1.0 + _erf(x / np.sqrt(2.0)))
    pdf = np.exp(-0.5 * x * x) / np.sqrt(2.0 * np.pi)
    out = Tensor(x * cdf, requires_grad=_rg(a), _parents=(a,))

    d
…[truncated 17629 chars]
output
appended; lines:
1090 /app/submission/autograd.py
Let me run the autograd checks:
shell
python3 run_checks.py --only autograd_grads 2>&1 | tail -40
output
grad/prod_axis                           OK    (max_abs=5.65e-10)
  grad/cumsum_ax1                          OK    (max_abs=3.79e-11)
  grad/logsumexp_ax1                       OK    (max_abs=4.93e-11)
  grad/pad2d                               OK    (max_abs=5.10e-11)
  grad/groupnorm_x                         OK  
  grad/rmsnorm_x                           OK  
  grad/layernorm_x                         OK  
  grad/batchnorm_x                         OK  
  grad/embedding                           OK  
  grad/mse_loss                            OK  
  grad/cross_entropy                       OK  
  grad/kl_div_q                            OK  
  grad/kl_div_p                            OK  
  grad/conv2d_input                        OK    (max_abs=1.33e-09)
  grad/conv2d_weight                       OK    (max_abs=3.61e-09)
  grad/conv2d_bias                         OK  
  grad/conv2d_pad0_input                   OK    (max_abs=8.78e-10)
  grad/maxpool2d                           OK  
  grad/avgpool2d                           OK  
  grad/nn.Conv2d_x                         FAIL  (raised NotImplementedError: implement Conv2d.forward)
  grad/nn.Linear_x                         FAIL  (raised NotImplementedError: implement Linear.forward)
  grad/nn.LayerNorm_x                      FAIL  (raised NotImplementedError: implement LayerNorm.forward)
  grad/nn.BatchNorm1d_x                    FAIL  (raised NotImplementedError: implement BatchNorm1d.forward)
  grad/cnn_grad_fc2.bias
…[truncated 1493 chars]
All autograd ops pass. Now let me implement `nn.py` forwards.

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.conv2d(x, weight, bias, pad)."""
        raise NotImplementedError("implement Conv2d.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.conv2d(x, weight, bias, pad)."""
        return ag.conv2d(x, self.weight, self.bias, self.pad)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.maxpool2d(x, k)."""
        raise NotImplementedError("implement MaxPool2d.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.maxpool2d(x, k)."""
        return ag.maxpool2d(x, self.k)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.avgpool2d(x, k)."""
        raise NotImplementedError("implement AvgPool2d.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.avgpool2d(x, k)."""
        return ag.avgpool2d(x, self.k)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.matmul(x, weight) + bias."""
        raise NotImplementedError("implement Linear.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.matmul(x, weight) + bias."""
        return ag.add(ag.matmul(x, self.weight), self.bias)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.layernorm(x, weight, bias, eps)."""
        raise NotImplementedError("implement LayerNorm.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.layernorm(x, weight, bias, eps)."""
        return ag.layernorm(x, self.weight, self.bias, self.eps)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.batchnorm(x, weight, bias, eps)."""
        raise NotImplementedError("implement BatchNorm1d.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.batchnorm(x, weight, bias, eps)."""
        return ag.batchnorm(x, self.weight, self.bias, self.eps)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x):
        """linear -> relu (between layers) -> ... -> linear (no final activation)."""
        raise NotImplementedError("implement MLP.forward")
+ added
    def forward(self, x):
        """linear -> relu (between layers) -> ... -> linear (no final activation)."""
        for i, lin in enumerate(self.layers):
            x = lin(x)
            if i < len(self.layers) - 1:
                x = ag.relu(x)
        return x

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x):
        """for each conv: pool(relu(conv(x))); then flatten -> relu(fc1) -> fc2."""
        raise NotImplementedError("implement ConvNet.forward")
+ added
    def forward(self, x):
        """for each conv: pool(relu(conv(x))); then flatten -> relu(fc1) -> fc2."""
        if not isinstance(x, Tensor):
            x = Tensor(x)
        for conv in self.convs:
            x = self.pool(ag.relu(conv(x)))
        n = x.shape[0]
        x = x.reshape((n, -1))
        x = ag.relu(self.fc1(x))
        return self.fc2(x)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.groupnorm(x, weight, bias, num_groups, eps)."""
        raise NotImplementedError("implement GroupNorm.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.groupnorm(x, weight, bias, num_groups, eps)."""
        return ag.groupnorm(x, self.weight, self.bias, self.num_groups, self.eps)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor) -> Tensor:
        """ag.rmsnorm(x, weight, eps)."""
        raise NotImplementedError("implement RMSNorm.forward")
+ added
    def forward(self, x: Tensor) -> Tensor:
        """ag.rmsnorm(x, weight, eps)."""
        return ag.rmsnorm(x, self.weight, self.eps)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the recurrent cells and the CNN forwards:

/app/submission/nn.py

− removed
    def forward(self, x: Tensor, h: Tensor) -> Tensor:
        """h' = tanh(x @ weight_ih^T + bias_ih + h @ weight_hh^T + bias_hh)."""
        raise NotImplementedError("implement RNNCell.forward")
+ added
    def forward(self, x: Tensor, h: Tensor) -> Tensor:
        """h' = tanh(x @ weight_ih^T + bias_ih + h @ weight_hh^T + bias_hh)."""
        a = ag.add(ag.matmul(x, ag.transpose(self.weight_ih)), self.bias_ih)
        b = ag.add(ag.matmul(h, ag.transpose(self.weight_hh)), self.bias_hh)
        return ag.tanh(ag.add(a, b))

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor, h: Tensor) -> Tensor:
        """the GRU update above (slice the 3 gates out of the (N,3H) pre-activations)."""
        raise NotImplementedError("implement GRUCell.forward")
+ added
    def forward(self, x: Tensor, h: Tensor) -> Tensor:
        """the GRU update above (slice the 3 gates out of the (N,3H) pre-activations)."""
        H = self.hidden_size
        gi = ag.add(ag.matmul(x, ag.transpose(self.weight_ih)), self.bias_ih)
        gh = ag.add(ag.matmul(h, ag.transpose(self.weight_hh)), self.bias_hh)
        i_r = gi[:, 0:H]; i_z = gi[:, H:2 * H]; i_n = gi[:, 2 * H:3 * H]
        h_r = gh[:, 0:H]; h_z = gh[:, H:2 * H]; h_n = gh[:, 2 * H:3 * H]
        r = ag.sigmoid(ag.add(i_r, h_r))
        z = ag.sigmoid(ag.add(i_z, h_z))
        n = ag.tanh(ag.add(i_n, ag.mul(r, h_n)))
        one_minus_z = ag.sub(1.0, z)
        return ag.add(ag.mul(one_minus_z, n), ag.mul(z, h))

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x: Tensor, h: Tensor, c: Tensor):
        """the LSTM update above; return (h', c')."""
        raise NotImplementedError("implement LSTMCell.forward")
+ added
    def forward(self, x: Tensor, h: Tensor, c: Tensor):
        """the LSTM update above; return (h', c')."""
        H = self.hidden_size
        g = ag.add(ag.add(ag.matmul(x, ag.transpose(self.weight_ih)), self.bias_ih),
                   ag.add(ag.matmul(h, ag.transpose(self.weight_hh)), self.bias_hh))
        i = ag.sigmoid(g[:, 0:H])
        f = ag.sigmoid(g[:, H:2 * H])
        gg = ag.tanh(g[:, 2 * H:3 * H])
        o = ag.sigmoid(g[:, 3 * H:4 * H])
        c2 = ag.add(ag.mul(f, c), ag.mul(i, gg))
        h2 = ag.mul(o, ag.tanh(c2))
        return h2, c2

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x):
        """h = pool(relu(conv1(x))); res = conv2b(relu(conv2a(h))); h = relu(h + res); flatten -> fc."""
        raise NotImplementedError("implement SmallResCNN.forward")
+ added
    def forward(self, x):
        """h = pool(relu(conv1(x))); res = conv2b(relu(conv2a(h))); h = relu(h + res); flatten -> fc."""
        if not isinstance(x, Tensor):
            x = Tensor(x)
        h = self.pool(ag.relu(self.conv1(x)))
        res = self.conv2b(ag.relu(self.conv2a(h)))
        h = ag.relu(ag.add(h, res))
        n = h.shape[0]
        h = h.reshape((n, -1))
        return self.fc(h)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/nn.py

− removed
    def forward(self, x) -> Tensor:
        """conv1 -> relu -> pool -> conv2 -> relu -> pool -> flatten -> fc1 -> relu -> fc2."""
        raise NotImplementedError("implement SmallCNN.forward")
+ added
    def forward(self, x) -> Tensor:
        """conv1 -> relu -> pool -> conv2 -> relu -> pool -> flatten -> fc1 -> relu -> fc2."""
        if not isinstance(x, Tensor):
            x = Tensor(x)
        x = self.pool(ag.relu(self.conv1(x)))
        x = self.pool(ag.relu(self.conv2(x)))
        n = x.shape[0]
        x = x.reshape((n, -1))
        x = ag.relu(self.fc1(x))
        return self.fc2(x)

contents
The file /app/submission/nn.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only autograd_grads 2>&1 | tail -6 && python3 run_checks.py --only nn_forward 2>&1 | tail -6
output
grad/rescnn_input                        OK    (max_abs=2.21e-11)

------------------------------------------------------------------------
autograd_grads 80/82
TOTAL  80/82 public checks passing
Fix the FAIL lines above, then re-run. Each names a backward/forward/optimizer/attack/adversarial-training bug.
  fwd/SmallCNN_state_dict_roundtrip        OK    (state_dict round-trips)

------------------------------------------------------------------------
nn_forward 22/22
TOTAL  22/22 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy threshold; the grader re-checks with DIFFERENT seeds/shapes + its OWN strong PGD.
shell
python3 run_checks.py --only autograd_grads 2>&1 | grep FAIL
output
grad/mean_all                            FAIL  (raised AxisError: axis 1 is out of bounds for array of dimension 0)
  grad/mean_axis                           FAIL  (raised AxisError: axis 4 is out of bounds for array of dimension 0)
Fix the FAIL lines above, then re-run. Each names a backward/forward/optimizer/attack/adversarial-training bug.
shell
cd /app/submission && python3 -c "
import numpy as np, autograd as ag
t=ag.Tensor(np.random.randn(4,5),requires_grad=True)
ag.sum(ag.mean(t)).backward()
print('mean_all ok', t.grad.shape)
t2=ag.Tensor(np.random.randn(4,5),requires_grad=True)
ag.sum(ag.mean(t2,axis=1)).backward()
print('mean_axis ok', t2.grad.shape)
"
output
Exit code 1
Traceback (most recent call last):
  File "<string>", line 4, in <module>
  File "/app/submission/autograd.py", line 352, in mean
    n = a.data.size / max(1, od.size)
                      ^^^^^^^^^^^^^^^
  File "/app/submission/autograd.py", line 363, in max
    md = a.data.max(axis=axis, keepdims=True)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/numpy/_core/_methods.py", line 44, in _amax
    return umr_maximum(a, axis, None, out, keepdims, initial, where)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
numpy.exceptions.AxisError: axis 1 is out of bounds for array of dimension 0
The module-level `max` shadows builtin. Let me fix `mean`:

/app/submission/autograd.py

− removed
    out = Tensor(od, requires_grad=_rg(a), _parents=(a,))
    n = a.data.size / max(1, od.size)
+ added
    out = Tensor(od, requires_grad=_rg(a), _parents=(a,))
    n = a.data.size / (od.size if od.size else 1)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only autograd_grads 2>&1 | tail -4
output
------------------------------------------------------------------------
autograd_grads 82/82
TOTAL  82/82 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy threshold; the grader re-checks with DIFFERENT seeds/shapes + its OWN strong PGD.
Now `optim.py`. Let me implement all optimizers, clippers, and schedulers.

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement SGD.step")
+ added
    def step(self):
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            v = self.momentum * self._v[i] + g
            self._v[i] = v
            step = (g + self.momentum * v) if self.nesterov else v
            p.data -= self.lr * step

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement Adagrad.step")
+ added
    def step(self):
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._s[i] += g * g
            p.data -= self.lr * g / (np.sqrt(self._s[i]) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement RMSprop.step")
+ added
    def step(self):
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._s[i] = self.alpha * self._s[i] + (1 - self.alpha) * (g * g)
            p.data -= self.lr * g / (np.sqrt(self._s[i]) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement Adam.step")
+ added
    def step(self):
        self.t += 1
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._m[i] = self.b1 * self._m[i] + (1 - self.b1) * g
            self._v[i] = self.b2 * self._v[i] + (1 - self.b2) * (g * g)
            mhat = self._m[i] / (1 - self.b1 ** self.t)
            vhat = self._v[i] / (1 - self.b2 ** self.t)
            p.data -= self.lr * mhat / (np.sqrt(vhat) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement AdamW.step")
+ added
    def step(self):
        self.t += 1
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad
            self._m[i] = self.b1 * self._m[i] + (1 - self.b1) * g
            self._v[i] = self.b2 * self._v[i] + (1 - self.b2) * (g * g)
            mhat = self._m[i] / (1 - self.b1 ** self.t)
            vhat = self._v[i] / (1 - self.b2 ** self.t)
            wd_eff = 0.0 if p.ndim <= self.no_decay_ndim else self.weight_decay
            p.data -= self.lr * (mhat / (np.sqrt(vhat) + self.eps) + wd_eff * p.data)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement Adamax.step")
+ added
    def step(self):
        self.t += 1
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._m[i] = self.b1 * self._m[i] + (1 - self.b1) * g
            self._u[i] = np.maximum(self.b2 * self._u[i], np.abs(g))
            p.data -= (self.lr / (1 - self.b1 ** self.t)) * self._m[i] / (self._u[i] + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement NAdam.step")
+ added
    def step(self):
        self.t += 1
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._m[i] = self.b1 * self._m[i] + (1 - self.b1) * g
            self._v[i] = self.b2 * self._v[i] + (1 - self.b2) * (g * g)
            mhat = self._m[i] / (1 - self.b1 ** self.t)
            vhat = self._v[i] / (1 - self.b2 ** self.t)
            mnes = self.b1 * mhat + (1 - self.b1) * g / (1 - self.b1 ** self.t)
            p.data -= self.lr * mnes / (np.sqrt(vhat) + self.eps)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement Lion.step")
+ added
    def step(self):
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad
            c = np.sign(self.b1 * self._m[i] + (1 - self.b1) * g)
            p.data -= self.lr * (c + self.weight_decay * p.data)
            self._m[i] = self.b2 * self._m[i] + (1 - self.b2) * g

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    def step(self):
        raise NotImplementedError("implement Adadelta.step")
+ added
    def step(self):
        for i, p in enumerate(self.params):
            if p.grad is None:
                continue
            g = p.grad + self.weight_decay * p.data
            self._s[i] = self.rho * self._s[i] + (1 - self.rho) * (g * g)
            delta = np.sqrt(self._d[i] + self.eps) / np.sqrt(self._s[i] + self.eps) * g
            p.data -= self.lr * delta
            self._d[i] = self.rho * self._d[i] + (1 - self.rho) * (delta * delta)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now the clippers and schedulers:

/app/submission/optim.py

− removed
    the L2 gradient-norm clipping. Return the pre-clip total norm. If total > max_norm, scale
    every grad by max_norm/(total+1e-6)."""
    raise NotImplementedError("implement clip_grad_norm")
+ added
    the L2 gradient-norm clipping. Return the pre-clip total norm. If total > max_norm, scale
    every grad by max_norm/(total+1e-6)."""
    total = 0.0
    for p in params:
        if p.grad is not None:
            total += float((p.grad ** 2).sum())
    total = math.sqrt(total)
    if total > max_norm:
        scale = max_norm / (total + 1e-6)
        for p in params:
            if p.grad is not None:
                p.grad = p.grad * scale
    return total

contents
<tool_use_error>String to replace not found in file.
String:     the L2 gradient-norm clipping. Return the pre-clip total norm. If total > max_norm, scale
    every grad by max_norm/(total+1e-6)."""
    raise NotImplementedError("implement clip_grad_norm")</tool_use_error>

/app/submission/optim.py

− removed
    raise NotImplementedError("implement clip_grad_norm")
+ added
    total = 0.0
    for p in params:
        if p.grad is not None:
            total += float((p.grad ** 2).sum())
    total = math.sqrt(total)
    if total > max_norm:
        scale = max_norm / (total + 1e-6)
        for p in params:
            if p.grad is not None:
                p.grad = p.grad * scale
    return total

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement clip_grad_value")
+ added
    for p in params:
        if p.grad is not None:
            p.grad = np.clip(p.grad, -clip_value, clip_value)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement cosine_lr")
+ added
    if warmup > 0 and step < warmup:
        return base_lr * (step + 1) / warmup
    prog = min(1.0, max(0.0, (step - warmup) / max(1, total - warmup)))
    return min_lr + 0.5 * (base_lr - min_lr) * (1 + math.cos(math.pi * prog))

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement warmup_lr")
+ added
    return base_lr * (step + 1) / warmup if step < warmup else base_lr

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement step_lr")
+ added
    return base_lr * (gamma ** (step // step_size))

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement exponential_lr")
+ added
    return base_lr * (gamma ** step)

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement polynomial_lr")
+ added
    prog = min(1.0, max(0.0, step / total))
    return (base_lr - min_lr) * ((1.0 - prog) ** power) + min_lr

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/optim.py

− removed
    raise NotImplementedError("implement linear_lr")
+ added
    prog = min(1.0, max(0.0, step / total))
    return base_lr + (min_lr - base_lr) * prog

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only optim 2>&1 | tail -5 && python3 run_checks.py --only data 2>&1 | grep -E "FAIL|TOTAL"
output
------------------------------------------------------------------------
optim 20/20
TOTAL  20/20 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy threshold; the grader re-checks with DIFFERENT seeds/shapes + its OWN strong PGD.
  data/get_batch_shape                     FAIL  (raised NotImplementedError: implement get_batch)
  data/train_val_split                     FAIL  (raised NotImplementedError: implement train_val_split)
  data/to_onehot                           FAIL  (raised NotImplementedError: implement to_onehot)
TOTAL  0/3 public checks passing
Fix the FAIL lines above, then re-run. Each names a backward/forward/optimizer/attack/adversarial-training bug.
Optim all pass. Now `data.py`:

/app/submission/data.py

− removed
def load_npz(path: str) -> Tuple[np.ndarray, np.ndarray]:
    raise NotImplementedError("implement load_npz")


def train_val_split(X: np.ndarray, y: np.ndarray, val_frac: float,
                    rng: np.random.Generator):
    raise NotImplementedError("implement train_val_split")


def iter_batches(X: np.ndarray, y: np.ndarray, batch_size: int,
                 rng: np.random.Generator) -> Iterator[Tuple[np.ndarray, np.ndarray]]:
    raise NotImplementedError("implement iter_batches")


def get_batch(X: np.ndarray, y: np.ndarray, batch_size: int,
              rng: np.random.Generator) -> Tuple[np.ndarray, np.ndarray]:
    """A single random minibatch (without replacement if possible). Shape-preserving."""
    raise NotImplementedError("implement get_batch")


def to_onehot(y: np.ndarray, n_classes: int) -> np.ndarray:
    """(N, n_classes) one-hot float matrix from integer labels y."""
    raise NotImplementedError("implement to_onehot")


def clip01(X: np.ndarray) -> np.ndarray:
    """Clamp X into the [0,1] pixel domain (the valid attack range)."""
    raise NotImplementedError("implement clip01")
+ added
def load_npz(path: str) -> Tuple[np.ndarray, np.ndarray]:
    d = np.load(path)
    X = np.asarray(d["X"], dtype=np.float64)
    y = np.asarray(d["y"], dtype=np.int64)
    return X, y


def train_val_split(X: np.ndarray, y: np.ndarray, val_frac: float,
                    rng: np.random.Generator):
    n = len(X)
    perm = rng.permutation(n)
    n_val = int(round(n * val_frac))
    val_idx = perm[:n_val]
    tr_idx = perm[n_val:]
    return (X[tr_idx], y[tr_idx]), (X[val_idx], y[val_idx])


def iter_batches(X: np.ndarray, y: np.ndarray, batch_size: int,
                 rng: np.random.Generator) -> Iterator[Tuple[np.ndarray, np.ndarray]]:
    n = len(X)
    perm = rng.permutation(n)
    for s in range(0, n, batch_size):
        idx = perm[s:s + batch_size]
        yield X[idx], y[idx]


def get_batch(X: np.ndarray, y: np.ndarray, batch_size: int,
              rng: np.random.Generator) -> Tuple[np.ndarray, np.ndarray]:
    """A single random minibatch (without replacement if possible). Shape-preserving."""
    n = len(X)
    if batch_size <= n:
        idx = rng.choice(n, size=batch_size, replace=False)
    else:
        idx = rng.choice(n, size=batch_size, replace=True)
    return X[idx], y[idx]


def to_onehot(y: np.ndarray, n_classes: int) -> np.ndarray:
    """(N, n_classes) one-hot float matrix from integer labels y."""
    y = np.asarray(y).astype(int)
    oh = np.zeros((len(y), n_classes), dtype=np.float64)
    oh[np.arange(len(y)), y] = 1.0
    return oh


def clip01
…[truncated 134 chars]

contents
The file /app/submission/data.py has been updated successfully. (file state is current in your context , no need to Read it back)
Now `attack.py`. I'll rewrite the whole file:
write · /app/submission/attack.py
"""White-box evasion attacks built on the from-scratch autograd engine."""
from __future__ import annotations

from typing import Callable, Optional, Tuple

import numpy as np

import autograd as ag
from autograd import Tensor


def loss_input_grad(model, x: np.ndarray, y: np.ndarray,
                    loss_fn: Callable[[Tensor, np.ndarray], Tensor]) -> np.ndarray:
    xt = Tensor(np.asarray(x, dtype=np.float64), requires_grad=True)
    logits = model(xt)
    loss = loss_fn(logits, y)
    loss.backward()
    return np.asarray(xt.grad, dtype=np.float64)


def input_grad(model, x: np.ndarray, y: np.ndarray) -> np.ndarray:
    return loss_input_grad(model, x, y, lambda lg, t: ag.cross_entropy(lg, t))


def cw_margin_loss(logits, y, kappa: float = 0.0) -> Tensor:
    logits = logits if isinstance(logits, Tensor) else Tensor(logits)
    N, C = logits.shape
    y = np.asarray(y).astype(int)
    onehot = np.zeros((N, C), dtype=np.float64)
    onehot[np.arange(N), y] = 1.0
    z_y = ag.sum(ag.mul(logits, Tensor(onehot)), axis=1)
    masked = ag.add(logits, Tensor(onehot * -1e30))
    max_other = ag.max(masked, axis=1)
    margin = ag.sub(z_y, max_other)
    neg = ag.mul(margin, -1.0)
    return ag.mean(ag.maximum(neg, -float(kappa)))


def dlr_loss(logits, y, eps: float = 1e-12) -> Tensor:
    logits = logits if isinstance(logits, Tensor) else Tensor(logits)
    N, C = logits.shape
    y = np.asarray(y).astype(int)
    onehot = np.zeros((N, C), dtype=np.float64)
    onehot[np.arang
…[truncated 7808 chars]

contents
The file /app/submission/attack.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only attack 2>&1 | tail -25
output
[attack]  18/18
  attack/input_grad_fd                     OK    (max_abs=2.13e-11)
  attack/cw_loss_input_grad_fd             OK    (max_abs=2.41e-12)
  attack/dlr_loss_grad                     OK    (max_abs=1.04e-09)
  attack/dlr_loss_input_grad_fd            OK    (max_abs=2.81e-11)
  attack/fgsm_step                         OK  
  attack/pgd_projection                    OK  
  attack/mi_fgsm_projection                OK  
  attack/cw_pgd_projection                 OK  
  attack/pgd_l2_projection                 OK  
  attack/bim_projection                    OK  
  attack/rfgsm_projection                  OK  
  attack/ni_fgsm_projection                OK  
  attack/pgd_restarts_projection           OK  
  attack/dlr_pgd_projection                OK  
  attack/pgd_stronger_than_fgsm            OK    (fgsm=1.450 pgd=1.469)
  attack/bim_stronger_than_fgsm            OK    (fgsm=1.411 bim=1.423)
  attack/pgd_restarts_worst_case           OK    (single=1.521 restarts=1.525)
  attack/targeted_pgd_lowers_target_ce     OK    (1.388->1.333)

------------------------------------------------------------------------
attack 18/18
TOTAL  18/18 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy threshold; the grader re-checks with DIFFERENT seeds/shapes + its OWN strong PGD.
All attack checks pass. Now `advtrain.py`:

/app/submission/advtrain.py

− removed
def pgd_at_loss(model, x_adv: np.ndarray, y: np.ndarray) -> Tensor:
    """Madry PGD-AT loss: cross-entropy on the adversarial batch (trains parameters)."""
    raise NotImplementedError("implement pgd_at_loss")


def trades_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.ndarray,
                beta: float = 6.0) -> Tuple[Tensor, Dict[str, float]]:
    """TRADES loss = CE(clean, y) + beta * KL(stopgrad(softmax(clean)) || softmax(adv))."""
    raise NotImplementedError("implement trades_loss")


def mart_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.ndarray,
              beta: float = 5.0) -> Tuple[Tensor, Dict[str, float]]:
    """MART loss (boosted CE on adv + misclassification-aware weighted KL with the clean target
    DETACHED); see the module docstring for the exact form."""
    raise NotImplementedError("implement mart_loss")


def alp_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.ndarray,
             lam: float = 0.5) -> Tuple[Tensor, Dict[str, float]]:
    """Adversarial Logit Pairing: 0.5*(CE(clean)+CE(adv)) + lam*mean||z_clean - z_adv||^2 (no detach)."""
    raise NotImplementedError("implement alp_loss")


def label_smoothed_ce(logits, y, eps_ls: float = 0.1, n_classes: int = None) -> Tensor:
    """CE against a label-smoothed target ((1-eps_ls)*onehot + eps_ls/C*uniform), via log_softmax."""
    raise NotImplementedError("implement label_smoothed_ce")


def robust_ce_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.nd
…[truncated 1782 chars]
+ added
def _detach(t: Tensor) -> Tensor:
    return Tensor(t.data.copy())


def _softmax_np(x):
    z = x - x.max(axis=-1, keepdims=True)
    e = np.exp(z)
    return e / e.sum(axis=-1, keepdims=True)


def pgd_at_loss(model, x_adv: np.ndarray, y: np.ndarray) -> Tensor:
    """Madry PGD-AT loss: cross-entropy on the adversarial batch (trains parameters)."""
    return ag.cross_entropy(model(x_adv), y)


def trades_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.ndarray,
                beta: float = 6.0) -> Tuple[Tensor, Dict[str, float]]:
    """TRADES loss = CE(clean, y) + beta * KL(stopgrad(softmax(clean)) || softmax(adv))."""
    cl = model(x_clean)
    ad = model(x_adv)
    ce = ag.cross_entropy(cl, y)
    tgt = _detach(cl)
    kl = ag.kl_div(tgt, ad)
    loss = ag.add(ce, ag.mul(kl, float(beta)))
    return loss, {"ce": float(ce.data), "kl": float(kl.data)}


def mart_loss(model, x_clean: np.ndarray, x_adv: np.ndarray, y: np.ndarray,
              beta: float = 5.0) -> Tuple[Tensor, Dict[str, float]]:
    """MART loss (boosted CE on adv + misclassification-aware weighted KL with clean detached)."""
    cl = model(x_clean)
    ad = model(x_adv)
    N, C = ad.shape
    y = np.asarray(y).astype(int)
    onehot = np.zeros((N, C), dtype=np.float64)
    onehot[np.arange(N), y] = 1.0
    p_adv = ag.softmax(ad)
    ce = ag.cross_entropy(ad, y)
    mop = ag.max(ag.add(p_adv, Tensor(onehot * -1e30)), axis=1)
    boost = ag.mul(ag.mean(ag.log(ag.sub(1.0, mop))), -1.0)
    boost
…[truncated 3842 chars]

contents
The file /app/submission/advtrain.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 run_checks.py --only advtrain 2>&1 | tail -20 && python3 run_checks.py --only integration 2>&1 | tail -6
output
[advtrain]  14/14
  advtrain/at_param_grad                   OK    (max_abs=2.56e-11)
  advtrain/trades_param_grad               OK    (max_abs=5.66e-04)
  advtrain/mart_param_grad                 OK    (max_abs=1.14e-04)
  advtrain/alp_param_grad                  OK    (max_abs=2.60e-11)
  advtrain/robust_ce_param_grad            OK    (max_abs=5.12e-11)
  advtrain/clp_param_grad                  OK    (max_abs=2.84e-05)
  advtrain/kl_at_param_grad                OK    (max_abs=1.62e-03)
  advtrain/logit_squeeze_param_grad        OK    (max_abs=4.80e-11)
  advtrain/ls_at_param_grad                OK    (max_abs=2.76e-11)
  advtrain/label_smoothed_ce_grad          OK  
  advtrain/trades_stopgrad                 OK    (max_abs=0.00e+00)
  advtrain/alp_pairing                     OK    (max_abs=0.00e+00)
  advtrain/clp_stopgrad                    OK    (max_abs=0.00e+00)
  advtrain/kl_at_stopgrad                  OK    (max_abs=0.00e+00)

------------------------------------------------------------------------
advtrain 14/14
TOTAL  14/14 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy threshold; the grader re-checks with DIFFERENT seeds/shapes + its OWN strong PGD.
  integration/trades_decreases             OK    (1.3933->1.3367)

------------------------------------------------------------------------
integration 4/4
TOTAL  4/4 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROB
…[truncated 94 chars]
All component checks pass. Let me run the full suite to confirm:
shell
python3 run_checks.py 2>&1 | tail -4
output
------------------------------------------------------------------------
autograd_grads 82/82 | nn_forward 22/22 | optim 20/20 | attack 18/18 | advtrain 14/14 | integration 4/4 | data 3/3
TOTAL  163/163 public checks passing
All public checks pass. Now make sure model.npz clears the held-out ROBUST-accuracy threshold; the grader re-checks with DIFFERENT seeds/shapes + its OWN strong PGD.
All 163 public checks pass. Now let me implement the training loop in `train.py`:

/app/submission/train.py

− removed
def train(train_path, out_path, epochs=12, batch_size=128, lr=1.2e-3, eps=0.12,
          at_steps=7, alpha=0.03, grad_clip=1.0, weight_decay=5e-4, val_frac=0.15,
          sel_steps=7, seed=0, log_every=1):
    """Run multi-step PGD adversarial training and save the best-by-robust-val checkpoint to
    ``out_path``. See the module docstring for the recipe."""
    raise NotImplementedError("implement the adversarial-training loop")
+ added
def _accuracy(model, X, y, bs=256):
    correct = 0
    for s in range(0, len(X), bs):
        logits = model(X[s:s + bs]).data
        correct += int((logits.argmax(1) == y[s:s + bs]).sum())
    return correct / len(X)


def _robust_accuracy(model, X, y, eps, steps, alpha, restarts, seed, bs=256):
    """Worst-case robust accuracy: correct clean AND surviving every restart."""
    rng = np.random.default_rng(seed)
    robust = 0
    for s in range(0, len(X), bs):
        xb = X[s:s + bs]
        yb = y[s:s + bs]
        clean_ok = model(xb).data.argmax(1) == yb
        surv = clean_ok.copy()
        for _ in range(restarts):
            xa = A.pgd_attack(model, xb, yb, eps, steps, alpha, rng=rng)
            pred = model(xa).data.argmax(1)
            surv = surv & (pred == yb)
        robust += int(surv.sum())
    return robust / len(X)


def train(train_path, out_path, epochs=30, batch_size=128, lr=1.2e-3, eps=0.12,
          at_steps=10, alpha=0.03, grad_clip=1.0, weight_decay=5e-4, val_frac=0.12,
          sel_steps=10, seed=0, log_every=1):
    """Run multi-step PGD adversarial training and save the best-by-robust-val checkpoint."""
    rng = np.random.default_rng(seed)
    X, y = D.load_npz(train_path)
    n_classes = int(y.max()) + 1
    c_in, img = X.shape[1], X.shape[2]
    (Xtr, ytr), (Xval, yval) = D.train_val_split(X, y, val_frac, rng)
    print(f"data: X={X.shape} n_classes={n_classes} img={img} c_in={c_in} "
          f"train={len(Xtr)} val={len(Xval)}", flush=
…[truncated 2091 chars]

contents
The file /app/submission/train.py has been updated successfully. (file state is current in your context , no need to Read it back)
Let me do a quick sanity run (few epochs) to check timing and behavior:
shell
cd /app/submission && time python3 -c "
import train
train.train('/app/data/train.npz','/tmp/test_model.npz', epochs=3, at_steps=7, sel_steps=7)
" 2>&1 | tail -12
output
data: X=(3600, 1, 16, 16) n_classes=6 img=16 c_in=1 train=3168 val=432

real	0m0.592s
user	0m0.872s
sys	0m0.154s
shell
python3 -c "
import train
train.train('/app/data/train.npz','/tmp/test_model.npz', epochs=1, at_steps=7, sel_steps=7)
" 2>&1 | head -30
output
data: X=(3600, 1, 16, 16) n_classes=6 img=16 c_in=1 train=3168 val=432
shell
python3 -c "
import numpy as np, train, attack as A
from nn import SmallCNN
import data as D
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
xb,yb=X[:16],y[:16]
print('forward', m(xb).data.shape)
xa=A.pgd_attack(m,xb,yb,0.12,7,0.03,rng=np.random.default_rng(0))
print('pgd done', xa.shape)
" 2>&1 | head -30
output
forward (16, 6)
pgd done (16, 1, 16, 16)
shell
python3 -u -c "
import train
r=train.train('/app/data/train.npz','/tmp/test_model.npz', epochs=1, at_steps=7, sel_steps=7)
print('returned', r[1])
"; echo "EXIT=$?"
output
data: X=(3600, 1, 16, 16) n_classes=6 img=16 c_in=1 train=3168 val=432
/bin/bash: line 9:  1551 Killed                  python3 -u -c "
import train
r=train.train('/app/data/train.npz','/tmp/test_model.npz', epochs=1, at_steps=7, sel_steps=7)
print('returned', r[1])
"
EXIT=137
shell
free -m; echo "---"; ulimit -a 2>/dev/null | grep -iE "mem|virt" 
output
total        used        free      shared  buff/cache   available
Mem:             481         250         180           1          65         231
Swap:              0           0           0
---
max locked memory           (kbytes, -l) 8192
max memory size             (kbytes, -m) unlimited
virtual memory              (kbytes, -v) unlimited
Very tight memory (only ~230MB free). Let me test memory usage of a training batch and add GC:
shell
python3 -u -c "
import numpy as np, gc, resource
import attack as A, advtrain as AT, optim as O, data as D
from nn import SmallCNN
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
opt=O.AdamW(m.params(),lr=1e-3,no_decay_ndim=1)
for step in range(40):
    idx=np.random.default_rng(step).integers(0,len(X),64)
    xb,yb=X[idx],y[idx]
    xa=A.pgd_attack(m,xb,yb,0.12,7,0.03,rng=np.random.default_rng(step))
    loss=AT.pgd_at_loss(m,xa,yb)
    opt.zero_grad(); loss.backward(); O.clip_grad_norm(m.params(),1.0); opt.step()
    if step%10==0:
        mb=resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024
        print(step, 'maxrss MB', round(mb,1))
" 2>&1 | tail
output
0 maxrss MB 120.4
Memory leak from reference cycles (closure ↔ output tensor). Let me break the cycle after `backward`:

/app/submission/autograd.py

− removed
        build(self)
        for t in reversed(topo):
            t._backward()
+ added
        build(self)
        for t in reversed(topo):
            t._backward()
        # break closure<->tensor reference cycles so intermediate arrays free immediately
        for t in topo:
            t._backward = _noop
            t._parents = ()

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)

/app/submission/autograd.py

− removed
def _as_f64(x) -> np.ndarray:
    return np.asarray(x, dtype=np.float64)
+ added
def _noop():
    return None


def _as_f64(x) -> np.ndarray:
    return np.asarray(x, dtype=np.float64)

contents
The file /app/submission/autograd.py has been updated successfully. (file state is current in your context , no need to Read it back)
shell
python3 -u -c "
import numpy as np, resource
import attack as A, advtrain as AT, optim as O, data as D
from nn import SmallCNN
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
opt=O.AdamW(m.params(),lr=1e-3,no_decay_ndim=1)
for step in range(60):
    idx=np.random.default_rng(step).integers(0,len(X),64)
    xb,yb=X[idx],y[idx]
    xa=A.pgd_attack(m,xb,yb,0.12,7,0.03,rng=np.random.default_rng(step))
    loss=AT.pgd_at_loss(m,xa,yb)
    opt.zero_grad(); loss.backward(); O.clip_grad_norm(m.params(),1.0); opt.step()
    if step%20==0:
        print(step,'maxrss MB', round(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024,1))
print('done')
" 2>&1 | tail
output
0 maxrss MB 152.8
shell
python3 -u -c "
import numpy as np, resource, gc
import attack as A, data as D
from nn import SmallCNN
def rss(): return round(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024,1)
X,y=D.load_npz('/app/data/train.npz')
print('base', rss())
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
xb,yb=X[:64],y[:64]
print('after fwd', m(xb).data.shape, rss())
for k in range(10):
    g=A.input_grad(m,xb,yb)
    print('input_grad',k, rss())
" 2>&1 | tail -15
output
base 36.1
after fwd (64, 6) 51.5
input_grad 0 63.0
input_grad 1 73.9
input_grad 2 86.5
input_grad 3 99.4
input_grad 4 112.1
input_grad 5 124.7
input_grad 6 137.3
input_grad 7 150.2
input_grad 8 162.8
input_grad 9 175.5
shell
python3 -u -c "
import numpy as np, gc
import attack as A, data as D
from nn import SmallCNN
def rss():
    with open('/proc/self/statm') as f: return round(int(f.read().split()[1])*4096/1e6,1)
X,y=D.load_npz('/app/data/train.npz')
m=SmallCNN(n_classes=6,c_in=1,img=16,c1=14,c2=28,ff=96,seed=0)
xb,yb=X[:64],y[:64]
for k in range(12):
    g=A.input_grad(m,xb,yb)
    if k%3==0: print('cur RSS',k, rss(), 'gcobj', len(gc.get_objects()))
gc.collect(); print('after collect', rss(), len(gc.get_objects()))
" 2>&1 | tail
output
cur RSS 0 60.7 gcobj 19823
cur RSS 3 104.2 gcobj 19887
cur RSS 6 135.9 gcobj 19708
cur RSS 9 135.9 gcobj 19771
after collect 124.7 19544
Peak plateaus ~135MB for batch 64 , borderline with ~180MB free. Let me use smaller batches and cap malloc arenas. Let me test a real 2-epoch run with batch 32:
shell
MALLOC_ARENA_MAX=2 python3 -u -c "
import time,train
t=time.time()
train.train('/app/data/train.npz','/tmp/m.npz', epochs=2, batch_size=32, at_steps=10, sel_steps=10)
print('elapsed', round(time.time()-t,1))
" 2>&1 | tail -12
Final diff , what the agent changed

No file changes, the agent left the workspace untouched.

Verifier output , the proof behind the reward
tests/test.sh
=== SyncVals verifier (local re-grade of the agent's own checkpoint) ===

COMPONENT CONFORMANCE SUITE: 201/201 cases passed  (all milestones pass: True)
FINAL METRIC: PGD robust accuracy = 0.5737  < threshold 0.6

REWARD = 0   (1 iff every component milestone passes AND the sealed held-out metric clears its threshold)

NOTE: the in-sandbox training in the 481MB e2b box was OOM-killed (0-byte checkpoint), so the raw
in-sandbox reward was an infrastructure artifact. This reward is from a faithful LOCAL re-train of the
agent's OWN train.py (24GB, no OOM) with its own default hyperparameters, then re-graded by the real verifier.

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_c919a58c3ee24119. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_c919a58c3ee24119 · verifier authoritative; classifier explanatory.