SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

qat-int2-cifar

claude-code claude-sonnet-4-6 ✗ 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.
SubtypeIncomplete Implementation
EvidenceComponent conformance: 276/278 cases passed. Integration milestone failed with 21/23 cases passing. The instruction explicitly requires 'REWARD = 1 iff every component milestone fully passes AND ... held-out top-1 >= threshold'. The agent met the held-out threshold (0.912 >= 0.7) but failed to pass all component milestones (integration milestone has 2 failures). Test output confirms: 'failing milestones: integration (21/23)'
Root causeThe agent successfully implemented most of the framework (276/278 components) and achieved the held-out accuracy metric, but 2 of 23 integration test cases failed, indicating incomplete or incorrect implementation of either the backward pass, quantization logic, or training loop. These subtle bugs in the framework prevented all component milestones from passing, which is explicitly required for reward=1.
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
49 tool calls · 4 tool types · 63 steps
Agent session started, model: claude-sonnet-4-6 · 29 tools available · cwd: /app
I'll start by exploring the project structure to understand what needs to be implemented.

Explore project structure

shell
find /app -type f | head -50 && echo "---" && ls /app/submission/
output
/app/run_checks.py
/app/test.sh
/app/timer.sh
/app/PROMPT.txt
/app/agent.pid
/app/run.log
/app/agent_trajectory.jsonl
/app/agent.stderr
/app/submission/nn.py
/app/submission/autograd.py
/app/submission/train.py
/app/submission/optim.py
/app/submission/data.py
/app/data/train.npz
---
autograd.py
data.py
nn.py
optim.py
train.py

Run initial checks to see starting state

shell
python3 /app/run_checks.py --quiet 2>&1 | head -50
output
------------------------------------------------------------------------
autograd_grads 0/115 | quant_grads 3/21 | nn_forward 42/53 | optim 1/25 | integration 0/6 | data 0/2
TOTAL  46/222 public checks passing
Fix the FAIL lines above (each is a backward/forward/optimizer bug). Re-run until all green, then train.

/app/submission/autograd.py

contents
1	"""Reverse-mode automatic differentiation over numpy arrays.
2	
3	YOU MUST IMPLEMENT EVERYTHING MARKED ``# TODO`` / ``raise NotImplementedError`` using numpy
4	ONLY. No torch/jax/tensorflow/autograd/etc. The grader's conformance suite (a) differentiates the
5	differentiable ops below with central finite differences and compares against YOUR analytic
6	backward, and (b) checks the LSQ ``fake_quant`` STE + scale gradient against the reference
7	definition, so every backward must be correct (a single wrong reduction / STE / Jacobian fails
8	the gradient checks and zeroes the reward).
9	
10	A ``Tensor`` wraps one ``numpy.ndarray`` (stored as ``float64`` in ``self.data``) and records the
11	op that produced it so ``.backward()`` can accumulate ``.grad`` into every leaf.
12	
13	CONTRACT (the grader builds its own reference against this exact API):
14	* ``Tensor(data, requires_grad=False)`` -- ``self.data`` is ``float64``; ``self.grad`` is None
15	  until backward, then a same-shape ``float64`` array. requires_grad leaves accumulate grad.
16	* Every op returns a NEW Tensor whose ``requires_grad`` is the OR of its differentiable inputs,
17	  and whose ``_backward`` closure does ``input._accum(local_grad)`` (so multiple paths add up).
18	* ``t.backward(grad=None)`` -- seeds ``grad`` (all-ones for a scalar) and walks the graph in
19	  reverse topological order, calling each node's ``_backward``. Repeated backward accumulates.
20	* BROADCASTING: binary ops broadcast like numpy; the ba
…[truncated 54775 chars]
Now let me read the other files:

/app/submission/nn.py

contents
1	"""QAT layers + a small INT2 CNN, built on YOUR autograd engine.
2	
3	Implement every ``# TODO`` forward (the parameters + ``named_params``/``buffers`` naming are
4	already wired for you; you compose the autograd ops). The grader checks each layer's forward
5	against its OWN reference AND finite-difference-checks the gradients that flow through your
6	autograd, so the composition must be exactly right.
7	
8	CHECKPOINT NAMING CONTRACT (the grader loads YOUR ``qat_model.npz`` into its own reference
9	QuantCNN by these exact keys/shapes -- do not rename):
10	  stem.conv.weight (W0,3,3,3) | stem.conv.wq.scale (1,) | stem.bn.gamma/.beta (W0,) | stem.aq.scale (1,)
11	  blocks.{i}.conv.weight (Cout,Cin,3,3) | blocks.{i}.conv.wq.scale (1,)
12	  blocks.{i}.bn.gamma/.beta (Cout,) | blocks.{i}.aq.scale (1,)
13	  head.weight (Cfeat,n_classes) | head.wq.scale (1,) | head.bias (n_classes,)
14	BN running stats are BUFFERS (saved alongside params, NOT trained by the optimizer, NOT audited):
15	  stem.bn.running_mean/.running_var (W0,) | blocks.{i}.bn.running_mean/.running_var (Cout,)
16	
17	Quantization: every conv/head WEIGHT is LSQ-quantized to a signed 2-bit grid {-2,-1,0,1} via a
18	per-tensor learnable step before use; every block activation (post-relu) is LSQ-quantized to an
19	unsigned 2-bit grid {0,1,2,3}. Conv = 3x3 same-padding cross-correlation. Linear head = x@weight+bias.
20	"""
21	from __future__ import annotations
22	
23	from typing import Dict, List
24	
25	import numpy as n
…[truncated 35167 chars]

/app/submission/optim.py

/app/submission/data.py

contents
1	"""Optimizers over autograd ``Tensor`` parameters.
2	
3	Implement the ``# TODO`` update math. Both optimizers update ``param.data`` IN PLACE using
4	``param.grad``. The grader runs one (and several) steps and compares your updated params against
5	its reference within a tight tolerance, so the math must be exact.
6	
7	SGD (with momentum ``mu`` and coupled weight decay ``wd``):
8	    g = grad + wd * param;  v = mu * v + g;  param -= lr * v
9	
10	AdamW (DECOUPLED weight decay -- the decay is applied to the PARAM, not folded into the moments):
11	    m = b1*m + (1-b1)*g;  v = b2*v + (1-b2)*g^2
12	    mhat = m / (1 - b1^t);  vhat = v / (1 - b2^t)        # t = 1-based step count
13	    param -= lr * ( mhat / (sqrt(vhat) + eps) + wd * param )
14	
15	PARAM GROUPS: both optimizers must accept EITHER a flat param list OR a list of
16	``{"params": [...], "weight_decay": wd}`` dicts, so weight decay can be applied to SOME params
17	and not others. This matters for low-bit LSQ QAT: the per-tensor quantizer ``scale`` params,
18	BatchNorm gamma/beta, and biases must be EXCLUDED from weight decay. ``_normalize_groups`` and
19	``split_decay_params`` are provided; honour the per-group weight decay in ``step``.
20	"""
21	from __future__ import annotations
22	
23	import math
24	
25	from typing import Dict, List
26	
27	import numpy as np
28	
29	from autograd import Tensor
30	
31	
32	def split_decay_params(model) -> Dict[str, List[Tensor]]:
33	    """Partition a model's named params into weight
…[truncated 11129 chars]

contents
1	"""Image data loading + normalization + batching.
2	
3	The dataset is a procedurally-generated CIFAR-style set: ``X`` is ``uint8`` (N,3,S,S) in [0,255],
4	``y`` is the integer class label in [0, n_classes). The shipped training split is at
5	``/app/data/train.npz``; the SEALED held-out split is regenerated by the verifier (never shipped).
6	
7	Implement the ``# TODO`` bodies (numpy only). The verifier normalizes the held-out split with the
8	SAME transform, so match it exactly.
9	
10	Contract:
11	  load_npz(path) -> (X uint8 (N,3,S,S), y int64 (N,))       [provided]
12	  normalize(X)   -> float64: x = (X/255 - 0.5) / 0.25       [per-channel, the grader's transform]
13	  iter_minibatches(Xn, y, batch_size, rng, shuffle=True) -> yields (xb, yb)
14	"""
15	from __future__ import annotations
16	
17	from typing import Tuple
18	
19	import numpy as np
20	
21	NORM_MEAN = 0.5
22	NORM_STD = 0.25
23	
24	
25	def load_npz(path: str) -> Tuple[np.ndarray, np.ndarray]:
26	    d = np.load(path)
27	    X = np.asarray(d["X"]).astype(np.uint8)
28	    y = np.asarray(d["y"]).astype(np.int64).reshape(-1)
29	    return X, y
30	
31	
32	def normalize(X: np.ndarray) -> np.ndarray:
33	    """uint8 (N,3,S,S) -> float64, x = (X/255 - NORM_MEAN) / NORM_STD."""
34	    # TODO: cast to float, scale to [0,1], subtract NORM_MEAN, divide by NORM_STD.
35	    raise NotImplementedError("normalize")
36	
37	
38	def iter_minibatches(Xn: np.ndarray, y: np.ndarray, batch_size: int,
39	                     rng: np.rando
…[truncated 281 chars]

/app/submission/train.py

contents
1	"""Training entry point. Implement the QAT loop, train your INT2 CNN on /app/data/train.npz, and
2	SAVE the checkpoint to /app/submission/qat_model.npz (numpy .npz of the model state_dict: every
3	param + every BN running buffer, by the nn.QuantCNN naming contract).
4	
5	The grader (verify.py) will:
6	  (1) run the conformance suite over your autograd/nn/optim,
7	  (2) BIT-AUDIT every conv/head weight tensor in your checkpoint to <= 4 distinct float values,
8	  (3) load your weights into its OWN QuantCNN and score held-out top-1 on a SEALED split.
9	
10	So at SAVE time you must BAKE the quantized weights back into each ``weight`` tensor (replace it
11	with round(clip(w/s, -W_NEG, W_POS)) * s using the learned wq.scale) so the saved weights already
12	lie on the 2-bit grid and pass the audit. Reaching the top-1 floor at INT-2 needs a real recipe:
13	sensible LSQ STEP-SIZE INITIALIZATION (a default scale of 1.0 quantizes the small init weights to
14	all-zeros -> a dead network at chance), per-tensor learnable scales, weight decay EXCLUDED from the
15	scale/BN/bias params, gradient clipping, a decaying LR, and enough epochs. Naive post-training
16	rounding or under-training lands at chance.
17	
18	This file is a skeleton; the loop body is yours to write.
19	"""
20	from __future__ import annotations
21	
22	import argparse
23	import os
24	import sys
25	
26	import numpy as np
27	
28	sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
29	sys.path.insert(0, "/app")
30	
3
…[truncated 1513 chars]
I have a complete picture of what needs to be implemented. Let me implement all the framework files systematically, starting with `autograd.py`.
write · /app/submission/autograd.py
"""Reverse-mode automatic differentiation over numpy arrays."""
from __future__ import annotations
from typing import Callable, Iterable, List, Optional
import numpy as np

_bi_max = max
_bi_min = min


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


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


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.data)
        self._accum(grad)
        topo 
…[truncated 49821 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 let me implement the `gather` backward more carefully (the current implementation has a bug with multi-dimensional indices), and also fix it, then write nn.py:

/app/submission/autograd.py

− removed
def gather(a, idx, axis: int) -> Tensor:
    a = _ensure(a)
    idx = np.asarray(idx)
    out = _mk(np.take_along_axis(a.data, idx, axis=axis), (a,), a.requires_grad)
    def _bw():
        g = out.grad
        if g is None: return
        if a.requires_grad:
            da = np.zeros_like(a.data)
            np.add.at(da, tuple(
                idx if i == axis else np.arange(a.data.shape[i]).reshape(
                    [-1 if i == j else 1 for j in range(a.data.ndim)])
                for i in range(a.data.ndim)
            ), g)
            a._accum(da)
    out._backward = _bw
    return out
+ added
def gather(a, idx, axis: int) -> Tensor:
    a = _ensure(a)
    idx = np.asarray(idx)
    out = _mk(np.take_along_axis(a.data, idx, axis=axis), (a,), a.requires_grad)
    def _bw():
        g = out.grad
        if g is None: return
        if a.requires_grad:
            da = np.zeros_like(a.data)
            np.add.at(da, _gather_idx(idx, axis, a.data.ndim), g)
            a._accum(da)
    out._backward = _bw
    return out


def _gather_idx(idx, axis, ndim):
    """Build the index tuple for scatter-add in gather backward."""
    full = []
    for i in range(ndim):
        if i == axis:
            full.append(idx)
        else:
            shape = [1] * ndim
            shape[i] = -1
            full.append(np.arange(idx.shape[i]).reshape(shape))
    return tuple(full)

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 write nn.py:
write · /app/submission/nn.py
"""QAT layers + a small INT2 CNN, built on YOUR autograd engine."""
from __future__ import annotations
from typing import Dict, List
import numpy as np
import autograd as ag
from autograd import Tensor

W_NEG, W_POS = 2, 1      # signed weights: {-2,-1,0,1}
A_NEG, A_POS = 0, 3      # unsigned activations (post-relu): {0,1,2,3}


class Module:
    def params(self) -> List[Tensor]:
        return list(self.named_params().values())

    def named_params(self) -> Dict[str, Tensor]:
        raise NotImplementedError

    def buffers(self) -> Dict[str, np.ndarray]:
        return {}

    def __call__(self, *a, **k):
        return self.forward(*a, **k)


def _kaiming(rng, fan_in, shape, gain=1.0):
    return rng.standard_normal(shape) * (gain / np.sqrt(fan_in))


class Linear(Module):
    def __init__(self, n_in, n_out, rng, bias=True, gain=1.0):
        self.weight = Tensor(_kaiming(rng, n_in, (n_in, n_out), gain), requires_grad=True)
        self.bias = Tensor(np.zeros(n_out), requires_grad=True) if bias else None

    def forward(self, x: Tensor) -> Tensor:
        out = ag.matmul(x, self.weight)
        if self.bias is not None:
            out = ag.add(out, self.bias)
        return out

    def named_params(self):
        d = {"weight": self.weight}
        if self.bias is not None:
            d["bias"] = self.bias
        return d


class ReLU(Module):
    def forward(self, x: Tensor) -> Tensor:
        return ag.relu(x)

    def named_params(self):
        return {}


clas
…[truncated 25587 chars]

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 write optim.py and data.py:
write · /app/submission/optim.py
"""Optimizers over autograd Tensor parameters."""
from __future__ import annotations
import math
from typing import Dict, List
import numpy as np
from autograd import Tensor


def split_decay_params(model) -> Dict[str, List[Tensor]]:
    decay, no_decay = [], []
    for name, p in model.named_params().items():
        lname = name.lower()
        if lname.endswith("scale") or "bn." in lname or lname.endswith("gamma") \
                or lname.endswith("beta") or lname.endswith("bias"):
            no_decay.append(p)
        else:
            decay.append(p)
    return {"decay": decay, "no_decay": no_decay}


def _normalize_groups(params):
    plist = list(params)
    if plist and isinstance(plist[0], dict):
        return [(list(g["params"]), g.get("weight_decay", None)) for g in plist]
    return [(plist, None)]


class Optimizer:
    def __init__(self, params):
        self._groups = _normalize_groups(params)
        self.params: List[Tensor] = [p for g, _ in self._groups for p in g]

    def zero_grad(self):
        for p in self.params:
            p.grad = None


class SGD(Optimizer):
    def __init__(self, params, lr=0.1, momentum=0.0, weight_decay=0.0):
        super().__init__(params)
        self.lr = lr
        self.momentum = momentum
        self.weight_decay = weight_decay
        self._v = [np.zeros_like(p.data) for p in self.params]

    def step(self):
        idx = 0
        for group, wd_override in self._groups:
            wd = self.weight_decay if wd_ove
…[truncated 11134 chars]

contents
The file /app/submission/optim.py has been updated successfully. (file state is current in your context , no need to Read it back)
write · /app/submission/data.py
"""Image data loading + normalization + batching."""
from __future__ import annotations
from typing import Tuple
import numpy as np

NORM_MEAN = 0.5
NORM_STD = 0.25


def load_npz(path: str) -> Tuple[np.ndarray, np.ndarray]:
    d = np.load(path)
    X = np.asarray(d["X"]).astype(np.uint8)
    y = np.asarray(d["y"]).astype(np.int64).reshape(-1)
    return X, y


def normalize(X: np.ndarray) -> np.ndarray:
    return (X.astype(np.float64) / 255.0 - NORM_MEAN) / NORM_STD


def iter_minibatches(Xn: np.ndarray, y: np.ndarray, batch_size: int,
                     rng: np.random.Generator, shuffle: bool = True):
    N = len(y)
    idx = np.arange(N)
    if shuffle:
        rng.shuffle(idx)
    for start in range(0, N, batch_size):
        batch_idx = idx[start:start + batch_size]
        yield Xn[batch_idx], y[batch_idx]

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 run the checks to see where we stand:

Run checks to see current status

shell
python3 run_checks.py 2>&1 | tail -30
output
optim/NesterovSGD_5step                  OK    (max_abs=0.0e+00)
  optim/param_groups                       OK  
  optim/split_decay_params                 OK  
  optim/clip_grad_norm_clips               OK    (max_abs=0.0e+00)
  optim/clip_grad_norm_noop                OK    (max_abs=0.0e+00)
  optim/sched_cosine                       OK    (max_abs=0.0e+00)
  optim/sched_warmup                       OK    (max_abs=0.0e+00)
  optim/sched_step                         OK    (max_abs=0.0e+00)
  optim/sched_exponential                  OK    (max_abs=0.0e+00)
  optim/sched_polynomial                   OK    (max_abs=0.0e+00)
  optim/sched_linear                       OK    (max_abs=1.7e-18)
  optim/sched_multistep                    OK    (max_abs=0.0e+00)
  optim/sched_cosine_restarts              OK    (max_abs=0.0e+00)

[integration]  6/6
  integration/qcnn_finite                  OK    (1.787->1.018)
  integration/qcnn_loss_decreases          OK    (1.7869->min 1.0175)
  integration/qmlp_finite                  OK    (1.981->0.237)
  integration/qmlp_loss_decreases          OK    (1.9807->min 0.2374)
  integration/qsepcnn_finite               OK    (1.925->1.655)
  integration/qsepcnn_loss_decreases       OK    (1.9249->min 1.6340)

[data]  2/2
  data/normalize_def                       OK  
  data/iter_minibatches_cover              OK    (covered 23/23)

------------------------------------------------------------------------
autograd_grads 115/115 | quant_grads 21/21 | 
…[truncated 238 chars]
All 222/222 checks pass. Now I need to implement the training loop and train the model:
write · /app/submission/train.py
"""Training entry point for QAT INT-2 CNN."""
from __future__ import annotations
import argparse
import os
import sys
import numpy as np

sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
sys.path.insert(0, "/app")

import autograd as ag
import data as D
import optim as O
from nn import QuantCNN, W_NEG, W_POS, A_NEG, A_POS

WIDTHS = (16, 32)


def init_lsq_scales(model, Xn_batch):
    """Initialize LSQ step sizes from the actual activation distributions."""
    # For weights: scale = max(|w|) / Qp
    params = model.named_params()
    Qp_w = float(W_POS)
    Qp_a = float(A_POS)

    # Init weight scales from weight magnitude
    for name, p in params.items():
        if name.endswith("wq.scale"):
            # Find the corresponding weight
            base = name[:-len("wq.scale")]
            wname = base + "weight"
            if wname in params:
                w = params[wname].data
                s = np.max(np.abs(w)) / Qp_w
                s = max(s, 1e-4)
                p.data[...] = s
            else:
                p.data[...] = 0.1

    # Run a forward pass to init activation scales
    model.set_training(False)
    x = ag.Tensor(Xn_batch)
    with_acts = _collect_activations(model, x)
    model.set_training(True)

    for name, act_val in with_acts.items():
        scale_name = name
        if scale_name in params:
            s = np.max(np.abs(act_val)) / Qp_a
            s = max(s, 1e-4)
            params[scale_name].data[...] = s


def _collect
…[truncated 5193 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)

Quick test of training loop

shell
python3 submission/train.py --epochs 5 2>&1 | head -20
output
(Bash completed with no output)

Test training loop with 5 epochs

shell
python3 submission/train.py --epochs 5 2>&1
output
Exit code 137
/bin/bash: line 1:  1491 Killed                  python3 submission/train.py --epochs 5 2>&1

Check time remaining

shell
cat /app/timer.sh && bash /app/timer.sh 2>&1 | head -5
output
#!/bin/bash
# Reports remaining agent time (mirrors task.toml [agent] timeout_sec).
TIMEOUT_SEC=36000

ELAPSED=$(ps -o etimes= -p 1 2>/dev/null | tr -d ' ')
if ! [[ "$ELAPSED" =~ ^[0-9]+$ ]]; then
	START_FILE="$(dirname "$0")/.timer_start"
	if [ ! -f "$START_FILE" ]; then
		date +%s >"$START_FILE"
	fi
	START_DATE=$(cat "$START_FILE")
	NOW=$(date +%s)
	ELAPSED=$((NOW - START_DATE))
fi
REMAINING=$((TIMEOUT_SEC - ELAPSED))

if [ $REMAINING -le 0 ]; then
	echo "Timer expired!"
else
	echo "Remaining time (hours:minutes)":
	HOURS=$((REMAINING / 3600))
	MINUTES=$(((REMAINING % 3600) / 60))
	printf "%d:%02d\n" $HOURS $MINUTES
fi
Remaining time (hours:minutes):
9:44

Quick test of one forward/backward pass

shell
timeout 120 python3 -c "
import sys
sys.path.insert(0, 'submission')
import numpy as np
import data as D
import autograd as ag
import optim as O
from nn import QuantCNN

X_raw, y = D.load_npz('data/train.npz')
print('Data shape:', X_raw.shape, y.shape, 'classes:', np.unique(y))
Xn = D.normalize(X_raw)
model = QuantCNN(n_classes=10, widths=(16,32), seed=0)
model.set_training(True)

# Small test: 1 batch
xb = Xn[:32]
yb = y[:32]
xb_t = ag.Tensor(xb)
logits = model(xb_t)
print('logits shape:', logits.shape)
loss = ag.cross_entropy(logits, yb)
print('loss:', float(loss.data))
loss.backward()
print('stem weight grad:', model.stem.conv.weight.grad is not None)
" 2>&1
output
Data shape: (2500, 3, 16, 16) (2500,) classes: [0 1 2 3 4 5 6 7 8 9]
logits shape: (32, 10)
loss: 2.302585092994046
stem weight grad: True

Time a few training batches

shell
timeout 120 python3 -c "
import sys, time
sys.path.insert(0, 'submission')
import numpy as np
import data as D
import autograd as ag
import optim as O
from nn import QuantCNN

X_raw, y = D.load_npz('data/train.npz')
Xn = D.normalize(X_raw)
model = QuantCNN(n_classes=10, widths=(16,32), seed=0)
model.set_training(True)

optimizer = O.AdamW(model.params(), lr=1e-2, weight_decay=1e-4)

t0 = time.time()
for i in range(5):
    xb = Xn[i*32:(i+1)*32]
    yb = y[i*32:(i+1)*32]
    optimizer.zero_grad()
    xb_t = ag.Tensor(xb)
    logits = model(xb_t)
    loss = ag.cross_entropy(logits, yb)
    loss.backward()
    optimizer.step()
    print(f'batch {i}: loss={float(loss.data):.4f}, time={time.time()-t0:.2f}s')
" 2>&1
output
batch 0: loss=2.3026, time=0.14s
batch 1: loss=2.3030, time=0.28s
batch 2: loss=2.3040, time=0.42s
batch 3: loss=2.3026, time=0.56s
batch 4: loss=2.3065, time=0.68s

Test training for 3 epochs

shell
timeout 300 python3 -c "
import sys, time, traceback
sys.path.insert(0, 'submission')
import numpy as np
import data as D
import autograd as ag
import optim as O
from nn import QuantCNN, W_NEG, W_POS, A_NEG, A_POS

X_raw, y = D.load_npz('data/train.npz')
Xn = D.normalize(X_raw)
N_total = len(y)

model = QuantCNN(n_classes=10, widths=(16,32), seed=0)
model.set_training(True)

# Simple scale init: just use 0.1 for weights, 0.1 for activations
params = model.named_params()
for name, p in params.items():
    if 'wq.scale' in name:
        # Find corresponding weight
        base = name[:-len('wq.scale')]
        wname = base + 'weight'
        if wname in params:
            w = params[wname].data
            p.data[...] = max(np.max(np.abs(w)) / float(W_POS), 1e-4)
    if 'aq.scale' in name:
        p.data[...] = 0.5

groups_dict = O.split_decay_params(model)
param_groups = [
    {'params': groups_dict['decay'], 'weight_decay': 1e-4},
    {'params': groups_dict['no_decay'], 'weight_decay': 0.0},
]

base_lr = 5e-3
optimizer = O.AdamW(param_groups, lr=base_lr, betas=(0.9, 0.999), eps=1e-8, weight_decay=1e-4)

rng = np.random.default_rng(42)
batch_size = 64
epochs = 3

t0 = time.time()
for epoch in range(epochs):
    epoch_loss = 0
    n_batches = 0
    correct = 0
    total = 0
    for xb, yb in D.iter_minibatches(Xn, y, batch_size, rng, shuffle=True):
        optimizer.zero_grad()
        xb_t = ag.Tensor(xb)
        logits = model(xb_t)
        loss = ag.cross_entropy(logits, yb
…[truncated 412 chars]
output
Exit code 137
/bin/bash: line 131:  1578 Killed                  timeout 300 python3 -c "
import sys, time, traceback
sys.path.insert(0, 'submission')
import numpy as np
import data as D
import autograd as ag
import optim as O
from nn import QuantCNN, W_NEG, W_POS, A_NEG, A_POS

X_raw, y = D.load_npz('data/train.npz')
Xn = D.normalize(X_raw)
N_total = len(y)

model = QuantCNN(n_classes=10, widths=(16,32), seed=0)
model.set_training(True)

# Simple scale init: just use 0.1 for weights, 0.1 for activations
params = model.named_params()
for name, p in params.items():
    if 'wq.scale' in name:
        # Find corresponding weight
        base = name[:-len('wq.scale')]
        wname = base + 'weight'
        if wname in params:
            w = params[wname].data
            p.data[...] = max(np.max(np.abs(w)) / float(W_POS), 1e-4)
    if 'aq.scale' in name:
        p.data[...] = 0.5

groups_dict = O.split_decay_params(model)
param_groups = [
    {'params': groups_dict['decay'], 'weight_decay': 1e-4},
    {'params': groups_dict['no_decay'], 'weight_decay': 0.0},
]

base_lr = 5e-3
optimizer = O.AdamW(param_groups, lr=base_lr, betas=(0.9, 0.999), eps=1e-8, weight_decay=1e-4)

rng = np.random.default_rng(42)
batch_size = 64
epochs = 3

t0 = time.time()
for epoch in range(epochs):
    epoch_loss = 0
    n_batches = 0
    correct = 0
    total = 0
    for xb, yb in D.iter_minibatches(Xn, y, batch_size, rng, shuffle=True):
        optimizer.zero_grad()
        xb_t = ag.Tensor(xb)
      
…[truncated 477 chars]
Memory is the issue. Let me check available memory and add explicit GC:

Check memory available and usage estimate

shell
free -m && python3 -c "
import numpy as np
# Estimate memory per batch
bs = 64
# im2col for stem: (64, 27, 256)
cols_stem = 64 * 27 * 256 * 8 / 1024 / 1024
# out: (64, 16, 256)
out_stem = 64 * 16 * 256 * 8 / 1024 / 1024
# block 0: (64, 32, 64)
cols_b0 = 64 * (16*9) * (8*8) * 8 / 1024 / 1024
print(f'Stem cols: {cols_stem:.1f} MB')
print(f'Stem out: {out_stem:.1f} MB')
print(f'Block0 cols: {cols_b0:.1f} MB')
# Total per batch estimate
total = (cols_stem + out_stem) * 2 + (cols_b0 * 2) * 2  # factor 2 for bwd
print(f'Total estimate: {total:.1f} MB')
"
output
total        used        free      shared  buff/cache   available
Mem:             481         255         172           1          67         226
Swap:              0           0           0
Stem cols: 3.4 MB
Stem out: 2.0 MB
Block0 cols: 4.5 MB
Total estimate: 28.8 MB

Test with batch size 16 and explicit gc

shell
timeout 60 python3 -c "
import sys, time, gc
sys.path.insert(0, 'submission')
import numpy as np
import data as D
import autograd as ag
import optim as O
from nn import QuantCNN

X_raw, y = D.load_npz('data/train.npz')
Xn = D.normalize(X_raw)

model = QuantCNN(n_classes=10, widths=(16,32), seed=0)
model.set_training(True)
optimizer = O.AdamW(model.params(), lr=1e-2, weight_decay=1e-4)

rng = np.random.default_rng(42)
batch_size = 16

t0 = time.time()
for i, (xb, yb) in enumerate(D.iter_minibatches(Xn, y, batch_size, rng)):
    optimizer.zero_grad()
    xb_t = ag.Tensor(xb)
    logits = model(xb_t)
    loss = ag.cross_entropy(logits, yb)
    loss.backward()
    O.clip_grad_norm(model.params(), 1.0)
    optimizer.step()
    lv = float(loss.data)
    del logits, loss, xb_t
    gc.collect()
    if i % 10 == 0:
        print(f'batch {i}: loss={lv:.4f}, t={time.time()-t0:.2f}s')
    if i >= 40:
        break
print('done')
" 2>&1
output
batch 0: loss=2.3026, t=0.08s
batch 10: loss=2.3069, t=0.75s
batch 20: loss=2.3106, t=1.40s
batch 30: loss=2.3096, t=2.03s
batch 40: loss=2.3086, t=2.69s
done

Test different batch sizes with gc

shell
timeout 60 python3 -c "
import sys, time, gc
sys.path.insert(0, 'submission')
import numpy as np
import data as D
import autograd as ag
import optim as O
from nn import QuantCNN

X_raw, y = D.load_npz('data/train.npz')
Xn = D.normalize(X_raw)

model = QuantCNN(n_classes=10, widths=(16,32), seed=0)
model.set_training(True)
optimizer = O.AdamW(model.params(), lr=1e-2, weight_decay=1e-4)

rng = np.random.default_rng(42)

t0 = time.time()
for bs in [32, 64, 128]:
    gc.collect()
    for i, (xb, yb) in enumerate(D.iter_minibatches(Xn, y, bs, rng)):
        optimizer.zero_grad()
        xb_t = ag.Tensor(xb)
        logits = model(xb_t)
        loss = ag.cross_entropy(logits, yb)
        loss.backward()
        O.clip_grad_norm(model.params(), 1.0)
        optimizer.step()
        lv = float(loss.data)
        del logits, loss, xb_t
        gc.collect()
        if i >= 2: break
    print(f'batch_size={bs}: loss={lv:.4f}, t={time.time()-t0:.2f}s')
print('done')
" 2>&1
output
batch_size=32: loss=2.3035, t=0.40s
batch_size=64: loss=2.3013, t=1.19s
batch_size=128: loss=2.3054, t=2.89s
done

Find optimal batch size for throughput

shell
timeout 60 python3 -c "
import sys, time, gc
sys.path.insert(0, 'submission')
import numpy as np
import data as D
import autograd as ag
import optim as O
from nn import QuantCNN

X_raw, y = D.load_npz('data/train.npz')
Xn = D.normalize(X_raw)
model = QuantCNN(n_classes=10, widths=(16,32), seed=0)
model.set_training(True)
optimizer = O.AdamW(model.params(), lr=1e-2, weight_decay=1e-4)
rng = np.random.default_rng(42)

for bs in [16, 32, 64]:
    gc.collect()
    t0 = time.time()
    n = 0
    for xb, yb in D.iter_minibatches(Xn, y, bs, rng, shuffle=False):
        optimizer.zero_grad()
        xb_t = ag.Tensor(xb)
        logits = model(xb_t)
        loss = ag.cross_entropy(logits, yb)
        loss.backward()
        optimizer.step()
        del logits, loss, xb_t
        gc.collect()
        n += len(yb)
        if n >= 500: break
    t1 = time.time()
    print(f'bs={bs}: {n} samples in {t1-t0:.2f}s = {n/(t1-t0):.0f} samples/sec')
" 2>&1
output
bs=16: 512 samples in 2.13s = 241 samples/sec
bs=32: 512 samples in 2.18s = 235 samples/sec
bs=64: 512 samples in 2.17s = 236 samples/sec
The OOM issue is memory not being freed. Let me fix the training script:
write · /app/submission/train.py
"""Training entry point for QAT INT-2 CNN."""
from __future__ import annotations
import argparse
import gc
import os
import sys
import numpy as np

sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
sys.path.insert(0, "/app")

import autograd as ag
import data as D
import optim as O
from nn import QuantCNN, W_NEG, W_POS, A_NEG, A_POS

WIDTHS = (16, 32)


def init_weight_scales(model):
    """Set each weight-quantizer step to max(|w|)/Qp so weights span the grid."""
    params = model.named_params()
    Qp_w = float(W_POS)
    for name, p in params.items():
        if name.endswith("wq.scale"):
            base = name[:-len("wq.scale")]
            wname = base + "weight"
            if wname in params:
                w = params[wname].data
                s = max(float(np.max(np.abs(w))) / Qp_w, 1e-4)
                p.data[...] = s


def init_act_scales(model, Xn, y, batch_size=128):
    """Run one forward pass (BN in training mode) and set activation scales
    from the observed activation ranges (no grad needed)."""
    rng0 = np.random.default_rng(999)
    params = model.named_params()
    Qp_a = float(A_POS)

    # Collect activations by instrumenting the forward
    # We run block-by-block manually
    model.set_training(True)
    n_batches = 0
    act_accum = {}  # name -> list of max values

    for xb, yb in D.iter_minibatches(Xn, y, batch_size, rng0, shuffle=True):
        xb_t = ag.Tensor(xb)

        # Manually run stem
        h = model.stem.conv(xb_
…[truncated 5827 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)

Test training for 10 epochs

shell
timeout 300 python3 submission/train.py --epochs 10 2>&1
output
Command running in background with ID: by5z1mnk6. Output is being written to: /tmp/claude-1000/-app/db724dd1-4684-4463-91c3-a513dd2c5506/tasks/by5z1mnk6.output. You will be notified when it completes. To check interim output, use Read on that file path.

Check training progress after 30 seconds

shell
sleep 30 && cat /tmp/claude-1000/-app/db724dd1-4684-4463-91c3-a513dd2c5506/tasks/by5z1mnk6.output 2>&1
output
<tool_use_error>Blocked: sleep 30 followed by: cat /tmp/claude-1000/-app/db724dd1-4684-4463-91c3-a513dd2c5506/tasks/by5z1mnk6.output. To wait for a condition, use Monitor with an until-loop (e.g. `until <check>; do sleep 2; done`). To wait for a command you started, use run_in_background: true. Do not chain shorter sleeps to work around this block.</tool_use_error>

/tmp/claude-1000/-app/db724dd1-4684-4463-91c3-a513dd2c5506/tasks/by5z1mnk6.output

contents
<system-reminder>Warning: the file exists but is shorter than the provided offset (1). The file has 1 lines.</system-reminder>

Check current training output

shell
cat /tmp/claude-1000/-app/db724dd1-4684-4463-91c3-a513dd2c5506/tasks/by5z1mnk6.output
output
(Bash completed with no output)

Check if training is still running

shell
jobs -l 2>&1; ps aux | grep train | grep -v grep
output
<persisted-output>
Output too large (30.4KB). Full output saved to: /home/user/.claude/projects/-app/db724dd1-4684-4463-91c3-a513dd2c5506/tool-results/bah72dn6e.txt

Preview (first 2KB):
user        1330  0.0  0.0   2504   104 ?        S    22:11   0:00 timeout 7200 claude -p You are an autonomous engineer in a fresh Linux sandbox. Working dir is /app. Implement the solution by editing the stub files under /app/submission/ . Run `python3 /app/run_checks.py` for the public component checks and `bash /app/test.sh` for an env smoke. Save all required outputs (e.g. the trained checkpoint) before you finish. numpy is the only allowed dependency. Work fully autonomously, do not ask questions, keep iterating until checks pass or you run out of time.  ----- TASK -----  # Build a QAT framework from scratch, then train an INT-2 CNN with it  You are given a **stubbed, numpy-only deep-learning framework** and a small CIFAR-style image dataset. Your job has two parts, and **both are graded**:  1. **Implement the entire framework from scratch** ??? fill in every `# TODO` / `raise    NotImplementedError` in the files under `/app/submission/`. This includes a reverse-mode    automatic-differentiation engine (you implement the backward pass for every operation    yourself), the convolution / batch-norm / pooling ops, the **Learned Step Size Quantization    (LSQ) fake-quantizer** with the **straight-through estimator**, the neural-network layers, the    optimizers, and the data pipeline. 2. **
…[truncated 711 chars]

Read training output

shell
cat /tmp/claude-1000/-app/db724dd1-4684-4463-91c3-a513dd2c5506/tasks/by5z1mnk6.output
output
Scale init done
  stem.conv.wq.scale: 1.0267
  stem.aq.scale: 0.8112
  blocks.0.conv.wq.scale: 0.4596
  blocks.0.aq.scale: 1.5803
  blocks.1.conv.wq.scale: 0.3288
  blocks.1.aq.scale: 1.7614
  head.wq.scale: 0.5377
Epoch   1/10 | loss=2.3667 | train=0.093 | val=0.118 | lr=0.005000
Epoch   2/10 | loss=2.1771 | train=0.231 | val=0.329 | lr=0.004853
Epoch   3/10 | loss=1.5478 | train=0.536 | val=0.530 | lr=0.004423
Epoch   4/10 | loss=1.0449 | train=0.718 | val=0.796 | lr=0.003762
Epoch   5/10 | loss=0.7679 | train=0.826 | val=0.824 | lr=0.002949
Epoch  10/10 | loss=0.3934 | train=0.924 | val=0.937 | lr=0.000010
Best val_acc: 0.9372
Saved checkpoint to /app/submission/qat_model.npz
Great results! 93.7% accuracy after 10 epochs. Let me verify the checkpoint and bit-audit:

Check checkpoint and bit-audit

shell
python3 -c "
import numpy as np
sd = np.load('submission/qat_model.npz')
print('Keys:', sorted(sd.keys()))
print()
for k in sorted(sd.keys()):
    v = sd[k]
    if k.endswith('.weight') or k == 'head.weight':
        uvals = np.unique(v)
        print(f'{k}: shape={v.shape}, unique={len(uvals)} values: {uvals[:8]}')
" 2>&1
output
Keys: ['blocks.0.aq.scale', 'blocks.0.bn.beta', 'blocks.0.bn.gamma', 'blocks.0.bn.running_mean', 'blocks.0.bn.running_var', 'blocks.0.conv.weight', 'blocks.0.conv.wq.scale', 'blocks.1.aq.scale', 'blocks.1.bn.beta', 'blocks.1.bn.gamma', 'blocks.1.bn.running_mean', 'blocks.1.bn.running_var', 'blocks.1.conv.weight', 'blocks.1.conv.wq.scale', 'head.bias', 'head.weight', 'head.wq.scale', 'stem.aq.scale', 'stem.bn.beta', 'stem.bn.gamma', 'stem.bn.running_mean', 'stem.bn.running_var', 'stem.conv.weight', 'stem.conv.wq.scale']

blocks.0.conv.weight: shape=(32, 16, 3, 3), unique=4 values: [-0.22941945 -0.11470973  0.          0.11470973]
blocks.1.conv.weight: shape=(32, 32, 3, 3), unique=4 values: [-0.24754164 -0.12377082  0.          0.12377082]
head.weight: shape=(32, 10), unique=3 values: [-1.0043414  0.         1.0043414]
stem.conv.weight: shape=(16, 3, 3, 3), unique=4 values: [-0.5662906 -0.2831453 -0.         0.2831453]
Bit-audit passes. Now let me run a full training with more epochs to get better generalization, and verify all checks still pass:

Verify all checks still pass

shell
python3 run_checks.py --quiet 2>&1
output
------------------------------------------------------------------------
autograd_grads 115/115 | quant_grads 21/21 | nn_forward 53/53 | optim 25/25 | integration 6/6 | data 2/2
TOTAL  222/222 public checks passing
All public checks pass. Now train qat_model.npz to clear the held-out top-1 threshold (the grader re-checks components with DIFFERENT seeds).
All 222/222 checks pass. Now let me run a full training for more epochs to maximize held-out accuracy:

Start full 80-epoch training

shell
python3 submission/train.py --epochs 80 2>&1 &
echo "Training started as PID $!"
output
Training started as PID 1646

Wait for training to complete

shell
until [ ! -d /proc/1646 ]; do sleep 2; done; echo "Training complete"
output
Command running in background with ID: bs6a37m8a. Output is being written to: /tmp/claude-1000/-app/db724dd1-4684-4463-91c3-a513dd2c5506/tasks/bs6a37m8a.output. You will be notified when it completes. To check interim output, use Read on that file path.

Confirm training is running

shell
ps aux | grep train.py | grep -v grep
output
<persisted-output>
Output too large (30.5KB). Full output saved to: /home/user/.claude/projects/-app/db724dd1-4684-4463-91c3-a513dd2c5506/tool-results/brq51ripi.txt

Preview (first 2KB):
user        1330  0.0  0.0   2504   104 ?        S    22:11   0:00 timeout 7200 claude -p You are an autonomous engineer in a fresh Linux sandbox. Working dir is /app. Implement the solution by editing the stub files under /app/submission/ . Run `python3 /app/run_checks.py` for the public component checks and `bash /app/test.sh` for an env smoke. Save all required outputs (e.g. the trained checkpoint) before you finish. numpy is the only allowed dependency. Work fully autonomously, do not ask questions, keep iterating until checks pass or you run out of time.  ----- TASK -----  # Build a QAT framework from scratch, then train an INT-2 CNN with it  You are given a **stubbed, numpy-only deep-learning framework** and a small CIFAR-style image dataset. Your job has two parts, and **both are graded**:  1. **Implement the entire framework from scratch** ??? fill in every `# TODO` / `raise    NotImplementedError` in the files under `/app/submission/`. This includes a reverse-mode    automatic-differentiation engine (you implement the backward pass for every operation    yourself), the convolution / batch-norm / pooling ops, the **Learned Step Size Quantization    (LSQ) fake-quantizer** with the **straight-through estimator**, the neural-network layers, the    optimizers, and the data pipeline. 2. **
…[truncated 711 chars]

Wait for background training process

shell
wait 1646 2>/dev/null; echo "wait complete"
output
wait complete

Check training log

shell
cat /tmp/run_log_train.txt 2>/dev/null || ls /tmp/ | head -20
output
claude-1000
systemd-private-87c33bad8a594d4caefd62a7781643a2-chrony-wait.service-c3XH0Q
systemd-private-87c33bad8a594d4caefd62a7781643a2-chrony.service-1C5zZP

Check if checkpoint was updated by the 80-epoch run

shell
python3 -c "
import numpy as np
sd = np.load('submission/qat_model.npz')
for k in ['stem.conv.weight','blocks.0.conv.weight','head.weight']:
    v = sd[k]
    print(f'{k}: unique={len(np.unique(v))} values')
" 2>&1
output
stem.conv.weight: unique=4 values
blocks.0.conv.weight: unique=4 values
head.weight: unique=3 values

Check checkpoint file modification time

shell
# Check what happened to the 80-epoch training
ls -la /app/submission/qat_model.npz
output
-rw-r--r-- 1 user user 66086 Jun 30 22:32 /app/submission/qat_model.npz

Check checkpoint accuracy on training data

shell
date && ls -la /app/submission/qat_model.npz && python3 -c "
import numpy as np
import sys
sys.path.insert(0,'submission')
import data as D
import autograd as ag
from nn import QuantCNN
X_raw, y = D.load_npz('data/train.npz')
Xn = D.normalize(X_raw)
model = QuantCNN(n_classes=10, widths=(16,32), seed=0)
sd = {k:v for k,v in np.load('submission/qat_model.npz').items()}
model.load_state_dict(sd)
model.set_training(False)
correct=0
total=0
import gc
rng=__import__('numpy').random.default_rng(42)
for xb,yb in D.iter_minibatches(Xn,y,128,rng,shuffle=False):
    xb_t = ag.Tensor(xb)
    logits = model(xb_t)
    preds = logits.data.argmax(axis=1)
    correct += int((preds==yb).sum())
    total += len(yb)
    del logits, xb_t; gc.collect()
print(f'Train acc from checkpoint: {correct/total:.4f}')
" 2>&1
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: 276/278 cases passed  (all milestones pass: False)
  failing milestones: integration (21/23)
FINAL METRIC: held-out INT2 top-1 = 0.912  >= threshold 0.7

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_719a33bbb76a40f9. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_719a33bbb76a40f9 · verifier authoritative; classifier explanatory.