SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

qat-int2-cifar

claude-code claude-opus-4-8 ✓ resolved GOOD_SUCCESS ↑ 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_SUCCESSLegitimate solve, implements the asked-for behavior; tests verify real functionality.
SubtypeLegitimate Solution
EvidenceTest output shows: 'COMPONENT CONFORMANCE SUITE: 278/278 cases passed (all milestones pass: True)' and 'FINAL METRIC: held-out INT2 top-1 = 0.8527 >= threshold 0.7' and 'REWARD = 1'. The verifier note explains: '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.' This is a documented re-grading using the agent's own code, not a harness manipulation.
Root causeThe agent successfully implemented a complete quantization-aware training framework from scratch (all 278 conformance tests pass), including reverse-mode autodiff, convolution operations, LSQ quantizers with straight-through estimators, and training logic. The trained INT-2 model achieved 85.27% accuracy on held-out test data, exceeding the 70% threshold. The verifier re-graded with adequate memory because the sandbox was undersized, but this is a legitimate verification procedure using the agent's own code.
RecommendationN/A - task is fine
Trajectory
Tool-by-tool agent trajectory
73 tool calls · 5 tool types · 108 steps
Agent session started, model: claude-opus-4-8 · 29 tools available · cwd: /app
I'll start by exploring the environment to understand the structure and what needs to be implemented.

Explore app directory structure

shell
ls -la && echo "---SUBMISSION---" && ls -la submission/ && echo "---DATA---" && ls -la data/ && echo "---CHECKS---" && wc -l run_checks.py test.sh 2>/dev/null
output
total 117
drwxr-xr-x  4 user user  4096 Jun 30 22:13 .
drwxr-xr-x 21 root root  4096 Jun 30 22:13 ..
-rw-r--r--  1 user user 15364 Jun 30 22:13 PROMPT.txt
-rw-r--r--  1 user user     5 Jun 30 22:13 agent.pid
-rw-r--r--  1 user user     0 Jun 30 22:13 agent.stderr
-rw-r--r--  1 user user  4644 Jun 30 22:13 agent_trajectory.jsonl
drwxr-xr-x  2 user user    60 Jun 30 22:13 data
-rw-r--r--  1 user user     0 Jun 30 22:13 run.log
-rwxr-xr-x  1 user user 76773 Jun 30 10:02 run_checks.py
drwxr-xr-x  2 user user   128 Jun 30 22:13 submission
-rwxr-xr-x  1 user user   804 Jun 30 10:02 test.sh
-rwxr-xr-x  1 user user   629 Jun 30 10:02 timer.sh
---SUBMISSION---
total 112
drwxr-xr-x 2 user user   128 Jun 30 22:13 .
drwxr-xr-x 4 user user  4096 Jun 30 22:13 ..
-rw-r--r-- 1 user user 50472 Jun 30 10:02 autograd.py
-rw-r--r-- 1 user user  1661 Jun 30 10:02 data.py
-rw-r--r-- 1 user user 33295 Jun 30 10:02 nn.py
-rw-r--r-- 1 user user 11509 Jun 30 10:02 optim.py
-rw-r--r-- 1 user user  2827 Jun 30 10:02 train.py
---DATA---
total 1900
drwxr-xr-x 2 user user      60 Jun 30 22:13 .
drwxr-xr-x 4 user user    4096 Jun 30 22:13 ..
-rw-r--r-- 1 user user 1940490 Jun 30 10:02 train.npz
---CHECKS---
 1522 run_checks.py
   18 test.sh
 1540 total
This is a large task. Let me read all the stub files and the check runner to understand the contracts.

Read test.sh and timer.sh

shell
cat test.sh && echo "===TIMER===" && cat timer.sh
output
#!/usr/bin/env bash
# Smoke test (NOT the grader): confirms the environment is wired -- numpy imports, the train split
# loads, and the submission stubs are present. It does NOT check correctness (the stubs raise
# NotImplementedError until you implement them).
set -uo pipefail

python3 - <<'PY'
import numpy as np, os
assert os.path.exists("/app/data/train.npz"), "missing train.npz"
d = np.load("/app/data/train.npz")
X, y = d["X"], d["y"]
print(f"train: X={X.shape} {X.dtype}, y={y.shape}, classes={len(set(y.tolist()))}")
for f in ("autograd.py", "nn.py", "optim.py", "data.py", "train.py"):
    assert os.path.exists(f"/app/submission/{f}"), f"missing /app/submission/{f}"
print("submission stubs present:", os.listdir("/app/submission"))
print("numpy", np.__version__)
PY
echo "app_test smoke OK"
===TIMER===
#!/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
I have 10 hours. Let me read the stub files carefully, starting with autograd.py.

/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 nn.py, optim.py, data.py, train.py.

/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]
Now optim.py, data.py, train.py:

/app/submission/optim.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]

/app/submission/data.py

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]
Now let me examine run_checks.py to understand the exact grading contract, especially tolerances and reference implementations.

Grep structure of run_checks.py

shell
grep -n "def \|MILESTONE\|tol\|grad_scale\|reference\|class " run_checks.py | head -120
output
17:This runner is a DEBUGGING AID, not the grader. It checks YOUR framework against references it can
33:The REAL grader (the verifier) runs the SAME categories but with its OWN reference framework,
37:  * The grader ALSO bit-audits + loads your trained qat_model.npz into its own reference QuantCNN
64:def _load_module(name, path, inject=None):
84:def load_framework(root):
93:def _num_grad_input(forward, x, eps=EPS):
108:def _max_abs(a, b):
112:def _bsum(it):
119:def _imax(a, b):
124:def check_autograd_grads(fw, sb):
130:    def case(name, build, shape, seed, upstream=None):
135:            def wrapped(t):
193:    def two_path():
204:    def loss_grad(name, lossfn, shape, seed, inttgt):
218:    def norm_param(name, which, seed):
237:    def conv_grad(name, which, seed):
265:    def pool_grad(name, op, seed, jitter=False):
281:    def bn_grad(name, dim, which, seed):
316:    def layer_grad(name, make, in_shape, seed):
334:    # composes -- the grader checks these grads to the reference exactly).
335:    def quant_model_backprop(name, build, make_X, seed):
382:    def gn_x():
395:    def gn_param(name, which, seed):
413:    def cell_grad(name, make, in_shape, hid, seed, two_state=False):
424:                def fwd(xv):
438:    def cell_param_grad(name, make, in_shape, hid, pkey, seed, two_state=False):
450:                def fwd(pv):
455:                def fwd(pv):
479:    def hub_grad(name, seed, scale_in, delta):
493:    def kl_grad_pub():
505:    def emb_grad_pub():
517:  
…[truncated 3165 chars]

More structure of run_checks.py

shell
grep -n "def \|MILESTONE\|EPS\|TOL\|tol" run_checks.py | sed -n '120,220p'
output
1059:    def lsqplus_grid():
1065:    def qsepcnn_shape():
1070:    def qsepcnn_roundtrip():
1106:def check_optim(fw, sb):
1112:    def mk(seed):
1116:    def run(name, opt_fn, ref_step, nsteps, gseed):
1130:            results.append((f"optim/{name}", err < TOL_OPT, f"max_abs={err:.1e}"))
1134:    def sgd_step(lr, mu, wd):
1135:        def f(i, p, g, t, st):
1143:    def adagrad_step(lr, eps, wd):
1144:        def f(i, p, g, t, st):
1152:    def rmsprop_step(lr, alpha, eps, wd):
1153:        def f(i, p, g, t, st):
1161:    def adam_step(lr, b1, b2, eps, wd, decoupled):
1162:        def f(i, p, g, t, st):
1174:    def lion_step(lr, b1, b2, wd):
1175:        def f(i, p, g, t, st):
1196:    def adamax_step(lr, b1, b2, eps, wd):
1197:        def f(i, p, g, t, st):
1206:    def nadam_step(lr, b1, b2, eps, wd):
1207:        def f(i, p, g, t, st):
1218:    def adadelta_step(lr, rho, eps, wd):
1219:        def f(i, p, g, t, st):
1230:    def nesterov_step(lr, mu, wd):
1231:        def f(i, p, g, t, st):
1248:    def group_case():
1250:            def build():
1268:            ok = _max_abs(a0, r0) < TOL_OPT and _max_abs(a1, r1) < TOL_OPT
1274:    def split_case():
1293:    def clip_case(name, scale_in, max_norm):
1304:            results.append((f"optim/{name}", err < TOL_OPT and abs(ret - total) < 1e-6, f"max_abs={err:.1e}"))
1310:    def sched(name, fn, ref):
1313:            results.append((f"optim/{name}", err < TOL_SCHED, f"max_abs={err:.1e}"))
1317:    def ref_cosine(s):
1328:
…[truncated 424 chars]
Let me read the full run_checks.py to understand exact reference math and tolerances.

/app/run_checks.py

contents
84	def load_framework(root):
85	    ag = _load_module("agent_autograd", root / "autograd.py")
86	    nn = _load_module("agent_nn", root / "nn.py", inject={"autograd": ag})
87	    opt = _load_module("agent_optim", root / "optim.py", inject={"autograd": ag})
88	    data = _load_module("agent_data", root / "data.py")
89	    return {"autograd": ag, "nn": nn, "optim": opt, "data": data}
90	
91	
92	# --------------------------------------------------------------------------- numeric helpers
93	def _num_grad_input(forward, x, eps=EPS):
94	    g = np.zeros_like(x)
95	    flat = x.reshape(-1)
96	    gf = g.reshape(-1)
97	    for i in range(flat.size):
98	        old = flat[i]
99	        flat[i] = old + eps
100	        fp = float(np.sum(forward(x)))
101	        flat[i] = old - eps
102	        fm = float(np.sum(forward(x)))
103	        flat[i] = old
104	        gf[i] = (fp - fm) / (2 * eps)
105	    return g
106	
107	
108	def _max_abs(a, b):
109	    return float(np.max(np.abs(np.asarray(a, np.float64) - np.asarray(b, np.float64))))
110	
111	
112	def _bsum(it):
113	    s = 0
114	    for x in it:
115	        s += int(bool(x))
116	    return s
117	
118	
119	def _imax(a, b):
120	    return a if a > b else b
121	
122	
123	# ======================================================================= autograd_grads
124	def check_autograd_grads(fw, sb):
125	    ag = fw["autograd"]
126	    nn = fw["nn"]
127	    T = ag.Tensor
128	    results = []
129	
130	    def case(name, build, shape, seed, upstrea
…[truncated 12793 chars]

/app/run_checks.py

contents
344	                    p.data[...] = 1.0
345	            m.set_training(True)
346	            X = make_X(sb + seed + 5)
347	            tgt = np.array([0, 2])
348	            for p in m.params():
349	                p.grad = None
350	            ag.cross_entropy(m(X), tgt).backward()
351	            allfinite = all(p.grad is not None and np.all(np.isfinite(p.grad)) for p in m.params())
352	            ngrad = sum(1 for p in m.params() if p.grad is not None)
353	            results.append((f"grad/{name}", allfinite and ngrad == len(m.params()),
354	                            f"{ngrad}/{len(m.params())} grads, finite={allfinite}"))
355	        except Exception as e:  # noqa: BLE001
356	            results.append((f"grad/{name}", False, f"raised {type(e).__name__}: {e}"))
357	    quant_model_backprop("QuantCNN_backprop", lambda s: nn.QuantCNN(6, widths=(8, 16), seed=s),
358	                         lambda s: np.random.default_rng(s).standard_normal((2, 3, 16, 16)), 90)
359	    quant_model_backprop("QuantMLP_backprop", lambda s: nn.QuantMLP(6, img_size=8, hidden=(32, 16), seed=s),
360	                         lambda s: np.random.default_rng(s).standard_normal((2, 3, 8, 8)), 100)
361	
362	    # ---- EXTRA generic ops (same coverage as the held-out grader) ----
363	    case("square", lambda t: ag.square(t), (4, 5), 110)
364	    case("rsqrt", lambda t: ag.rsqrt(ag.add(t, T(5.0))), (4, 5), 111)
365	    case("reciprocal", lambda t: ag.reciprocal(ag.add(t, T(5.0))), (4, 5), 112)
366	
…[truncated 14060 chars]
Let me continue reading the quant_grads and remaining checks.

/app/run_checks.py

contents
583	# ======================================================================= quant_grads (LSQ / STE)
584	def check_quant_grads(fw, sb):
585	    ag = fw["autograd"]
586	    results = []
587	
588	    def grads(v0, s0, Qn, Qp, up):
589	        vt = ag.Tensor(v0.copy(), requires_grad=True)
590	        st = ag.Tensor(np.array([s0]), requires_grad=True)
591	        out = ag.fake_quant(vt, st, Qn, Qp)
592	        out.backward(up.copy())
593	        return np.asarray(vt.grad, np.float64), np.asarray(st.grad, np.float64), out.data.copy()
594	
595	    def ste_indicator(name, seed, Qn, Qp, s0):
596	        try:
597	            rng = np.random.default_rng(sb + seed)
598	            v0 = rng.standard_normal((5, 5)) * 2.0
599	            up = rng.standard_normal((5, 5))
600	            gv, _, _ = grads(v0, s0, Qn, Qp, up)
601	            r = v0 / s0
602	            middle = (r >= -Qn) & (r <= Qp)
603	            expected = up * middle
604	            ok = _max_abs(gv, expected) < 1e-9 and np.all(gv[~middle] == 0.0)
605	            results.append((f"quant/{name}", ok, f"err={_max_abs(gv, expected):.1e}"))
606	        except Exception as e:  # noqa: BLE001
607	            results.append((f"quant/{name}", False, f"raised {type(e).__name__}: {e}"))
608	    ste_indicator("ste_indicator_w", 60, 2, 1, 0.7)
609	    ste_indicator("ste_indicator_a", 61, 0, 3, 0.5)
610	
611	    def scale_clip(name, seed, Qn, Qp, s0, fill, bound):
612	        try:
613	            v0 = np.full((4, 4), fill)
614	      
…[truncated 16955 chars]

/app/run_checks.py

contents
922	
923	    def qmlp_roundtrip():
924	        m = nn.QuantMLP(10, img_size=16, hidden=(64, 32), seed=sb + 31)
925	        sd = m.state_dict()
926	        m2 = nn.QuantMLP(10, img_size=16, hidden=(64, 32), seed=sb + 32)
927	        m2.load_state_dict(sd)
928	        return True, f"keys={len(sd)}"
929	
930	    # ---- EXTRA op / activation / layer property checks (match the held-out coverage) ----
931	    def square_def():
932	        x = np.random.default_rng(sb + 40).standard_normal((4, 5))
933	        return _max_abs(ag.square(T(x)).data, x * x) < 1e-9, ""
934	
935	    def rsqrt_def():
936	        x = np.abs(np.random.default_rng(sb + 41).standard_normal((4, 5))) + 0.5
937	        return _max_abs(ag.rsqrt(T(x)).data, 1.0 / np.sqrt(x)) < 1e-9, ""
938	
939	    def var_def():
940	        x = np.random.default_rng(sb + 42).standard_normal((4, 5))
941	        return _max_abs(ag.var(T(x), axis=1).data, x.var(axis=1)) < 1e-9, ""
942	
943	    def std_def():
944	        x = np.random.default_rng(sb + 43).standard_normal((4, 5))
945	        return _max_abs(ag.std(T(x), axis=1).data, x.std(axis=1)) < 1e-9, ""
946	
947	    def softplus_def():
948	        x = np.random.default_rng(sb + 44).standard_normal((4, 5))
949	        return _max_abs(ag.softplus(T(x)).data, np.log1p(np.exp(x))) < 1e-6, ""
950	
951	    def silu_def():
952	        x = np.random.default_rng(sb + 45).standard_normal((4, 5))
953	        return _max_abs(ag.silu(T(x)).data, x / (1 + np.exp(-x))) < 1e-6, ""
954	
955	    d
…[truncated 9362 chars]
Now let me read the optim reference steps and schedulers, and the integration check.

/app/run_checks.py

contents
1122	            for s in range(nsteps):
1123	                grng = np.random.default_rng(gseed + s)
1124	                grads = [grng.standard_normal(p.data.shape) for p in ps]
1125	                for p, g in zip(ps, grads):
1126	                    p.grad = g.copy()
1127	                o.step()
1128	                ref = [ref_step(i, ref[i], grads[i].copy(), s + 1, st) for i in range(len(ps))]
1129	            err = max(_max_abs(p.data, ref[i]) for i, p in enumerate(ps))
1130	            results.append((f"optim/{name}", err < TOL_OPT, f"max_abs={err:.1e}"))
1131	        except Exception as e:  # noqa: BLE001
1132	            results.append((f"optim/{name}", False, f"raised {type(e).__name__}: {e}"))
1133	
1134	    def sgd_step(lr, mu, wd):
1135	        def f(i, p, g, t, st):
1136	            v = st.get(("v", i), np.zeros_like(p))
1137	            g = g + wd * p
1138	            v = mu * v + g
1139	            st[("v", i)] = v
1140	            return p - lr * v
1141	        return f
1142	
1143	    def adagrad_step(lr, eps, wd):
1144	        def f(i, p, g, t, st):
1145	            s = st.get(("s", i), np.zeros_like(p))
1146	            g = g + wd * p
1147	            s = s + g * g
1148	            st[("s", i)] = s
1149	            return p - lr * g / (np.sqrt(s) + eps)
1150	        return f
1151	
1152	    def rmsprop_step(lr, alpha, eps, wd):
1153	        def f(i, p, g, t, st):
1154	            s = st.get(("s", i), np.zeros_like(p))
1155	            g = g + wd * p
1156	  
…[truncated 16049 chars]
Let me check the tolerance constants and remaining bits.

/app/run_checks.py

contents
40	reward = 1 from the grader iff (every component milestone fully passes on the held-out cases) AND
41	(the bit-audit passes) AND (held-out top-1 >= the threshold). Drive THIS runner to all-green first,
42	then train. Exit code is 0 iff every public check here passes.
43	"""
44	from __future__ import annotations
45	
46	import argparse
47	import importlib.util
48	import math
49	import sys
50	from pathlib import Path
51	
52	import numpy as np
53	
54	TOL_GRAD = 2e-3
55	TOL_PROP = 1e-6
56	TOL_OPT = 1e-7
57	TOL_SCHED = 1e-9
58	EPS = 1e-5
59	
60	PUBLIC_SEED_BASE = 1000   # the GRADER uses a DIFFERENT base; do not curve-fit to these seeds.
61	
62	
63	# --------------------------------------------------------------------------- module loading
64	def _load_module(name, path, inject=None):
65	    saved = {}
66	    if inject:
67	        for k, v in inject.items():
68	            saved[k] = sys.modules.get(k)
69	            sys.modules[k] = v
70	    try:
71	        spec = importlib.util.spec_from_file_location(name, str(path))
72	        mod = importlib.util.module_from_spec(spec)
73	        spec.loader.exec_module(mod)
74	        return mod
75	    finally:
76	        if inject:
77	            for k, old in saved.items():
78	                if old is None:
79	                    sys.modules.pop(k, None)
80	                else:
81	                    sys.modules[k] = old
82	
83
I have a thorough understanding now. Let me check which functions referenced by checks are missing from the autograd stub (e.g. `batchnorm1d`).

Check missing functions and data shape

shell
cd /app/submission && for f in batchnorm1d conv2d conv2d_gen conv_transpose2d avgpool2d_s maxpool2d_s; do echo -n "$f: "; grep -c "^def $f" autograd.py; done
echo "--- data shape ---"
python3 -c "import numpy as np; d=np.load('/app/data/train.npz'); print(d['X'].shape, d['X'].dtype, d['y'].shape, np.unique(d['y']))"
output
batchnorm1d: 0
conv2d: 2
conv2d_gen: 1
conv_transpose2d: 1
avgpool2d_s: 1
maxpool2d_s: 1
--- data shape ---
(2500, 3, 16, 16) uint8 (2500,) [0 1 2 3 4 5 6 7 8 9]
I now fully understand the contracts. Let me check the data shape confirmed (2500×3×16×16, 10 classes). `batchnorm1d` is missing and must be added. I'll implement everything via a verified patcher script (no ARG_MAX issue with Write). Let me start with autograd.py.
write · /app/submission/_patch_ag.py
import io, sys
P = "/app/submission/autograd.py"
src = open(P).read()

R = []
def add(key, code):
    R.append((key, code))

# ---- backward orchestration
add('raise NotImplementedError("Tensor.backward")', '''topo = []
        visited = set()
        def build(t):
            if id(t) in visited:
                return
            visited.add(id(t))
            for p in t._parents:
                build(p)
            topo.append(t)
        build(self)
        if grad is None:
            grad = np.ones_like(self.data)
        self._accum(_as_f64(grad))
        for t in reversed(topo):
            if t.grad is not None:
                t._backward()''')

# ---- element-wise binary
add('raise NotImplementedError("add backward")', '''a._accum(_unbroadcast(out.grad, a.data.shape))
        b._accum(_unbroadcast(out.grad, b.data.shape))''')
add('raise NotImplementedError("sub backward")', '''a._accum(_unbroadcast(out.grad, a.data.shape))
        b._accum(_unbroadcast(-out.grad, b.data.shape))''')
add('raise NotImplementedError("mul backward")', '''a._accum(_unbroadcast(out.grad * b.data, a.data.shape))
        b._accum(_unbroadcast(out.grad * a.data, b.data.shape))''')
add('raise NotImplementedError("div backward")', '''a._accum(_unbroadcast(out.grad / b.data, a.data.shape))
        b._accum(_unbroadcast(-out.grad * a.data / (b.data * b.data), b.data.shape))''')
add('raise NotImplementedError("power backward")', '''a._accum(out.grad * p * (a.data ** (p - 1.0)))''')
add('raise Not
…[truncated 5709 chars]

contents
File created successfully at: /app/submission/_patch_ag.py (file state is current in your context , no need to Read it back)

Apply autograd patch batch 1

shell
python3 _patch_ag.py
output
patch batch 1 OK, replaced 34
Now batch 2: domain ops, batchnorm1d (new), fake_quant, and all extended ops.
write · /app/submission/_patch_ag2.py
P = "/app/submission/autograd.py"
src = open(P).read()
R = []
def add(key, code):
    R.append((key, code))

# ---- conv2d backward
add('raise NotImplementedError("conv2d backward")', '''g = out.grad
        dout_mat = g.reshape(N, Cout, OH * OW)
        dW = np.einsum("nop,ncp->oc", dout_mat, cols).reshape(Cout, Cin, KH, KW)
        weight._accum(dW)
        if has_bias:
            bias._accum(dout_mat.sum(axis=(0, 2)))
        dcols = np.einsum("oc,nop->ncp", Wm, dout_mat)
        dxp = _col2im(dcols, xp.shape, KH, KW, stride, OH, OW)
        if pad > 0:
            x._accum(dxp[:, :, pad:-pad, pad:-pad])
        else:
            x._accum(dxp)''')

# ---- avgpool2d backward
add('raise NotImplementedError("avgpool2d backward")', '''g = out.grad
        OHk, OWk = OH * k, OW * k
        gg = (g / (k * k))[:, :, :, None, :, None]
        gx = np.broadcast_to(gg, (N, C, OH, k, OW, k)).reshape(N, C, OHk, OWk)
        full = np.zeros_like(x.data)
        full[:, :, :OHk, :OWk] = gx
        x._accum(full)''')

# ---- maxpool2d backward
add('raise NotImplementedError("maxpool2d backward")', '''g = out.grad
        OHk, OWk = OH * k, OW * k
        xr2 = x.data[:, :, :OHk, :OWk].reshape(N, C, OH, k, OW, k)
        mx = xr2.max(axis=(3, 5), keepdims=True)
        mask = (xr2 == mx)
        cnt = mask.sum(axis=(3, 5), keepdims=True)
        gg = g[:, :, :, None, :, None]
        gx = (mask * gg / cnt).reshape(N, C, OHk, OWk)
        full = np.zeros_like(x.data)
        full[:, :, :O
…[truncated 5340 chars]

contents
File created successfully at: /app/submission/_patch_ag2.py (file state is current in your context , no need to Read it back)

Apply autograd patch batch 2

shell
python3 _patch_ag2.py
output
patch batch 2 OK, replaced 21
Now batch 3: v2 ops, transposed/grouped conv, overlapping pools, LSQ+, and inserting the missing `batchnorm1d`.
write · /app/submission/_patch_ag3.py
P = "/app/submission/autograd.py"
src = open(P).read()
R = []
def add(key, code):
    R.append((key, code))

# ---- v2 generic ops
add('raise NotImplementedError("cumsum backward")', '''g = out.grad
        a._accum(np.flip(np.cumsum(np.flip(g, axis=axis), axis=axis), axis=axis))''')
add('raise NotImplementedError("flip backward")', '''a._accum(np.flip(out.grad, axis=axis))''')
add('raise NotImplementedError("logsumexp backward")', '''g = out.grad
        if not keepdims:
            g = np.expand_dims(g, axis)
        a._accum(sm * g)''')
add('raise NotImplementedError("logaddexp backward")', '''g = out.grad
        wa = np.exp(a.data - out_data)
        wb = np.exp(b.data - out_data)
        a._accum(_unbroadcast(g * wa, a.data.shape))
        b._accum(_unbroadcast(g * wb, b.data.shape))''')
add('raise NotImplementedError("l2_normalize backward")', '''g = out.grad
        dot = (y * g).sum(axis=axis, keepdims=True)
        a._accum((g - y * dot) / nrm)''')
add('raise NotImplementedError("rms_norm backward")', '''g = out.grad
        ga = g * gamma.data
        s = (ga * xd).sum(axis=-1, keepdims=True)
        dx = inv * ga - (xd * (inv ** 3) / D) * s
        lead = tuple(range(g.ndim - 1))
        dgamma = (g * xhat).sum(axis=lead)
        x._accum(dx)
        gamma._accum(dgamma)''')
add('raise NotImplementedError("instance_norm backward")', '''g = out.grad
        dgamma = (g * xhat).sum(axis=(0, 2, 3))
        dbeta = g.sum(axis=(0, 2, 3))
        gg = (g * gamma.data.re
…[truncated 6032 chars]

contents
File created successfully at: /app/submission/_patch_ag3.py (file state is current in your context , no need to Read it back)

Apply batch 3 and import autograd

shell
python3 _patch_ag3.py && python3 -c "import sys; sys.path.insert(0,'/app/submission'); import autograd; print('import ok'); 
import subprocess
print([n for n in dir(autograd) if not n.startswith('_')][:50])"
output
patch batch 3 OK, replaced 15 + batchnorm1d
import ok
['Callable', 'Iterable', 'List', 'Optional', 'Tensor', 'abs', 'add', 'annotations', 'avgpool2d', 'avgpool2d_s', 'batchnorm1d', 'batchnorm2d', 'clip', 'concat', 'conv2d', 'conv2d_gen', 'conv_transpose2d', 'cross_entropy', 'cumsum', 'div', 'elu', 'embedding', 'exp', 'fake_quant', 'fake_quant_affine', 'fake_quant_lsq_plus', 'fake_quant_per_channel', 'flip', 'gather', 'gelu', 'getitem', 'groupnorm', 'hardsigmoid', 'hardtanh', 'huber_loss', 'instance_norm', 'kl_div', 'l2_normalize', 'layernorm', 'leaky_relu', 'log', 'log_softmax', 'logaddexp', 'logsumexp', 'matmul', 'max', 'maximum', 'maxpool2d', 'maxpool2d_s', 'mean']
Now let me fill in nn.py, optim.py, data.py via a patcher.
write · /app/submission/_patch_nn.py
P = "/app/submission/nn.py"
src = open(P).read()
R = []
def add(key, code):
    R.append((key, code))

add('raise NotImplementedError("Linear.forward")', '''y = ag.matmul(x, self.weight)
        if self.bias is not None:
            y = ag.add(y, self.bias)
        return y''')
add('raise NotImplementedError("MLP.forward")', '''return ag.add(x, self.fc2(ag.gelu(self.fc1(x))))''')
add('raise NotImplementedError("LayerNorm.forward")', '''return ag.layernorm(x, self.gamma, self.beta, self.eps)''')
add('raise NotImplementedError("Conv2d.forward")', '''return ag.conv2d(x, self.weight, bias=self.bias, stride=self.stride, pad=self.padding)''')
add('raise NotImplementedError("MaxPool2d.forward")', '''return ag.maxpool2d(x, self.k)''')
add('raise NotImplementedError("AvgPool2d.forward")', '''return ag.avgpool2d(x, self.k)''')
add('raise NotImplementedError("WeightQuant.quant")', '''return ag.fake_quant(w, self.scale, W_NEG, W_POS)''')
add('raise NotImplementedError("ActQuant.forward")', '''return ag.fake_quant(x, self.scale, A_NEG, A_POS)''')
add('raise NotImplementedError("BatchNorm2d.forward")', '''return ag.batchnorm2d(x, self.gamma, self.beta, self.eps,
                             self.running_mean, self.running_var, self.momentum, self.training)''')
add('raise NotImplementedError("BatchNorm1d.forward")', '''return ag.batchnorm1d(x, self.gamma, self.beta, self.eps,
                             self.running_mean, self.running_var, self.momentum, self.training)''')
add('raise NotIm
…[truncated 4880 chars]

contents
File created successfully at: /app/submission/_patch_nn.py (file state is current in your context , no need to Read it back)

Apply nn patch

shell
python3 _patch_nn.py
output
nn patched, replaced 32
Now optim.py and data.py:
write · /app/submission/_patch_opt.py
P = "/app/submission/optim.py"
src = open(P).read()
R = []
def add(key, code):
    R.append((key, code))

add('raise NotImplementedError("SGD.step")', '''idx = 0
        for plist, override in self._groups:
            wd = self.weight_decay if override is None else override
            for p in plist:
                if p.grad is None:
                    idx += 1
                    continue
                g = p.grad + wd * p.data
                self._v[idx] = self.momentum * self._v[idx] + g
                p.data -= self.lr * self._v[idx]
                idx += 1''')

add('raise NotImplementedError("AdamW.step")', '''self.t += 1
        idx = 0
        for plist, override in self._groups:
            wd = self.weight_decay if override is None else override
            for p in plist:
                if p.grad is None:
                    idx += 1
                    continue
                g = p.grad
                self._m[idx] = self.b1 * self._m[idx] + (1 - self.b1) * g
                self._v[idx] = self.b2 * self._v[idx] + (1 - self.b2) * (g * g)
                mhat = self._m[idx] / (1 - self.b1 ** self.t)
                vhat = self._v[idx] / (1 - self.b2 ** self.t)
                p.data -= self.lr * (mhat / (np.sqrt(vhat) + self.eps) + wd * p.data)
                idx += 1''')

add('raise NotImplementedError("Adam.step")', '''self.t += 1
        idx = 0
        for plist, override in self._groups:
            wd = self.weight_decay if override is None else ove
…[truncated 6570 chars]

contents
File created successfully at: /app/submission/_patch_opt.py (file state is current in your context , no need to Read it back)

Apply optim patch

shell
python3 _patch_opt.py
output
optim patched, replaced 19

/app/submission/data.py

− removed
    # TODO: cast to float, scale to [0,1], subtract NORM_MEAN, divide by NORM_STD.
    raise NotImplementedError("normalize")
+ added
    return (X.astype(np.float64) / 255.0 - NORM_MEAN) / NORM_STD

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

/app/submission/data.py

− removed
    # TODO: optionally shuffle an index array, then yield contiguous batch_size slices of it.
    raise NotImplementedError("iter_minibatches")
+ added
    n = Xn.shape[0]
    idx = np.arange(n)
    if shuffle:
        rng.shuffle(idx)
    for start in range(0, n, batch_size):
        sel = idx[start:start + batch_size]
        yield Xn[sel], y[sel]

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 let me run the public checks:

Run all public checks quiet

shell
cd /app && python3 run_checks.py --quiet 2>&1 | tail -20
output
------------------------------------------------------------------------
autograd_grads 114/115 | quant_grads 21/21 | nn_forward 53/53 | optim 25/25 | integration 6/6 | data 2/2
TOTAL  221/222 public checks passing
Fix the FAIL lines above (each is a backward/forward/optimizer bug). Re-run until all green, then train.
Excellent , 221/222. Let me find the one failing autograd check.

Find failing autograd check

shell
python3 run_checks.py --only autograd_grads 2>&1 | grep -i fail
output
grad/pad2d                               FAIL  (raised NameError: name 'a' is not defined)
Fix the FAIL lines above (each is a backward/forward/optimizer bug). Re-run until all green, then train.
The pad2d input is named `x`, not `a`. Let me fix that.

/app/submission/autograd.py

− removed
        g = out.grad
        if pad > 0:
            a._accum(g[:, :, pad:-pad, pad:-pad])
        else:
            a._accum(g)  # TODO
+ added
        g = out.grad
        if pad > 0:
            x._accum(g[:, :, pad:-pad, pad:-pad])
        else:
            x._accum(g)  # TODO

contents
<tool_use_error>File has been modified since read, either by the user or by a linter. Read it again before attempting to write it.</tool_use_error>

Fix pad2d input name

shell
cd /app/submission && python3 - <<'PY'
P="autograd.py"; s=open(P).read()
old='''        g = out.grad
        if pad > 0:
            a._accum(g[:, :, pad:-pad, pad:-pad])
        else:
            a._accum(g)  # TODO'''
new='''        g = out.grad
        if pad > 0:
            x._accum(g[:, :, pad:-pad, pad:-pad])
        else:
            x._accum(g)  # TODO'''
assert s.count(old)==1, s.count(old)
open(P,"w").write(s.replace(old,new)); print("fixed pad2d")
PY
output
fixed pad2d

Re-run all checks

shell
cd /app && python3 run_checks.py --quiet 2>&1 | tail -4
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 public checks pass. Now let me write the training loop in train.py.

/app/submission/train.py

− removed
def train(data_path, out_path, epochs=30, seed=0, n_classes=10):
    # TODO: load + normalize the data; build QuantCNN(n_classes, WIDTHS, seed); initialize the LSQ
    # step sizes; build the optimizer with weight decay only on the conv/head weights; run the QAT
    # loop (forward -> cross_entropy -> backward -> clip_grad_norm -> step) with an LR schedule;
    # keep your best epoch; BAKE the quantized weights; save the state_dict to out_path.
    raise NotImplementedError("implement the QAT training loop")
+ added
W_NEG, W_POS = 2, 1


def _init_scales(m):
    nps = m.named_params()
    for nm, p in nps.items():
        if nm.endswith("wq.scale"):
            wkey = nm[:-len("wq.scale")] + "weight"
            p.data[...] = max(2.0 * float(np.mean(np.abs(nps[wkey].data))) / np.sqrt(W_POS), 1e-2)
        elif nm.endswith("aq.scale"):
            p.data[...] = 1.0


def _accuracy(m, Xn, y, bs=256):
    m.set_training(False)
    correct = 0
    for s in range(0, Xn.shape[0], bs):
        xb = Xn[s:s + bs]
        logits = m(xb).data
        correct += int((logits.argmax(axis=1) == y[s:s + bs]).sum())
    return correct / Xn.shape[0]


def _bake(m):
    """Replace each conv/head weight with its 2-bit-quantized values (round(clip(w/s))*s)."""
    nps = m.named_params()
    for nm, p in nps.items():
        if nm.endswith("wq.scale"):
            wkey = nm[:-len("wq.scale")] + "weight"
            w = nps[wkey]
            s = float(p.data.reshape(()))
            s = s if abs(s) > 1e-12 else 1e-12
            q = np.round(np.clip(w.data / s, -W_NEG, W_POS))
            w.data[...] = q * s


def train(data_path, out_path, epochs=40, seed=0, n_classes=10):
    X, y = D.load_npz(data_path)
    Xn = D.normalize(X)
    rng = np.random.default_rng(1234)
    perm = rng.permutation(Xn.shape[0])
    Xn, y = Xn[perm], y[perm]
    n_val = 400
    Xtr, ytr = Xn[n_val:], y[n_val:]
    Xva, yva = Xn[:n_val], y[:n_val]

    m = QuantCNN(n_classes, WIDTHS, seed=seed)
    _init_scales(m)

    groups = O.spl
…[truncated 1593 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 4-epoch smoke run to verify training works and gauge accuracy.

Smoke train 4 epochs

shell
cd /app/submission && time python3 train.py --epochs 4 --out /tmp/qat_test.npz 2>&1 | tail -10
output
real	0m0.836s
user	0m0.768s
sys	0m0.136s

Run train showing errors

shell
python3 train.py --epochs 2 --out /tmp/qat_test.npz 2>&1 | head -30
output
(Bash completed with no output)

Run train unbuffered with exit code

shell
python3 -u train.py --epochs 2 --out /tmp/qat_test.npz; echo "EXIT=$?"
output
/bin/bash: line 1:  1535 Killed                  python3 -u train.py --epochs 2 --out /tmp/qat_test.npz
EXIT=137
Killed quickly , likely a memory blowup. Let me isolate with a minimal forward/backward.

Minimal forward/backward memory test

shell
python3 -u - <<'PY'
import numpy as np, resource, sys
import autograd as ag, data as D
from nn import QuantCNN
X,y=D.load_npz("/app/data/train.npz"); Xn=D.normalize(X)
m=QuantCNN(10,(16,32),seed=0); m.set_training(True)
xb=Xn[:128]; yb=y[:128]
print("forward..."); sys.stdout.flush()
logits=m(xb)
print("logits",logits.data.shape)
loss=ag.cross_entropy(logits,yb)
print("loss",float(loss.data)); sys.stdout.flush()
loss.backward()
print("backward done")
print("maxrss MB", resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/1024)
PY
echo "EXIT=$?"
output
forward...
logits (128, 10)
loss 2.302585092994046
backward done
maxrss MB 195.04296875
EXIT=0
Single step is fine (195MB). Let me check available memory and run the train function with step-by-step prints.

Check memory and run one epoch loop

shell
free -m | head -2; echo "---"; python3 -u - <<'PY'
import numpy as np, resource, sys
import autograd as ag, data as D, optim as O
from nn import QuantCNN
X,y=D.load_npz("/app/data/train.npz"); Xn=D.normalize(X)
m=QuantCNN(10,(16,32),seed=0); m.set_training(True)
g=O.split_decay_params(m)
opt=O.Adam([{"params":g["decay"],"weight_decay":5e-4},{"params":g["no_decay"],"weight_decay":0.0}],lr=4e-3)
drng=np.random.default_rng(7)
for i,(xb,yb) in enumerate(D.iter_minibatches(Xn[:2000],y[:2000],128,drng)):
    logits=m(xb); loss=ag.cross_entropy(logits,yb)
    opt.zero_grad(); loss.backward(); O.clip_grad_norm(m.params(),3.0); opt.step()
    if i%4==0:
        print(i, float(loss.data), "rss", resource.getrusage(resource.RUSAGE_SELF).ru_maxrss//1024); sys.stdout.flush()
print("epoch done")
PY
echo EXIT=$?
output
total        used        free      shared  buff/cache   available
Mem:             481         229         174           1          91         252
---
0 2.302585092994046 rss 196
/bin/bash: line 32:  1549 Killed                  python3 -u - <<'PY'
import numpy as np, resource, sys
import autograd as ag, data as D, optim as O
from nn import QuantCNN
X,y=D.load_npz("/app/data/train.npz"); Xn=D.normalize(X)
m=QuantCNN(10,(16,32),seed=0); m.set_training(True)
g=O.split_decay_params(m)
opt=O.Adam([{"params":g["decay"],"weight_decay":5e-4},{"params":g["no_decay"],"weight_decay":0.0}],lr=4e-3)
drng=np.random.default_rng(7)
for i,(xb,yb) in enumerate(D.iter_minibatches(Xn[:2000],y[:2000],128,drng)):
    logits=m(xb); loss=ag.cross_entropy(logits,yb)
    opt.zero_grad(); loss.backward(); O.clip_grad_norm(m.params(),3.0); opt.step()
    if i%4==0:
        print(i, float(loss.data), "rss", resource.getrusage(resource.RUSAGE_SELF).ru_maxrss//1024); sys.stdout.flush()
print("epoch done")
PY

EXIT=137
Only 481MB RAM total, and autograd graph cycles (Tensor↔closure) aren't freed by refcounting. Let me add `gc.collect()` and use a smaller batch.

Test with gc.collect and batch 64

shell
python3 -u - <<'PY'
import numpy as np, resource, sys, gc
import autograd as ag, data as D, optim as O
from nn import QuantCNN
X,y=D.load_npz("/app/data/train.npz"); Xn=D.normalize(X)
m=QuantCNN(10,(16,32),seed=0); m.set_training(True)
g=O.split_decay_params(m)
opt=O.Adam([{"params":g["decay"],"weight_decay":5e-4},{"params":g["no_decay"],"weight_decay":0.0}],lr=4e-3)
drng=np.random.default_rng(7)
for i,(xb,yb) in enumerate(D.iter_minibatches(Xn[:2000],y[:2000],64,drng)):
    logits=m(xb); loss=ag.cross_entropy(logits,yb)
    opt.zero_grad(); loss.backward(); O.clip_grad_norm(m.params(),3.0); opt.step()
    del logits, loss; gc.collect()
    if i%8==0:
        print(i, "rss", resource.getrusage(resource.RUSAGE_SELF).ru_maxrss//1024); sys.stdout.flush()
print("epoch done rss", resource.getrusage(resource.RUSAGE_SELF).ru_maxrss//1024)
PY
echo EXIT=$?
output
0 rss 123
8 rss 126
16 rss 126
24 rss 127
epoch done rss 127
EXIT=0
Memory stable at ~127MB with gc. Let me update train.py to free graphs each step and use batch 64.

/app/submission/train.py

− removed
import numpy as np

sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+ added
import gc

import numpy as np

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

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

/app/submission/train.py

− removed
def _accuracy(m, Xn, y, bs=256):
    m.set_training(False)
    correct = 0
    for s in range(0, Xn.shape[0], bs):
        xb = Xn[s:s + bs]
        logits = m(xb).data
        correct += int((logits.argmax(axis=1) == y[s:s + bs]).sum())
    return correct / Xn.shape[0]
+ added
def _accuracy(m, Xn, y, bs=128):
    m.set_training(False)
    correct = 0
    for s in range(0, Xn.shape[0], bs):
        xb = Xn[s:s + bs]
        out = m(xb)
        correct += int((out.data.argmax(axis=1) == y[s:s + bs]).sum())
        del out
        gc.collect()
    return correct / Xn.shape[0]

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

/app/submission/train.py

− removed
    bs = 128
    steps_per_epoch = int(np.ceil(Xtr.shape[0] / bs))
+ added
    bs = 64
    steps_per_epoch = int(np.ceil(Xtr.shape[0] / bs))

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

/app/submission/train.py

− removed
            O.clip_grad_norm(m.params(), 3.0)
            opt.step()
            gstep += 1
+ added
            O.clip_grad_norm(m.params(), 3.0)
            opt.step()
            del logits, loss
            gc.collect()
            gstep += 1

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

Train 6 epochs to gauge accuracy/time

shell
time python3 -u train.py --epochs 6 --out /tmp/qat_test.npz 2>&1 | tail -12; echo EXIT=$?
output
Traceback (most recent call last):
  File "/app/submission/train.py", line 154, in <module>
    main()
  File "/app/submission/train.py", line 150, in main
    train(args.data, args.out, epochs=args.epochs, seed=args.seed, n_classes=args.n_classes)
  File "/app/submission/train.py", line 122, in train
    print(f"epoch {ep+1}/{epochs} lr={lr:.4f} loss={float(loss.data):.3f} val={acc:.3f} tr={tr_acc:.3f}", flush=True)
                                                          ^^^^
UnboundLocalError: cannot access local variable 'loss' where it is not associated with a value

real	0m10.547s
user	0m9.795s
sys	0m0.840s
EXIT=0
I deleted `loss` before the print. Let me capture the value first.

/app/submission/train.py

− removed
            O.clip_grad_norm(m.params(), 3.0)
            opt.step()
            del logits, loss
            gc.collect()
            gstep += 1
        acc = _accuracy(m, Xva, yva)
        tr_acc = _accuracy(m, Xtr[:1000], ytr[:1000])
        print(f"epoch {ep+1}/{epochs} lr={lr:.4f} loss={float(loss.data):.3f} val={acc:.3f} tr={tr_acc:.3f}", flush=True)
+ added
            O.clip_grad_norm(m.params(), 3.0)
            opt.step()
            last_loss = float(loss.data)
            del logits, loss
            gc.collect()
            gstep += 1
        acc = _accuracy(m, Xva, yva)
        tr_acc = _accuracy(m, Xtr[:1000], ytr[:1000])
        print(f"epoch {ep+1}/{epochs} lr={lr:.4f} loss={last_loss:.3f} val={acc:.3f} tr={tr_acc:.3f}", flush=True)

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

Train 8 epochs gauge

shell
time python3 -u train.py --epochs 8 --out /tmp/qat_test.npz 2>&1 | tail -12; echo EXIT=$?
output
epoch 1/8 lr=0.0040 loss=2.288 val=0.133 tr=0.165
epoch 2/8 lr=0.0038 loss=2.051 val=0.135 tr=0.196
epoch 3/8 lr=0.0033 loss=1.668 val=0.340 tr=0.409
epoch 4/8 lr=0.0025 loss=1.324 val=0.645 tr=0.694
epoch 5/8 lr=0.0016 loss=0.939 val=0.550 tr=0.622
epoch 6/8 lr=0.0008 loss=0.919 val=0.772 tr=0.829
epoch 7/8 lr=0.0003 loss=0.736 val=0.800 tr=0.837
epoch 8/8 lr=0.0001 loss=0.791 val=0.820 tr=0.849
best_val=0.820 baked_val=0.820 saved->/tmp/qat_test.npz

real	1m24.139s
user	1m17.647s
sys	0m6.574s
EXIT=0
Working well , val=0.82 at INT-2, baked matches. Let me verify the checkpoint bit-audit and key contract, then run a longer training.

Verify checkpoint audit and load

shell
python3 -u - <<'PY'
import numpy as np
from nn import QuantCNN
d=np.load("/tmp/qat_test.npz")
m=QuantCNN(10,(16,32),seed=0)
sd={k:d[k] for k in d.files}
m.load_state_dict(sd)  # validates keys/shapes
# bit audit
bad=0
for k in d.files:
    if k.endswith("weight") and ("conv" in k or "head" in k):
        u=np.unique(d[k])
        if u.size>4: bad+=1; print("AUDIT FAIL",k,u.size)
print("audit ok" if bad==0 else "AUDIT FAIL", "; total keys",len(d.files))
print("sample weight uniques:", np.unique(d["stem.conv.weight"]).size, np.unique(d["head.weight"]).size)
PY
output
audit ok ; total keys 24
sample weight uniques: 4 3
Audit passes. Now let me run a full training (36 epochs) saving to the real checkpoint path, in the background.

Start full training in background

shell
nohup python3 -u train.py --epochs 36 --out /app/submission/qat_model.npz > /tmp/train_full.log 2>&1 &
echo "started pid $!"
output
started pid 1582

Wait and check training progress

shell
sleep 180; tail -8 /tmp/train_full.log
output
<tool_use_error>Blocked: sleep 180 followed by: tail -8 /tmp/train_full.log. 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>

Wait for training to finish then show log

shell
until ! kill -0 1582 2>/dev/null; do sleep 10; done; echo "=== DONE ==="; tail -15 /tmp/train_full.log
output
Command running in background with ID: b2wdjci7u. Output is being written to: /tmp/claude-1000/-app/18edea3b-2147-48c9-a1cb-d8972ca3194c/tasks/b2wdjci7u.output. You will be notified when it completes. To check interim output, use Read on that file path.

Peek at training log

shell
sleep 60; tail -6 /tmp/train_full.log
output
<tool_use_error>Blocked: sleep 60 followed by: tail -6 /tmp/train_full.log. 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>
I'll wait for the background monitor to notify me. Let me peek at the log directly meanwhile.

/tmp/train_full.log

contents
1	epoch 1/36 lr=0.0040 loss=2.288 val=0.133 tr=0.165
2
Training is running. Let me clean up the temporary patcher scripts while waiting (they're no longer needed).

Remove temporary patch scripts

shell
rm -f _patch_ag.py _patch_ag2.py _patch_ag3.py _patch_nn.py _patch_opt.py && ls
output
__pycache__
autograd.py
data.py
nn.py
optim.py
train.py
Everything is clean and on track. Let me wait for the training run to complete.

Block until training process exits

shell
until ! kill -0 1582 2>/dev/null; do sleep 15; done; echo DONE
output
Command running in background with ID: bo7qgd1fd. Output is being written to: /tmp/claude-1000/-app/18edea3b-2147-48c9-a1cb-d8972ca3194c/tasks/bo7qgd1fd.output. You will be notified when it completes. To check interim output, use Read on that file path.
ScheduleWakeup
{
  "delaySeconds": 360,
  "reason": "Waiting for 36-epoch CPU training (~6 min) to finish, then verify checkpoint.",
  "prompt": "Check training completion and verify final qat_model.npz"
}

contents
Next wakeup scheduled for 22:35:00 (in 412s). Nothing more to do this turn , the harness re-invokes you when the wakeup fires or a task-notification arrives.
I'll wait for the training to complete. The background monitor will notify me.

/tmp/train_full.log

contents
1	epoch 1/36 lr=0.0040 loss=2.288 val=0.133 tr=0.165
2	epoch 2/36 lr=0.0040 loss=2.070 val=0.107 tr=0.138
3	epoch 3/36 lr=0.0040 loss=1.621 val=0.383 tr=0.450
4	epoch 4/36 lr=0.0039 loss=1.209 val=0.655 tr=0.686
5
Training is progressing well (epoch 4: val=0.655). I'll wait for completion notification.

/tmp/train_full.log

contents
Wasted call , file unchanged since your last Read. Refer to that earlier tool_result instead.
I'll stop polling and wait for the background task notification.
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: 278/278 cases passed  (all milestones pass: True)
FINAL METRIC: held-out INT2 top-1 = 0.8527  >= threshold 0.7

REWARD = 1   (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_faa5dd0f181b47ab. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_faa5dd0f181b47ab · verifier authoritative; classifier explanatory.