playground // telemetry bench
Monaco sandbox for firmware-style traces.
Run snippets inside a worker-isolated Monaco editor with the lab-fabricator dataset baked in. Share the entire session via the URL payload—code, input, and timer limits stay intact across devices.
- VS Code keybinds, diagnostics, and JS/TS language services in the browser.
- Dataset helpers for the telemetry bench: frame integrity, spiral offsets, salted XOR, and SHA-256 verification.
- Worker runtime isolates the code, overriding console/timers for safe output.
Desktop-only
The Monaco playground currently targets desktop browsers. Load this page on a laptop or desktop to edit and run snippets, or read the walkthrough below for the decoding steps.
Lab-fabricator write-up →Code
Console
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playground // telemetry bench
Decode the trace, prove the flag.
The dataset hides each byte across paired frames. Spiral offsets salt every index, an XOR pass ties it to the key, and the worker sandbox verifies the recovered flag with SHA-256. You only need the math.
- Integrity first: ensure
frames[i] ^ keyShift === frames[i-1]before decoding. - Undo the spiral offset, XOR with the key, rotate right by three bits, and concatenate.
- Submit the recovered string via the flag verifier below to confirm the hash.
const spiral = (n) => (n * n + 11 * n + 7) & 0xff;
for (let i = 0; i < frames.length; i += 2) {
const idx = i / 2;
const A = frames[i];
const B = frames[i + 1];
const salted = (A - spiral(idx) + 256) & 0xff;
const rotated = salted ^ key[idx % key.length];
bytes.push(rotRight8(rotated, 3));
}Stats: 66 bytes · 33 chars · key length 6.
Tip: load the dataset button, convert the byte array, then verify via SHA-256.
Need a guide? The lab-fabricator write-up covers each step.
Lab-fabricator write-up →