Razorpay AI Buildathon, Track 2

Mule-ring detection,
built on graph structure.

A graph neural network flags coordinated mule-account rings by looking at who an account is connected to, not just its own transaction history.

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Recall: real mule accounts correctly caught in the held-out test set
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Precision
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F1
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False alarms
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Mules in test set
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Why a graph, not a flat feature table

A single mule account often doesn't look suspicious on its own: normal-ish transaction count, normal-ish amounts. What gives it away is who it's connected to. A chain of accounts passing the same money along fast, or a cluster of ordinary accounts quietly feeding into one collection point. A flat per-account model can't see that, because "my neighbor also looks weird" isn't a column in a feature table. A GNN can. It passes information along edges, so a node's prediction is built from its own features and its neighbors'.

Account Lookup

Inspect any test-set account.

See the model's prediction, its confidence, and the immediate transaction neighborhood that shaped it.

Guided walkthrough
node 304

Also worth a look: , a false positive the model's own features can actually explain.

predicted mule predicted normal predicted, but wrong arrows show transaction direction scroll to zoom, drag to pan, click a ringed neighbor to jump in
PREDICTION
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CONFIDENCE
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TRUE LABEL
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Error Analysis

Where it succeeds, where it fails.

Read honestly, including the mistakes that don't have a tidy explanation.

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Layering-chain recall
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Funnel recall
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Funnel mules are harder to catch. They only look unusual once the model sees that their neighbor (the collector) has an abnormal in-degree, and that needs 2-hop reasoning, learned from just 6 funnel-collector examples in training.

False positives