Open Agent Hackathon 2026 — Track 3: Reasoning Architecture

The trust layer that lets AI agents spend money safely.

An agent that can complete a purchase can also be manipulated into paying for something the user never asked for. PayWall.ai authorizes every agent-initiated payment against the user's intent, policy, and risk — before it ever reaches Razorpay.

Zetaris data layerMeterless NightshiftMeterless H-MEM memoryNVIDIA Nemotron

Guard Decision

Live simulation

Payment request

Nike Running Shoes

₹4,799

4
DecisionAllow

Matches user intent, within budget, low-risk merchant.

The problem

Traditional fraud detection asks the wrong question.

Traditional fraud detection

“Is this transaction fraudulent?”

PayWall.ai

“Is this transaction authorized, consistent with the user's intent, within policy, and safe to execute?”

How it decides

Three layers, one bounded decision.

Layer 1

Hard Policy Rules

Deterministic checks — agent status, merchant blocklist, transaction and daily limits, category authorization. Any violation blocks outright, no ML or LLM required.

Layer 2

ML Risk Model

An XGBoost classifier scores every transaction 0–100 on amount deviation, merchant risk, velocity, and budget headroom.

Layer 3

LLM Intent Match

Compares what's being paid for against what the user actually asked for. Falls back to a deterministic scorer and fails closed to REVIEW if the LLM is unavailable — never guesses.

AllowReviewBlock

Revenue growth, not just safety

One pipeline. Two outcomes.

The Upsell Agent proposes one relevant, budget-aware add-on after a purchase — and it has no special authority. Its proposal is evaluated by the exact same Guard as any other payment.

Legitimate upsell

Running socks, ₹149 — offered after a shoe purchase

Same category, within remaining budget, relevant to intent

ALLOW → counts as incremental GMV

Manipulated “upsell”

Protection plan, ₹14,999 — disguised as a checkout add-on

Unrelated category, exceeds authorization, low intent match

BLOCK → exposure prevented

Architecture

The agent proposes. The Guard authorizes.

1

User states intent

“Buy running shoes under ₹5,000”

2

Agent proposes a payment

POST /transactions/evaluate

3

Guard decides

Policy → Risk → Intent, combined

4

Razorpay executes

Only after ALLOW, or REVIEW + human approval

Let AI agents transact.
Don't let them transact beyond what the user authorized.