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Portir is a non-custodial app and agent for buying tokenized US stocks on BNB Chain at a fair price. It checks the US market session and the exchange price before every order, runs your recurring plans only when the price is fair, and keeps loans against your stocks out of liquidation. Stocks, not tokens: what you hold is the issuer’s stock token (Ondo, bStocks or xStocks) in your own wallet.
The Guard: four checks before every order

The Guard: four checks before every order

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The problem

Tokenized US stocks trade on BNB Chain around the clock. The stocks they track do not.
It is 3 AM in Jakarta and the NYSE is closed. The on-chain pool keeps trading with no exchange price to anchor it. On one night NVIDIA traded 1.4% above its close. A buyer who taps Buy at that moment overpays, and nothing in a normal wallet tells them so.
Ondo, bStocks and xStocks all list NVIDIA, with different multipliers (shares per token), different halts (dividends, splits, earnings) and different staleness. A naive “cheapest token” choice often picks the one whose price is simply out of date.
Dollar-cost averaging works best when it is boring and automatic. On-chain, “automatic” usually means a bot that buys at the scheduled minute, whatever the price and whether or not the market is open.
Venus accepts tokenized stocks as collateral. A sharp move overnight can push a position past its liquidation threshold before the borrower wakes up.

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The solution

1

A Guard before every order

Portir reads the US session and the exchange reference price from the Binance RWA Data API, compares it with the on-chain price, and answers GO, WARN or BLOCK with one plain sentence. Above a 1% premium the order is blocked. See The Guard.
2

Plans that wait for a fair price

You set a stock or a basket, an amount and a cadence. An agent on BNB Agent Studio checks every 15 minutes and never buys into a blocked price. With smart timing on, it also waits for the US market to open and the price to be fair, up to 48 hours past the due time. See Plans.
3

Your money never sits with Portir

Plans live in the PlanRegistry contract. You approve the registry, not the agent, and the agent can pull at most one run’s amount per due plan. Shares land in your own wallet.
4

Every decision on-chain

Each run is recorded as Executed, Waited or Skipped with a one-sentence reason, readable by anyone on BscScan.
5

A guard for your loan, too

LoanGuard repays part of a Venus loan from your own safety buffer once it crosses your trigger, after re-checking the position on-chain. See Loan Guard.
Loan Guard: from 85.7% back to 60% in one repayment

Loan Guard: from 85.7% back to 60% in one repayment

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Who it is for

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One engine, every surface

The app, the MCP server and the agent all run the same Guard engine. A verdict you see in the app is the verdict Claude sees over MCP and the one the agent acts on.

How it works

The full flow from tap to transaction.

Quickstart

Your first guarded buy on testnet in five minutes.