AI agent execution infrastructure for Robinhood Chain and Arbitrum, helping agents access models, call tools, monitor markets, and execute onchain actions with better control.
Sumplus Cashier is a control and verification layer for AI agent spending on Arbitrum and Robinhood Chain.
As AI agents begin to call tools, APIs, models, and services on their own, a normal gateway only shows the bill after money is spent. Cashier adds control before execution and proof after execution.
Before each paid call, Cashier checks policy rules such as per-call ceiling, session cap, host allowlist, and allowed actions. If the call is allowed, it proceeds to the upstream service. If it is refused, the refusal is also recorded with a clear reason.
After each decision, Cashier creates a hash-chained receipt. Anyone can recompute the receipt chain and verify whether the spending record has been modified, without trusting Sumplus as the operator.
For this buildathon, Cashier is positioned for agentic finance on Arbitrum and Robinhood Chain, where AI agents may need to pay for models, data, APIs, trading signals, and execution services under clear spending limits.
Sumplus Cashier has a working live demo and public GitHub repository.
Current progress includes:
Live deployed demo on Railway
Policy checks before agent-paid calls
Refused calls with human-readable reasons
Hash-chained receipt ledger
Receipt verification page
Negative control test showing edited receipts are rejected
Integration with Arsenal capability data
Integration with SafeRouter attestation and verification flow
Local run instructions and verification scripts
The current demo is read-only and does not move real funds. It demonstrates how AI agent spending can be controlled and verified before being extended to real payment and execution flows on Arbitrum / Robinhood Chain.
Sumplus is currently in an early product and ecosystem growth stage.
The team is focused on building trusted execution infrastructure for AI agents through SafeRouter, Arsenal, Maria, and Cashier.
Cashier extends this stack by adding policy-based spending control and verifiable receipts for agent payments, especially for agentic finance, tokenized assets, AI-driven trading, and onchain service payments on ecosystems such as Arbitrum and Robinhood Chain.
Current traction includes:
48K+ X / Twitter followers
51K+ global community users
5000+ core users
300+ ecosystem partners
Arsenal with 166 live Skills
2 hackathon recognitions: Solana × Metaplex Hackathon 2nd Place and Mantle Turing Test Hackathon 2026 Project Deployment Award
Sumplus is open to ecosystem partnerships, grants, strategic support, and potential investment discussions.