GPT wallet AiFinPay

A self-custodial multichain wallet inside ChatGPT that lets users and AI agents manage balances, prepare payments, set spending rules, approve transactions, and operate across 12 blockchain networks.

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Inspiration

AI agents are becoming capable of researching, booking services, calling APIs and completing complex tasks, but they still cannot independently manage payments inside a conversation. We wanted to build a secure payment layer that allows both users and autonomous AI agents to prepare, approve and execute transactions without leaving ChatGPT.

What it does

AiFinPay Wallet for ChatGPT is a programmable multichain wallet and payment approval layer built directly into ChatGPT.

Users can:

  • Create or connect a wallet
  • View balances and transaction history
  • Receive assets
  • Prepare and send payments through natural-language commands
  • Select between 12 supported blockchain networks
  • Set transaction limits and spending policies
  • Review and approve payments before execution
  • Track transaction status, receipts and audit history

The wallet is also designed for autonomous AI agents. An agent can prepare a payment request, but execution remains controlled by wallet permissions, limits and user approval rules.

Private keys and seed phrases are never exposed to ChatGPT or the language model.

How we built it

We built the project using GPT-5.6, Codex, the OpenAI Apps SDK and the Model Context Protocol.

The application consists of:

  • A ChatGPT interface built with the OpenAI Apps SDK
  • An MCP server with wallet and payment tools
  • A Node.js and TypeScript backend
  • A React-based wallet interface
  • Persistent wallet linking through OAuth
  • Multichain balance and transaction services
  • A policy engine for limits and payment approvals
  • SQLite storage for transaction history and audit events
  • Idempotency protection to prevent duplicate payments
  • An audit hash chain for verifiable operation history

GPT-5.6 helped us design the product architecture, user flows, security model and MCP tool structure. Codex was used to generate, refactor, debug and test the implementation.

Challenges we ran into

The main challenge was combining a conversational AI interface with secure wallet operations.

We had to make sure that:

  • ChatGPT never receives private keys or seed phrases
  • Payments cannot be executed twice
  • The correct blockchain network is always selected
  • Wallet sessions remain connected between conversations
  • Agent-initiated payments follow spending limits and approval policies
  • The interface works correctly on both desktop and mobile
  • Blockchain errors are translated into clear responses for the user

Another challenge was creating one consistent user experience across multiple blockchain networks with different transaction formats and fee models.

Accomplishments that we're proud of

We built a working multichain wallet experience inside ChatGPT.

The project includes:

  • A functional ChatGPT application
  • 12 supported blockchain networks
  • 16 MCP wallet and payment tools
  • Persistent wallet linking
  • Real balance retrieval
  • Payment preparation and approval flows
  • Programmable spending policies
  • Transaction receipts and status tracking
  • An auditable transaction history
  • A mobile-compatible wallet interface

The result is a working foundation for both human-controlled payments and autonomous AI-agent commerce directly inside ChatGPT.

What we learned

We learned that AI-agent payments require more than a basic wallet connection. Agents need programmable permissions, transaction limits, approval rules, receipts, idempotency and a complete audit trail.

We also learned how to combine the OpenAI Apps SDK and MCP into one product where ChatGPT handles intent and interaction, while sensitive wallet logic remains isolated in a secure external service.

What's next

Our next step is to complete production-grade transaction signing and expand the wallet into a full payment infrastructure for autonomous AI agents.

We plan to add:

  • More assets and blockchain networks
  • Stablecoin payment support
  • Agent-specific wallets and spending budgets
  • Merchant payment requests
  • x402 and AIFP-1 payment flows
  • Subscription and usage-based payments
  • More advanced security and approval policies

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Updates

posted an update —

Post-submission update: AiFinPay GPT Wallet has moved significantly closer to production readiness Since our original hackathon submission, we have continued developing and testing the AiFinPay GPT Wallet instead of freezing the project at the demo stage. The main improvements completed after submission include: Production transaction signing flow. Users can now initiate a transfer directly from ChatGPT, review the transaction details and network fee, open the encrypted wallet vault, approve the transaction, and sign it locally on the device. Non-custodial architecture strengthened. Private keys remain inside the encrypted client-side vault. The backend does not sign transactions and does not receive the user's recovery phrase or private key. The server is used only to broadcast signed transactions. Mobile and desktop wallet flow fixed. We resolved issues that affected wallet actions when the ChatGPT integration was opened from different devices. The current wallet flow has been tested again from both mobile and desktop environments. Real on-chain payment testing. We completed end-to-end transaction tests with real blockchain transactions rather than simulated payments. AiFinPay payment infrastructure integration. A real payment was executed through the updated AiFinPay splitter contract and the payment split was verified on-chain. Swap functionality fixed and activated. We identified and corrected an incorrect ChangeNOW quote configuration that prevented live swap quotes from being returned. The wallet can now request valid live swap quotes. Improved swap error handling. Provider errors are now surfaced correctly instead of being replaced by a generic “Could not load a live quote” message, which makes unsupported pairs and other provider-side failures much easier to diagnose. Transaction review and approval UX improved. The wallet now provides a clear review step before signing, including transaction amount, destination, estimated fee and an explicit user approval step. Wallet reliability improved. Several integration and frontend issues discovered during real mobile/desktop testing were fixed to make the ChatGPT wallet experience more stable. Architecture prepared for autonomous-agent payments. The wallet is being developed as part of the broader AiFinPay infrastructure for AI agents, including agent wallets, programmable spending controls, x402/AIFP payment flows, receipts and merchant payments. We are continuing development after the hackathon. The next engineering steps include broader network and asset support, deeper stablecoin support, agent-specific wallets and spending policies, merchant payment requests, AIFP-1/x402 payment flows, subscription and usage-based payments, stronger monitoring and security controls, and product analytics for wallet usage. The goal is to turn the hackathon implementation into a production-grade financial wallet and payment layer that AI agents can use directly from conversational interfaces such as ChatGPT.

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