CoinBot
Request, Earn and Pay with Crypto.
Created on 24th May 2025
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CoinBot
Request, Earn and Pay with Crypto.
The problem CoinBot solves
🚀 CoinBot — Secure Web3 Messaging with Onchain Power
CoinBot transforms how users interact in Web3 — combining encrypted wallet-to-wallet messaging with seamless crypto payments on Base. CoinBot is more than just chat agent, it’s a trustless coordination layer for money and people, especially in emerging markets where Web3 adoption is surging.
🔐 What It Does
CoinBot enables users to:
- Chat securely using wallet-based identity (via XMTP)
- Send or request crypto directly within conversations — no tab switching
- Confirm payments instantly with onchain proofs and explorer links
- Get real-time push alerts for messages and transactions
- Speak your language with multilingual support for major African dialects (coming soon)
All powered by the Base L2 network for low fees and fast confirmations.
💡 Why It Matters
Most crypto interactions today are fragmented and risky:
- You chat on Telegram, then switch apps to pay
- You copy-paste addresses (a recipe for scams)
- You can’t verify the other party’s wallet on-chain
- You miss time-sensitive messages or payouts
CoinBot solves all this.
It puts everything you need to transact securely in one place — messages, payments, and notifications — with your wallet as your identity.
✅ Use Cases
- Freelancers & clients agreeing to terms and paying in crypto
- Merchants and customers coordinating orders and invoices
- Friends splitting bills or gifting tokens
- DAOs coordinating bounties and grants securely
🔄 How It Makes Life Easier
- Safer: No copy-pasting of wallet addresses. Everything is verified.
- Faster: Send tokens while chatting — no tab switching.
- Smarter: Automatically formats messages like “send 0.01 ETH to…” into real transactions.
- Localized: Multilingual support makes it inclusive from day one.
Challenges I ran into
Other than stubborn errors with newer versions of xmtp/browser-sdk, which kept failing with minimal debug procedures, not triggering the signing prompt with connected wallet, below are some of the notable challenges we experienced.
🔍 1. Silent Contract Call Failures
We ran into persistent errors while calling
balanceOf()
on ERC-20 contracts across testnets like Base Sepolia. Despite using valid ABIs and checksummed addresses, the function kept returning empty data ("0x"
), causingContractFunctionExecutionError
.Solution:
- Verified contract addresses for each network manually (some tokens don’t exist on certain chains).
- Added defensive checks to only call contracts that exist on the current network.
🏗️ 2. Invalid or Misformatted Addresses
Some wallet addresses were flagged as invalid due to checksum mismatches or incorrect formatting — especially when passed as string literals or unvalidated user input.
Solution:
- Used Viem’s
isAddress()
andgetAddress()
helpers to validate and normalize addresses. - Enforced checksummed formatting across the app, especially in contract call arguments.
📉 3. BigNumber Underflow Errors
Passing decimal balances directly into onchain functions led to
NUMERIC_FAULT
underflow errors, especially with tokens like USDC that have 6 decimals.Solution:
- Switched to using
parseUnits()
from Viem to convert stringified numbers into properBigInt
values. - Standardized decimal handling across tokens to avoid mismatches.
🌐 4. Reliable Wallet Detection Across Browsers
Supporting multiple wallets (MetaMask, Trust Wallet, Phantom, Coinbase Wallet) proved tricky due to inconsistent injection behavior and window detection quirks.
Solution:
- Switched to Reown Modal and Wagmi with
WalletClient
to handle wallet onboarding and fallback logic cleanly. - Unified provider handling using a single connection layer to reduce friction for users.
Technologies used
Cheer Project
Cheering for a project means supporting a project you like with as little as 0.0025 ETH. Right now, you can Cheer using ETH on Arbitrum, Optimism and Base.