Sarthak Gupta
I build agent systems, payment infrastructure, and the tooling that keeps both honest.
Four years building payments and tokenized-debt infrastructure that had to survive real users and real regulators. Now I work on the layer that decides what an agent with a wallet is actually allowed to do.
About
>4 years of production engineering, all of it at a fintech startup I joined as a founding SDE. I shipped the consumer app behind 1.6M monthly actives, led the technical architecture for a regulated co-branded credit card, architected the 9-node Besu chain underneath our tokenized debt platform, and built stablecoin issuance and the bridges out of it.
The agent work grew out of that stack rather than around it. Once you have a stablecoin, an x402 paywall on top of it is obvious, and once agents can pay, the question stops being what they can do and becomes what they should be allowed to do. That is where most of what I build now sits: conformance suites, policy engines, and wallets an agent can use without ever holding the key.
Payments, identity, and the chain underneath them
Architected the React Native app behind 2.3M downloads and 1.6M monthly actives, with custom Firebase monitoring across 5+ production Next.js and Vite frontends.
Built the payment microservices on Razorpay and banking SDKs: 120K transactions a month at sub-0.1% failure, on idempotent webhook reconciliation and an event-driven settlement path.
Ran Node and Deno services through 10K concurrent requests during flash sales, cutting API latency from 450ms to 85ms with Redis caching and query optimization.
Led the technical architecture for a co-branded credit card, onboarding 650K paid users in 4 months. RBI-mandated SIM binding and device fingerprinting, PCI-DSS audits, shipped 2 weeks early.
Designed KYC as three assurance tiers matched to capability, from platform PAN and Aadhaar through to underwriting-grade credit onboarding. Migrated the platform tier to DigiLocker and built a cost-ordered vendor cascade with latency-bounded failover.
Took the bureau pull and decision engine off the user's critical path so eligibility computed in parallel with document verification, and cut manual KYC overhead by 60% with OCR-based PAN and Aadhaar extraction.
Architected ANQChain, a public 9-node QBFT Hyperledger Besu network, Chainlist-listed.
Shipped an institutional-grade platform for tokenized government and corporate debt: built the marketplace end to end across backend and frontend, and contributed the Parent Factory and Coupon Manager contracts.
Built the custody layer on Fireblocks and Gnosis Safe, with on-chain KYC whitelisting enforcing who could hold what.
Built stablecoin issuance, and put a multisig in front of master mint so a single compromised key could not mint at will.
Bridged the chain outward: ANQChain to Base Sepolia and Polygon, plus LayerZero routing between Ethereum Sepolia and Base Sepolia.
Shipped arc402, an x402-style ERC-20 paywall on the ANQ stablecoin, and wallet-mcp, an MCP server that lets agents move that stablecoin without holding a key.
Shipped a production LangChain CRM agent with custom tool-calling and human-in-the-loop authorization: autonomous on reads, asks before writes.
Frontend performance and graph APIs
Migrated a legacy React SPA to Next.js server rendering, cutting initial page load from 4.2s to 0.9s.
Designed Pathom3 resolvers in Clojure that unified 3 microservices behind a single graph API over Datomic.
compliance-os
Next.js · Claude API · PrismaTwo-agent KYC pipeline. An extraction agent reads the documents, a verification agent challenges what it found, and a human reviews only the disagreements over a streaming dashboard. Handles bank statements, Form 26AS, and NACH mandates.
KYC automation does not fail on extraction accuracy, it fails because nobody can see why the machine decided what it decided.
two-agent review dashboard, live disagreement
agent-eval-core
Python · conformance suiteA deterministic conformance suite for the policy engines that gate money-moving agents. YAML attack scenarios like cap breach and split-to-evade run against any engine implementing the protocol, a reference engine with seven checks supplies ground truth, and a CLI renders the pass/fail comparison across engines.
Money-path rules need ground truth, not a judge model. Every check here is deterministic on purpose.
compare passthrough reference
wallet-mcp
MCP server · EVMAn MCP server that hands an agent a wallet: create, import, check balance, send ERC20, across any EVM chain, without ever exposing a private key. Built at ANQ against our own stablecoin, open-sourced after. Settled a real transaction on Base Sepolia, verifiable on chain.
Building it convinced me the missing piece is not giving agents a wallet, it is the thing standing between the agent and the wallet.
settled ERC20 transfer, Base Sepolia
TypeScript
Node
Python
Solidity
Clojure
MCP
LangGraph
Claude API
Next.js
React Native
Deno
Prisma
Postgres
Redis
Gnosis Safe
EVM
Docker