I build identity and payment infrastructure for the agentic web — end-to-end and solo, under UIG Studios LLC. Shipped deepest on Sui, taking the same settlement-semantics work cross-rail to Solana / SVM and EVM.

The throughline: x402 proves an agent paid · my settlement-receipt binding proves the payment maps to the action · PoR proves the actor is a real, human-backed entity. Together that's a verified agent — and I've shipped a working piece of every layer.

Right now: my x402 Settlement-Receipt Binding extension is open for review in the Linux Foundation's x402 repo, its conformance gate reproduced green by independent issuers across two rails. An outside implementer who ran a clean-room recompute against those vectors pushed back on what a passing signature actually proves; I turned that into normative §5 text — a green gate establishes key custody and byte-integrity, not that the issuer was honest or that the result is an independent finding — and they confirmed it belongs there. Meanwhile the same settlement-semantics work is going cross-rail to Solana / SVM, running end-to-end in an x402 charging agent (an EV that pays for its own charge — mainnet on Sui, settling on Solana devnet).

A Sui-native proof-of-personhood credential: prove you're a real, unique human (passkey + zkLogin onboarding, no personal data captured) and raise your assurance through verifiable real-world actions.

• Live credential, attestor & Move package · SDK on npm → por-sdk (Apache-2.0)
• Device-attested real-world action — App Attest proven on a real iPhone: a walk mints an on-chain Verified Real credential, end-to-end, with a device nullifier that dedupes one credential per device — built and proven; enforcement still gated off during rollout
• por-proof-of-real.netlify.app · mainnet contracts, testnet attestor — personhood, not "sybil-proof"

• x402-sui-stack — the x402 builder stack for Sui (Sui Overflow 2026): the facilitator + tooling + a one-command demo that settles a real $0.01 USDC payment on mainnet and lets anyone recompute it in-browser → live · code
• x402 facilitator that settles on Sui — non-custodial, zero-fee, live on mainnet → sui-x402-facilitator · live facilitator
• First x402 payment on Litecoin — deployed the canonical x402 Permit2 proxies to LitVM (Litecoin's EVM L2, LiteForge testnet) and settled the first payment through them — provable on-chain: the proxy's tx history begins with it → litvm-x402 · testnet; day-one facilitator support planned for their mainnet
• Authoring a proposed x402 standard extension — Settlement-Receipt Binding: bind an on-chain settlement to a signed execution receipt, recomputable from published bytes with an independent verifier — its conformance gate reproduced green by two independent issuers across two rails, plus a live gasless-Sui settlement vector → x402-foundation/x402#2666
• Taking the standard cross-rail — a conformance demo for Solana's upto scheme proving settlement-receipt binding on SVM, plus shaping the verify()-soundness invariant on Hedera (#2701) and Solana's allowance-draw design (#2699); one binding, multiple rails (EVM · SVM · Sui)
• x402-pilot — an open-source, non-custodial x402 dev tool + conformance MCP (Apache-2.0)

An EV that pays for its own charge, no human in the loop — the whole stack composed in one artifact:

• x402 upto metered billing + my Settlement-Receipt Binding (#2666) over a real-world action — authorize a ceiling, meter the kWh, settle the actual, emit a receipt an independent checker verifies
• PoR-gated — only a verified human's agent may charge (the personhood layer, live)
• mainnet-proven on Sui, also settling on Solana devnet; bridged to real charging networks via OCPI (DeCharge / Starpower-ready)
• x402-charging-agent · vehicle + charging network mocked behind their real interfaces

• FairLine — a risk-managed, multi-user liquidity vault on DeepBook Predict ("be the house, verifiably"): senior/junior tranches, capacity cap, on-chain reserve floor + emergency pause, redemption-anchored NAV · testnet, unaudited
• Gulp City — an installable 3D PWA arcade game
• Jamie Buddy — a local-LLM writing assistant
• Yomp — the consumer front door for PoR: walk to prove you're real (Sui testnet). The walk is what mints the credential's real-world-action tier.

8 pull requests merged into repos I don't own, across 5 organisations — someone else's maintainer decided each one was worth carrying:

• openmed (medical NLP) — release signing & supply-chain evidence: the publish workflow now attaches its SLSA provenance bundle and artifact digests to the tagged release and keylessly signs every wheel and sdist with Sigstore, so a release can be verified offline with no round trip to GitHub's attestation API. Structured so evidence generation can never gate the PyPI upload — but evidence that is produced must verify against the exact workflow identity and release commit, or the job fails → #1604. Earlier: an interactive synthetic-data Gradio de-identification demo, and a memory-mapping toggle for the MLX weight-loading path, both with import-safe test coverage → #1023 · #1024
• Tessera — a recovery_hint() API across the error types of a local-first AI testing IDE (Rust) → #103
• x402 — a cross-SDK exact error-code parity fix (the TS SDK was the lone outlier vs Go / Python) → #2744 · the project moved under the Linux Foundation in July 2026, so this now sits in the standard's own repo
• huggingface.js — two correctness fixes where the existing tests looked like they covered the contract. The public language() lookup used code in TABLE, and in walks the prototype chain, so language("toString") returned Object.prototype.toString — a function — out of a signature typed Language | null; the invalid-code test passed only because its input wasn't on Object.prototype → #2320. And in @huggingface/hub, a completed SHA-256 hash left its abort listener attached, so a later abort of that signal terminated a worker already returned to the pool and rejected an already-returned generator. Fixed in one place — cleanup() now drops the listener on every exit path — with a deterministic worker stand-in to reproduce it → #2325
• Nodle rollup — migrated the L1 bridge's deposit & quote paths off the deprecated ZKsync Mailbox to Bridgehub (Solidity). My commits landed with authorship preserved in #122 after the maintainer validated the work against a fork of live-mainnet state and hardened it; the sequencing issue it raised shipped alongside as a withdrawal-replay guard. Originally submitted as #121, closed in favour of the hardened branch · earlier, docs for manual vested-grant claims → #120

Open and in review: a release run-ledger binding build artifacts to their gate decisions in openmed (#1899).

Contributing upstream to Mysten's Sui stack — filed a cached-price payment race in @mysten/walrus that was taking out mainnet writes (ts-sdks#1127), reviewed the maintainer's fix (#1128), and reviewed the MemWal relayer's recovery for the same class of bug. Reported that setSender() was a silent no-op behind Seal's owned-object access pattern, with a two-SDK-version repro (seal#507) — the SDK behaviour it described was fixed in ts-sdks#1136 and shipped in 2.20.3.

Available for contract, consulting, grants & engineering roles — identity and x402 / agentic payments, across Sui, Solana/SVM and EVM. Deepest on Sui, actively building cross-rail.

📫 tjagodka@gmail.com · 𝕏 @DrVelvetFog · 🌐 portfolio · 💼 Algora · 🏢 UIG Studios

Lines I don't cross: no custody · no token-for-money sales · no PII capture · honest labeling (testnet/unaudited stated plainly).