§1 — Penumbra in one paragraph.
Penumbra in one paragraph.
Penumbra is a private, cross-chain proof-of-stake network built on Cosmos, with shielded transactions, private staking, and a private decentralized exchange. The privacy model composes multiple cryptographic primitives — commitments, range proofs, set-membership proofs, and encryption — into a single user-visible flow. Browser-based access to such a network requires non-trivial wallet engineering (key management, signing, account abstraction in the browser context, shielded-transaction handling) and gRPC services (efficient browser-to-chain protocol-buffer communication for shielded operations).
§2 — What Zpoken contributed.
What Zpoken contributed.
Zpoken developed key infrastructure for Penumbra's browser surface — including the initial Penumbra Web Wallet (the Chrome extension that became Prax Wallet), first shipped for Penumbra’s testnets — and the gRPC services that support browser-based blockchain interaction with a privacy-preserving network.
[01]
Chrome extension wallet — the original Penumbra web wallet; the store listing Zpoken published is today Prax Wallet
─ SHIPPED · BECAME PRAX
[02]
Wallet SDK — penumbra-web-assembly (104 npm releases) + TypeScript crypto SDK
─ SHIPPED
[03]
Protocol contributions — wasm crate merged upstream (Mar 2023); 10+ merged PRs through Jan 2024
─ MERGED UPSTREAM
[04]
Block explorer — frontend + indexer, live at penumbra.zpoken.io through 2023
─ SHIPPED · RETIRED
[05]
Penumbra dApp — transferred upstream; hosted as the testnet dApp
─ TRANSFERRED
The wallet work is the part of Penumbra's surface where shielded-transaction privacy intersects with the browser security model. Browser extensions for crypto wallets must reconcile chain-side cryptographic primitives — the kind that compose into a privacy guarantee — with browser-side constraints around storage, signing, and origin isolation. The gRPC services are the layer that lets the browser communicate with the Penumbra node infrastructure efficiently for shielded operations, which is non-trivial because the protocol-buffer schemas and message flows for shielded transactions are not the same as for transparent ones.
Zpoken worked inside the Penumbra ecosystem from 2022 to 2024 — in the repos, in Discord, on community calls. The record is public on Penumbra's side: the blog credits the Web Wallet, the protocol monorepo carries the merged wasm crate and PRs, and Penumbra Labs' own issues document protocol changes made at Zpoken's request. The Chrome Web Store listing Zpoken published in December 2022 is, today, the Prax Wallet listing.
§3 — What this work actually involves.
What this work actually involves.
Browser wallet for a shielded-transaction protocol.
A wallet for a privacy DEX is not the same shape as a wallet for an EVM chain. Key management has to handle viewing keys and spending keys separately. Signing has to construct shielded transaction proofs without leaking the witness. Account abstraction in the browser context cannot fall back to popular EVM patterns because the privacy model invalidates them. This extension — whose store listing is today Prax Wallet — was the initial browser wallet for Penumbra.
gRPC services for browser-shielded interaction.
Penumbra's chain-side interface is gRPC. Browsers do not speak raw gRPC efficiently. The bridge between them — gRPC-Web, message-buffer translation, streaming for sync — is its own engineering surface. Doing this for shielded operations specifically (rather than transparent ones) means the message flows include zero-knowledge witness construction and proof submission, which require careful handling on both sides.
§4 — Public surface.
Public surface.