Gloam

Public chains put finance on public rails: every holding, every size, every move is visible. Robinhood Chain does it for tokenized stocks and crypto; Tempo does it for stablecoin payments. Gloam is the sealed chamber on top. Shield a balance, pay privately, and later prove exactly what you choose to a counterparty or auditor, and nothing else. It is not a dark theme on a public DEX; it is a private-execution primitive that other onchain apps and AI agents build on — live today on Robinhood Chain (flagship) and Tempo.

Three surfaces, one private core

The vault app is the reference implementation, not the whole product.

All three share one core: a Poseidon note scheme, a depth-20 incremental Merkle tree, circom witness builders, real Groth16 verification, and one canonical intent shape.

What works today (testnet, real ZK proofs)

Every private action is proof-gated on-chain. No mock fills, no theatrical privacy. If a path cannot be both private and solvent yet, it waits. See contracts/audit/H1-SWAP-SOLVENCY.md.

Selective disclosure: private by default, proven by choice

The answer to the "dark pool" objection. A holder mints a disclosure for one note; the recipient verifies, entirely in the browser, that the holder owns that exact balance in the vault, without learning their identity, their note secret, or any other holding. It reuses the shield circuit (no new trusted setup): the proof binds the commitment to (amount, asset), and the verifier confirms the commitment is a live note via pool.commitmentSeen. Generate at /app/disclose, verify at /verify.

Robinhood Chain native

Robinhood Chain is an Arbitrum Orbit L2 (Nitro, mainnet live since July 2026), ETH gas, Ethereum blob DA. Gloam targets what the chain actually ships:

• Chainlink oracles from block zero. RH Chain prices tokenized equities on-chain via standard AggregatorV3 feeds. Gloam's OracleRates module binds sealed-trade rates to the live feed with L2 sequencer-uptime, staleness, and positivity guards, and a ratio-tolerance check that is also on-chain slippage protection. Built and tested (contracts/src/lib/OracleRates.sol); it activates when private trade re-enables.
• Tokenized stocks are ERC-20s (18 decimals, ERC-8056 Total-Return value). Gloam shields the canonical set (TSLA, NVDA, AMZN, and more).
• Groth16 runs native. bn254 pairing precompiles are present and the 96 KB code-size cap fits large verifier contracts, so shield / unshield / transfer proofs verify with no special infra.
• First-class ERC-4337 opens the door to gasless private transactions.

Live on Tempo

The same private core now runs on Tempo, the payments-first stablecoin L1, as private stablecoin payments for people and agents. Tempo ships its own operator-run privacy (Zones); Gloam is the self-custodial, permissionless complement, with issuer-compatible selective disclosure. The sealed pool and verifiers are deployed on Tempo Moderato (42431), and the app's runtime network toggle switches the whole product between chains — shield PathUSD, send, and cash out, proof-gated end to end. Because Tempo blocks native msg.value and pays gas in stablecoins, Gloam shields ERC-20 stablecoins there instead of a native asset. Design and constraints: TEMPO_EXPANSION.md.

Trust, verified

Privacy earns the mainnet gate only when it is auditable and correct.

• Self-audited, then re-verified. A Kensho pass found a critical funded drain, two highs, and a set of mediums in the sealed pool and client. Every critical and high is fixed and verified on-chain and in code (independent re-audit): the drainable pool drained and de-published, value-binding enforced at deposit (C1), the swap path disabled (H1), the re-open path closed (one-way verifier + two-step ownership). Full status: contracts/audit/REMEDIATION.md.
• No middlemen. Redeployed 2026-09-29 on both networks with no admin withdraw: nobody, including the team, can move pooled funds, and after setup every verifier, rate or oracle change must be queued on-chain 3 days ahead (endSetup(), queueChange, 93/93 tests). Verify setupMode() == false on the pools listed below.
• Selective disclosure, not a mixer. Prove balance or a payment to a counterparty or auditor without revealing everything. The right posture for a regulated-sponsor chain.
• Fast vault sync, same privacy. The app loads the vault's public leaf list (every commitment, in order) from /api/vault-leaves in one request instead of walking the chain, rebuilds the Merkle tree in the browser, and uses it only if the root matches the pool's on-chain root; otherwise it reads the chain itself. The request names only the network and is the same for everyone, so the server never learns which notes are yours.
• Honest gates. The trusted setup is a dev ceremony and mainnet needs a multi-party one; note secrets are encrypted at rest (AES-GCM under a device key, audit M-1), though the key is device-bound. These are disclosed, not hidden. Mainnet 4663 is blocked in-product.

Using the SDK

Deposit privately into the hardened pool in a few lines. The SDK mints the note and generates the shield proof; you sign the resolved call.

import { buildShieldBoundIntent, artifactProver } from "@gloamtrade/sdk";import { parseEther } from "viem";
const intent = await buildShieldBoundIntent({  amountWei: parseEther("0.001"),  prover: artifactProver({ wasm: "shield.wasm", zkey: "shield_final.zkey" }),});
// intent.exec is the resolved shieldBound(asset, amount, commitment, proof) call.// Persist intent.note.secret to spend the balance later.await wallet.writeContract({ ...intent.exec, abi: shieldPoolAbi });

A complete runnable agent is in examples/agent-shield.

Architecture

gloam/  packages/sdk/          @gloamtrade/sdk  the private path as a reusable package  mcp/                   @gloamtrade/mcp  agent server (plan + signed execution)  examples/agent-shield/ reference wrapper: an agent shields via the SDK  app/                   Next.js reference app + docs → Vercel root: app  contracts/             Foundry · ShieldPoolPoseidon vault, verifiers, circuits, audit

Contracts — Robinhood Chain testnet 46630

Contracts — Tempo Moderato testnet 42431

The pre-C1 RH pool 0x4F38… is drained and retired, never use it. Circuits (Groth16 + Poseidon + depth-20 Merkle membership): shield, transfer, unshield, sealedSwap. Details in contracts/ARCHITECTURE.md.

Local

pnpm installpnpm --filter @gloamtrade/sdk build        # build the SDKcd contracts && forge test            # contracts (67 tests)pnpm --filter @gloamtrade/sdk test         # SDK core self-tests

Run the reference app from app/ (next dev), or open gloam.trade/app. The in-app network toggle switches between chains. Robinhood testnet ETH + stock tokens: faucet.testnet.chain.robinhood.com. Tempo test stablecoins (PathUSD and friends): the Tempo faucet (tempo_fundAddress).

Guardrails

• Testnet only until a production ceremony + external audit. Mainnet 4663 blocked in-product.
• Real privacy only. Never fake or mock a private success.
• Selective disclosure over opacity. Verifiable, not just hidden.
• Brand: Twilight, paper #F4F3EF, ink #121316, indigo #3B3766. Light, spacious, plain-language.

No private keys in-repo. Deploy with DEPLOYER_PK env only. Circuit zkeys are dev-ceremony artifacts. See SECURITY.md.