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The Robin Staking Vault takes paired Polymarket outcome tokens, merges them into USDC, supplies that USDC to an ERC-4626 vault, and issues ERC-1155 shares that track each depositor’s claim plus accrued yield. This page walks through the contracts, the deposit and withdraw pipelines, and the share accounting that ties them together.

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The moving parts

A deposit flows through three on-chain pieces — the vault, the TWAP oracle, and Polymarket’s Conditional Tokens Framework — and external yield sources. RobinLens sits alongside as a read-only aggregator for the data you need to build and preview transactions.

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Contracts

Contract addresses and governance

Full address table for Polygon mainnet, including the vault proxy, oracle, lens, CTF, and USDC.e.

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Deposit pipeline

When you deposit, the vault matches opposing sides within each market and converts the matched pair into yield-bearing USDC.
1

Pair opposing sides

Within a single market, the vault pairs YES against NO. A YES and a NO token of the same market together represent a full set worth 1 USDC of collateral.
2

Merge to USDC

The vault merges each matched pair on the Polymarket CTF, burning the paired outcome tokens and releasing the underlying USDC.
3

Supply to Yield Strategy

The merged USDC is supplied to one or multiple ERC-4626 vaults, where it earns organic yield for the life of the deposit.
Unmatched tokens stay idle. If you deposit more of one side than there is of the opposite side to pair with, the surplus sits in the vault until a counterpart arrives to pair with it. The yield that the vault earns is socialized between all depositors (matched or unmatched) of a market.
The vault supports two transport paths for getting tokens in — a PULL path (Safe proxy only) and a PUSH path (both wallet kinds). See Deposits for the call construction and array-encoding rules.

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Withdraw pipeline

A withdrawal reverses the pipeline: it burns your shares, reconstitutes the outcome tokens, and returns them alongside the organic yield those shares earned.
1

Burn shares

The vault burns the ERC-1155 shares you specify for each market and side.
2

Withdraw USDC and split

If outcome tokens are needed, the vault withdraws USDC from the yield startegy vault and splits that USDC back into YES and NO tokens on the Polymarket CTF.
3

Return tokens and yield

You receive the underlying outcome tokens plus the organic USDC yield those shares accrued.
batchWithdraw can wrap the USDC.e yield to PolyUSD via Polymarket’s CollateralOnramp when you pass wrapYieldToPolyUsd=true; it falls back to USDC.e if the wrap fails. The bonus payout is sent separately by Robin afterwards, not by this call. See Conventions for the full signature.

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Shares & accounting

Shares are ERC-1155 — one token per (market, side) pair. The vault tracks each side independently because YES and NO can be matched, valued, and withdrawn at different rates. The vault uses dual-index accounting to value those shares:
  • lossIndex — tracks impermanent loss on a side, so shares redeem for the loss-adjusted amount of outcome tokens they are currently worth.
  • yieldPerShare — tracks accrued organic yield per share, so each share claims its proportional cut of the on-chain yield.
Both indices use INDEX_SCALE=1e18. Organic yield is split three ways before it reaches a wallet:
  1. Per market, by TVL — native yield is socialized across the market in proportion to staked value.
  2. Per side, by TWAP price — the market’s TWAP (PRICE_SCALE=1e6) determines how that market’s yield divides between the YES and NO sides.
  3. Per user, by indices — the lossIndex and yieldPerShare snapshots resolve each wallet’s individual share of its side.
Read these values directly from RobinLens — batchGetUserYield, batchGetMarketIndexes, and batchGetUserPortfolio return them aligned to your conditionIds. See Reading on-chain state for the twapPricesYes convention used by those calls.

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Organic yield vs. bonuses

The contracts pay only the organic yield, distributed through the lossIndex + yieldPerShare accounting above. The 6% guarantee floor, the +1% matching bonus, and the +1% points boost are an off-chain programme operated by Robin. They are computed at withdrawal and paid in a single USDC transaction from Robin’s operator wallet, separate from the on-chain withdrawal — the vault itself never touches them. See Conventions for the APY breakdown, and the Yield Guarantee overview for the programme details.

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Next steps

Conventions

Units, ids, the Side enum, and the APY breakdown shape.

Deposits

Build PULL and PUSH deposits with correctly sorted, aligned arrays.

Reading on-chain state

Query shares, assets, yield, and previews through RobinLens.