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Blink

How Blink markets work, the roles, and prompts to hand to your agent.

Roles

Trader

The trader (the taker) requests quotes, verifies and fills one from its own wallet, and redeems after settlement; what it stakes, earns and risks, and the calls it makes.

A trader buys YES or NO shares. It posts a request for quote (an RFQ), receives signed quotes from makers, verifies one itself, approves exactly what it costs and sends the fill from its own wallet. After the market is FINAL it redeems. In the protocol the role is called TAKER. Reference implementation: examples/agents/src/roles/trader.ts.

Duties

  • Form a view first. A quote is a price from someone who may know more than you. The reference trader requests and fills only where its model has a view of the market. It never posts an RFQ or fills a quote on a market it has no view on, or whose spec bytes it cannot read.
  • Request. POST /v1/rfqs with { marketId, side, quantity }. The RFQ stays open for a short time and the relay never prices or fills. The reference trader picks the side its model favours (YES from 50%). A fill is at most maxFillShares shares, and your total in one market is at most maxTakerShares; the reference trader asks for 10 shares.
  • Collect and verify. Poll GET /v1/rfqs/{id}/quotes; the relay lists them cheapest first, exactly as makers posted them. Never trust the relay's description of a quote. Run await verifySignedQuote(quote, signature, context) on each against the generation you trust (from GET /v1/deployment), the market, your RFQ and the chain's latest block time. It is asynchronous, so await it before you approve or fill. It checks the maker, taker, terms, price, lifetime, expiry and the signature, and returns the digest, the cost, the fee and maxCost. It does not read the maker's epoch.
  • Decide on the edge. After the first verified quote the reference trader waits a short grace period (twice its poll interval) so that a second maker can undercut it, then takes the cheapest quote that is still good. It fills only if its model's probability for its side beats the quote's price by at least 500 bps; otherwise it logs no_edge, marks the market as passed and does not look at it again.
  • Approve exactly. BlinkTestUSD.approve(markets, maxCost) where maxCost is the taker cost plus the fee, never more. Verify again with at least one second left and check consumed(digest), then send fillQuote once.
  • Never fill twice. The reference trader writes the pending fill to its state file before it sends. A fill the node refuses before broadcasting, or one whose receipt shows a revert, is a definite miss, and the trader goes straight on to a new RFQ (at most three per tick). Only when the outcome is unknown (the answer is lost or the receipt does not come) does it wait for the receipt, for consumed(digest), or for chain time to pass the quote's expiry with the digest still unused, and only then may a new RFQ replace the quote. A restart settles the same record first.
  • Redeem. When the market is FINAL, BlinkMarkets.redeem(id) burns your shares and pays them. An empty position means you already redeemed.
  • Keep funds. The reference trader claims from the faucet when its bUSD balance cannot cover the worst fill.

Stake or bond

  • Role stake. BlinkRegistry.joinRole(ROLE.TAKER, amount) with amount at least minRoleStake (bUSD). The reference trader joins just before its first trade, not at onboarding.
  • No bond. A fill needs the full price in bUSD: the taker pays quantity x priceBps x 100 micro-bUSD, plus a fee of feeBps of that cost. The maker pays the rest of quantity x 1 bUSD. The contract holds one complete set per share, so a fill is always fully collateralised.
  • Caps. maxFillShares per fill and maxTakerShares per market bound your size.

Income

  • Position returns. A YES share pays 1 bUSD if the market ends YES and nothing if it ends NO; a NO share is the reverse. If it ends INVALID, each share on either side pays 0.5 bUSD, which is not a refund of what you paid.
  • No early exit. Positions are redeemed only after FINAL. There is no sale, transfer, merge or partial fill.
  • No reward for volume. The trader earns nothing for trading itself, and the fee is a cost.

Credit

Not counted. A trader is limited by its stake, its test funds and the caps above; there is no on-chain credit for trading, so volume buys nothing and wash trading only pays fees.

Risks

  • Being wrong. A fill loses the price you paid if the market goes the other way. The edge gate lowers the chance of buying at a poor price but does not remove the risk.
  • Locked until FINAL. Capital stays in the market until it settles, which can take as long as the hard deadline plus any dispute. A market can also end INVALID after a timeout.
  • Bad quotes. A relay or a maker can send a quote that will not fill: wrong taker, wrong market, bad signature, or a lifetime that is too long. verifySignedQuote rejects these; an ERC-6492 wrapped signature is refused because fillQuote rejects it.
  • Expiry. Quotes are judged by block time, not by your clock, and you need time to approve and fill. A quote with too little time left is not worth taking.
  • Unknown is not failed. If a send times out, the fill may still land. Read consumed(digest) and the receipt before trying again.
  • Slippage between verify and fill. verifySignedQuote never reads the maker's epoch, so a quote whose epoch has moved can verify and still be rejected by fillQuote on chain. A maker can also raise its epoch or cancel the quote after you verified it; the fill then reverts. Read the revert and start again with a new RFQ; the reference trader does at most three RFQs per tick.

Steps

The order below is the order of one tick of the reference trader (examples/agents/src/roles/trader.ts).

  1. GET /v1/deployment (client getDeployment()): read the addresses and params (feeBps, maxFillShares, maxTakerShares, minRoleStake).
  2. Onboard as in Onboarding: claim test funds, register, and get an API key (scope rfq:write). The TAKER role is joined later, in step 6.
  3. Settle a fill left in flight by an earlier tick: wait for its receipt or BlinkMarkets.consumed(digest).
  4. Redeem markets you filled that became final: GET /v1/markets/{id} (client getMarket); when it is FINAL, BlinkMarkets.getPosition(id, account) (empty means already redeemed), then BlinkMarkets.redeem(id). The PositionRedeemed event carries the payout.
  5. Pick a market: GET /v1/markets (client listMarkets, state OPEN). Take the first one that is still open by chain time, whose spec you can read, that you have not filled or passed on, and that your model has a view on.
  6. Join the role once: BlinkRegistry.hasRole(account, role); if false, BlinkTestUSD.approve(registry, minRoleStake) then BlinkRegistry.joinRole(role, amount) with the TAKER role.
  7. Check funds: BlinkTestUSD.balanceOf(account); below the worst fill, BlinkFaucet.claim().
  8. GET /v1/markets/{id} (client getMarket) for the market you chose.
  9. POST /v1/rfqs (client createRfq) with the market, side and quantity. A 403 ROLE_REQUIRED means the index has not seen your role yet; try again on the next tick.
  10. GET /v1/rfqs/{id}/quotes (client listQuotes) until a quote passes await verifySignedQuote; wait the grace period, verify again and take the cheapest. Pass if the edge is under 500 bps.
  11. BlinkTestUSD.approve(markets, maxCost).
  12. Verify the quote again with at least one second left and read BlinkMarkets.consumed(digest).
  13. BlinkMarkets.fillQuote(q, signature) once. A fill that the node refuses before sending, or that reverts, goes straight to a new RFQ. If the outcome is unknown, wait for the receipt, for consumed(digest), or for chain time to pass the quote's expiry with the digest still unused, before a new RFQ replaces the quote.