# Pull-based Oracles

In pull-based oracles, dApps retrieve signed price data atomically from within their users’ transactions (e.g., for liquidations). These setups are preferential in some cases due to real-time price data and lower centralized costs. This model increases flexibility but makes it easier for Oracle Extractable Value (OEV) to leak to external actors:

* Without a solid solution, liquidators engage in priority fee wars, leaking value to block builders and validators.
* Neither the user, nor the dApps, nor the Oracle service originating this value are able to reclaim or redistribute this OEV.

### Blink Labs solution

Blink Labs offers an OEV capture system to solve this inefficiency with minimal integration cost for the oracle provider and zero lift for already integrated and future dApps.

#### How it works

Blink labs introduces an **express-lane auction system** with a simple signature-based verification change coupled with Blink Labs’ auction recovery service via our RPC. The flow is described in the following steps:

1. **Oracle Price Data Delivery**
   1. The oracle publishes signed price updates to the centralized price data API.
   2. Liquidators pull the price from the API and append it to their liquidation transaction
2. **Blink Labs Express Lane**
   1. Blink Labs operates a private RPC endpoint for liquidators and other dApp users.
   2. Submissions via this RPC receive a **500ms latency advantage** versus public mempool posting.
3. **OEV Capture and Exclusivity Check**
   1. An auction takes place for the right to utilize the price update with direct on-chain payment.
   2. Blink Labs guarantees exclusivity for the winning bidder in the advantaged time period.

### Advantages

| Minimal Integration       | Only a simple line needs to be added to the verification contract. No change to your signing infra.    |
| ------------------------- | ------------------------------------------------------------------------------------------------------ |
| Backward Compatible       | Slow-lane (public RPC) path still works for non-OEV-critical flows; no breakage.                       |
| Deterministic OEV Capture | Express-lane rules ensure MEV from price updates flows to you/dApps, not validators.                   |
| Market-Driven Pricing     | Blink Labs’ sealed-bid auction guarantees competitive pricing for transaction ordering.                |
| Low Latency Advantage     | 500ms is enough to capture almost all MEV while preventing censorship and enabling open participation. |
| No Friction for End Users | Liquidators simply switch to the Blink RPC; no new signing steps or client-side complexity.            |
| Composable                | Can extend to multiple protocols and chains without altering data feed architecture.                   |


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