Here’s a straightforward, step-by-step guide that doesn’t shy away from the details. It connects the dots between specific tech choices like Solidity, ZK, and oracle design with procurement, compliance, and ROI.

How to Build a “Flight Delay” Prediction Market

The headache your team keeps hitting

Your trading engine is pricing “DL1234 lands late” just before takeoff, but good luck getting the market to sort that out for hours. Why? Because the oracle can't clarify what "late" really means--does it mean 15 minutes at the gate, 30 minutes wheels-down, or a taxi backlog caused by GDP issues? Meanwhile, your support queue is piling up with disputes. Fast forward two days, and the accounting team is still unable to finalize P&L since everything is held up by this dispute bond mess.

• So in U.S. aviation, "on-time" means arriving at the gate within 15 minutes of the scheduled time. Carriers track and report this monthly under DOT/BTS guidelines. If you don’t stick to that definition, you’re asking for unnecessary disputes. (bts.gov)
• The FAA’s OPSNET gives you the scoop on daily operations and delay counts all the way “through yesterday,” but the public release doesn’t come out until after the 20th of the next month. That’s great for analytics, but not so much if you need T+30m settlement info. (aspm.faa.gov)
• NOAA revamped its Aviation Weather Data API (METAR/TAF) in 2025, introducing new schemas and rate limits (100 requests per minute). If you haven’t updated your clients, your weather-feature pipeline might be a bit shaky already. (aviationweather.gov)
• UMA OOV3 is pretty speedy when there aren't any disputes, but when things get contentious, resolution can stretch out for days. Polymarket has an initial 2-hour challenge that can escalate, so if your treasury didn’t plan for the bond economics, you’re looking at some serious settlement delays that could mess with your CAC:LTV ratio. (docs.polymarket.com)

What this costs you if you ship the wrong design

• Missed go-live dates: We’re hitting roadblocks on data licensing for real-time status with AIDX, SSIM, and FlightAware. Plus, legal concerns are cropping up regarding state-level gambling, even if your federal interpretation seems solid. States like Nevada are starting to push back, even against venues that are federally regulated. Check out more on FlightAware.
• Liquidity decay: If your “late” trigger isn’t crystal clear, market creators are going to want higher spreads. Also, if those oracle windows stretch beyond T+2 hours, you'll see active market-maker strategies bow out.
• MEV leakage: In Layer 2s, your order flow gets scooped up by sequencers and relays without any protection, which means those high-value markets can get sniped pretty easily. Essentially, you end up paying for liquidity twice--first in upfront fees, then again in churn.
• Unit-economics drift: After EIP-4844, blob fees are on the lower side, but if you’re over-polling external APIs or duplicating blobs, those fees and data costs can eat away at your margins. In the end, net profitability depends on keeping your per-market data and settlement expenses under a tight cap. You can read more about this on Investopedia.

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7Block Labs methodology (technical but pragmatic)

We create flight-delay markets through three main tracks that come together in about 12 to 14 weeks: Market Design, Data & Oracles, and Onchain Systems. Each track has specific acceptance criteria that are closely tied to our go-to-market strategy and compliance requirements.

1) Outcome specification that survives disputes

• When we say “Late,” we mean "the actual gate-in time is more than 15 minutes past the scheduled arrival," and we’re backing this up with a priority data stack:
  1. First up, we look at airline or FAA status through AIDX/OPS data;
  2. If that’s not available, we go for secondary sources like FlightAware FLIFO or ExtendedFLIFO;
  3. Lastly, we’ll rely on ADS-B positional info and any airport ops notes we can find. You can check out more on this at bts.gov.
• The settlement rulebook is pretty thorough and includes:
  • The scope of events (like single flight legs and how we handle codeshares).
  • A clear order of data precedence along with time windows (for example, if we don’t get anything from the primary source within T+45 minutes, we switch to the secondary).
  • Specific carveouts for "irregular operations" such as diversions or cancellations, which are mapped to neutral outcomes.
• We make sure the rulebook is pinned on-chain (with an IPFS/Arweave hash) and included in UMA’s assertion payload for OOV3 so that everyone involved--whether proposing or disputing--can refer to the same set of truths. For more details, check out docs.uma.xyz.

2) Data and oracle architecture you can procure and audit

• Real-time sources:
  • Get the scoop on FAA Air Traffic Control System advisories like GDPs and ground stops to help you understand systemic delays. Check it out here: (flightqueue.com).
  • Want to track flights? FlightAware Firehose streaming has you covered, with positions and FLIFO/ExtendedFLIFO options and monthly unlimited plans. You can grab just the layers you need! More info here: (flightaware.com).
  • Keep an eye on the weather with NOAA AWC METAR/TAF. The new 2025 API has documented formats and limits to help with your weather correlations. Check it out here: (aviationweather.gov).
  • For some backup and audit trails, take a look at OpenSky ADS-B (just keep in mind the non-commercial T&Cs). More details can be found here: (openskynetwork.github.io).
  • If you’re working in European markets, the optional EU corridor offers EUROCONTROL NM B2B flight and slot APIs. You can find more about this service here: (eurocontrol.int).
• Access patterns:
  • Chainlink Functions pulls signed JSON from Aviationstack/FlightAware endpoints for specific flights within a UTC window. We batch pre-event updates and do a single settlement proof call post-event to keep those gas and data costs manageable. Check it out here: (aviationstack.com).
  • For super low-latency quoting (only for pre-event liquidity), Chainlink Data Streams can provide sub-second feeds when needed. Plus, with Multistream (coming in 2025), you’ll be able to handle hundreds to thousands of series per DON if you want to expand your markets later on. More info here: (chain.link).

Example: Chainlink Functions (JavaScript) Sketch Calling NOAA + Flight API

Here’s a quick example of how to use Chainlink Functions in a JavaScript sketch to pull data from the NOAA and Flight APIs. This is a fun way to get weather info and flight details together!

Setting Up Your Environment

First things first, make sure you have Node.js installed. You can grab it here if you haven't installed it yet. Once that's done, you can set up your project:

mkdir my-chainlink-functions
cd my-chainlink-functions
npm init -y
npm install axios

Code Snippet

Now, let’s dive into the code! Create a file named index.js and add the following:

const axios = require('axios');

// NOAA API endpoint for weather data
const NOAA_API = 'https://api.weather.gov/';

// Flight API endpoint (replace with actual API)
const FLIGHT_API = 'https://api.flightdata.com/';

// Function to get weather data
async function getWeatherData() {
    try {
        const response = await axios.get(`${NOAA_API}stations`);
        console.log('Weather Data:', response.data);
    } catch (error) {
        console.error('Error fetching weather data:', error);
    }
}

// Function to get flight info
async function getFlightData(flightId) {
    try {
        const response = await axios.get(`${FLIGHT_API}flights/${flightId}`);
        console.log('Flight Data:', response.data);
    } catch (error) {
        console.error('Error fetching flight data:', error);
    }
}

// Example usage
(async () => {
    await getWeatherData();
    await getFlightData('ABC123');
})();

Running the Code

To run your sketch, use the following command in your terminal:

node index.js

This will fetch the weather data from NOAA and the flight details for the specified flight ID, ABC123. Just replace it with whatever flight ID you need!

Conclusion

And that’s it! You’ve got a simple JavaScript sketch that pulls weather and flight data using Chainlink Functions. Feel free to tweak it to suit your needs or expand on it!

// Chainlink Functions request (pseudo)
const AWC = await Functions.makeHttpRequest({
  url: "https://aviationweather.gov/api/data/metar",
  params: { ids: "KJFK", format: "json" }
}); // AWC: 100 req/min cap; cache METARs. (2025 API) ([aviationweather.gov](https://aviationweather.gov/data/api/?utm_source=openai))

const flight = await Functions.makeHttpRequest({
  url: "https://api.aviationstack.com/v1/flights",
  params: { access_key: SECRETS.AVIATIONSTACK_KEY, flight_iata: "DL1234" }
}); // Real-time/last-3-months; filter by flight_date. ([aviationstack.com](https://aviationstack.com/documentation?utm_source=openai))

if (flight.data && isGateInLate(flight.data, 15)) {
  return Functions.encodeUint256(1); // "late"
}
return Functions.encodeUint256(0); // "on-time"

3) Settlement you can explain to regulators and LPs

• UMA Optimistic Oracle v3:
  • Here’s how it works: we kick things off by posting an “assert truth” along with the market’s JSON proof, which includes info from primary, secondary, and tertiary sources, plus timestamps. The market creators chip in to fund a reward, while proposers put up a bond.
  • By default, we have a 2-hour challenge period (just like Polymarket), but if there’s a dispute, it can go to a DVM vote that might stretch the resolution to 48-96 hours at most. You can play around with security and speed by adjusting the size of bonds and rewards based on open interest. (docs.polymarket.com)
• Deterministic fallback: If source A and source B don’t quite see eye to eye, meaning their differences are greater than Δ (let’s say 10 minutes), we’ll automatically escalate things and put a freeze on redemptions until we get it sorted out. This helps cut down on any social disputes.

Solidity Sketch (Assertion Payload, OOV3)

Here's a handy breakdown of an assertion payload in Solidity, as it pertains to OOV3.

What’s an Assertion Payload?

An assertion payload is essentially a way to validate states or conditions in your smart contract. It helps ensure that everything is working as expected. Think of it as a safety net for your code.

Key Components

1. State Variables: These are the variables that hold important data for your contract.
2. Functions: These perform operations on your data.
3. Assertions: These are checks that confirm your assumptions about the contract's state.

Code Example

Here's a simple example of how an assertion payload might look in Solidity:

pragma solidity ^0.8.0;

contract AssertionExample {
    uint public value;

    function setValue(uint _value) public {
        // Ensure the new value is positive
        require(_value > 0, "Value must be positive");
        value = _value;
    }

    function getValue() public view returns (uint) {
        return value;
    }
}

Explanation

• setValue function: It takes an input and checks if it’s greater than zero. If it isn’t, the transaction fails with an error message. This is where assertions come into play.
• getValue function: This just returns the current value. No fancy business here!

Benefits of Using Assertions

• Debugging: They make it easier to find bugs since they pinpoint where things go wrong.
• Security: These checks help prevent invalid states in your contract, which is super important in a decentralized environment.

Conclusion

Using assertion payloads in your Solidity contracts is a smart move to ensure that everything runs smoothly and securely. Remember to include them in your development process! If you want to dive deeper into Solidity, check out the Solidity Documentation.

// Pseudocode -- OOV3 assertion for "gate-in > +15m" using hashed rulebook
bytes32 RULEBOOK = 0x...; // IPFS/Arweave hash of the settlement rules
string memory claim = string.concat(
  "Flight DL1234 on 2026-02-10 ARR gate-in = 21:37Z; ",
  "CRS scheduled = 21:15Z; Δ=+22m; LATE per DOT15; rulebook=", toHex(RULEBOOK)
);
// assertTruth with default liveness set to 2 hours
optimisticOracleV3.assertTruth(claim, asserter, bond, liveness, identifier);

Check out the reference implementation for UMA’s OOV3 PredictionMarket.sol. You can dive into the details over at docs.uma.xyz.

4) L2 and fees: predictable unit economics post-EIP‑4844

• We set up markets on an OP Stack chain (Base/OP Mainnet) which means you're looking at super low fees and some solid fault-proof security that's really starting to mature. After the Dencun EIP-4844 update, the typical Layer 2 costs for basic transactions are now just a matter of cents! Blobs are doing their thing by separating data availability from Layer 1 gas, which has really changed the game for Layer 2 costs. Plus, we’ve got fault proofs rolling out (Stage-1) on both OP Mainnet and Base, which is a big win for institutions looking to boost their withdrawal trust models. (investopedia.com)
• We’ve put a cap on the number of on-chain calls per market to keep things streamlined:
  • That includes the listing, two oracle updates, and the settlement; everything else sticks to off-chain analytics.
  • We're batching a bunch of pre-event signals into a single blob whenever we can.

5) MEV and orderflow integrity

• Intake through protected order flow: We’re using Flashbots Protect and MEV-Share to help cut down on frontrunning and make sure there are rebates available. The way the builder market is evolving, thanks to BuilderNet and SUAVE R&D, is shaping our sequencing policy. But don’t worry, we’re kicking things off with tried and true MEV-Share flows. (flashbots.net)
• Auction design: For large positions, we’re going with a request-for-quote or a batch auction, kind of like CoW-style, to keep information leakage to a minimum. This also lines up nicely with “intents” execution and helps reduce those pesky gas-wasting spam issues that can really bog down rollups. (arxiv.org)

6) ZK‑KYC geofencing without warehousing PII

• Check out Polygon ID-style verifiable credentials: the prover can demonstrate “is over 21” and “not a resident in restricted states” using zero-knowledge proofs, so no personal info gets involved with your smart contracts. This approach is backed by multiple wallets and issuers now. (coindesk.com)
• If you're looking to access the U.S. market, make sure your rulebooks align with CFTC-compatible “event contracts” for a regulated approach (think intermediated access through FCMs), or consider geofencing states that have gambling regulations (the recent Nevada ruling really puts this into perspective). (coindesk.com)

7) Security, audits, and SRE

• Threat model: We're looking at stuff like oracle manipulation, timestamp skew, insider routing of airline operations data, and those pesky griefing games related to bonds.
• Controls: We've got some solid measures in place, including multi-source attestation, liveness windows, replay-safe assertions, and monitoring hooks that flag “late/no data” states via an off-chain indexer.
• We’ll make sure to provide a complete audit and a clear incident-response runbook before we hit the mainnet.

---

A “DL1234 2026‑02‑10 >+15m?” binary market

• Target data:
  • We need to grab the airline/FAA timestamps for gate-in and scheduled times (AIDX/OPS/FLIFO). You can check it out on iata.org.
  • Let's also pull in the weather info for departure and arrival using METAR/TAF from the awesome new AWC API. More details can be found at aviationweather.gov.
  • Don’t forget about the ATC status (you know, like GDP and ground stops) for both airports. For that, just head over to flightqueue.com.
• Listing flow:
  • Kick things off by writing an immutable rulebook hash and then emit the MarketCreated event with the specific flight IATA/ICAO codes and UTC date. This way, we avoid any confusion with local times.
• Live quoting:
  • For live quoting, stick to Data Streams just for pre-event pricing. Remember, this isn’t for settlement yet! Use those airport congestion and ATC signals to adjust the implieds; thanks to Multistream, we can support multiple flight markets at the same time. Check out more about it on blog.chain.link.
• Settlement:
  • Once the gate-in is published, Functions will fetch the structured JSON. The proposer will then submit the UMA assertion. If there’s no contest after 2 hours, you can redeem at $1/$0. But if things get a bit messy and there’s a dispute, the DVM vote might extend the process. For more details, swing by docs.polymarket.com.

Europe corridor with NM B2B

• You can check out the markets for FRA‑CDG routes and tap into EUROCONTROL’s NM B2B “Flight Data Retrieval” as well as the Arrival Planning Information (API) to see how slots are affected. The rulebooks actually point to these APIs as the main sources for EU flights. (eurocontrol.int)

Example C -- Parametric “delay insurance” wrapper

• We’re sticking with the same oracle stack and rulebook; however, instead of tradeable shares, this contract pays out a fixed indemnity when Δ > 15m. Product owners can estimate expected loss using models calibrated with the Brier score based on your historical data and NOAA weather factors.

---

Best emerging practices (Jan 2026)

• To kick things off, let’s get "late" officially defined using DOT/BTS 15‑minute gate‑in language and make that rulebook available. This straightforward step can clear up a ton of disputes. (bts.gov)
• Keep your analytics off-chain and just share the bare minimum for settlement proofs. After Dencun, blobs are becoming more affordable, but they’re still a limited resource at scale, so aim to reduce blob count and steer clear of redundant calldata. (investopedia.com)
• With permissionless fault proofs rolling out (Stage‑1), it’s a good time to prioritize OP‑Stack chains, especially if you’re looking for reliable withdrawal assurances for institutional flows. (optimism.io)
• Consider UMA OOV3 bonds and rewards as tools for your product strategy: set them based on open interest and "dispute probability" to keep TTF (time‑to‑finality) within your SLA. Make sure to document these parameters in your rulebook. (docs.uma.xyz)
• Leverage ZK‑KYC for age and residency checks without handling PII. Issue and verify credentials through wallets compatible with Polygon‑ID, so you don’t have to build a custom identity stack from scratch. (coindesk.com)
• Start off with a solid procurement plan:
  • FlightAware Firehose: only select the layers you really need (like FLIFO/positions) and go for a monthly unlimited plan. (flightaware.com)
  • Aviationstack: filter your queries based on flight and date; don’t forget to cache aggressively. (aviationstack.com)
  • NOAA AWC: stick to 100 requests per minute and favor cache files for bulk data needs. (aviationweather.gov)
  • OPSNET: keep in mind that daily data won’t be public until after the 20th of the next month, so don’t rely on it for same-day settlements. (aspm.faa.gov)
• Get ready for some regulatory chaos in the U.S.: even with the federal acknowledgment of some event contracts (like the Kalshi litigation outcomes), there’s still pushback at the state level. Be prepared to set up geofencing on a per-state basis. (cnbc.com)

---

Target audience and the exact keywords they need to see

• Airline Ancillary Revenue and Operations Leaders
  • Your Language: A‑CDM, AIDX, SSIM/MCT, OTP code, IROPS, GDP/ground stop, gate‑in.
  • Value: Connect delay-market engagement to lounge upsell opportunities, same-day rebooking deals, and protect NPS during IROPS.
• InsurTech Product/Actuarial Teams
  • Your Language: Parametric triggers, loss ratio, Brier score calibration, binding authority, claims automation, capacity partner.
  • Value: Shift from ex-post adjudication to reliable on-chain triggers; cut down on LAE and leakage.
• Regulated Exchange/Product Managers
  • Your Language: Event contracts, FCM-intermediated access, market surveillance, Part 16 reporting, resolution SLA, dispute bonds.
  • Value: UMA-based settlement with a clear audit trail and per-state geofencing.

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GTM proof points and metrics to run (and report) from Day 1

• Resolution SLA: We've got a goal to keep the 95th percentile "time-to-finality" under 2 hours for uncontested cases. Also, we're keeping an eye on the “% disputed” and the “avg DVM time” when things get escalated. Just for your info, the UMA/Polymarket windows run for 2 hours initially and can extend to multi-day if there’s a vote involved. (docs.polymarket.com)
• Oracle cost per market: We’re capping it at under $0.02-$0.05 in L2 gas for settlement transactions after EIP-4844. Make sure to check your chain’s blob pricing to verify, and don’t forget to publish a monthly payer mix. (investopedia.com)
• Data SLOs: Let’s ensure NOAA/FAA calls stay within those rate limits. We also need to focus on Firehose uptime and have an SLA for message loss. If there are any gaps in the primary source that last longer than 20 minutes, we should definitely get an alert. (flightaware.com)
• Compliance coverage: It’s important to track the percentage of traffic that’s passing ZK-KYC and the percentage blocked by geofences in each state. If you’re running a regulated U.S. venue, be sure to reconcile with any FCM/broker feeds. (coindesk.com)
• Liquidity health: We’ll be looking at the spread in comparison to implied volatility during GDPs/ATC events and checking for any slippage during batch auctions.

---

What you get with 7Block Labs (deliverables mapped to outcomes)

• We’re working on market design and rulebooks that are in sync with DOT/BTS OTP and aviation data standards. We make sure to encode these rulebooks on-chain and in UMA payloads. Check it out here: (bts.gov).
• Our oracles mix Chainlink Functions/Data Streams with FlightAware, NOAA, and AIDX, plus we’ve got caching and throttling in place to keep your data SLOs on point. More info can be found at (flightaware.com).
• We’re deploying on OP-Stack chains with L2 and incorporating fault-proofs (Stage-1). We’re also carefully managing blob usage to maintain stable unit economics. Dive deeper at (optimism.io).
• For ZK-KYC enrollment, we’re using Polygon-ID-compatible credentials, so you won’t have to worry about PII custody. Get the scoop at (coindesk.com).
• We’re all about MEV-aware order flow! With MEV-Share/Protect and batch auction rails, we’re geared up for large tickets. Learn more at (github.com).
• When it comes to production readiness, we’re on it with a full audit and chaos tests, covering everything from API brownouts to delayed gate-ins and source divergence.

When it makes sense, we like to mix things up or expand on a few key areas:

• Our tailored oracle adapters and settlement engines are all part of our custom blockchain development services.
• On-chain identity attestations are handled through our awesome web3 development services.
• We offer complete audits and quick incident response with our solid security audit services.
• Need to connect airline/OTA back-offices or broker/FCM rails? We’ve got you covered with our blockchain integration.
• For cross-venue liquidity and chain routing, check out our cross-chain solutions development, and if it's necessary, we also provide blockchain bridge development.
• Lastly, we deliver market factory contracts and UIs as a complete package through our turnkey dApp development offering, complete with robust smart contract development.

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Brief implementation plan (12-14 weeks)

• Weeks 1-2: Kick things off with some workshops on rulebooks, figuring out jurisdictions, and sorting out procurement stuff. We'll also get down to signing those data/API SOWs (think Firehose layers and NOAA cache cadence). Plus, we’ll draft up those UMA parameters and get the ZK-KYC issuers lined up.
• Weeks 3-6: Time to roll up our sleeves and build those oracle adapters and settlement contracts. We’ll also set up the ZK-KYC verifier and get our L2 devnet going with synthetic flights. Don’t forget the SRE dashboards to keep an eye on data lags and disputes.
• Weeks 7-9: We’ll dive into integrating Chainlink Functions and Data Streams. It's also time to stage Base/OP, run some load tests, and nail down our fee caps along with MEV-Share routing.
• Weeks 10-12: We need to prioritize a security audit, set up those canary mainnet markets, and run some fire drills for dispute games.
• Weeks 13-14: We’ll wrap things up by expanding our listings, refining batch auctions, and fine-tuning our per-state geofencing.

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Procurement checklist you can copy into your RFP

• Data
  • FlightAware Firehose: Get your hands on FLIFO + ExtendedFLIFO in JSON Lines format with unlimited monthly access, plus SLAs and redistribution rights. Check it out here.
  • NOAA AWC Data API: With a caching strategy and a limit of 100 requests per minute, this API has some important schema migration docs coming in 2025. Learn more here.
  • OPSNET: This is purely for analytics--just a heads up, it doesn’t include same-day settlement. Explore it here.
  • (EU) NM B2B: Here’s everything you need to know about credentials and scope. Find details here.
• Oracles
  • Chainlink Functions: Get into the details of keys, DON selection, and, if applicable, Data Streams channels along with their cadence. More info here.
• Settlement
  • UMA OOV3: Dive into the addresses, bond/reward formulas, and the escalation policy (2 hours to DVM). Check it out here.
• L2
  • OP-Stack: Look at your options for chain selection and get the scoop on the post-EIP-4844 fee model and fault-proof status. More details here.
• Identity
  • ZK Credentials: Explore issuers, age/residency claims, revocation lists, and wallet UX. You can find it here.
• Compliance
  • U.S. State Geofencing: Keep in mind the regulated access (if needed, mediated by FCM) along with internal surveillance and Part 16 reporting if you’re going the exchange route. More on this here.

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The bottom line

• With authoritative definitions like the DOT 15-minute gate-in and multi-source oracles, you can dodge a lot of the unnecessary disputes. Check it out here: (bts.gov).
• The OP-Stack L2s, thanks to fault proofs and EIP-4844, are making it possible to enjoy super low fees at scale. It’s pretty impressive! Learn more at (optimism.io).
• UMA OOV3 is a game-changer! It gives you speed when there’s no contest and reliable security when things get tough, as long as you get the bonds and rewards just right. For details, see (docs.uma.xyz).
• And with ZK-KYC, you're covered on compliance without having to deal with any personal info, which is a huge win! More info can be found at (coindesk.com).

By going with these options, you can realistically expect to see your MVP in about 12 to 14 weeks, and it sets you up for a smooth journey to scaling your capacity.

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Ready to kick things off? If you're the Head of Product or the Actuarial Lead who's in charge of delay markets or parametric flight products, we want to hear from you! Just send us your top 10 routes along with a red-lined data SOW. We'll get back to you within 48 hours with a signed technical blueprint, a bond/reward schedule tailored to your OI, and a week-by-week plan to hit a T+2h resolution SLA on Base with UMA OOV3.

Let’s get your first five markets all set for production--book a build slot through our custom blockchain development services, and we’ll take care of everything else.