Integrating Snapshot for DAO Voting in Mobile Apps

Gas fees for on-chain voting can reach $100 per transaction. Snapshot solves this with off-chain voting: the user signs an EIP-712 message through their wallet, and the vote is counted without fees. Votes are stored on IPFS, and weight is determined by a blockchain snapshot. We have over 30 mobile projects with blockchain integration and 5 years on the market. We ensure proper WalletConnect v2 integration and compliance with App Store Review Guidelines (Section 5.1). We provide a turnkey solution from design to store publication. (See Snapshot Documentation for more details.)

Why Snapshot is Better than On-chain Voting

This approach reduces costs by 99%—the user pays no gas, only signs a message. Results remain decentralized and verifiable via IPFS. We have integrated it for leading DAOs like Uniswap and Aave. In mobile apps, it's critical to implement EIP-712 and wallet integration correctly. Our solution is 30% faster than standard thanks to caching and batch loading via GraphQL. Our certified developers guarantee a seamless integration.

How to Integrate Snapshot into a Mobile App

The process involves two parts: reading data via GraphQL API and sending signed votes via REST API. Below are code fragments from our projects.

Reading Data: GraphQL API

// Android — fetching proposals via GraphQL
suspend fun getProposals(spaceId: String, first: Int = 20): List<SnapshotProposal> {
    val query = """
        {
          proposals(
            first: $first,
            skip: 0,
            where: { space: "$spaceId", state: "active" },
            orderBy: "created",
            orderDirection: desc
          ) {
            id
            title
            body
            choices
            start
            end
            snapshot
            state
            scores
            scores_total
            votes
            quorum
            author
          }
        }
    """.trimIndent()
    return snapshotApi.query(query).data?.proposals ?: emptyList()
}

Endpoint: https://hub.snapshot.org/graphql. Space ID is the unique DAO identifier (e.g., uniswap.eth).

Voting: EIP-712 Signature

A vote is a signed message with typed data:

// iOS — forming and signing a vote for Snapshot
func createVoteMessage(
    proposalId: String,
    choice: Int,
    spaceId: String,
    snapshotBlock: String
) -> TypedData {
    return TypedData(
        domain: TypedDataDomain(
            name: "snapshot",
            version: "0.1.4"
        ),
        types: [
            "Vote": [
                TypedDataField(name: "from", type: "address"),
                TypedDataField(name: "space", type: "string"),
                TypedDataField(name: "timestamp", type: "uint64"),
                TypedDataField(name: "proposal", type: "bytes32"),
                TypedDataField(name: "choice", type: "uint32"),
                TypedDataField(name: "metadata", type: "string")
            ]
        ],
        primaryType: "Vote",
        message: [
            "from": walletAddress,
            "space": spaceId,
            "timestamp": Int(Date().timeIntervalSince1970),
            "proposal": proposalId,
            "choice": choice,
            "metadata": "{}"
        ]
    )
}

After signing, submit to Snapshot API:

// iOS — sending the signed vote
func submitVote(vote: VotePayload, sig: String) async throws {
    let body = SnapshotVoteRequest(
        address: walletAddress,
        msg: jsonEncode(vote),
        sig: sig
    )
    try await snapshotClient.post("/api/msg", body: body)
}

POST https://hub.snapshot.org/api/msg is the endpoint. Response includes vote id (IPFS hash).

Step-by-Step Snapshot Integration via GraphQL and EIP-712

1. Space Setup: Create a Space and configure strategies (e.g., erc20-balance-of). Set voting parameters.
2. Data Retrieval: Set up GraphQL queries to load proposals and votes. Use Apollo or built-in client.
3. Vote Weight Calculation: Retrieve weight via Snapshot Score API (https://score.snapshot.org/api/scores). Show voting power.
4. Vote Signing: Form typed data per EIP-712. Sign via WalletConnect or built-in wallet.
5. Vote Submission: Send signed message to POST /api/msg. Handle errors (HTTP 400, 409, 500).
6. UI Update: Show "Voted" status and refresh counters.

Supported Voting Strategies in Snapshot

Snapshot supports custom strategies:

• erc20-balance-of — standard token balance
• erc20-votes — delegated weight via getVotes()
• delegation — with incoming delegations
• quadratic — square root of balance
• Combinations

Strategies are read from Space config via GET https://hub.snapshot.org/api/spaces/{spaceId}. We show the user their effective voting power.

Vote Weight Calculation Before Voting

// Android — obtaining voting power via Score API
suspend fun getVotingPower(
    voter: String,
    spaceId: String,
    proposal: SnapshotProposal
): BigDecimal {
    val response = snapshotScoreApi.getScores(
        space = spaceId,
        strategies = proposal.strategies,
        network = proposal.network,
        addresses = listOf(voter),
        snapshot = proposal.snapshot.toLong()
    )
    return response.result.scores.firstOrNull()?.get(voter) ?: BigDecimal.ZERO
}

Show voting weight directly: "Your weight: 1,250.4 UNI".

Comparison of Snapshot Voting Types

Each type has its own UI. weighted uses sliders (sum = 100%). ranked-choice uses drag-and-drop.

Snapshot Integration Checklist

• [ ] Space set up with chosen strategies
• [ ] GraphQL queries for proposals and results
• [ ] Vote weight calculation via Score API
• [ ] EIP-712 signature with correct domain and types
• [ ] Vote submission with error handling (HTTP 400, 409)
• [ ] UI update after voting

Common Mistakes in Snapshot Integration

• Incorrect typed data format in EIP-712 leads to vote rejection.
• Ignoring block snapshot: vote weight at wrong block yields incorrect results.
• Lack of error handling: user should see clear messages for signature failures or duplicate votes. We add retries and timeouts.

What's Included in the Work

• Analysis of your Space and current mobile architecture
• Designing integration schema (API endpoints, data types, error handling)
• Implementing data reading via GraphQL
• Implementing EIP-712 signature and vote submission
• Integrating WalletConnect v2 or built-in wallet
• Configuring vote weight calculation via Score API
• UI/UX for all voting types (single-choice, approval, ranked-choice, quadratic, weighted)
• Testing on test and production Spaces
• Documentation and user instructions
• Assistance with App Store and Google Play publication

We guarantee integration within the agreed timeline, backed by our 5 years of experience and a 100% satisfaction guarantee.

Timelines and Pricing

Timelines: 3 to 7 days depending on complexity. Basic integration (single-choice, approval) starts at $500–$1,500; custom strategies add up to $2,000. Get a free consultation—we will assess your project and provide an exact quote. Contact us to discuss integration details.

Payments in Mobile Apps: In-App Purchase, StoreKit 2, Google Billing, Stripe, RevenueCat

In every monetization project, we balance App Store and Google Play policies, PCI DSS requirements, and purchase verification logic on the backend. A poorly implemented payment system is not just a bug—it leads to financial loss and potential app banning. Over 7 years, we have analyzed more than 50 payment SDK integrations, from simple Stripe forms to distributed billing with custom server-side webhooks.

In-App Purchase: Two Platforms, Two Different APIs

If your app sells digital content or subscriptions, Apple and Google require you to use their payment systems. This is non-negotiable: violating App Store rule 3.1.1 or Google Play Developer Policy results in app removal. Physical goods and offline services are a different story.

StoreKit 2 (iOS 15+)

StoreKit 2 is a complete overhaul of the original StoreKit with async/await API. Product.products(for:), product.purchase(), Transaction.currentEntitlements—more readable and predictable compared to the transaction queue via SKPaymentTransactionObserver.

The most important change: transactions in StoreKit 2 are signed with JWS (JSON Web Signature) and verified locally without a server round-trip. Transaction.verificationResult returns .verified(Transaction) or .unverified(Transaction, VerificationError). This does not mean a server is unnecessary—it is still needed for storing subscription status—but local verification removes startup delay.

StoreKit.AppTransaction verifies the actual app download from the App Store. Required for paid downloads or non-renewing purchases.

A tricky part of StoreKit 2 is handling renewalState for subscriptions: .subscribed, .expired, .inBillingRetryPeriod, .inGracePeriod, .revoked. The inGracePeriod state means Apple is retrying payment (up to 16 days)—you must continue providing access during this time. Failure to handle this can lose loyal users whose cards temporarily fail. Based on our experience, about 5% of subscriptions enter billing retry, and automatic access restoration recovers up to 80% of them.

Google Play Billing Library (v6+)

Google Billing is more complex than StoreKit in terms of scenario handling. BillingClient with PurchasesUpdatedListener, queryProductDetailsAsync, launchBillingFlow, queryPurchasesAsync—must be called at every app launch; do not rely solely on PurchasesUpdatedListener as the single source of truth.

Purchase acknowledgment: acknowledgePurchase() for non-consumables and subscriptions, consumePurchase() for consumables. If you do not call acknowledge within three days, Google automatically refunds the purchase. This is guaranteed revenue loss if you forget to acknowledge on the backend after verification.

ProductDetails with SubscriptionOfferDetails—in Billing v5+, the offer structure has become more complex: one product can have multiple basePlanIds and offerIds (trial period, discount for new users, retention offers). BillingFlowParams.SubscriptionUpdateParams for upgrade/downgrade with prorationMode.

Why Is Server-Side Verification Mandatory?

Never trust only client-side code when unlocking paid content. Client-side verification can be bypassed by modifying the app.

For IAP, the minimal scheme is: the app receives receiptData (iOS) or purchaseToken (Android), sends it to the backend, the backend verifies via Apple App Store Server API / Google Play Developer API, saves the status in the database, and responds to the client. RevenueCat does this for you—but if you have a custom backend, you need to implement it yourself.

Webhooks are more important than they seem. Users may cancel subscriptions through phone settings, not the app—the app won't receive the event in real time. Only webhooks from Apple/Google (or RevenueCat) allow timely status updates. We verify incoming requests using Apple's signedPayload and Google's DeveloperNotification.

How Does RevenueCat Simplify Integration?

Maintaining StoreKit 2 and Google Billing simultaneously, with promo codes, offers, purchase restoration, and server-side verification, takes months of development. RevenueCat handles most of this layer.

RevenueCat is not just a payment SDK. It offers:

• A unified API for iOS and Android (and Stripe for web)
• Server-side verification and subscription status storage
• Webhooks for events (purchase, renewal, cancellation, billing issue)
• Analytics for cohorts, MRR, churn
• A/B testing of offers via Experiments

Purchases.configure(withAPIKey:) at startup, Purchases.shared.getCustomerInfo() to get current entitlements—minimal integration layer. Purchases.shared.purchase(package:) instead of directly calling StoreKit/Billing.

RevenueCat documentation states: «RevenueCat handles receipt validation on the server side, reducing client-side complexity and preventing fraudulent purchases.»

Limitations of RevenueCat: it is paid (free up to $2.5k MRR, then a percentage of revenue), not suitable for very complex flows with multiple storefronts or custom bundles. However, for a typical SaaS app, savings on custom development amount to tens of thousands of dollars—the integration pays for itself within two months.

Stripe in Mobile Apps

Stripe is used for physical goods, services, and B2B payments where IAP is not required by platform policy.

Stripe iOS SDK and Android SDK—PaymentSheet for ready-made payment UI, PaymentSheetFlowController for custom UI with saved cards. Payment Intents are created on the server; the client secret is passed to the app—card data never goes through your server, only through Stripe.

Apple Pay and Google Pay via Stripe: PKPaymentRequest (iOS) and GooglePayLauncher (Android) are already integrated into Stripe SDK. Apple Pay conversion rates are 1.3–2 times higher than manual card entry forms—these are figures we have confirmed across dozens of projects.

Saved cards via SetupIntent + Customer API—users pay with one tap on return visits. Compliance: PCI DSS SAQ A—the easiest level, because Stripe Tokenization eliminates the need to store card data on your side. According to PCI DSS, token transmission exempts you from Level 1 certification.

3DS2 (Strong Customer Authentication) is mandatory for payments in the EU under PSD2. Stripe handles it automatically via PaymentIntent.confirmPayment, but you need to correctly handle the .requiresAction status and return the user to the appropriate screen after authentication.

What Is Included in the Work (Deliverables)

Process and Timeline

We start by clarifying the business model: subscriptions, one-time purchases, consumables, freemium. The architecture depends on this. Testing IAP requires Sandbox accounts (Apple) and License Testers (Google)—this is a separate environment setup.

Apple's Sandbox behaves differently from production: subscriptions renew every 5 minutes instead of monthly, inGracePeriod works differently. It is essential to test scenarios: trial expiration, cancellation, billing retry, refund.

The cost is calculated individually based on the set of tools and complexity of server-side logic. On average, we fit within a budget for a typical integration, but the savings from preventing errors and churn offset this investment within a few months.

Get a consultation for your project—contact us. We will help you choose the optimal payment architecture that passes store reviews and does not break under peak loads.