Launching a token airdrop requires an automatic airdrop claim system that combines off-chain calculations and on-chain verification via a Merkle proof structure. This cryptographic commitment scheme distributes tokens fairly while minimizing transaction costs. Our turnkey token distribution system covers the full cycle: snapshot, anti-Sybil analysis, tree construction, smart contract deployment, and claim UI. With over 5 years in the market and more than 50 completed projects, we ensure security and transparency. According to Optimism distribution data, Sybil filtering saves a project between $50,000 and $200,000 depending on pool size. For a standard airdrop with 100,000 addresses, the development cost is approximately $20,000. Typical project cost ranges from $15,000 to $50,000 depending on complexity.
Development of an automatic airdrop claim system
At the core is a Merkle proof system serving as a verifiable proof of inclusion. Each leaf node is computed as keccak256(keccak256(abi.encode(account, amount))). The smart contract stores only the root hash (32 bytes). For one million addresses, the proof consists of 20 hashes (640 bytes calldata), achieving a 5000x gas reduction compared to on-chain mapping. Users execute a single claim() transaction with their proof.
What are the benefits of automation?
This automatic airdrop claim system eliminates manual errors, speeds distribution, and cuts gas expenditure. For one million participants, total gas remains under $10,000 at standard prices. A custom indexer processes data in hours instead of days. Consequently, a ready system is delivered in 2–3 weeks rather than months of development.
Gas optimization using tree-based verification
Using a Merkle structure reduces claim costs to one transaction per user. For a pool of 1 million addresses, savings exceed $50,000 compared to full mapping. The distribution contract is further optimized for cold storage reads.
How do we protect against Sybil attacks?
The Sybil problem
Creating multiple addresses to receive a larger token allocation is a real threat. According to Optimism data, ~17% of eligible addresses were flagged as fake. Our automatic airdrop claim system employs three methods:
- Address funding analysis: We build a funding graph; if N addresses received ETH from one source and performed similar actions within a narrow window, they are clustered as Sybils.
- Temporal clustering: We scan for mass registrations over short periods. A cluster of 50 addresses activated within 10 minutes triggers a stop signal.
- On-chain identity verification: We account for ENS, Lens Profile, and Gitcoin Passport. An ENS name reduces Sybil probability to almost zero.
Filtering results
| Metric | Before filter | After |
|---|---|---|
| Unique addresses | 150,000 | 124,000 |
| Token volume (pool) | 10M | 8.3M |
| Gas savings (claim) | — | 23% |
With a 10M token pool, anti-Sybil analysis saves the project about $200,000. The 23% reduction in claim gas further saves ~$5,000 at distribution.
Airdrop system development components
- Snapshot and indexing: Collect historical events via RPC or The Graph. For large volumes, we write a custom indexer using TypeScript + viem + PostgreSQL.
- Criterion definition: Assign weight to actions (volume, frequency, activity time). Logarithmic scaling prevents whale dominance.
- Merkle proof construction: Off-chain calculation of root and proofs per address using OpenZeppelin standard with double hashing.
- Smart contract: Solidity + Foundry, support for deadline and return of unclaimed tokens to treasury.
- Claim UI: React + wagmi + RainbowKit, eligibility check via API, protection against viewing amounts before start.
- Audit and testing: Formal verification with Slither, Mythril, and Echidna fuzzing. Code warranty provided.
Example of proof calculation
Leaf = `keccak256(keccak256(abi.encode(account, amount)))`. The contract stores only the root (32 bytes). Proof size for 1M addresses is 20 hashes (640 bytes calldata). This is 5000 times cheaper than storing the full list on-chain.Smart contract security assurance
In addition to standard tools (Slither, Mythril), we conduct formal verification with Echidna for fuzzing. Contracts are tested for reentrancy, overflow, and race conditions. For sensitive projects, external audits are engaged.
Development timeline
| Stage | Timeline |
|---|---|
| MVP with ready snapshot | 2–3 weeks |
| Full system with indexer and Sybil protection | 5–8 weeks |
| With adaptation for specific criteria | 6–10 weeks |
Cost is calculated individually depending on data complexity and functionality. Order an estimate in 1 day—we will send a commercial proposal. To get an estimate, fill out the form on the website, and we will contact you within a day.
Deliverables and support
Deliverables: Full smart contract source code, customizable claim UI source code, deployment scripts, administrative dashboard, technical documentation with API reference, airdrop launch guide, and post-deployment support for the first month. Optionally, we provide team training.
Our expertise and guarantees
With 5+ years of experience and over 50 realized airdrops, we ensure your token drop proceeds without technical failures or Sybil exploitation. Get a consultation on your project today by leaving a request.