Union was one of the better-known “testnet with a dashboard” projects of 2024 and 2025: bridge some test assets, complete missions, collect XP and wait. The wait ended almost a year ago. Union’s mainnet went live on September 4, 2025, the U token launched with it, and the genesis U Drop was claimable only for a limited period by people who had pre-claimed. Searching for a Union testnet airdrop today will mostly surface stale guides and, increasingly, fake claim pages. This article explains what Union actually is, how the U Drop worked, what U is used for now, what remains for ordinary users, and which upcoming dates matter.
What Union does
Union describes itself as a zero-knowledge interoperability network that acts as a settlement and liquidity layer between blockchains. In plain terms, it lets assets and messages move between chains such as Ethereum, Cosmos-based networks and Bitcoin-adjacent ecosystems without relying on a multisig committee to vouch for each transfer. Instead, each side verifies a cryptographic proof that the event really happened on the other chain.
The design is an extension of IBC, the Inter-Blockchain Communication standard from the Cosmos world, adapted so that chains which cannot run Cosmos light clients cheaply, Ethereum in particular, can still verify Union’s state. Union runs its own proof-of-stake layer 1, called union-1, using CometBLS, a fork of CometBFT that swaps in BLS signatures to make consensus easier to prove in zero knowledge. The validator set is capped at 128. The Union documentation covers this architecture in detail, including the CometBLS specification and the light clients Union maintains for each connected chain.
During its alpha mainnet phase, before the public launch, more than $145 million in Bitcoin liquid staking tokens, BABY (Babylon’s token) and other assets moved across Union routes. Bitcoin finance has remained one of Union’s main use cases, alongside general cross-chain transfers through the app at app.union.build.
How the testnet era worked
Union ran a long sequence of numbered testnets. The Union Dashboard, introduced on the official blog, turned participation into missions and achievements that earned XP. XP determined community levels and unlocked rewards such as Discord roles, and achievements covered earlier work as well as live tasks, including Testnet 8, the Trusted Setup Ceremony for Union’s zero-knowledge circuits, and later Testnet 9. Users could link X, GitHub and Discord to their dashboard profile, which is how Union connected on-chain activity with social contributions.
In parallel, Union ran a creator campaign called Mad Yaps for people posting about the project on X. Korean coverage reported that Mad Yaps was funded with 1% of supply drawn from the ecosystem fund, separate from the U Drop itself. Union did not publish an exact formula for how XP, levels or Yaps translated into token amounts, and we have not seen an official document that settles it.
The U Drop: pre-claim, claim and deadline
The token launch was preceded by a mandatory pre-claim. The pre-claim opened on August 30, 2025, and Union described it as a required step for anyone who wanted to claim at the token generation event. Users logged into the dashboard with a linked X, GitHub or Discord account and registered an EVM address; that same address then had to be used for the actual claim.
When mainnet launched on September 4, 2025, Union’s announcement stated that the genesis U Drop was claimable, but only for those who had pre-claimed. Airdrop trackers and exchange research pages reported a claim deadline of September 18, 2025. The program was administered by Parachute Services Inc., a Panama company acting as an independent service provider to the Union entities, and its terms excluded jurisdictions where participation was prohibited.
The practical upshot is simple. If you did not pre-claim in late August 2025, you were not able to claim the genesis drop, and if you pre-claimed but did not claim by mid-September, that window has closed. Union has not announced a reopening.
U tokenomics in one table
Union published its token design on August 21, 2025. U is an ERC-20 token on Ethereum with a genesis supply of 10 billion and an initial circulating supply of 1,919,050,000, a little over 19%. The official contract address is 0xba5eD44733953d79717F6269357C77718C8Ba5ed; any other “U” contract presented as Union’s is not.
| Category | Share | Unlock schedule |
|---|---|---|
| Community incentives | 12% | 4% at launch (Genesis Drop and testnet), 8% reserved for future airdrops and incentives |
| Ecosystem | 14.1% | 40% at launch, rest linear over 2 years |
| DAO treasury | 12.5% | 12.5% at launch, rest linear over 3 years |
| Foundation | 20% | 40% at launch, rest linear over 2 years |
| Strategic investors | 21.4% | 1-year cliff, then 1 year linear |
| Core contributors | 20% | 1-year cliff, then 2 years linear |
Inflation starts at 6% a year and falls by 10% annually toward a long-term floor of 2%. Unlike many Cosmos SDK chains, Union does not target a particular staked ratio, so the rate does not jump if staking participation drops. Staking rewards for core contributors and strategic investors are locked for 12 months, follow the vesting of the underlying tokens and are lent to the Union Foundation for ecosystem incentives.
What U is used for
U has three jobs. It is the gas and fee token for Union’s dynamic fee market, paid for proof aggregation and verification, light-client updates, creating or freezing connections and setting up new cross-chain routes. It secures the union-1 chain through delegated proof of stake. And it is the basis of Union’s crosschain governance, which lets holders stake and delegate from connected chains, starting with Ethereum, without bridging to Union first. Direct cross-chain voting is listed as a future step.
Liquid staking runs through Escher Finance. Staking U through Escher’s contract on Ethereum mints eU, a liquid staked version of U. At launch, Union also deployed a 12-month staking vault on Tower DEX, hosted on Babylon Genesis. Depositors receive vU tokens representing their position; roughly half of each deposit is converted to eU, and the U/eU pair is used in a price-constrained liquidity strategy. Union estimated the vault’s reward rate at 120% to 140% for the first six months, highest at the start. That figure was an estimate, not a promise, and it was explicitly front-loaded. Withdrawals take about 48 hours on the fast path or 27 days on the secure path.
What is left for users now
The genesis drop is history, but the 8% of supply reserved for future incentives has not been spent. Union has not published a schedule, a points system or eligibility rules for that pool, so nobody can tell you how to qualify. What a reasonable user can do is use Union for what it is built for and keep the activity clean and verifiable.
- Move assets you actually need to move. Use app.union.build for cross-chain transfers, starting with small amounts, and check each transfer’s status on the app before assuming it has landed.
- Consider staking only if you understand the trade-offs. Delegating U secures the network and earns emissions minus validator commission. Liquid staking through Escher adds smart-contract risk, and the Tower DEX vault adds liquidity-pool risk on top of that.
- Follow governance. Crosschain governance means holders on Ethereum can delegate without bridging, which lowers the cost of participating and keeps you close to any future incentive announcements.
- Keep records. Save transaction hashes and the addresses you use. If Union ever runs a second drop tied to on-chain activity, a single consistent address with genuine history is easier to defend than a cluster of wallets.
Union’s testnet continues to exist for developers integrating the protocol, and the docs still explain how to join it and obtain testnet tokens. It is a development environment, not a reward program.
Dates to watch
The most important upcoming event is the end of the one-year cliff for strategic investors and core contributors, which together hold 41.4% of supply. Twelve months from the September 2025 launch places this in September 2026. Union’s tokenomics specify that these post-cliff unlocks are staggered over a 60-day linear period starting at the 12-month mark rather than released in a single block, followed by the longer linear schedules in the table above. Unlocks of that size often weigh on price, so anyone holding U should be aware of the timing. The Tower DEX staking vault’s 12-month run also ends around the same period.
Avoiding fake Union claim pages
Because the U Drop had a short window and a mandatory pre-claim, many eligible people missed it, and that creates a ready audience for “late claim” scams. Basic rules:
- Official properties are union.build, docs.union.build, app.union.build and the Escher site at escher.finance. The official X accounts are @union_build and @UnionFDN for foundation updates.
- Check the U contract against the address published in the docs before buying, staking or approving anything.
- No legitimate Union page asks for a seed phrase or a private key, and no claim requires you to pay a fee to “unlock” U.
- Pages offering to “recover unclaimed U Drop” or “check Season 2 eligibility” are not from Union, which has announced neither.
- Be wary of lookalikes such as union-build, unionbuild-claim or union.build spelled with a different top-level domain.
Frequently asked questions
Can I still claim the Union U Drop?
Not according to anything Union has published. The claim was open only to wallets that pre-claimed from August 30, 2025, and trackers reported a September 18, 2025 deadline.
Will Union run another airdrop?
Union reserved 8% of supply for future airdrops and incentives, so further programs are possible, but no dates, criteria or mechanics have been announced.
Does bridging on testnet still count for anything?
No reward has been tied to current testnet activity. The testnet is for developers and for learning the interface without risking funds.
What is the difference between U, eU and vU?
U is the base token. eU is U staked through Escher’s liquid staking contract. vU represents a position in the Tower DEX staking vault, which holds a mix of U and eU.
Verdict
Union is an interesting piece of infrastructure: proof-based interoperability built on a modified IBC, with Bitcoin finance as an early anchor. For airdrop purposes, though, the main event is over. The genesis drop went to people who pre-claimed in late August 2025 and claimed within a few weeks of mainnet, and the remaining 8% incentive pool has no published rules. If you want to stay involved, use the bridge when you genuinely need it, understand the layered risks of eU and the staking vault before depositing, and keep an eye on the investor and contributor unlocks scheduled to begin in the autumn.
This article is for information only and is not financial advice. Token unlocks, staking yields and incentive programs can change without notice.
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