Four Years, Eighteen Minutes: Inside Ergo's Storage-Rent Harvest

Ergo chain warning — if you hold any asset on Ergo, read this first. All funds are safe on Flux and on the parallel-asset chains, and every Flux balance is honored through Fusion. On Ergo, however, anyone can claim a box that has sat unmoved for four years, without your private key. If that box holds less than about 0.15 ERG, the claimant keeps everything in it — ERG, tokens, NFTs, all of it. This is not an exploit and not a hack: it is Ergo’s storage rent, designed and documented. It is running right now at industrial scale. If you hold assets on Ergo, consolidate aging boxes and keep at least 1 ERG on every token box. You can check your own boxes free, live, with no wallet connection, at ergo.runonflux.com.

Fluxers! At 23:00:58 UTC on 21 September 2026, a transaction nobody at our company signed — that nobody could have signed — took 400,000,000 FLUX out of the Flux bridge reserve on Ergo. Eighteen minutes later, a second one took the remaining 15,000,000.

First, the part that matters most to Flux holders: no user funds were lost, no private key was compromised, and every FLUX balance captured at our snapshot block is honored 1:1 in native FLUX, claimable inside Fusion. This is not a story about a breach of Flux.

It is a story about what we found when we pulled the thread on how those transactions were possible: a protocol rule that transfers dormant assets to strangers without a key, and an automated industry operating it at a scale that, as far as we can tell, nobody had documented — until now.

The mechanism, precisely

Ergo is a UTXO chain. Balances live in “boxes,” each with an ERG value, optional tokens, and a guarding script. Two protocol rules matter here.

The storage period. A box that has not moved for 1,051,200 blocks — four years at Ergo’s roughly two-minute blocks — can be spent by anyone. The guarding script, whether P2PK, multisig or any contract, is never evaluated. The spending-proof field in the transaction is literally empty. No key exists that could stop it, because no key is consulted.

The rent. The collector charges a storage fee of roughly 0.1 ERG per four-year period, and the outcome splits in two:

The box can pay (0.15 ERG or more): the protocol forces an output back to the owner’s script, minus the rent. You lose about 0.099 ERG per period to someone who chose to “refresh” your box for you.
The box cannot pay: the claimant keeps the entire box — ERG, tokens, NFTs, everything.

Here is why that second branch matters so much. Wallet software on Ergo routinely attaches the protocol minimum, 0.001 ERG, to token transfers. Every such box lands in the second branch. Every token transfer creates a box with a four-year fuse on it, and almost nobody knows.

The anatomy of the taking

Our bridge reserve sat in two boxes created on 30 August 2022, holding 400M and 15M FLUX with 0.001 ERG each. Rent eligibility is height-based: box creation plus 1,051,200 blocks. The big box became claimable at height 1,878,283. It was claimed at height 1,878,293 — ten blocks, roughly twenty minutes, after becoming legal.

Inspect them yourself. spendingProof: null on our boxes. The only signed input belongs to the collector, funding the transaction from their own wallet.

One thing deserves saying plainly. The mechanism is not secret. It is in the whitepaper and the protocol source, and Ergo’s docs acknowledge — on a page in the mining section, added in July 2023, after we had integrated — that users “may lose valuable assets unintentionally.” But it is not where wallet developers look. None of the wallet-developer pages in Ergo’s docs mention storage rent. The integration guide mentions a rent fee in one line, not that tokens can be taken. The SDKs wallets are built on (Fleet, AppKit, ergo-lib) carry no warnings, and Fleet’s default box value for token outputs is 0.001 ERG — the exact amount that puts a box in the confiscation branch. We are a professional custody team and we still failed to account for it; that failure is ours, and we own it. But if a wallet team in regular contact with the Ergo team never had it flagged, “documented” is not the same as “communicated” — and even then, the real question is whether any documentation makes a confiscation branch acceptable for token custody. On that, the numbers below are our answer.

The same night produced a perfect control experiment. The bridge also held a 1 ERG box from the same 2022 vintage. Because it could pay its rent, the collector’s sweep was forced to return 0.90125 ERG to our own script, keeping about 0.099 ERG. Same mechanism, same night, same collectors — two outcomes decided solely by the ERG balance sitting in the box.

The harvest is an industry

This is not a hobbyist stumbling on a forgotten box. All of it is documented in the transactions themselves.

Professional operators. Two collector addresses executed the sweep of our reserve and split it 50/50. The larger operation has 77,532 lifetime transactions; the other, 29,547.
Fee infrastructure. These transactions pay no standard miner fee. They route payments through a script that substitutes the current block miner’s public key into the output — direct miner payouts for including confiscation transactions. We verified that the drain block’s miner key matches the timelock key the fee boxes consolidate into. Miners are paid participants in the harvest.
Latency engineering. Across 30 days of observed sweeps, the median time between a box becoming claimable and being claimed was about six minutes. In the most recent week, 100% of eligible boxes were claimed within 24 hours. Nothing survives the threshold. In our audit of all 90,490 boxes that have ever held FLUX, the number of unspent boxes older than four years is zero.

The receipts: one week, one month

Walking the two principal collectors’ transaction histories, over the last 7 days and the last 30 days respectively:

Sweep transactions: 1,245 → 4,399
Boxes claimed: 12,986 → 42,433
Victim addresses: 3,675 → 5,402
Boxes confiscated outright (dust — whole box including tokens): 3,089 → 6,300
ERG inside those confiscated boxes: 114 ERG → 286 ERG
Funded boxes rent-bled (returned minus ~0.099 ERG): ~9,900 → ~36,100
Rent skimmed from them: ~990 ERG → ~3,600 ERG
Distinct tokens among victims: 100+ → 458

About 8 million ERG passed through swept boxes in the 30-day window — but by protocol rule the funded remainder is returned to owner scripts, so it is not lost. We verified this at box level twice: the bridge’s own 1 ERG box (1.0000 returned as 0.90125), and a collector transaction (69f06c7f…) where a 1.0470 ERG victim box came back as 0.9483 ERG to the owner’s exact script, with 0.0988 kept as rent.

What about ERG itself? The rule does not distinguish ERG from tokens — it distinguishes funded from underfunded boxes. A dust box holding only ERG is confiscated whole (286 ERG across 30 days). A funded ERG box loses about 0.099 ERG per four-year period, at a stranger’s initiative rather than the owner’s, and Ergo’s own documentation notes that a 1 ERG box survives roughly 32 years of rent before being fully consumed.

The primary victim class is tokens in dust boxes, because that is exactly what default wallet behaviour creates: 3,257 token boxes confiscated outright in 30 days, spanning 458 tokens — wrapped assets (WT_ERG, WT_ADA), the SigUSD stablecoin, staking keys, NFT collections, and community tokens. Our 415M FLUX was precisely this branch.

And 98.8% of the 30-day victims were boxes created in August 2022. The chain’s 2022-era activity is now marching through its four-year anniversaries, box by box, day by day.

What is coming next

For FLUX specifically, from a complete enumeration of every box that has ever held the token:

Next 30 days: 786 boxes going claimable, 7,632,296 FLUX at risk, across 588 addresses
Next 90 days: 1,418 boxes, 11,694,506 FLUX, across 1,000 addresses
Through 2028: 3,747 boxes, 18,397,132 FLUX, across 2,488 addresses

99.97% of that FLUX sits in dust boxes — whole-box claimable by strangers. Fourteen boxes holding 11.5M FLUX in the 90-day window are bridge-controlled deposits, and we are consolidating those ourselves ahead of their dates.

For the Ergo ecosystem, the same arithmetic applies to every token. At the observed rate of 1,400 to 1,850 boxes per day, on the order of 130,000 to 170,000 boxes will be claimed in the next three months, and every one of them becomes available to the fastest bot at the exact block it turns four. The vintage created September to December 2022 is already queued. If your Ergo wallet shows a box older than about three years carrying less than 0.15 ERG, assume it is scheduled.

No other chain does this

Chains that charge for state solved this without confiscation. Solana enforces rent-exempt minimums, so accounts that could be drained by others cannot exist in the first place. Cardano mandates a minimum ADA per UTXO at creation. Nervos prices state in the asset itself. Ethereum debated rent for years and never shipped it, rather than ship this.

Ergo’s documentation describes storage rent as garbage collection. Destruction is a bug; harvesting is an industry — and the confiscation branch is funded by the protocol’s own incentive design.

What we are doing

Flux ends on Ergo. The bridge is terminated permanently. This aligns with our published roadmap of consolidating parallel assets and becoming the infrastructure layer on which agents deploy — this decision simply expedites that timeline. From October onward, dormant boxes become claimable by strangers (7.6M FLUX within 30 days alone), and we will not hold users’ funds on a chain with a built-in timer on them, period.

A snapshot at block 1,878,291 (22:54:55 UTC, 21 September 2026 — two blocks before the drain) honors every circulating FLUX balance 1:1, claimable inside Fusion. Roughly 483,623.36 FLUX across 2,842 addresses is user-claimable per the published snapshot; check your balance at ergo.runonflux.com. Claims do not depend on the recovery of the bridge reserve.

Some practical points on claiming:

Claims are made inside Fusion — no external sites. If something claims to be a Flux–Ergo claim portal outside Fusion, it is a scam.
The claim window opens in early October, and a complete guide will be published before it opens.
Unclaimed Fusion snapshot balances and mining rewards remain claimable on the Flux main chain. No action is needed and nothing is lost.
The snapshot has already passed. FLUX acquired on Ergo after 22:54:55 UTC on 21 September carries no claim. Do not buy FLUX on the Ergo chain.

On the reserve itself: the operators of the collection scripts returned it in full within 24 hours — the bulk of it back at the bridge roughly eight hours after the drain, verified on-chain on 22 September — and we granted a 100,000 FLUX critical bug bounty for the responsible disclosure and return. Our thanks to them, and to the Ergo team, for doing the right thing and notifying us immediately. A protocol-legal action that everyone involved — the collectors included — recognises as a critical defect is the strongest confirmation of the problem we could ask for.

Zelcore stays on Ergo — loudly changed. Zelcore is not going anywhere; our users’ access to their own assets is non-negotiable, on every chain, always. But Ergo support changes with our next release, shipping at the end of September: a minimum of 1 ERG attached to every Ergo token transfer, which is decades of rent coverage instead of a four-year fuse, and severe plain-language warnings wherever Ergo assets are held, received or sent. We are further considering flagging Ergo boxes older than three years and offering one-tap consolidation.

We are publishing everything. Box-level CSVs of the vulnerable Flux boxes, the full sweep log, the statistics pack and the EIP text are all public at github.com/RunOnFlux/flux-ergo-claims. We have also built and published the tools the chain lacks, at ergo.runonflux.com: a live box-safety checker, a sweep detector, a coming-due radar, a known-harvesters registry, and a community shield bot — all open source, built for every Ergo user rather than only for Flux holders.

What you should do

If you hold anything on Ergo, in any wallet: consolidate aging boxes into funded ones, keep at least 1 ERG on every token box, and treat the four-year mark as the hard deadline it is. If you custody other people’s Ergo assets, audit your boxes against creationHeight + 1,051,200 today, not at the next incident.

This can be unchosen

Our criticism is of a design, not of people. We thank the Ergo team for notifying us and working with us closely throughout, and we hope to keep that relationship and keep working together to make Ergo and the wider space safer.

To Ergo’s leadership, core developers, miners and community, we are asking publicly and today:

Ship rent-exempt-style minimum balances — or any rule that makes third-party confiscation of a box impossible — as an emergency protocol change. Not at the next scheduled hard fork. Now.
Until it ships, publish the list of dormant boxes approaching eligibility and notify holders, the way any responsible custodian of user funds would.
Acknowledge the scale. The documentation calls this garbage collection. Nearly 13,000 boxes taken from 3,675 addresses in a single week, 100% of them claimed within 24 hours of eligibility, is not garbage collection.

To that end, we have submitted EIP-0049: Prepaid Storage Rent with Archival and Revival — a complete protocol proposal that eliminates the confiscation branch while preserving rent income and state cleanup. Boxes deplete rent continuously per block; exhausted boxes enter an archived state the owner can revive at any time. No cliff. No confiscation. No third party can ever claim another’s assets.

Every day of delay is another 1,850 boxes or so. The design decision that permits this was known and chosen. It can be unchosen. Until it is, we do not consider Ergo safe for token custody at global scale — not for our users, and not for anyone’s.

Evidence and methodology

Everything in this article is independently verifiable on-chain. The full evidence pack, the CSVs and the methodology are in the public repository, and the live tools are at ergo.runonflux.com.

Drain transactions: bb3607fa… and bafedb4a…
Snapshot block 1,878,291 (ID 6c088a23…, 22:54:55 UTC); drain block 1,878,293 (23:00:58 UTC).
Data: complete enumeration of all 90,490 boxes ever holding FLUX (api.ergoplatform.com, box level); a 30-day transaction walk of the two principal collector addresses covering 4,399 sweep transactions; height-to-date conversion by anchored linear interpolation, accurate to within hours.
Miner-fee plumbing verified by matching the drain block’s powSolutions.pk to the fee-box timelock key.
Funded-box preservation verified at box level on txs cae23424… (bridge 1 ERG returned as 0.90125) and 69f06c7f… (1.0470 returned as 0.9483, 0.0988 rent).
Files: ergo-flux-vulnerable-boxes.csv (3,747 rows), ergo-rent-sweep-log.csv (12,986 rows over 7 days), ergo-storage-rent-evidence-stats.md, and the EIP-0049 text.

— The Flux and Zelcore team