Backstop rides the FAssets protocol's own default proof — and it's proven on-chain.
Not an app that talks to Flare — a product whose claim trigger is the exact attestation
(ReferencedPaymentNonexistence) the protocol itself accepts for a redemption default. We ran the round-trip for real.
99.3s
FDC proof round-trip on Coston2 — verify…Nonexistence returned true
6
Flare engine methods exercised on real Coston2 — none mocked
2
podium slots in Bounty 1 — and our lane is empty (0 rival BUIDLs)
The problem
Redeem FXRP. Agent vanishes. You hold the bag.
03
10:02 · Maya burns 5,000 FXRP
A redeemer asks the FAssets AssetManager for her underlying XRP back. A specific agent is on the hook to pay it to her XRPL address by a deadline.
10:02 + deadline · nothing arrives
The agent never sends the XRP — insolvent, offline, or malicious. The redemption simply defaults.
After · the recourse is thin
She must notice the miss, commission an FDC proof herself, call redemptionPaymentDefault, and take collateral in FLR at a haircut. She wanted her XRP. She is not made whole.
Why it matters to the whole ecosystem
Redemption reliability is the trust anchor of the FXRP peg. Every lending market, DEX, and treasury built on FXRP inherits this default risk — and prices it in as thinner liquidity.
FLR
what liquidation pays — not the XRP she was owed
0
make-whole products for a defaulted FXRP redemption today
The solution
A guard on your redemption ticket.
04
Before you redeem, buy a Guard bound to your exact redemption ticket for an FTSO-priced premium.
If the agent defaults, anyone can submit a real on-chain proof that unlocks a make-whole payout from a shared pool. If they pay, the premium goes to underwriters. One narrow flow, done to the metal.
→
01 · BIND
buyGuard()
Binds to a real redemption ticket via redemptionRequestInfo; premium priced by FTSO.
→
02 · WATCH
autonomous keeper
Watches the deadline. Agent misses it → requests an FDC attestation off-chain.
→
03 · PROVE
verifyReferencedPaymentNonexistence
The claim gate. Payout is impossible unless this on-chain proof returns true — it does, in 99.3s.
4 live on the deployed on-chain Solidity surface a judge can verify · 2 in the keeper the FDC protocol architecturally requires — all exercised on real Coston2.
Bar is 5+ engine methods — we clear it, and none are mocked.
Live demo · /integrations/verify
The proof a screenshot can't fake.
07
backstop.app/integrations/verify
1
2
FDC DEFAULT PROOF · READ FROM COSTON2
ReferencedPaymentNonexistence
verify()
true ✓
Round-trip request → on-chain verify
headline
99.3 s
Voting round
FDC
1,409,442
Attestation tx
Flarescan
0x5774…c540a ↗
Backstop contract
verified
0x38EB…DDca ↗
1
Live pool state, no wallet
TVL, share price, guards — all read live from the deployed Coston2 contracts, plus the global solvency cap (coverage bounded by live pool value via FTSO).
2
The gate returned true
The decoded non-existence proof the contract verified — round 1,409,442, 99.3s. Not our assertion, the protocol's.
Disclosed honestly: the FDC proof is real and on-chain, run as a spike against a synthetic non-payment reference (we can't summon a live agent default on demand). An end-to-end Claimed event through the deployed contract awaits live FXRP — stated in bold, never hidden.
Why only Flare · the moat
Take Flare out — you'd build four systems.
08
What a strong rival ships
FXRP lending market — an ERC-20 that happens to be FXRP
FXRP DEX / AMM — a thin, swap-in-swap-out integration
Happy-path FDC Payment proof at best
What Backstop does instead
Rides ReferencedPaymentNonexistence — the protocol's canonical default trigger, proven on-chain
Verifies the proof in the contract, not off-chain trust
Makes every other FXRP product safer — infra, not a vertical
6 engine call-sites across FDC + FAssets + FTSO + Registry, on real Coston2
Without Flare you'd need four separate systems: an XRPL light client, a decentralized
"payment-did-not-happen" attestation network, a price oracle, and a canonical FXRP redemption registry.
Flare enshrines all four — which is why Backstop is ~600 lines of Solidity and almost no other chain can host it.
Honest status · what's proven vs what's left
Done and proven — two honest steps left.
09
We separate proven-on-chain from still-to-come, in bold. The load-bearing assertion — the
FDC round-trip on Coston2 — is PASSED. Here's the full ledger.
Built & proven
✓
Day-4 FDC gate PASSED — verify…Nonexistence = true in 99.3s on Coston2 (round 1409442)
✓
Deployed + source-verified on Coston2 — Backstop 0x38EB…DDca, Pool 0xc18B…0045
6 Flare engine methods on real Coston2 — none mocked · global solvency cap (FTSO-bounded)
The only two steps left
◷
Live demo URL — /integrations/verify ships to Vercel (route + screenshot done; hosting pending)
◷
End-to-end Claimed event through the deployed contract — awaits live FXRP redemption tickets
Why this is credible
The hard part — proving Flare's own default attestation verifies on-chain — is done. What's left is packaging (a host) and an input we don't control (a live FXRP ticket), not new protocol risk.
Why show this? Flare weights "evidence of new work" and "does the demo work?" — honesty plus a judge-clickable proof beats an over-claimed screenshot every time.
Contracts deployed + source-verified on Coston2, an autonomous keeper, the premium engine, brand system, and the /integrations/verify proof route — all net-new for Flare Summer Signal. Nothing ported.
The ask
Back the backstop.
11
Judge us on integration quality — open the Backstop contract on Flarescan and the verify…Nonexistence attestation tx.
Award a Bounty 1 podium slot — the deepest FAssets integration in an empty lane, proven on-chain.
See Backstop as infrastructure: it de-risks the whole FXRP redemption side for every other builder.
Backstop · redemption insurance for FXRP
Coston2 · Bounty 1 (FAssets) · Flare Summer Signal
